WorldWideScience

Sample records for adaptors regulate floral

  1. DMPD: The SAP family of adaptors in immune regulation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15541655 The SAP family of adaptors in immune regulation. Latour S, Veillette A. Se...min Immunol. 2004 Dec;16(6):409-19. (.png) (.svg) (.html) (.csml) Show The SAP family of adaptors in immune ...regulation. PubmedID 15541655 Title The SAP family of adaptors in immune regulation. Authors Latour S, Veill

  2. DMPD: Structure, function and regulation of the Toll/IL-1 receptor adaptor proteins. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17667936 Structure, function and regulation of the Toll/IL-1 receptor adaptor proteins... (.svg) (.html) (.csml) Show Structure, function and regulation of the Toll/IL-1 receptor adaptor proteins. ...PubmedID 17667936 Title Structure, function and regulation of the Toll/IL-1 receptor adaptor proteins

  3. Eps15: a multifunctional adaptor protein regulating intracellular trafficking

    Directory of Open Access Journals (Sweden)

    van Bergen en Henegouwen Paul MP

    2009-10-01

    Full Text Available Abstract Over expression of receptor tyrosine kinases is responsible for the development of a wide variety of malignancies. Termination of growth factor signaling is primarily determined by the down regulation of active growth factor/receptor complexes. In recent years, considerable insight has been gained in the endocytosis and degradation of growth factor receptors. A crucial player in this process is the EGFR Protein tyrosine kinase Substrate #15, or Eps15. This protein functions as a scaffolding adaptor protein and is involved both in secretion and endocytosis. Eps15 has been shown to bind to AP-1 and AP-2 complexes, to bind to inositol lipids and to several other proteins involved in the regulation of intracellular trafficking. In addition, Eps15 has been detected in the nucleus of mammalian cells. Activation of growth factor receptors induces tyrosine phosphorylation and mono-ubiquitination of Eps15. The role of these post translational modifications of Eps15 is still a mystery. It is proposed that Eps15 and its family members Eps15R and Eps15b are involved in the regulation of membrane morphology, which is required for intracellular vesicle formation and trafficking.

  4. Glucose regulates clathrin adaptors at the trans-Golgi network and endosomes

    Science.gov (United States)

    Aoh, Quyen L.; Graves, Lee M.; Duncan, Mara C.

    2011-01-01

    Glucose is a rich source of energy and the raw material for biomass increase. Many eukaryotic cells remodel their physiology in the presence and absence of glucose. The yeast Saccharomyces cerevisiae undergoes changes in transcription, translation, metabolism, and cell polarity in response to glucose availability. Upon glucose starvation, translation initiation and cell polarity are immediately inhibited, and then gradually recover. In this paper, we provide evidence that, as in cell polarity and translation, traffic at the trans-Golgi network (TGN) and endosomes is regulated by glucose via an unknown mechanism that depends on protein kinase A (PKA). Upon glucose withdrawal, clathrin adaptors exhibit a biphasic change in localization: they initially delocalize from the membrane within minutes and later partially recover onto membranes. Additionally, the removal of glucose induces changes in posttranslational modifications of adaptors. Ras and Gpr1 signaling pathways, which converge on PKA, are required for changes in adaptor localization and changes in posttranslational modifications. Acute inhibition of PKA demonstrates that inhibition of PKA prior to glucose withdrawal prevents several adaptor responses to starvation. This study demonstrates that PKA activity prior to glucose starvation primes membrane traffic at the TGN and endosomes in response to glucose starvation. PMID:21832155

  5. FON2 SPARE1 Redundantly Regulates Floral Meristem Maintenance with FLORAL ORGAN NUMBER2 in Rice

    Science.gov (United States)

    Suzaki, Takuya; Ohneda, Masako; Toriba, Taiyo; Yoshida, Akiko; Hirano, Hiro-Yuki

    2009-01-01

    CLAVATA signaling restricts stem cell identity in the shoot apical meristem (SAM) in Arabidopsis thaliana. In rice (Oryza sativa), FLORAL ORGAN NUMBER2 (FON2), closely related to CLV3, is involved as a signaling molecule in a similar pathway to negatively regulate stem cell proliferation in the floral meristem (FM). Here we show that the FON2 SPARE1 (FOS1) gene encoding a CLE protein functions along with FON2 in maintenance of the FM. In addition, FOS1 appears to be involved in maintenance of the SAM in the vegetative phase, because constitutive expression of FOS1 caused termination of the vegetative SAM. Genetic analysis revealed that FOS1 does not need FON1, the putative receptor of FON2, for its action, suggesting that FOS1 and FON2 may function in meristem maintenance as signaling molecules in independent pathways. Initially, we identified FOS1 as a suppressor that originates from O. sativa indica and suppresses the fon2 mutation in O. sativa japonica. FOS1 function in japonica appears to be compromised by a functional nucleotide polymorphism (FNP) at the putative processing site of the signal peptide. Sequence comparison of FOS1 in about 150 domesticated rice and wild rice species indicates that this FNP is present only in japonica, suggesting that redundant regulation by FOS1 and FON2 is commonplace in species in the Oryza genus. Distribution of the FNP also suggests that this mutation may have occurred during the divergence of japonica from its wild ancestor. Stem cell maintenance may be regulated by at least three negative pathways in rice, and each pathway may contribute differently to this regulation depending on the type of the meristem. This situation contrasts with that in Arabidopsis, where CLV signaling is the major single pathway in all meristems. PMID:19834537

  6. FON2 SPARE1 redundantly regulates floral meristem maintenance with FLORAL ORGAN NUMBER2 in rice.

    Directory of Open Access Journals (Sweden)

    Takuya Suzaki

    2009-10-01

    Full Text Available CLAVATA signaling restricts stem cell identity in the shoot apical meristem (SAM in Arabidopsis thaliana. In rice (Oryza sativa, FLORAL ORGAN NUMBER2 (FON2, closely related to CLV3, is involved as a signaling molecule in a similar pathway to negatively regulate stem cell proliferation in the floral meristem (FM. Here we show that the FON2 SPARE1 (FOS1 gene encoding a CLE protein functions along with FON2 in maintenance of the FM. In addition, FOS1 appears to be involved in maintenance of the SAM in the vegetative phase, because constitutive expression of FOS1 caused termination of the vegetative SAM. Genetic analysis revealed that FOS1 does not need FON1, the putative receptor of FON2, for its action, suggesting that FOS1 and FON2 may function in meristem maintenance as signaling molecules in independent pathways. Initially, we identified FOS1 as a suppressor that originates from O. sativa indica and suppresses the fon2 mutation in O. sativa japonica. FOS1 function in japonica appears to be compromised by a functional nucleotide polymorphism (FNP at the putative processing site of the signal peptide. Sequence comparison of FOS1 in about 150 domesticated rice and wild rice species indicates that this FNP is present only in japonica, suggesting that redundant regulation by FOS1 and FON2 is commonplace in species in the Oryza genus. Distribution of the FNP also suggests that this mutation may have occurred during the divergence of japonica from its wild ancestor. Stem cell maintenance may be regulated by at least three negative pathways in rice, and each pathway may contribute differently to this regulation depending on the type of the meristem. This situation contrasts with that in Arabidopsis, where CLV signaling is the major single pathway in all meristems.

  7. Nuclear adaptor Ldb1 regulates a transcriptional program essential for the maintenance of hematopoietic stem cells.

    Science.gov (United States)

    Li, LiQi; Jothi, Raja; Cui, Kairong; Lee, Jan Y; Cohen, Tsadok; Gorivodsky, Marat; Tzchori, Itai; Zhao, Yangu; Hayes, Sandra M; Bresnick, Emery H; Zhao, Keji; Westphal, Heiner; Love, Paul E

    2011-02-01

    The nuclear adaptor Ldb1 functions as a core component of multiprotein transcription complexes that regulate differentiation in diverse cell types. In the hematopoietic lineage, Ldb1 forms a complex with the non-DNA-binding adaptor Lmo2 and the transcription factors E2A, Scl and GATA-1 (or GATA-2). Here we demonstrate a critical and continuous requirement for Ldb1 in the maintenance of both fetal and adult mouse hematopoietic stem cells (HSCs). Deletion of Ldb1 in hematopoietic progenitors resulted in the downregulation of many transcripts required for HSC maintenance. Genome-wide profiling by chromatin immunoprecipitation followed by sequencing (ChIP-Seq) identified Ldb1 complex-binding sites at highly conserved regions in the promoters of genes involved in HSC maintenance. Our results identify a central role for Ldb1 in regulating the transcriptional program responsible for the maintenance of HSCs.

  8. SUPERMAN, a regulator of floral homeotic genes in Arabidopsis.

    Science.gov (United States)

    Bowman, J L; Sakai, H; Jack, T; Weigel, D; Mayer, U; Meyerowitz, E M

    1992-03-01

    We describe a locus, SUPERMAN, mutations in which result in extra stamens developing at the expense of the central carpels in the Arabidopsis thaliana flower. The development of superman flowers, from initial primordium to mature flower, is described by scanning electron microscopy. The development of doubly and triply mutant strains, constructed with superman alleles and previously identified homeotic mutations that cause alterations in floral organ identity, is also described. Essentially additive phenotypes are observed in superman agamous and superman apetala2 double mutants. The epistatic relationships observed between either apetala3 or pistillata and superman alleles suggest that the SUPERMAN gene product could be a regulator of these floral homeotic genes. To test this, the expression patterns of AGAMOUS and APETALA3 were examined in superman flowers. In wild-type flowers, APETALA3 expression is restricted to the second and third whorls where it is required for the specification of petals and stamens. In contrast, in superman flowers, APETALA3 expression expands to include most of the cells that would normally constitute the fourth whorl. This ectopic APETALA3 expression is proposed to be one of the causes of the development of the extra stamens in superman flowers. The spatial pattern of AGAMOUS expression remains unaltered in superman flowers as compared to wild-type flowers. Taken together these data indicate that one of the functions of the wild-type SUPERMAN gene product is to negatively regulate APETALA3 in the fourth whorl of the flower. In addition, superman mutants exhibit a loss of determinacy of the floral meristem, an effect that appears to be mediated by the APETALA3 and PISTILLATA gene products.

  9. The Lnk adaptor protein: a key regulator of normal and pathological hematopoiesis.

    Science.gov (United States)

    Velazquez, Laura

    2012-12-01

    The development and function of blood cells are regulated by specific growth factors/cytokines and their receptors' signaling pathways. In this way, these factors influence cell survival, proliferation and differentiation of hematopoietic cells. Central to this positive and/or negative control are the adaptor proteins. Since their identification 10 years ago, members of the Lnk adaptor protein family have proved to be important activators and/or inhibitors in the hematopoietic, immune and vascular system. In particular, the generation of animal and cellular models for the Lnk and APS proteins has helped establish the physiological role of these molecules through the identification of their specific signaling pathways and the characterization of their binding partners. Moreover, the recent identification of mutations in the LNK gene in myeloproliferative disorders, as well as the correlation of a single nucleotide polymorphism on LNK with hematological, immune and vascular diseases have suggested its involvement in the pathophysiology of these malignancies. The latter findings have thus raised the possibility of addressing Lnk signaling for the treatment of certain human diseases. This review therefore describes the pathophysiological role of this adaptor protein in hematological malignancies and the potential benefits of Lnk therapeutic targeting.

  10. Floral stem cell termination involves the direct regulation of AGAMOUS by PERIANTHIA.

    Science.gov (United States)

    Das, Pradeep; Ito, Toshiro; Wellmer, Frank; Vernoux, Teva; Dedieu, Annick; Traas, Jan; Meyerowitz, Elliot M

    2009-05-01

    In Arabidopsis, the population of stem cells present in young flower buds is lost after the production of a fixed number of floral organs. The precisely timed repression of the stem cell identity gene WUSCHEL (WUS) by the floral homeotic protein AGAMOUS (AG) is a key part of this process. In this study, we report on the identification of a novel input into the process of floral stem cell regulation. We use genetics and chromatin immunoprecipitation assays to demonstrate that the bZIP transcription factor PERIANTHIA (PAN) plays a role in regulating stem cell fate by directly controlling AG expression and suggest that this activity is spatially restricted to the centermost region of the AG expression domain. These results suggest that the termination of floral stem cell fate is a multiply redundant process involving loci with unrelated floral patterning functions.

  11. Regulation of floral meristem activity through the interaction of AGAMOUS, SUPERMAN, and CLAVATA3 in Arabidopsis.

    Science.gov (United States)

    Uemura, Akira; Yamaguchi, Nobutoshi; Xu, Yifeng; Wee, WanYi; Ichihashi, Yasunori; Suzuki, Takamasa; Shibata, Arisa; Shirasu, Ken; Ito, Toshiro

    2017-12-07

    Floral meristem size is redundantly controlled by CLAVATA3, AGAMOUS , and SUPERMAN in Arabidopsis. The proper regulation of floral meristem activity is key to the formation of optimally sized flowers with a fixed number of organs. In Arabidopsis thaliana, multiple regulators determine this activity. A small secreted peptide, CLAVATA3 (CLV3), functions as an important negative regulator of stem cell activity. Two transcription factors, AGAMOUS (AG) and SUPERMAN (SUP), act in different pathways to regulate the termination of floral meristem activity. Previous research has not addressed the genetic interactions among these three genes. Here, we quantified the floral developmental stage-specific phenotypic consequences of combining mutations of AG, SUP, and CLV3. Our detailed phenotypic and genetic analyses revealed that these three genes act in partially redundant pathways to coordinately modulate floral meristem sizes in a spatial and temporal manner. Analyses of the ag sup clv3 triple mutant, which developed a mass of undifferentiated cells in its flowers, allowed us to identify downstream targets of AG with roles in reproductive development and in the termination of floral meristem activity. Our study highlights the role of AG in repressing genes that are expressed in organ initial cells to control floral meristem activity.

  12. The Kinesin Adaptor Calsyntenin-1 Organizes Microtubule Polarity and Regulates Dynamics during Sensory Axon Arbor Development

    Directory of Open Access Journals (Sweden)

    Mary C. Halloran

    2017-04-01

    Full Text Available Axon growth and branching, and development of neuronal polarity are critically dependent on proper organization and dynamics of the microtubule (MT cytoskeleton. MTs must organize with correct polarity for delivery of diverse cargos to appropriate subcellular locations, yet the molecular mechanisms regulating MT polarity remain poorly understood. Moreover, how an actively branching axon reorganizes MTs to direct their plus ends distally at branch points is unknown. We used high-speed, in vivo imaging of polymerizing MT plus ends to characterize MT dynamics in developing sensory axon arbors in zebrafish embryos. We find that axonal MTs are highly dynamic throughout development, and that the peripheral and central axons of sensory neurons show differences in MT behaviors. Furthermore, we show that Calsyntenin-1 (Clstn-1, a kinesin adaptor required for sensory axon branching, also regulates MT polarity in developing axon arbors. In wild type neurons the vast majority of MTs are directed in the correct plus-end-distal orientation from early stages of development. Loss of Clstn-1 causes an increase in MTs polymerizing in the retrograde direction. These misoriented MTs most often are found near growth cones and branch points, suggesting Clstn-1 is particularly important for organizing MT polarity at these locations. Together, our results suggest that Clstn-1, in addition to regulating kinesin-mediated cargo transport, also organizes the underlying MT highway during axon arbor development.

  13. Histone locus regulation by the Drosophila dosage compensation adaptor protein CLAMP.

    Science.gov (United States)

    Rieder, Leila E; Koreski, Kaitlin P; Boltz, Kara A; Kuzu, Guray; Urban, Jennifer A; Bowman, Sarah K; Zeidman, Anna; Jordan, William T; Tolstorukov, Michael Y; Marzluff, William F; Duronio, Robert J; Larschan, Erica N

    2017-07-15

    The conserved histone locus body (HLB) assembles prior to zygotic gene activation early during development and concentrates factors into a nuclear domain of coordinated histone gene regulation. Although HLBs form specifically at replication-dependent histone loci, the cis and trans factors that target HLB components to histone genes remained unknown. Here we report that conserved GA repeat cis elements within the bidirectional histone3-histone4 promoter direct HLB formation in Drosophila In addition, the CLAMP (chromatin-linked adaptor for male-specific lethal [MSL] proteins) zinc finger protein binds these GA repeat motifs, increases chromatin accessibility, enhances histone gene transcription, and promotes HLB formation. We demonstrated previously that CLAMP also promotes the formation of another domain of coordinated gene regulation: the dosage-compensated male X chromosome. Therefore, CLAMP binding to GA repeat motifs promotes the formation of two distinct domains of coordinated gene activation located at different places in the genome. © 2017 Rieder et al.; Published by Cold Spring Harbor Laboratory Press.

  14. The ubiquitin ligase RNF5 regulates antiviral responses by mediating degradation of the adaptor protein MITA.

    Science.gov (United States)

    Zhong, Bo; Zhang, Lu; Lei, Caoqi; Li, Ying; Mao, Ai-Ping; Yang, Yan; Wang, Yan-Yi; Zhang, Xiao-Lian; Shu, Hong-Bing

    2009-03-20

    Viral infection activates transcription factors NF-kappaB and IRF3, which collaborate to induce type I interferons (IFNs) and elicit innate antiviral response. MITA (also known as STING) has recently been identified as an adaptor that links virus-sensing receptors to IRF3 activation. Here, we showed that the E3 ubiquitin ligase RNF5 interacted with MITA in a viral-infection-dependent manner. Overexpression of RNF5 inhibited virus-triggered IRF3 activation, IFNB1 expression, and cellular antiviral response, whereas knockdown of RNF5 had opposite effects. RNF5 targeted MITA at Lys150 for ubiquitination and degradation after viral infection. Both MITA and RNF5 were located at the mitochondria and endoplasmic reticulum (ER) and viral infection caused their redistribution to the ER and mitochondria, respectively. We further found that virus-induced ubiquitination and degradation of MITA by RNF5 occurred at the mitochondria. These findings suggest that RNF5 negatively regulates virus-triggered signaling by targeting MITA for ubiquitination and degradation at the mitochondria.

  15. SUPERMAN, a regulator of floral homeotic genes in Arabidopsis

    OpenAIRE

    Bowman, John L.; Sakai, Hajime; Jack, Thomas; Weigel, Detlef; Mayer, Ulrike; Meyerowitz, Elliot M.

    1992-01-01

    We describe a locus, SUPERMAN, mutations in which result in extra stamens developing at the expense of the central carpels in the Arabidopsis thaliana flower. The development of superman flowers, from initial primordium to mature flower, is described by scanning electron microscopy. The development of doubly and triply mutant strains, constructed with superman alleles and previously identified homeotic mutations that cause alterations in floral organ identity, is also described. Essentially a...

  16. ATP binding to p97/VCP D1 domain regulates selective recruitment of adaptors to its proximal N-domain.

    Directory of Open Access Journals (Sweden)

    Wei Sheng Chia

    Full Text Available p97/Valosin-containing protein (VCP is a member of the AAA-ATPase family involved in many cellular processes including cell division, intracellular trafficking and extraction of misfolded proteins in endoplasmic reticulum-associated degradation (ERAD. It is a homohexamer with each subunit containing two tandem D1 and D2 ATPase domains and N- and C-terminal regions that function as adaptor protein binding domains. p97/VCP is directed to its many different functional pathways by associating with various adaptor proteins. The regulation of the recruitment of the adaptor proteins remains unclear. Two adaptor proteins, Ufd1/Npl4 and p47, which bind exclusively to the p97/VCP N-domain and direct p97/VCP to either ERAD-related processes or homotypic fusion of Golgi fragments, were studied here. Surface plasmon resonance biosensor-based assays allowed the study of binding kinetics in real time. In competition experiments, it was observed that in the presence of ATP, Ufd1/Npl4 was able to compete more effectively with p47 for binding to p97/VCP. By using non-hydrolysable ATP analogues and the hexameric truncated p97/N-D1 fragment, it was shown that binding rather than hydrolysis of ATP to the proximal D1 domain strengthened the Ufd1/Npl4 association with the N-domain, thus regulating the recruitment of either Ufd1/Npl4 or p47. This novel role of ATP and an assigned function to the D1 AAA-ATPase domain link the multiple functions of p97/VCP to the metabolic status of the cell.

  17. An ortholog of LEAFY in Jatropha curcas regulates flowering time and floral organ development

    Science.gov (United States)

    Tang, Mingyong; Tao, Yan-Bin; Fu, Qiantang; Song, Yaling; Niu, Longjian; Xu, Zeng-Fu

    2016-01-01

    Jatropha curcas seeds are an excellent biofuel feedstock, but seed yields of Jatropha are limited by its poor flowering and fruiting ability. Thus, identifying genes controlling flowering is critical for genetic improvement of seed yield. We isolated the JcLFY, a Jatropha ortholog of Arabidopsis thaliana LEAFY (LFY), and identified JcLFY function by overexpressing it in Arabidopsis and Jatropha. JcLFY is expressed in Jatropha inflorescence buds, flower buds, and carpels, with highest expression in the early developmental stage of flower buds. JcLFY overexpression induced early flowering, solitary flowers, and terminal flowers in Arabidopsis, and also rescued the delayed flowering phenotype of lfy-15, a LFY loss-of-function Arabidopsis mutant. Microarray and qPCR analysis revealed several flower identity and flower organ development genes were upregulated in JcLFY-overexpressing Arabidopsis. JcLFY overexpression in Jatropha also induced early flowering. Significant changes in inflorescence structure, floral organs, and fruit shape occurred in JcLFY co-suppressed plants in which expression of several flower identity and floral organ development genes were changed. This suggests JcLFY is involved in regulating flower identity, floral organ patterns, and fruit shape, although JcLFY function in Jatropha floral meristem determination is not as strong as that of Arabidopsis. PMID:27869146

  18. Floral induction in tissue culture: a system for the analysis of LEAFY-dependent gene regulation.

    Science.gov (United States)

    Wagner, Doris; Wellmer, Frank; Dilks, Kieran; William, Dilusha; Smith, Michael R; Kumar, Prakash P; Riechmann, José Luis; Greenland, Andrew J; Meyerowitz, Elliot M

    2004-07-01

    We have developed a versatile floral induction system that is based on ectopic overexpression of the transcription factor LEAFY (LFY) in callus. During shoot regeneration, flowers or floral organs are formed directly from root explants without prior formation of rosette leaves. Morphological and reporter gene analyses show that leaf-like structures are converted to floral organs in response to LFY activity. Thus, increased levels of LFY activity are sufficient to bypass normal vegetative development and to direct formation of flowers in tissue culture. We found that about half of the cultured cells respond to inducible LFY activity with a rapid upregulation of the known direct target gene of LFY, APETALA1 (AP1). This dramatic increase in the number of LFY-responsive cells compared to whole plants suggested that the tissue culture system could greatly facilitate the analysis of LFY-dependent gene regulation by genomic approaches. To test this, we monitored the gene expression changes that occur in tissue culture after activation of LFY using a flower-specific cDNA microarray. Induction of known LFY target genes was readily detected in these experiments. In addition, several other genes were identified that had not been implicated in signaling downstream of LFY before. Thus, the floral induction system is suitable for the detection of low abundance transcripts whose expression is controlled in an LFY-dependent manner.

  19. Regulation of Floral Terpenoid Emission and Biosynthesis in Sweet Basil (Ocimum basilicum)

    Science.gov (United States)

    Jiang, Yifan; Ye, Jiayan; Li, Shuai; Niinemets, Ülo

    2018-01-01

    Past studies have focused on the composition of essential oil of Ocimum basilicum leaves, but data on composition and regulation of its aerial emissions, especially floral volatile emissions are scarce. We studied the chemical profile, within-flower spatial distribution (sepals, petals, pistils with stamina and pedicels), diurnal emission kinetics and effects of exogenous methyl jasmonate (MeJA) application on the emission of floral volatiles by dynamic headspace collection and identification using gas chromatography-mass spectrometry (GC-MS) and proton transfer reaction mass spectrometry (PTR-MS). We observed more abundant floral emissions from flowers compared with leaves. Sepals were the main emitters of floral volatiles among the flower parts studied. The emissions of lipoxygenase compounds (LOX) and monoterpenoids, but not sesquiterpene emissions, displayed a diurnal variation driven by light. Response to exogenous MeJA treatment of flowers consisted of a rapid stress response and a longer-term acclimation response. The initial response was associated with enhanced emissions of fatty acid derivatives, monoterpenoids, and sesquiterpenoids without variation of the composition of individual compounds. The longer-term response was associated with enhanced monoterpenoid and sesquiterpenoid emissions with profound changes in the emission spectrum. According to correlated patterns of terpenoid emission changes upon stress, highlighted by a hierarchical cluster analysis, candidate terpenoid synthases responsible for observed diversity and complexity of released terpenoid blends were postulated. We conclude that flower volatile emissions differ quantitatively and qualitatively from leaf emissions, and overall contribute importantly to O. basilicum flavor, especially under stress conditions. PMID:29367803

  20. Control of reproductive floral organ identity specification in Arabidopsis by the C function regulator AGAMOUS.

    Science.gov (United States)

    ÓMaoiléidigh, Diarmuid S; Wuest, Samuel E; Rae, Liina; Raganelli, Andrea; Ryan, Patrick T; Kwasniewska, Kamila; Das, Pradeep; Lohan, Amanda J; Loftus, Brendan; Graciet, Emmanuelle; Wellmer, Frank

    2013-07-01

    The floral organ identity factor AGAMOUS (AG) is a key regulator of Arabidopsis thaliana flower development, where it is involved in the formation of the reproductive floral organs as well as in the control of meristem determinacy. To obtain insights into how AG specifies organ fate, we determined the genes and processes acting downstream of this C function regulator during early flower development and distinguished between direct and indirect effects. To this end, we combined genome-wide localization studies, gene perturbation experiments, and computational analyses. Our results demonstrate that AG controls flower development to a large extent by controlling the expression of other genes with regulatory functions, which are involved in mediating a plethora of different developmental processes. One aspect of this function is the suppression of the leaf development program in emerging floral primordia. Using trichome initiation as an example, we demonstrate that AG inhibits an important aspect of leaf development through the direct control of key regulatory genes. A comparison of the gene expression programs controlled by AG and the B function regulators APETALA3 and PISTILLATA, respectively, showed that while they control many developmental processes in conjunction, they also have marked antagonistic, as well as independent activities.

  1. Ionized calcium-binding adaptor molecule 1 positive macrophages and HO-1 up-regulation in intestinal muscularis resident macrophages

    DEFF Research Database (Denmark)

    Mikkelsen, Hanne B; Huizinga, Jan D; Larsen, Jytte O

    2017-01-01

    Small intestinal muscularis externa macrophages have been associated with interstitial cells of Cajal (ICC). They have been proposed to play various roles in motility disorders and to take part in a microbiota-driven regulation of gastrointestinal motility. Our objective was to understand...... the reaction of resident macrophages of the musculature to a pro-inflammatory stimulator, lipopolysaccharide (LPS). Mice were injected with LPS or saline and sacrificed after 6 hours. Whole mounts were stained with antibodies toward CD169, ionized calcium-binding adaptor molecule 1 (iba1) (microglial/macrophage...... marker) and heme oxygenase-1 (HO-1). Cell densities were measured using unbiased stereology. RESULTS: iba1(pos) cells showed an overall higher density than CD169(pos) and HO-1(pos) cells. Most HO-1(pos) and iba1(pos) cells were positive for CD 169 in serosa and at Auerbach's plexus (AP). At the deep...

  2. Circadian regulation of sunflower heliotropism, floral orientation, and pollinator visits.

    Science.gov (United States)

    Atamian, Hagop S; Creux, Nicky M; Brown, Evan A; Garner, Austin G; Blackman, Benjamin K; Harmer, Stacey L

    2016-08-05

    Young sunflower plants track the Sun from east to west during the day and then reorient during the night to face east in anticipation of dawn. In contrast, mature plants cease movement with their flower heads facing east. We show that circadian regulation of directional growth pathways accounts for both phenomena and leads to increased vegetative biomass and enhanced pollinator visits to flowers. Solar tracking movements are driven by antiphasic patterns of elongation on the east and west sides of the stem. Genes implicated in control of phototropic growth, but not clock genes, are differentially expressed on the opposite sides of solar tracking stems. Thus, interactions between environmental response pathways and the internal circadian oscillator coordinate physiological processes with predictable changes in the environment to influence growth and reproduction. Copyright © 2016, American Association for the Advancement of Science.

  3. Phospho-dependent binding of the clathrin AP2 adaptor complex to GABAA receptors regulates the efficacy of inhibitory synaptic transmission

    OpenAIRE

    Kittler, Josef T.; Chen, Guojun; Honing, Stephan; Bogdanov, Yury; McAinsh, Kristina; Arancibia-Carcamo, I. Lorena; Jovanovic, Jasmina N.; Pangalos, Menelas N.; Haucke, Volker; Yan, Zhen; Moss, Stephen J.

    2005-01-01

    The efficacy of synaptic inhibition depends on the number of γ-aminobutyric acid type A receptors (GABAARs) expressed on the cell surface of neurons. The clathrin adaptor protein 2 (AP2) complex is a critical regulator of GABAAR endocytosis and, hence, surface receptor number. Here, we identify a previously uncharacterized atypical AP2 binding motif conserved within the intracellular domains of all GABAAR β subunit isoforms. This AP2 binding motif (KTHLRRRSSQLK in the β3 subunit) incorporates...

  4. Small RNA and transcriptome deep sequencing proffers insight into floral gene regulation in Rosa cultivars.

    Science.gov (United States)

    Kim, Jungeun; Park, June Hyun; Lim, Chan Ju; Lim, Jae Yun; Ryu, Jee-Youn; Lee, Bong-Woo; Choi, Jae-Pil; Kim, Woong Bom; Lee, Ha Yeon; Choi, Yourim; Kim, Donghyun; Hur, Cheol-Goo; Kim, Sukweon; Noh, Yoo-Sun; Shin, Chanseok; Kwon, Suk-Yoon

    2012-11-21

    Roses (Rosa sp.), which belong to the family Rosaceae, are the most economically important ornamental plants--making up 30% of the floriculture market. However, given high demand for roses, rose breeding programs are limited in molecular resources which can greatly enhance and speed breeding efforts. A better understanding of important genes that contribute to important floral development and desired phenotypes will lead to improved rose cultivars. For this study, we analyzed rose miRNAs and the rose flower transcriptome in order to generate a database to expound upon current knowledge regarding regulation of important floral characteristics. A rose genetic database will enable comprehensive analysis of gene expression and regulation via miRNA among different Rosa cultivars. We produced more than 0.5 million reads from expressed sequences, totalling more than 110 million bp. From these, we generated 35,657, 31,434, 34,725, and 39,722 flower unigenes from Rosa hybrid: 'Vital', 'Maroussia', and 'Sympathy' and Rosa rugosa Thunb., respectively. The unigenes were assigned functional annotations, domains, metabolic pathways, Gene Ontology (GO) terms, Plant Ontology (PO) terms, and MIPS Functional Catalogue (FunCat) terms. Rose flower transcripts were compared with genes from whole genome sequences of Rosaceae members (apple, strawberry, and peach) and grape. We also produced approximately 40 million small RNA reads from flower tissue for Rosa, representing 267 unique miRNA tags. Among identified miRNAs, 25 of them were novel and 242 of them were conserved miRNAs. Statistical analyses of miRNA profiles revealed both shared and species-specific miRNAs, which presumably effect flower development and phenotypes. In this study, we constructed a Rose miRNA and transcriptome database, and we analyzed the miRNAs and transcriptome generated from the flower tissues of four Rosa cultivars. The database provides a comprehensive genetic resource which can be used to better understand

  5. The Adaptor Protein SH2B3 (Lnk) Negatively Regulates Neurite Outgrowth of PC12 Cells and Cortical Neurons

    Science.gov (United States)

    Wang, Tien-Cheng; Chiu, Hsun; Chang, Yu-Jung; Hsu, Tai-Yu; Chiu, Ing-Ming; Chen, Linyi

    2011-01-01

    SH2B adaptor protein family members (SH2B1-3) regulate various physiological responses through affecting signaling, gene expression, and cell adhesion. SH2B1 and SH2B2 were reported to enhance nerve growth factor (NGF)-induced neuronal differentiation in PC12 cells, a well-established neuronal model system. In contrast, SH2B3 was reported to inhibit cell proliferation during the development of immune system. No study so far addresses the role of SH2B3 in the nervous system. In this study, we provide evidence suggesting that SH2B3 is expressed in the cortex of embryonic rat brain. Overexpression of SH2B3 not only inhibits NGF-induced differentiation of PC12 cells but also reduces neurite outgrowth of primary cortical neurons. SH2B3 does so by repressing NGF-induced activation of PLCγ, MEK-ERK1/2 and PI3K-AKT pathways and the expression of Egr-1. SH2B3 is capable of binding to phosphorylated NGF receptor, TrkA, as well as SH2B1β. Our data further demonstrate that overexpression of SH2B3 reduces the interaction between SH2B1β and TrkA. Consistent with this finding, overexpressing the SH2 domain of SH2B3 is sufficient to inhibit NGF-induced neurite outgrowth. Together, our data demonstrate that SH2B3, unlike the other two family members, inhibits neuronal differentiation of PC12 cells and primary cortical neurons. Its inhibitory mechanism is likely through the competition of TrkA binding with the positive-acting SH2B1 and SH2B2. PMID:22028877

  6. The adaptor protein alpha-syntrophin regulates adipocyte lipid droplet growth

    Energy Technology Data Exchange (ETDEWEB)

    Eisinger, Kristina; Rein-Fischboeck, Lisa; Pohl, Rebekka; Meier, Elisabeth M.; Krautbauer, Sabrina; Buechler, Christa, E-mail: christa.buechler@klinik.uni-regensburg.de

    2016-07-01

    The scaffold protein alpha-syntrophin (SNTA) regulates lipolysis indicating a role in lipid homeostasis. Adipocytes are the main lipid storage cells in the body, and here, the function of SNTA has been analyzed in 3T3-L1 cells. SNTA is expressed in preadipocytes and is induced early during adipogenesis. Knock-down of SNTA in preadipocytes increases their proliferation. Proteins which are induced during adipogenesis like adiponectin and caveolin-1, and the inflammatory cytokine IL-6 are at normal levels in the mature cells differentiated from preadipocytes with low SNTA. This suggests that SNTA does neither affect differentiation nor inflammation. Expression of proteins with a role in cholesterol and triglyceride homeostasis is unchanged. Consequently, basal and epinephrine induced lipolysis as well as insulin stimulated phosphorylation of Akt and ERK1/2 are normal. Importantly, adipocytes with low SNTA form smaller lipid droplets and store less triglycerides. Stearoyl-CoA reductase and MnSOD are reduced upon SNTA knock-down but do not contribute to lower lipid levels. Oleate uptake is even increased in cells with SNTA knock-down. In summary, current data show that SNTA is involved in the expansion of lipid droplets independent of adipogenesis. Enhanced preadipocyte proliferation and capacity to store surplus fatty acids may protect adipocytes with low SNTA from lipotoxicity in obesity. - Highlights: • Alpha-syntrophin (SNTA) is expressed in 3T3-L1adipocytes. • SNTA knock-down in preadipocytes has no effect on adipogenesis. • Mature 3T3-L1 differentiated from cells with low SNTA form small lipid droplets. • SCD1 and MnSOD are reduced in adipocytes with low SNTA. • SCD1 knock-down does not alter triglyceride levels.

  7. Small RNA and transcriptome deep sequencing proffers insight into floral gene regulation in Rosa cultivars

    Directory of Open Access Journals (Sweden)

    Kim Jungeun

    2012-11-01

    Full Text Available Abstract Background Roses (Rosa sp., which belong to the family Rosaceae, are the most economically important ornamental plants—making up 30% of the floriculture market. However, given high demand for roses, rose breeding programs are limited in molecular resources which can greatly enhance and speed breeding efforts. A better understanding of important genes that contribute to important floral development and desired phenotypes will lead to improved rose cultivars. For this study, we analyzed rose miRNAs and the rose flower transcriptome in order to generate a database to expound upon current knowledge regarding regulation of important floral characteristics. A rose genetic database will enable comprehensive analysis of gene expression and regulation via miRNA among different Rosa cultivars. Results We produced more than 0.5 million reads from expressed sequences, totalling more than 110 million bp. From these, we generated 35,657, 31,434, 34,725, and 39,722 flower unigenes from Rosa hybrid: ‘Vital’, ‘Maroussia’, and ‘Sympathy’ and Rosa rugosa Thunb. , respectively. The unigenes were assigned functional annotations, domains, metabolic pathways, Gene Ontology (GO terms, Plant Ontology (PO terms, and MIPS Functional Catalogue (FunCat terms. Rose flower transcripts were compared with genes from whole genome sequences of Rosaceae members (apple, strawberry, and peach and grape. We also produced approximately 40 million small RNA reads from flower tissue for Rosa, representing 267 unique miRNA tags. Among identified miRNAs, 25 of them were novel and 242 of them were conserved miRNAs. Statistical analyses of miRNA profiles revealed both shared and species-specific miRNAs, which presumably effect flower development and phenotypes. Conclusions In this study, we constructed a Rose miRNA and transcriptome database, and we analyzed the miRNAs and transcriptome generated from the flower tissues of four Rosa cultivars. The database provides a

  8. Regulation of protease-activated receptor 1 signaling by the adaptor protein complex 2 and R4 subfamily of regulator of G protein signaling proteins.

    Science.gov (United States)

    Chen, Buxin; Siderovski, David P; Neubig, Richard R; Lawson, Mark A; Trejo, Joann

    2014-01-17

    The G protein-coupled protease-activated receptor 1 (PAR1) is irreversibly proteolytically activated by thrombin. Hence, the precise regulation of PAR1 signaling is important for proper cellular responses. In addition to desensitization, internalization and lysosomal sorting of activated PAR1 are critical for the termination of signaling. Unlike most G protein-coupled receptors, PAR1 internalization is mediated by the clathrin adaptor protein complex 2 (AP-2) and epsin-1, rather than β-arrestins. However, the function of AP-2 and epsin-1 in the regulation of PAR1 signaling is not known. Here, we report that AP-2, and not epsin-1, regulates activated PAR1-stimulated phosphoinositide hydrolysis via two different mechanisms that involve, in part, a subset of R4 subfamily of "regulator of G protein signaling" (RGS) proteins. A significantly greater increase in activated PAR1 signaling was observed in cells depleted of AP-2 using siRNA or in cells expressing a PAR1 (420)AKKAA(424) mutant with defective AP-2 binding. This effect was attributed to AP-2 modulation of PAR1 surface expression and efficiency of G protein coupling. We further found that ectopic expression of R4 subfamily members RGS2, RGS3, RGS4, and RGS5 reduced activated PAR1 wild-type signaling, whereas signaling by the PAR1 AKKAA mutant was minimally affected. Intriguingly, siRNA-mediated depletion analysis revealed a function for RGS5 in the regulation of signaling by the PAR1 wild type but not the AKKAA mutant. Moreover, activation of the PAR1 wild type, and not the AKKAA mutant, induced Gαq association with RGS3 via an AP-2-dependent mechanism. Thus, AP-2 regulates activated PAR1 signaling by altering receptor surface expression and through recruitment of RGS proteins.

  9. Control of Reproductive Floral Organ Identity Specification in Arabidopsis by the C Function Regulator AGAMOUS[C][W

    Science.gov (United States)

    Ó’Maoiléidigh, Diarmuid S.; Wuest, Samuel E.; Rae, Liina; Raganelli, Andrea; Ryan, Patrick T.; Kwaśniewska, Kamila; Das, Pradeep; Lohan, Amanda J.; Loftus, Brendan; Graciet, Emmanuelle; Wellmer, Frank

    2013-01-01

    The floral organ identity factor AGAMOUS (AG) is a key regulator of Arabidopsis thaliana flower development, where it is involved in the formation of the reproductive floral organs as well as in the control of meristem determinacy. To obtain insights into how AG specifies organ fate, we determined the genes and processes acting downstream of this C function regulator during early flower development and distinguished between direct and indirect effects. To this end, we combined genome-wide localization studies, gene perturbation experiments, and computational analyses. Our results demonstrate that AG controls flower development to a large extent by controlling the expression of other genes with regulatory functions, which are involved in mediating a plethora of different developmental processes. One aspect of this function is the suppression of the leaf development program in emerging floral primordia. Using trichome initiation as an example, we demonstrate that AG inhibits an important aspect of leaf development through the direct control of key regulatory genes. A comparison of the gene expression programs controlled by AG and the B function regulators APETALA3 and PISTILLATA, respectively, showed that while they control many developmental processes in conjunction, they also have marked antagonistic, as well as independent activities. PMID:23821642

  10. A conserved function for Arabidopsis SUPERMAN in regulating floral-whorl cell proliferation in rice, a monocotyledonous plant.

    Science.gov (United States)

    Nandi, A K; Kushalappa, K; Prasad, K; Vijayraghavan, U

    2000-02-24

    Studies of floral organ development in two dicotyledonous plants, Arabidopsis thaliana and Antirrhinum majus, have shown that three sets of genes (A, B and C) can pattern sepals, petals, stamens and carpels [1] [2]. Mechanisms that define boundaries between these floral whorls are unclear, however. The Arabidopsis gene SUPERMAN (SUP), which encodes a putative transcription factor, maintains the boundary between stamens and carpels [3] [4] [5], possibly by regulating cell proliferation. By overexpressing SUP cDNA in rice, we examined whether its effects on whorl boundaries are conserved in a divergent monocotyledonous species. High-level ectopic SUP expression in transgenic rice resulted in juvenile death or dwarf plants with decreased axillary growth. Plants with lower levels of SUP RNA were vegetatively normal, but the flowers showed ubiquitous ventral carpel expansion. This was often coupled with reduced stamen number, or occurrence of third-whorl stamen-carpel mosaic organs. Additionally, proliferation of second-whorl ventral cells produced adventitious lodicules, and flowers lost the asymmetry that is normally inherent to this whorl. We predict that SUP is a conserved regulator of floral whorl boundaries and that it affects cell proliferation.

  11. The Shc Family Protein Adaptor, Rai, Negatively Regulates T Cell Antigen Receptor Signaling by Inhibiting ZAP-70 Recruitment and Activation

    OpenAIRE

    Ferro, Micol; Savino, Maria Teresa; Ortensi, Barbara; Finetti, Francesca; Genovese, Luca; Masi, Giulia; Ulivieri, Cristina; Benati, Daniela; Pelicci, Giuliana; Baldari, Cosima T.

    2011-01-01

    Rai/ShcC is a member of the Shc family of protein adaptors expressed with the highest abundance in the central nervous system, where it exerts a protective function by coupling neurotrophic receptors to the PI3K/Akt survival pathway. Rai is also expressed, albeit at lower levels, in other cell types, including T and B lymphocytes. We have previously reported that in these cells Rai attenuates antigen receptor signaling, thereby impairing not only cell proliferation but also, opposite to neuro...

  12. Genetic Regulation of GA Metabolism during Vernalization, Floral Bud Initiation and Development in Pak Choi (Brassica rapa ssp. chinensis Makino

    Directory of Open Access Journals (Sweden)

    Mengya Shang

    2017-09-01

    Full Text Available Pak choi (Brassica rapa ssp. chinensis Makino is a representative seed vernalization vegetable and premature bolting in spring can cause significant economic loss. Thus, it is critical to elucidate the mechanism of molecular regulation of vernalization and floral bud initiation to prevent premature bolting. Gibberellin (GA is the key plant hormone involved in regulating plant development. To gain a better understanding of GA metabolism in pak choi, the content of GA in pak choi was measured at different stages of plant development using enzyme-linked immunosorbent assay. The results showed that the GA content increased significantly after low-temperature treatment (4°C and then decreased rapidly with vegetative growth. During floral bud initiation, the GA content increased rapidly until it peaked upon floral bud differentiation. To elucidate these changes in GA content, the expression of homologous genes encoding enzymes directly involved in GA metabolism were analyzed. The results showed that the changes in the expression of four genes involved in GA synthesis (Bra035120 encoding ent-kaurene synthase, Bra009868 encoding ent-kaurene oxidase, Bra015394 encoding ent-kaurenoic acid oxidase, and Bra013890 encoding GA20-oxidase were correlated with the changes in GA content. In addition, by comparing the expression of genes involved in GA metabolism at different growth stages, seven differentially expressed genes (Bra005596, Bra009285, Bra022565, Bra008362, Bra033324, Bra010802, and Bra030500 were identified. The differential expression of these genes were directly correlated with changes in GA content, suggesting that these genes were directly related to vernalization, floral bud initiation and development. These results contribute to the understanding of the molecular mechanism of changes in GA content during different developmental phases in pak choi.

  13. The murine Nck SH2/SH3 adaptors are important for the development of mesoderm-derived embryonic structures and for regulating the cellular actin network.

    Science.gov (United States)

    Bladt, Friedhelm; Aippersbach, Elke; Gelkop, Sigal; Strasser, Geraldine A; Nash, Piers; Tafuri, Anna; Gertler, Frank B; Pawson, Tony

    2003-07-01

    Mammalian Nck1 and Nck2 are closely related adaptor proteins that possess three SH3 domains, followed by an SH2 domain, and are implicated in coupling phosphotyrosine signals to polypeptides that regulate the actin cytoskeleton. However, the in vivo functions of Nck1 and Nck2 have not been defined. We have mutated the murine Nck1 and Nck2 genes and incorporated beta-galactosidase reporters into the mutant loci. In mouse embryos, the two Nck genes have broad and overlapping expression patterns. They are functionally redundant in the sense that mice deficient for either Nck1 or Nck2 are viable, whereas inactivation of both Nck1 and Nck2 results in profound defects in mesoderm-derived notochord and embryonic lethality at embryonic day 9.5. Fibroblast cell lines derived from Nck1(-/-) Nck2(-/-) embryos have defects in cell motility and in the organization of the lamellipodial actin network. These data suggest that the Nck SH2/SH3 adaptors have important functions in the development of mesodermal structures during embryogenesis, potentially linked to a role in cell movement and cytoskeletal organization.

  14. A photo-responsive F-box protein FOF2 regulates floral initiation by promoting FLC expression in Arabidopsis.

    Science.gov (United States)

    He, Reqing; Li, Xinmei; Zhong, Ming; Yan, Jindong; Ji, Ronghuan; Li, Xu; Wang, Qin; Wu, Dan; Sun, Mengsi; Tang, Dongying; Lin, Jianzhong; Li, Hongyu; Liu, Bin; Liu, Hongtao; Liu, Xuanming; Zhao, Xiaoying; Lin, Chentao

    2017-09-01

    Floral initiation is regulated by various genetic pathways in response to light, temperature, hormones and developmental status; however, the molecular mechanisms underlying the interactions between different genetic pathways are not fully understood. Here, we show that the photoresponsive gene FOF2 (F-box of flowering 2) negatively regulates flowering. FOF2 encodes a putative F-box protein that interacts specifically with ASK14, and its overexpression results in later flowering under both long-day and short-day photoperiods. Conversely, transgenic plants expressing the F-box domain deletion mutant of FOF2 (FOF2ΔF), or double loss of function mutant of FOF2 and FOL1 (FOF2-LIKE 1) present early flowering phenotypes. The late flowering phenotype of the FOF2 overexpression lines is suppressed by the flc-3 loss-of-function mutation. Furthermore, FOF2 mRNA expression is regulated by autonomous pathway gene FCA, and the repressive effect of FOF2 in flowering can be overcome by vernalization. Interestingly, FOF2 expression is regulated by light. The protein level of FOF2 accumulates in response to light, whereas it is degraded under dark conditions via the 26S proteasome pathway. Our findings suggest a possible mechanistic link between light conditions and the autonomous floral promotion pathway in Arabidopsis. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  15. The ASK1 gene regulates development and interacts with the UFO gene to control floral organ identity in Arabidopsis.

    Science.gov (United States)

    Zhao, D; Yang, M; Solava, J; Ma, H

    1999-09-01

    Normal flower development likely requires both specific and general regulators. We have isolated an Arabidopsis mutant ask1-1 (for -Arabidopsis skp1-like1-1), which exhibits defects in both vegetative and reproductive development. In the ask1-1mutant, rosette leaf growth is reduced, resulting in smaller than normal rosette leaves, and internodes in the floral stem are shorter than normal. Examination of cell sizes in these organs indicates that cell expansion is normal in the mutant, but cell number is reduced. In the mutant, the numbers of petals and stamens are reduced, and many flowers have one or more petals with a reduced size. In addition, all mutant flowers have short stamen filaments. Furthermore, petal/stamen chimeric organs are found in many flowers. These results indicate that the ASK1 gene affects the size of vegetative and floral organs. The ask1 floral phenotype resembles somewhat that of the Arabidopsis ufo mutants in that both genes affect whorls 2 and 3. We therefore tested for possible interactions between ASK1 and UFO by analyzing the phenotypes of ufo-2 ask1-1 double mutant plants. In these plants, vegetative development is similar to that of the ask1-1 single mutant, whereas the floral defects are more severe than those in either single mutant. Interior to the first whorl, the double mutant flowers have more sepals or sepal-like organs than are found in ufo-2, and less petals than ask1-1. Our results suggest that ASK1 interacts with UFO to control floral organ identity in whorls 2 and 3. This is very intriguing because ASK1 is very similar in sequence to the yeast SKP1 protein and UFO contains an F-box, a motif known to interact with SKP1 in yeast. Although the precise mechanism of ASK1 and UFO action is unknown, our results support the hypothesis that these two proteins physically interact in vivo. Copyright 1999 Wiley-Liss, Inc.

  16. A conserved serine residue regulates the stability of Drosophila Salvador and human WW domain-containing adaptor 45 through proteasomal degradation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Di, E-mail: DiWu@mail.nankai.edu.cn; Wu, Shian

    2013-04-19

    Highlights: •Ser-17 is key for the stability of Drosophila Sav. •Ala mutation of Ser-17 promotes the proteasomal degradation of Sav. •Ser-17 residue is not the main target of Hpo-induced Sav stabilization. •Hpo-dependent and -independent mechanisms regulate Sav stability. •This mechanism is conserved in the homologue of Sav, human WW45. -- Abstract: The Hippo (Hpo) pathway is a conserved tumor suppressor pathway that controls organ size through the coordinated regulation of apoptosis and proliferation. Drosophila Salvador (Sav), which limits organ size, is a core component of the Hpo pathway. In this study, Ser-17 was shown to be important for the stability of Sav. Alanine mutation of Ser-17 promoted the proteasomal degradation of Sav. Destabilization and stabilization of the Sav protein mediated by alanine mutation of Ser-17 and by Hpo, respectively, were independent of each other. This implies that the stability of Sav is controlled by two mechanisms, one that is Ser-17-dependent and Hpo-independent, and another that is Ser-17-independent and Hpo-dependent. These dual mechanisms also regulated the human counterpart of Drosophila Sav, WW domain-containing adaptor 45 (WW45). The conservation of this regulation adds to its significance in normal physiology and tumorigenesis.

  17. The Adaptor Protein SAP Directly Associates with CD3ζ Chain and Regulates T Cell Receptor Signaling

    Science.gov (United States)

    Proust, Richard; Bertoglio, Jacques; Gesbert, Franck

    2012-01-01

    Mutations altering the gene encoding the SLAM associated protein (SAP) are responsible for the X-linked lymphoproliferative disease or XLP1. Its absence is correlated with a defective NKT cells development, a decrease in B cell functions and a reduced T cells and NK cells cytotoxic activities, thus leading to an immunodeficiency syndrome. SAP is a small 128 amino-acid long protein that is almost exclusively composed of an SH2 domain. It has been shown to interact with the CD150/SLAM family of receptors, and in a non-canonical manner with SH3 containing proteins such as Fyn, βPIX, PKCθ and Nck1. It would thus play the role of a minimal adaptor protein. It has been shown that SAP plays an important function in the activation of T cells through its interaction with the SLAM family of receptors. Therefore SAP defective T cells display a reduced activation of signaling events downstream of the TCR-CD3 complex triggering. In the present work, we evidence that SAP is a direct interactor of the CD3ζ chain. This direct interaction occurs through the first ITAM of CD3ζ, proximal to the membrane. Additionally, we show that, in the context of the TCR-CD3 signaling, an Sh-RNA mediated silencing of SAP is responsible for a decrease of several canonical T cell signaling pathways including Erk, Akt and PLCγ1 and to a reduced induction of IL-2 and IL-4 mRNA. Altogether, we show that SAP plays a central function in the T cell activation processes through a direct association with the CD3 complex. PMID:22912825

  18. The Shc family protein adaptor, Rai, negatively regulates T cell antigen receptor signaling by inhibiting ZAP-70 recruitment and activation.

    Directory of Open Access Journals (Sweden)

    Micol Ferro

    Full Text Available Rai/ShcC is a member of the Shc family of protein adaptors expressed with the highest abundance in the central nervous system, where it exerts a protective function by coupling neurotrophic receptors to the PI3K/Akt survival pathway. Rai is also expressed, albeit at lower levels, in other cell types, including T and B lymphocytes. We have previously reported that in these cells Rai attenuates antigen receptor signaling, thereby impairing not only cell proliferation but also, opposite to neurons, cell survival. Here we have addressed the mechanism underlying the inhibitory activity of Rai on TCR signaling. We show that Rai interferes with the TCR signaling cascade one of the earliest steps--recruitment of the initiating kinase ZAP-70 to the phosphorylated subunit of the TCR/CD3 complex, which results in a generalized dampening of the downstream signaling events. The inhibitory activity of Rai is associated to its inducible recruitment to phosphorylated CD3, which occurs in the physiological signaling context of the immune synapse. Rai is moreover found as a pre-assembled complex with ZAP-70 and also constitutively interacts with the regulatory p85 subunit of PI3K, similar to neuronal cells, notwithstanding the opposite biological outcome, i.e. impairment of PI-3K/Akt activation. The data highlight the ability of Rai to establish interactions with the TCR and key signaling mediators which, either directly (e.g. by inhibiting ZAP-70 recruitment to the TCR or sequestering ZAP-70/PI3K in the cytosol or indirectly (e.g. by promoting the recruitment of effectors responsible for signal extinction prevent full triggering of the TCR signaling cascade.

  19. The Shc family protein adaptor, Rai, negatively regulates T cell antigen receptor signaling by inhibiting ZAP-70 recruitment and activation.

    Science.gov (United States)

    Ferro, Micol; Savino, Maria Teresa; Ortensi, Barbara; Finetti, Francesca; Genovese, Luca; Masi, Giulia; Ulivieri, Cristina; Benati, Daniela; Pelicci, Giuliana; Baldari, Cosima T

    2011-01-01

    Rai/ShcC is a member of the Shc family of protein adaptors expressed with the highest abundance in the central nervous system, where it exerts a protective function by coupling neurotrophic receptors to the PI3K/Akt survival pathway. Rai is also expressed, albeit at lower levels, in other cell types, including T and B lymphocytes. We have previously reported that in these cells Rai attenuates antigen receptor signaling, thereby impairing not only cell proliferation but also, opposite to neurons, cell survival. Here we have addressed the mechanism underlying the inhibitory activity of Rai on TCR signaling. We show that Rai interferes with the TCR signaling cascade one of the earliest steps--recruitment of the initiating kinase ZAP-70 to the phosphorylated subunit of the TCR/CD3 complex, which results in a generalized dampening of the downstream signaling events. The inhibitory activity of Rai is associated to its inducible recruitment to phosphorylated CD3, which occurs in the physiological signaling context of the immune synapse. Rai is moreover found as a pre-assembled complex with ZAP-70 and also constitutively interacts with the regulatory p85 subunit of PI3K, similar to neuronal cells, notwithstanding the opposite biological outcome, i.e. impairment of PI-3K/Akt activation. The data highlight the ability of Rai to establish interactions with the TCR and key signaling mediators which, either directly (e.g. by inhibiting ZAP-70 recruitment to the TCR or sequestering ZAP-70/PI3K in the cytosol) or indirectly (e.g. by promoting the recruitment of effectors responsible for signal extinction) prevent full triggering of the TCR signaling cascade.

  20. The Shc Family Protein Adaptor, Rai, Negatively Regulates T Cell Antigen Receptor Signaling by Inhibiting ZAP-70 Recruitment and Activation

    Science.gov (United States)

    Ferro, Micol; Savino, Maria Teresa; Ortensi, Barbara; Finetti, Francesca; Genovese, Luca; Masi, Giulia; Ulivieri, Cristina; Benati, Daniela; Pelicci, Giuliana; Baldari, Cosima T.

    2011-01-01

    Rai/ShcC is a member of the Shc family of protein adaptors expressed with the highest abundance in the central nervous system, where it exerts a protective function by coupling neurotrophic receptors to the PI3K/Akt survival pathway. Rai is also expressed, albeit at lower levels, in other cell types, including T and B lymphocytes. We have previously reported that in these cells Rai attenuates antigen receptor signaling, thereby impairing not only cell proliferation but also, opposite to neurons, cell survival. Here we have addressed the mechanism underlying the inhibitory activity of Rai on TCR signaling. We show that Rai interferes with the TCR signaling cascade one of the earliest steps –recruitment of the initiating kinase ZAP-70 to the phosphorylated subunit of the TCR/CD3 complex, which results in a generalized dampening of the downstream signaling events. The inhibitory activity of Rai is associated to its inducible recruitment to phosphorylated CD3, which occurs in the physiological signaling context of the immune synapse. Rai is moreover found as a pre-assembled complex with ZAP-70 and also constitutively interacts with the regulatory p85 subunit of PI3K, similar to neuronal cells, notwithstanding the opposite biological outcome, i.e. impairment of PI-3K/Akt activation. The data highlight the ability of Rai to establish interactions with the TCR and key signaling mediators which, either directly (e.g. by inhibiting ZAP-70 recruitment to the TCR or sequestering ZAP-70/PI3K in the cytosol) or indirectly (e.g. by promoting the recruitment of effectors responsible for signal extinction) prevent full triggering of the TCR signaling cascade. PMID:22242145

  1. Skb5, an SH3 adaptor protein, regulates Pmk1 MAPK signaling by controlling the intracellular localization of the MAPKKK Mkh1.

    Science.gov (United States)

    Kanda, Yuki; Satoh, Ryosuke; Matsumoto, Saki; Ikeda, Chisato; Inutsuka, Natsumi; Hagihara, Kanako; Matzno, Sumio; Tsujimoto, Sho; Kita, Ayako; Sugiura, Reiko

    2016-08-15

    The mitogen-activated protein kinase (MAPK) cascade is a highly conserved signaling module composed of MAPK kinase kinases (MAPKKKs), MAPK kinases (MAPKK) and MAPKs. The MAPKKK Mkh1 is an initiating kinase in Pmk1 MAPK signaling, which regulates cell integrity in fission yeast (Schizosaccharomyces pombe). Our genetic screen for regulators of Pmk1 signaling identified Shk1 kinase binding protein 5 (Skb5), an SH3-domain-containing adaptor protein. Here, we show that Skb5 serves as an inhibitor of Pmk1 MAPK signaling activation by downregulating Mkh1 localization to cell tips through its interaction with the SH3 domain. Consistent with this, the Mkh1(3PA) mutant protein, with impaired Skb5 binding, remained in the cell tips, even when Skb5 was overproduced. Intriguingly, Skb5 needs Mkh1 to localize to the growing ends as Mkh1 deletion and disruption of Mkh1 binding impairs Skb5 localization. Deletion of Pck2, an upstream activator of Mkh1, impaired the cell tip localization of Mkh1 and Skb5 as well as the Mkh1-Skb5 interaction. Interestingly, both Pck2 and Mkh1 localized to the cell tips at the G1/S phase, which coincided with Pmk1 MAPK activation. Taken together, Mkh1 localization to cell tips is important for transmitting upstream signaling to Pmk1, and Skb5 spatially regulates this process. © 2016. Published by The Company of Biologists Ltd.

  2. Phospho-dependent binding of the clathrin AP2 adaptor complex to GABAA receptors regulates the efficacy of inhibitory synaptic transmission.

    Science.gov (United States)

    Kittler, Josef T; Chen, Guojun; Honing, Stephan; Bogdanov, Yury; McAinsh, Kristina; Arancibia-Carcamo, I Lorena; Jovanovic, Jasmina N; Pangalos, Menelas N; Haucke, Volker; Yan, Zhen; Moss, Stephen J

    2005-10-11

    The efficacy of synaptic inhibition depends on the number of gamma-aminobutyric acid type A receptors (GABA(A)Rs) expressed on the cell surface of neurons. The clathrin adaptor protein 2 (AP2) complex is a critical regulator of GABA(A)R endocytosis and, hence, surface receptor number. Here, we identify a previously uncharacterized atypical AP2 binding motif conserved within the intracellular domains of all GABA(A)R beta subunit isoforms. This AP2 binding motif (KTHLRRRSSQLK in the beta3 subunit) incorporates the major sites of serine phosphorylation within receptor beta subunits, and phosphorylation within this site inhibits AP2 binding. Furthermore, by using surface plasmon resonance, we establish that a peptide (pepbeta3) corresponding to the AP2 binding motif in the GABA(A)R beta3 subunit binds to AP2 with high affinity only when dephosphorylated. Moreover, the pepbeta3 peptide, but not its phosphorylated equivalent (pepbeta3-phos), enhanced the amplitude of miniature inhibitory synaptic current and whole cell GABA(A)R current. These effects of pepbeta3 on GABA(A)R current were occluded by inhibitors of dynamin-dependent endocytosis supporting an action of pepbeta3 on GABA(A)R endocytosis. Therefore phospho-dependent regulation of AP2 binding to GABA(A)Rs provides a mechanism to specify receptor cell surface number and the efficacy of inhibitory synaptic transmission.

  3. The adaptor protein SAP directly associates with PECAM-1 and regulates PECAM-1-mediated-cell adhesion in T-like cell lines.

    Science.gov (United States)

    Proust, Richard; Crouin, Catherine; Gandji, Leslie Yewakon; Bertoglio, Jacques; Gesbert, Franck

    2014-04-01

    SAP is a small cytosolic adaptor protein expressed in hematopoietic lineages whose main function is to regulate intracellular signaling pathways induced by the triggering of members of the SLAM receptor family. In this paper, we have identified the adhesion molecule PECAM-1 as a new partner for SAP in a conditional yeast two-hybrid screen. PECAM-1 is an immunoglobulin-like molecule expressed by endothelial cells and leukocytes, which possesses both pro- and anti-inflammatory properties. However, little is known about PECAM-1 functions in T cells. We show that SAP directly and specifically interacts with the cytosolic tyrosine 686 of PECAM-1. We generated different T-like cell lines in which SAP or PECAM-1 are expressed or down modulated and we demonstrate that a diminished SAP expression correlates with a diminished PECAM-1-mediated adhesion. Although SAP has mainly been shown to associate with SLAM receptors, we evidence here that SAP is a new actor downstream of PECAM-1. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Germline-specific MATH-BTB substrate adaptor MAB1 regulates spindle length and nuclei identity in maize.

    Science.gov (United States)

    Juranič, Martina; Srilunchang, Kanok-orn; Krohn, Nádia Graciele; Leljak-Levanic, Dunja; Sprunck, Stefanie; Dresselhaus, Thomas

    2012-12-01

    Germline and early embryo development constitute ideal model systems to study the establishment of polarity, cell identity, and asymmetric cell divisions (ACDs) in plants. We describe here the function of the MATH-BTB domain protein MAB1 that is exclusively expressed in the germ lineages and the zygote of maize (Zea mays). mab1 (RNA interference [RNAi]) mutant plants display chromosome segregation defects and short spindles during meiosis that cause insufficient separation and migration of nuclei. After the meiosis-to-mitosis transition, two attached nuclei of similar identity are formed in mab1 (RNAi) mutants leading to an arrest of further germline development. Transient expression studies of MAB1 in tobacco (Nicotiana tabacum) Bright Yellow-2 cells revealed a cell cycle-dependent nuclear localization pattern but no direct colocalization with the spindle apparatus. MAB1 is able to form homodimers and interacts with the E3 ubiquitin ligase component Cullin 3a (CUL3a) in the cytoplasm, likely as a substrate-specific adapter protein. The microtubule-severing subunit p60 of katanin was identified as a candidate substrate for MAB1, suggesting that MAB1 resembles the animal key ACD regulator Maternal Effect Lethal 26 (MEL-26). In summary, our findings provide further evidence for the importance of posttranslational regulation for asymmetric divisions and germline progression in plants and identified an unstable key protein that seems to be involved in regulating the stability of a spindle apparatus regulator(s).

  5. Germline-Specific MATH-BTB Substrate Adaptor MAB1 Regulates Spindle Length and Nuclei Identity in Maize[W

    Science.gov (United States)

    Juranić, Martina; Srilunchang, Kanok-orn; Krohn, Nádia Graciele; Leljak-Levanić, Dunja; Sprunck, Stefanie; Dresselhaus, Thomas

    2012-01-01

    Germline and early embryo development constitute ideal model systems to study the establishment of polarity, cell identity, and asymmetric cell divisions (ACDs) in plants. We describe here the function of the MATH-BTB domain protein MAB1 that is exclusively expressed in the germ lineages and the zygote of maize (Zea mays). mab1 (RNA interference [RNAi]) mutant plants display chromosome segregation defects and short spindles during meiosis that cause insufficient separation and migration of nuclei. After the meiosis-to-mitosis transition, two attached nuclei of similar identity are formed in mab1 (RNAi) mutants leading to an arrest of further germline development. Transient expression studies of MAB1 in tobacco (Nicotiana tabacum) Bright Yellow-2 cells revealed a cell cycle–dependent nuclear localization pattern but no direct colocalization with the spindle apparatus. MAB1 is able to form homodimers and interacts with the E3 ubiquitin ligase component Cullin 3a (CUL3a) in the cytoplasm, likely as a substrate-specific adapter protein. The microtubule-severing subunit p60 of katanin was identified as a candidate substrate for MAB1, suggesting that MAB1 resembles the animal key ACD regulator Maternal Effect Lethal 26 (MEL-26). In summary, our findings provide further evidence for the importance of posttranslational regulation for asymmetric divisions and germline progression in plants and identified an unstable key protein that seems to be involved in regulating the stability of a spindle apparatus regulator(s). PMID:23250449

  6. Three TFL1 homologues regulate floral initiation in the biofuel plant Jatropha curcas

    Science.gov (United States)

    Li, Chaoqiong; Fu, Qiantang; Niu, Longjian; Luo, Li; Chen, Jianghua; Xu, Zeng-Fu

    2017-01-01

    Recent research revealed that TERMINAL FLOWER 1 (TFL1) homologues are involved in the critical developmental process of floral initiation in several plant species. In this study, the functions of three putative TFL1 homologues (JcTFL1a, JcTFL1b and JcTFL1c) in the biofuel plant Jatropha curcas were analysed using the transgenic approach. JcTFL1b and JcTFL1c, but not JcTFL1a, could complement the TFL1 function and rescue early flowering and determinate inflorescence phenotype in tfl1-14 Arabidopsis mutant, thus suggesting that JcTFL1b and JcTFL1c may be homologues of TFL1. Transgenic Jatropha overexpressing JcTFL1a, JcTFL1b or JcTFL1c showed late flowering, whereas only JcTFL1b and JcTFL1c overexpression delayed flowering in transgenic Arabidopsis. JcTFL1b-RNAi transgenic Jatropha consistently exhibited moderately early flowering phenotype. JcFT and JcAP1 were significantly downregulated in transgenic Jatropha overexpressing JcTFL1a, JcTFL1b or JcTFL1c, which suggested that the late flowering phenotype of these transgenic Jatropha may result from the repressed expression of JcFT and JcAP1. Our results indicate that these three JcTFL1 genes play redundant roles in repressing flowering in Jatropha. PMID:28225036

  7. The Adaptor Protein SAP Regulates Type II NKT Cell Development, Cytokine Production and Cytotoxicity Against Lymphoma1

    Science.gov (United States)

    Weng, Xiufang; Liao, Chia-Min; Bagchi, Sreya; Cardell, Susanna L.; Stein, Paul L.; Wang, Chyung-Ru

    2014-01-01

    CD1d-restricted NKT cells represent a unique lineage of immunoregulatory T cells that are divided into two groups, type I and type II, based on their TCR usage. Because there are no specific tools to identify type II NKT cells, little is known about their developmental requirements and functional regulation. In our previous study, we showed that signaling lymphocytic activation molecule-associated protein (SAP) is essential for the development of type II NKT cells. Here, using a type II NKT cell TCR transgenic mouse model (24αβTg), we demonstrated that CD1d-expressing hematopoietic cells but not thymic epithelial cells meditate efficient selection of type II NKT cells. Further, we showed that SAP regulates type II NKT cell development by controlling Egr2 and PLZF expression. SAP-deficient 24αβ transgenic T cells (24αβ T cells) exhibited an immature phenotype with reduced Th2 cytokine-producing capacity and diminished cytotoxicity to CD1d-expressing lymphoma cells. The impaired IL-4 production by SAP-deficient 24αβ T cells was associated with reduced IRF4 and GATA-3 induction following TCR stimulation. Collectively, these data suggest that SAP is critical for regulating type II NKT cell responses. Aberrant responses of these T cells may contribute to the immune dysregulation observed in X-linked lymphoproliferative disease caused by mutations in SAP. PMID:25236978

  8. The adaptor protein SAP regulates type II NKT-cell development, cytokine production, and cytotoxicity against lymphoma.

    Science.gov (United States)

    Weng, Xiufang; Liao, Chia-Min; Bagchi, Sreya; Cardell, Susanna L; Stein, Paul L; Wang, Chyung-Ru

    2014-12-01

    CD1d-restricted NKT cells represent a unique lineage of immunoregulatory T cells that are divided into two groups, type I and type II, based on their TCR usage. Because there are no specific tools to identify type II NKT cells, little is known about their developmental requirements and functional regulation. In our previous study, we showed that signaling lymphocytic activation molecule associated protein (SAP) is essential for the development of type II NKT cells. Here, using a type II NKT-cell TCR transgenic mouse model, we demonstrated that CD1d-expressing hematopoietic cells, but not thymic epithelial cells, meditate efficient selection of type II NKT cells. Furthermore, we showed that SAP regulates type II NKT-cell development by controlling early growth response 2 protein and promyelocytic leukemia zinc finger expression. SAP-deficient 24αβ transgenic T cells (24αβ T cells) exhibited an immature phenotype with reduced Th2 cytokine-producing capacity and diminished cytotoxicity to CD1d-expressing lymphoma cells. The impaired IL-4 production by SAP-deficient 24αβ T cells was associated with reduced IFN regulatory factor 4 and GATA-3 induction following TCR stimulation. Collectively, these data suggest that SAP is critical for regulating type II NKT cell responses. Aberrant responses of these T cells may contribute to the immune dysregulation observed in X-linked lymphoproliferative disease caused by mutations in SAP. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. An Adaptor Molecule Afadin Regulates Lymphangiogenesis by Modulating RhoA Activity in the Developing Mouse Embryo.

    Directory of Open Access Journals (Sweden)

    Takashi Majima

    Full Text Available Afadin is an intracellular binding partner of nectins, cell-cell adhesion molecules, and plays important roles in the formation of cell-cell junctions. Afadin-knockout mice show early embryonic lethality, therefore little is known about the function of afadin during organ development. In this study, we generated mice lacking afadin expression in endothelial cells, and found that the majority of these mice were embryonically lethal as a result of severe subcutaneous edema. Defects in the lymphatic vessels of the skin were observed, although the morphology in the blood vessels was almost normal. Severe disruption of VE-cadherin-mediated cell-cell junctions occurred only in lymphatic endothelial cells, but not in blood endothelial cells. Knockout of afadin did not affect the differentiation and proliferation of lymphatic endothelial cells. Using in vitro assays with blood and lymphatic microvascular endothelial cells (BMVECs and LMVECs, respectively, knockdown of afadin caused elongated cell shapes and disruption of cell-cell junctions among LMVECs, but not BMVECs. In afadin-knockdown LMVECs, enhanced F-actin bundles at the cell periphery and reduced VE-cadherin immunostaining were found, and activation of RhoA was strongly increased compared with that in afadin-knockdown BMVECs. Conversely, inhibition of RhoA activation in afadin-knockdown LMVECs restored the cell morphology. These results indicate that afadin has different effects on blood and lymphatic endothelial cells by controlling the levels of RhoA activation, which may critically regulate the lymphangiogenesis of mouse embryos.

  10. The Shc family protein adaptor, Rai, acts as a negative regulator of Th17 and Th1 cell development.

    Science.gov (United States)

    Savino, Maria Teresa; Ulivieri, Cristina; Emmi, Giacomo; Prisco, Domenico; De Falco, Giulia; Ortensi, Barbara; Beccastrini, Enrico; Emmi, Lorenzo; Pelicci, Giuliana; D'Elios, Mario M; Baldari, Cosima T

    2013-04-01

    Rai, a Shc adapter family member, acts as a negative regulator of antigen receptor signaling in T and B cells. Rai(-/-) mice develop lupus-like autoimmunity associated to the spontaneous activation of self-reactive lymphocytes. Here, we have addressed the potential role of Rai in the development of the proinflammatory Th1 and Th17 subsets, which are centrally implicated in the pathogenesis of a number of autoimmune diseases, including lupus. We show that Rai(-/-) mice display a spontaneous Th1/Th17 bias. In vitro polarization experiments on naive and effector/memory CD4(+) T cells demonstrate that Rai(-/-) favors the development and expansion of Th17 but not Th1 cells, indicating that Rai modulates TCR signaling to antagonize the pathways driving naive CD4(+) T cell differentiation to the Th17 lineage, while indirectly limiting Th1 cell development in vivo. Th1 and Th17 cell infiltrates were found in the kidneys of Rai(-/-) mice, providing evidence that Rai(-/-) contributes to the development of lupus nephritis, not only by enhancing lymphocyte activation but also by promoting the development and expansion of proinflammatory effector T cells. Interestingly, T cells from SLE patients were found to have a defect in Rai expression, suggesting a role for Rai in disease pathogenesis.

  11. Transmembrane adaptor protein TRIM regulates T cell receptor (TCR) expression and TCR-mediated signaling via an association with the TCR zeta chain

    Czech Academy of Sciences Publication Activity Database

    Kirchgesser, H.; Dietrich, J.; Scherer, J.; Isomaki, P.; Kořínek, Vladimír; Hilgert, Ivan; Bruyns, E.; Leo, A.; Cope, A. P.; Schraven, B.

    2001-01-01

    Roč. 193, č. 11 (2001), s. 1269-1283 ISSN 0022-1007 R&D Projects: GA ČR GA204/99/0367 Institutional research plan: CEZ:AV0Z5052915 Keywords : receptor * adaptor protein * signaling Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 15.340, year: 2001

  12. A role for cargo in Arf-dependent adaptor recruitment.

    Science.gov (United States)

    Caster, Amanda H; Sztul, Elizabeth; Kahn, Richard A

    2013-05-24

    Membrane traffic requires the specific concentration of protein cargos and exclusion of other proteins into nascent carriers. Critical components of this selectivity are the protein adaptors that bind to short, linear motifs in the cytoplasmic tails of transmembrane protein cargos and sequester them into nascent carriers. The recruitment of the adaptors is mediated by activated Arf GTPases, and the Arf-adaptor complexes mark sites of carrier formation. However, the nature of the signal(s) that initiates carrier biogenesis remains unknown. We examined the specificity and initial sites of recruitment of Arf-dependent adaptors (AP-1 and GGAs) in response to the Golgi or endosomal localization of specific cargo proteins (furin, mannose-6-phosphate receptor (M6PR), and M6PR lacking a C-terminal domain M6PRΔC). We find that cargo promotes the recruitment of specific adaptors, suggesting that it is part of an upstream signaling event. Cargos do not promote adaptor recruitment to all compartments in which they reside, and thus additional factors regulate the cargo's ability to promote Arf activation and adaptor recruitment. We document that within a given compartment different cargos recruit different adaptors, suggesting that there is little or no free, activated Arf at the membrane and that Arf activation is spatially and temporally coupled to the cargo and the adaptor. Using temperature block, brefeldin A, and recovery from each, we found that the cytoplasmic tail of M6PR causes the recruitment of AP-1 and GGAs to recycling endosomes and not at the Golgi, as predicted by steady state staining profiles. These results are discussed with respect to the generation of novel models for cargo-dependent regulation of membrane traffic.

  13. A Role for Cargo in Arf-dependent Adaptor Recruitment*

    Science.gov (United States)

    Caster, Amanda H.; Sztul, Elizabeth; Kahn, Richard A.

    2013-01-01

    Membrane traffic requires the specific concentration of protein cargos and exclusion of other proteins into nascent carriers. Critical components of this selectivity are the protein adaptors that bind to short, linear motifs in the cytoplasmic tails of transmembrane protein cargos and sequester them into nascent carriers. The recruitment of the adaptors is mediated by activated Arf GTPases, and the Arf-adaptor complexes mark sites of carrier formation. However, the nature of the signal(s) that initiates carrier biogenesis remains unknown. We examined the specificity and initial sites of recruitment of Arf-dependent adaptors (AP-1 and GGAs) in response to the Golgi or endosomal localization of specific cargo proteins (furin, mannose-6-phosphate receptor (M6PR), and M6PR lacking a C-terminal domain M6PRΔC). We find that cargo promotes the recruitment of specific adaptors, suggesting that it is part of an upstream signaling event. Cargos do not promote adaptor recruitment to all compartments in which they reside, and thus additional factors regulate the cargo's ability to promote Arf activation and adaptor recruitment. We document that within a given compartment different cargos recruit different adaptors, suggesting that there is little or no free, activated Arf at the membrane and that Arf activation is spatially and temporally coupled to the cargo and the adaptor. Using temperature block, brefeldin A, and recovery from each, we found that the cytoplasmic tail of M6PR causes the recruitment of AP-1 and GGAs to recycling endosomes and not at the Golgi, as predicted by steady state staining profiles. These results are discussed with respect to the generation of novel models for cargo-dependent regulation of membrane traffic. PMID:23572528

  14. PRR7 Is a transmembrane adaptor protein expressed in activated T cells involved in regulation of T cell receptor signaling and apoptosis

    Czech Academy of Sciences Publication Activity Database

    Hrdinka, Matouš; Dráber, Peter; Štěpánek, Ondřej; Ormsby, Tereza; Otáhal, Pavel; Angelisová, Pavla; Brdička, Tomáš; Pačes, Jan; Hořejší, Václav; Drbal, Karel

    2011-01-01

    Roč. 286, č. 22 (2011), s. 19617-19629 ISSN 0021-9258 R&D Projects: GA MŠk 1M0506 Grant - others:GAČR(CZ) MEM/09/E011 Institutional research plan: CEZ:AV0Z50520514 Keywords : PRR7 * transmembrane adaptor protein * apoptosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.773, year: 2011

  15. The genome and transcriptome of Phalaenopsis yield insights into floral organ development and flowering regulation

    Directory of Open Access Journals (Sweden)

    Jian-Zhi Huang

    2016-05-01

    Full Text Available The Phalaenopsis orchid is an important potted flower of high economic value around the world. We report the 3.1 Gb draft genome assembly of an important winter flowering Phalaenopsis ‘KHM190’ cultivar. We generated 89.5 Gb RNA-seq and 113 million sRNA-seq reads to use these data to identify 41,153 protein-coding genes and 188 miRNA families. We also generated a draft genome for Phalaenopsis pulcherrima ‘B8802,’ a summer flowering species, via resequencing. Comparison of genome data between the two Phalaenopsis cultivars allowed the identification of 691,532 single-nucleotide polymorphisms. In this study, we reveal that the key role of PhAGL6b in the regulation of labellum organ development involves alternative splicing in the big lip mutant. Petal or sepal overexpressing PhAGL6b leads to the conversion into a lip-like structure. We also discovered that the gibberellin pathway that regulates the expression of flowering time genes during the reproductive phase change is induced by cool temperature. Our work thus depicted a valuable resource for the flowering control, flower architecture development, and breeding of the Phalaenopsis orchids.

  16. Changes in cis-regulatory elements of a key floral regulator are associated with divergence of inflorescence architectures

    NARCIS (Netherlands)

    Kusters, E.; Della Pina, S.; Castel, R.; Souer, E.; Koes, R.

    2015-01-01

    Higher plant species diverged extensively with regard to the moment (flowering time) and position (inflorescence architecture) at which flowers are formed. This seems largely caused by variation in the expression patterns of conserved genes that specify floral meristem identity (FMI), rather than

  17. Changes in cis-regulatory elements of a key floral regulator are associated with divergence of inflorescence architectures.

    NARCIS (Netherlands)

    Kusters, E.; Della Pina, S.; Castel, R.; Souer, E.J.; Koes, R.E.

    2015-01-01

    Higher plant species diverged extensively with regard to the moment (flowering time) and position (inflorescence architecture) at which flowers are formed. This seems largely caused by variation in the expression patterns of conserved genes that specify floral meristem identity (FMI), rather than

  18. Orchestration of floral initiation by APETALA1.

    Science.gov (United States)

    Kaufmann, Kerstin; Wellmer, Frank; Muiño, Jose M; Ferrier, Thilia; Wuest, Samuel E; Kumar, Vijaya; Serrano-Mislata, Antonio; Madueño, Francisco; Krajewski, Pawel; Meyerowitz, Elliot M; Angenent, Gerco C; Riechmann, José Luis

    2010-04-02

    The MADS-domain transcription factor APETALA1 (AP1) is a key regulator of Arabidopsis flower development. To understand the molecular mechanisms underlying AP1 function, we identified its target genes during floral initiation using a combination of gene expression profiling and genome-wide binding studies. Many of its targets encode transcriptional regulators, including known floral repressors. The latter genes are down-regulated by AP1, suggesting that it initiates floral development by abrogating the inhibitory effects of these genes. Although AP1 acts predominantly as a transcriptional repressor during the earliest stages of flower development, at more advanced stages it also activates regulatory genes required for floral organ formation, indicating a dynamic mode of action. Our results further imply that AP1 orchestrates floral initiation by integrating growth, patterning, and hormonal pathways.

  19. Retail Florist: Selling the Floral Product, Maintenance and Delivery.

    Science.gov (United States)

    Southern Illinois Univ., Carbondale.

    This retail florist unit guide is provided to help teachers teach units on sales of floral products and maintenance and delivery in a floral shop. Topics covered in the selling unit are basic mathematics; taxable items; sales etiquette; types of floral products; telephone etiquette; order form information; wire service regulations; care of floral…

  20. Tissue-Specific Floral Transcriptome Analysis of the Sexually Deceptive Orchid Chiloglottis trapeziformis Provides Insights into the Biosynthesis and Regulation of Its Unique UV-B Dependent Floral Volatile, Chiloglottone 1

    Directory of Open Access Journals (Sweden)

    Darren C. J. Wong

    2017-07-01

    Full Text Available The Australian sexually deceptive orchid, Chiloglottis trapeziformis, employs a unique UV-B-dependent floral volatile, chiloglottone 1, for specific male wasp pollinator attraction. Chiloglottone 1 and related variants (2,5-dialkylcyclohexane-1,3-diones, represent a unique class of specialized metabolites presumed to be the product of cyclization between two fatty acid (FA precursors. However, the genes involved in the biosynthesis of precursors, intermediates, and transcriptional regulation remains to be discovered. Chiloglottone 1 production occurs in the aggregation of calli (callus on the labellum under continuous UV-B light. Therefore, deep sequencing, transcriptome assembly, and differential expression (DE analysis were performed across different tissue types and UV-B treatments. Transcripts expressed in the callus and labellum (∼23,000 transcripts were highly specialized and enriched for a diversity of known and novel metabolic pathways. DE analysis between chiloglottone-emitting callus versus the remainder of the labellum showed strong coordinated induction of entire FA biosynthesis and β-oxidation pathways including genes encoding Ketoacyl-ACP Synthase, Acyl-CoA Oxidase, and Multifunctional Protein. Phylogenetic analysis revealed potential gene duplicates with tissue-specific differential regulation including two Acyl-ACP Thioesterase B and a Ketoacyl-ACP Synthase genes. UV-B treatment induced the activation of UVR8-mediated signaling and large-scale transcriptome changes in both tissues, however, neither FA biosynthesis/β-oxidation nor other lipid metabolic pathways showed clear indications of concerted DE. Gene co-expression network analysis identified three callus-specific modules enriched with various lipid metabolism categories. These networks also highlight promising candidates involved in the cyclization of chiloglottone 1 intermediates (e.g., Bet v I and dimeric α,β barrel proteins and orchestrating regulation of precursor

  1. Changes in cis-regulatory elements of a key floral regulator are associated with divergence of inflorescence architectures.

    Science.gov (United States)

    Kusters, Elske; Della Pina, Serena; Castel, Rob; Souer, Erik; Koes, Ronald

    2015-08-15

    Higher plant species diverged extensively with regard to the moment (flowering time) and position (inflorescence architecture) at which flowers are formed. This seems largely caused by variation in the expression patterns of conserved genes that specify floral meristem identity (FMI), rather than changes in the encoded proteins. Here, we report a functional comparison of the promoters of homologous FMI genes from Arabidopsis, petunia, tomato and Antirrhinum. Analysis of promoter-reporter constructs in petunia and Arabidopsis, as well as complementation experiments, showed that the divergent expression of leafy (LFY) and the petunia homolog aberrant leaf and flower (ALF) results from alterations in the upstream regulatory network rather than cis-regulatory changes. The divergent expression of unusual floral organs (UFO) from Arabidopsis, and the petunia homolog double top (DOT), however, is caused by the loss or gain of cis-regulatory promoter elements, which respond to trans-acting factors that are expressed in similar patterns in both species. Introduction of pUFO:UFO causes no obvious defects in Arabidopsis, but in petunia it causes the precocious and ectopic formation of flowers. This provides an example of how a change in a cis-regulatory region can account for a change in the plant body plan. © 2015. Published by The Company of Biologists Ltd.

  2. Transcriptional Regulations on the Low-Temperature-Induced Floral Transition in an Orchidaceae Species, Dendrobium nobile: An Expressed Sequence Tags Analysis

    Directory of Open Access Journals (Sweden)

    Shan Liang

    2012-01-01

    Full Text Available Vernalization-induced flowering is a cold-relevant adaptation in many species, but little is known about the genetic basis behind in Orchidaceae species. Here, we reported a collection of 15017 expressed sequence tags (ESTs from the vernalized axillary buds of an Orchidaceae species, Dendrobium nobile, which were assembled for 9616 unique gene clusters. Functional enrichment analysis showed that genes in relation to the responses to stresses, especially in the form of low temperatures, and those involving in protein biosynthesis and chromatin assembly were significantly overrepresented during 40 days of vernalization. Additionally, a total of 59 putative flowering-relevant genes were recognized, including those homologous to known key players in vernalization pathways in temperate cereals or Arabidopsis, such as cereal VRN1, FT/VRN3, and Arabidopsis AGL19. Results from this study suggest that the networks regulating vernalization-induced floral transition are conserved, but just in a part, in D. nobile, temperate cereals, and Arabidopsis.

  3. Identification, functional characterization, and regulation of the enzyme responsible for floral (E)-nerolidol biosynthesis in kiwifruit (Actinidia chinensis)

    Science.gov (United States)

    Green, Sol A.; Chen, Xiuyin; Nieuwenhuizen, Niels J.; Matich, Adam J.; Wang, Mindy Y.; Bunn, Barry J.; Yauk, Yar-Khing; Atkinson, Ross G.

    2012-01-01

    Flowers of the kiwifruit species Actinidia chinensis produce a mixture of sesquiterpenes derived from farnesyl diphosphate (FDP) and monoterpenes derived from geranyl diphosphate (GDP). The tertiary sesquiterpene alcohol (E)-nerolidol was the major emitted volatile detected by headspace analysis. Contrastingly, in solvent extracts of the flowers, unusually high amounts of (E,E)-farnesol were observed, as well as lesser amounts of (E)-nerolidol, various farnesol and farnesal isomers, and linalool. Using a genomics-based approach, a single gene (AcNES1) was identified in an A. chinensis expressed sequence tag library that had significant homology to known floral terpene synthase enzymes. In vitro characterization of recombinant AcNES1 revealed it was an enzyme that could catalyse the conversion of FDP and GDP to the respective (E)-nerolidol and linalool terpene alcohols. Enantiomeric analysis of both AcNES1 products in vitro and floral terpenes in planta showed that (S)-(E)-nerolidol was the predominant enantiomer. Real-time PCR analysis indicated peak expression of AcNES1 correlated with peak (E)-nerolidol, but not linalool accumulation in flowers. This result, together with subcellular protein localization to the cytoplasm, indicated that AcNES1 was acting as a (S)-(E)-nerolidol synthase in A. chinensis flowers. The synthesis of high (E,E)-farnesol levels appears to compete for the available pool of FDP utilized by AcNES1 for sesquiterpene biosynthesis and hence strongly influences the accumulation and emission of (E)-nerolidol in A. chinensis flowers. PMID:22162874

  4. G protein-coupled receptors regulate Na+,K+-ATPase activity and endocytosis by modulating the recruitment of adaptor protein 2 and clathrin

    Science.gov (United States)

    Ogimoto, Goichi; Yudowski, Guillermo A.; Barker, Christopher J.; Köhler, Martin; Katz, Adrian I.; Féraille, Eric; Pedemonte, Carlos H.; Berggren, Per-Olof; Bertorello, Alejandro M.

    2000-01-01

    Inhibition of Na+,K+-ATPase (NKA) activity in renal epithelial cells by activation of G protein-coupled receptors is mediated by phosphorylation of the catalytic α-subunit followed by endocytosis of active molecules. We examined whether agonists that counteract this effect do so by dephosphorylation of the α-subunit or by preventing its internalization through a direct interaction with the endocytic network. Oxymetazoline counteracted the action of dopamine on NKA activity, and this effect was achieved not by preventing α-subunit phosphorylation, but by impaired endocytosis of α-subunits into clathrin vesicles and early and late endosomes. Dopamine-induced inhibition of NKA activity and α-subunit endocytosis required the interaction of adaptor protein 2 (AP-2) with the catalytic α-subunit. Phosphorylation of the α-subunit is essential because dopamine failed to promote such interaction in cells lacking the protein kinase C phosphorylation residue (S18A). Confocal microscopy confirmed that oxymetazoline prevents incorporation of NKA molecules into clathrin vesicles by inhibiting the ability of dopamine to recruit clathrin to the plasma membrane. Dopamine decreased the basal levels of inositol hexakisphosphate (InsP6), whereas oxymetazoline prevented this effect. Similar increments (above basal) in the concentration of InsP6 induced by oxymetazoline prevented AP-2 binding to the NKA α-subunit in response to dopamine. In conclusion, inhibition of NKA activity can be reversed by preventing its endocytosis without altering the state of α-subunit phosphorylation; increased InsP6 in response to G protein-coupled receptor signals blocks the recruitment of AP-2 and thereby clathrin-dependent endocytosis of NKA. PMID:10716725

  5. The Arabidopsis adaptor protein AP-3µ interacts with the G-protein β subunit AGB1 and is involved in abscisic acid regulation of germination and post-germination development

    Science.gov (United States)

    Tsugama, Daisuke; Takano, Tetsuo

    2013-01-01

    Heterotrimeric G-proteins (G-proteins) have been implicated in ubiquitous signalling mechanisms in eukaryotes. In plants, G-proteins modulate hormonal and stress responses and regulate diverse developmental processes. However, the molecular mechanisms of their functions are largely unknown. A yeast two-hybrid screen was performed to identify interacting partners of the Arabidopsis G-protein β subunit AGB1. One of the identified AGB1-interacting proteins is the Arabidopsis adaptor protein AP-3µ. The interaction between AGB1 and AP-3µ was confirmed by an in vitro pull-down assay and bimolecular fluorescence complementation assay. Two ap-3µ T-DNA insertional mutants were found to be hyposensitive to abscisic acid (ABA) during germination and post-germination growth, whereas agb1 mutants were hypersensitive to ABA. During seed germination, agb1/ap-3µ double mutants were more sensitive to ABA than the wild type but less sensitive than agb1 mutants. However, in post-germination growth, the double mutants were as sensitive to ABA as agb1 mutants. These data suggest that AP-3µ positively regulates the ABA responses independently of AGB1 in seed germination, while AP-3µ does require AGB1 to regulate ABA responses during post-germination growth. PMID:24098050

  6. Characterization of Toll-like receptors in primary lung epithelial cells: strong impact of the TLR3 ligand poly(I:C on the regulation of Toll-like receptors, adaptor proteins and inflammatory response

    Directory of Open Access Journals (Sweden)

    Weith Andreas

    2005-11-01

    Full Text Available Abstract Background Bacterial and viral exacerbations play a crucial role in a variety of lung diseases including COPD or asthma. Since the lung epithelium is a major source of various inflammatory mediators that affect the immune response, we analyzed the inflammatory reaction of primary lung epithelial cells to different microbial molecules that are recognized by Toll-like receptors (TLR. Methods The effects of TLR ligands on primary small airway epithelial cells were analyzed in detail with respect to cytokine, chemokine and matrix metalloproteinase secretion. In addition, the regulation of the expression of TLRs and their adaptor proteins in small airway epithelial cells was investigated. Results Our data demonstrate that poly(I:C, a synthetic analog of viral dsRNA, mediated the strongest proinflammatory effects among the tested ligands, including an increased secretion of IL-6, IL-8, TNF-α, GM-CSF, GRO-α, TARC, MCP-1, MIP-3α, RANTES, IFN-β, IP-10 and ITAC as well as an increased release of MMP-1, MMP-8, MMP-9, MMP-10 and MMP-13. Furthermore, our data show that poly(I:C as well as type-1 and type-2 cytokines have a pronounced effect on the expression of TLRs and molecules involved in TLR signaling in small airway epithelial cells. Poly(I:C induced an elevated expression of TLR1, TLR2 and TLR3 and increased the gene expression of the general TLR adaptor MyD88 and IRAK-2. Simultaneously, poly(I:C decreased the expression of TLR5, TLR6 and TOLLIP. Conclusion Poly(I:C, an analog of viral dsRNA and a TLR3 ligand, triggers a strong inflammatory response in small airway epithelial cells that is likely to contribute to viral exacerbations of pulmonary diseases like asthma or COPD. The pronounced effects of poly(I:C on the expression of Toll-like receptors and molecules involved in TLR signaling is assumed to influence the immune response of the lung epithelium to viral and bacterial infections. Likewise, the regulation of TLR expression by type

  7. No time for candy: passionfruit (Passiflora edulis) plants down-regulate damage-induced extra floral nectar production in response to light signals of competition.

    Science.gov (United States)

    Izaguirre, Miriam M; Mazza, Carlos A; Astigueta, María S; Ciarla, Ana M; Ballaré, Carlos L

    2013-09-01

    Plant fitness is often defined by the combined effects of herbivory and competition, and plants must strike a delicate balance between their ability to capture limiting resources and defend against herbivore attack. Many plants use indirect defenses, such as volatile compounds and extra floral nectaries (EFN), to attract canopy arthropods that are natural enemies of herbivorous organisms. While recent evidence suggests that upon perception of low red to far-red (R:FR) ratios, which signal the proximity of competitors, plants down-regulate resource allocation to direct chemical defenses, it is unknown if a similar phytochrome-mediated response occurs for indirect defenses. We evaluated the interactive effects of R:FR ratio and simulated herbivory on nectar production by EFNs of passion fruit (Passiflora edulis f. flavicarpa). The activity of petiolar EFNs dramatically increased in response to simulated herbivory and hormonal treatment with methyl jasmonate (MeJA). Low R:FR ratios, which induced a classic "shade-avoidance" repertoire of increased stem elongation in P. edulis, strongly suppressed the EFN response triggered by simulated herbivory or MeJA application. Strikingly, the EFN response to wounding and light quality was localized to the branches that received the treatments. In vines like P. edulis, a local response would allow the plants to precisely adjust their light harvesting and defense phenotypes to the local conditions encountered by individual branches when foraging for resources in patchy canopies. Consistent with the emerging paradigm that phytochrome regulation of jasmonate signaling is a central modulator of adaptive phenotypic plasticity, our results demonstrate that light quality is a strong regulator of indirect defenses.

  8. Building beauty: the genetic control of floral patterning

    Energy Technology Data Exchange (ETDEWEB)

    Lohmann, J. U., and Weigel, D.

    2002-02-01

    OAK-B135 Floral organ identity is controlled by combinatorial action of homeotic genes expressed in different territories within the emerging flower. This review discusses recent progress in our understanding of floral homeotic genes, with an emphasis on how their region-specific expression is regulated.

  9. Role of adaptor proteins in secretory granule biogenesis and maturation

    Directory of Open Access Journals (Sweden)

    Mathilde L Bonnemaison

    2013-08-01

    Full Text Available In the regulated secretory pathway, secretory granules (SGs store peptide hormones that are released on demand. SGs are formed at the trans-Golgi network (TGN and must undergo a maturation process to become responsive to secretagogues. The production of mature SGs requires concentrating newly synthesized soluble content proteins in granules whose membranes contain the appropriate integral membrane proteins. The mechanisms underlying the sorting of soluble and integral membrane proteins destined for SGs from other proteins are not yet well understood. For soluble proteins, luminal pH and divalent metals can affect aggregation and interaction with surrounding membranes. The trafficking of granule membrane proteins can be controlled by both luminal and cytosolic factors. Cytosolic adaptor proteins, which recognize the cytosolic domains of proteins that span the SG membrane, have been shown to play essential roles in the assembly of functional SGs. Adaptor protein 1A (AP-1A is known to interact with specific motifs in its cargo proteins and with the clathrin heavy chain, contributing to the formation of a clathrin coat. AP-1A is present in patches on immature SG membranes, where it removes cargo and facilitates SG maturation. AP-1A recruitment to membranes can be modulated by PACS-1 (Phosphofurin Acidic Cluster Sorting protein 1, a cytosolic protein which interacts with both AP-1A and cargo that has been phosphorylated by casein kinase II. A cargo/PACS-1/AP-1A complex is necessary to drive the appropriate transport of several cargo proteins within the regulated secretory pathway. The GGA (Golgi-localized, -ear containing, ADP-ribosylation factor binding family of adaptor proteins serve a similar role. We review the functions of AP-1A, PACS-1 and GGAs in facilitating the retrieval of proteins from immature SGs and review examples of cargo proteins whose trafficking within the regulated secretory pathway is governed by adaptor proteins.

  10. Challenges in using cultured primary rodent hepatocytes or cell lines to study hepatic HDL receptor SR-BI regulation by its cytoplasmic adaptor PDZK1.

    Directory of Open Access Journals (Sweden)

    Kosuke Tsukamoto

    Full Text Available BACKGROUND: PDZK1 is a four PDZ-domain containing cytoplasmic protein that binds to a variety of membrane proteins via their C-termini and can influence the abundance, localization and/or function of its target proteins. One of these targets in hepatocytes in vivo is the HDL receptor SR-BI. Normal hepatic expression of SR-BI protein requires PDZK1 - <5% of normal hepatic SR-BI is seen in the livers of PDZK1 knockout mice. Progress has been made in identifying features of PDZK1 required to control hepatic SR-BI in vivo using hepatic expression of wild-type and mutant forms of PDZK1 in wild-type and PDZK1 KO transgenic mice. Such in vivo studies are time consuming and expensive, and cannot readily be used to explore many features of the underlying molecular and cellular mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: Here we have explored the potential to use either primary rodent hepatocytes in culture using 2D collagen gels with newly developed optimized conditions or PDZK1/SR-BI co-transfected cultured cell lines (COS, HEK293 for such studies. SR-BI and PDZK1 protein and mRNA expression levels fell rapidly in primary hepatocyte cultures, indicating this system does not adequately mimic hepatocytes in vivo for analysis of the PDZK1 dependence of SR-BI. Although PDZK1 did alter SR-BI protein expression in the cell lines, its influence was independent of SR-BI's C-terminus, and thus is not likely to occur via the same mechanism as that which occurs in hepatocytes in vivo. CONCLUSIONS/SIGNIFICANCE: Caution must be exercised in using primary hepatocytes or cultured cell lines when studying the mechanism underlying the regulation of hepatic SR-BI by PDZK1. It may be possible to use SR-BI and PDZK1 expression as sensitive markers for the in vivo-like state of hepatocytes to further improve primary hepatocyte cell culture conditions.

  11. Specification of floral organs in Arabidopsis.

    Science.gov (United States)

    Wellmer, Frank; Graciet, Emmanuelle; Riechmann, José Luis

    2014-01-01

    Floral organs are specified by the activities of a small group of transcriptional regulators, the floral organ identity factors. Extensive genetic and molecular analyses have shown that these proteins act as master regulators of flower development, and function not only in organ identity determination but also during organ morphogenesis. Although it is now well established that these transcription factors act in higher order protein complexes in the regulation of transcription, the gene expression programmes controlled by them have remained largely elusive. Only recently, detailed insights into their functions have been obtained through the combination of a wide range of experimental methods, including transcriptomic and proteomic approaches. Here, we review the progress that has been made in the characterization of the floral organ identity factors from the main model plant Arabidopsis thaliana, and we discuss what is known about the processes acting downstream of these regulators. We further outline open questions, which we believe need to be addressed to obtain a more complete view of the molecular processes that govern floral organ development and specification.

  12. Orchestration of floral initiation by APETALA1

    NARCIS (Netherlands)

    Kaufmann, K.; Wellmer, F.; Muino, J.M.; Ferrier, T.; Wuest, S.E.; Kumar, V.; Serrano-Mislata, A.; Madueno, F.; Krajweski, P.; Meyerowitz, E.M.; Angenent, G.C.; Riechmann, J.L.

    2010-01-01

    The MADS-domain transcription factor APETALA1 (AP1) is a key regulator of Arabidopsis flower development. To understand the molecular mechanisms underlying AP1 function, we identified its target genes during floral initiation using a combination of gene expression profiling and genome-wide binding

  13. Orchestration of Floral Initiation by APETALA1

    NARCIS (Netherlands)

    Kaufmann, K.; Muino Acuna, J.M.

    2010-01-01

    The MADS-domain transcription factor APETALA1 (AP1) is a key regulator of Arabidopsis flower development. To understand the molecular mechanisms underlying AP1 function, we identified its target genes during floral initiation using a combination of gene expression profiling and genome-wide binding

  14. Genetics of Floral Development (By Christine Fleet).

    Science.gov (United States)

    2017-11-01

    Summaryplantcell;29/11/tpc.117.tt1117/FIG1F1fig1A basic model for floral organ identity has been developed using model systems such as Arabidopsis thaliana , snapdragon ( Antirrhinum majus ), and petunia ( Petunia hybrida ). In this model, different combinations of proteins known as ABCDE proteins, mostly MADS-domain transcription factors, activate the transcription of target genes to specify the identity of each whorl of floral organs. Changes in the regulation or activation of these target genes contribute to the wide variety of floral forms that we see within and across species. In addition, duplications and divergence of these genes in different groups of flowering plants have resulted in differences in gene function and expression patterns, contributing to differences in flower form across species. Posted December 8, 2017.Click HERE to access Teaching Tool Components. © 2017 American Society of Plant Biologists. All rights reserved.

  15. Motors and Adaptors : Transport Regulation within Neurons

    NARCIS (Netherlands)

    van Spronsen, C.S.A.M.|info:eu-repo/dai/nl/337616655

    2012-01-01

    Human thoughts and behavior are the outcome of communication between neurons in our brains. There is an entire world inside each of these neurons where transactions are established and meeting points are set. By using molecular motors to transport proteins and organelles along cytoskeletal tracks,

  16. Styles of Creativity: Adaptors and Innovators in a Singapore Context

    Science.gov (United States)

    Ee, Jessie; Seng, Tan Oon; Kwang, Ng Aik

    2007-01-01

    Kirton (1976) described two creative styles, namely adaptors and innovators. Adaptors prefer to "do things better" whilst, innovators prefer to "do things differently". This study explored the relationship between two creative styles (adaptor and innovator) and the Big Five personality traits (extraversion, agreeableness, conscientiousness,…

  17. 21 CFR 870.3620 - Pacemaker lead adaptor.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker lead adaptor. 870.3620 Section 870.3620...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3620 Pacemaker lead adaptor. (a) Identification. A pacemaker lead adaptor is a device used to adapt a pacemaker lead so that it...

  18. Palmitoylated transmembrane adaptor proteins in leukocyte signaling

    Czech Academy of Sciences Publication Activity Database

    Štěpánek, Ondřej; Dráber, Peter; Hořejší, Václav

    2014-01-01

    Roč. 26, č. 5 (2014), s. 895-902 ISSN 0898-6568 R&D Projects: GA ČR(CZ) GBP302/12/G101 Institutional support: RVO:68378050 Keywords : Leukocyte * Adaptor * Palmitoylation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.315, year: 2014

  19. PAG - a multipurpose transmembrane adaptor protein

    Czech Academy of Sciences Publication Activity Database

    Hrdinka, Matouš; Hořejší, Václav

    2014-01-01

    Roč. 33, č. 41 (2014), s. 4881-4892 ISSN 0950-9232 R&D Projects: GA ČR(CZ) GBP302/12/G101 Institutional support: RVO:68378050 Keywords : PAG * adaptor protein * membrane raft Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 8.459, year: 2014

  20. Floral Transformation of Wheat

    Science.gov (United States)

    Agarwal, Sujata; Loar, Star; Steber, Camille; Zale, Janice

    A method is described for the floral transformation of wheat using a protocol similar to the floral dip of Arabidopsis. This method does not employ tissue culture of dissected embryos, but instead pre-anthesis spikes with clipped florets at the early, mid to late uninucleate microspore stage are dipped in Agrobacterium infiltration media harboring a vector carrying anthocyanin reporters and the NPTII selectable marker. T1 seeds are examined for color changes induced in the embryo by the anthocyanin reporters. Putatively transformed seeds are germinated and the seedlings are screened for the presence of the NPTII gene based on resistance to paromomycin spray and assayed with NPTII ELISAs. Genomic DNA of putative transformants is digested and analyzed on Southern blots for copy number to determine whether the T-DNA has integrated into the nucleus and to show the number of insertions. The non-optimized transformation efficiencies range from 0.3 to 0.6% (number of transformants/number of florets dipped) but the efficiencies are higher in terms of the number of transformants produced/number of seeds set ranging from 0.9 to 10%. Research is underway to maximize seed set and optimize the protocol by testing different Agrobacterium strains, visual reporters, vectors, and surfactants.

  1. POWERDRESS and diversified expression of the MIR172 gene family bolster the floral stem cell network.

    Directory of Open Access Journals (Sweden)

    Rae Eden Yumul

    Full Text Available Termination of the stem cells in the floral meristem (also known as floral determinacy is critical for the reproductive success of plants, and the molecular activities regulating floral determinacy are precisely orchestrated during the course of floral development. In Arabidopsis thaliana, regulators of floral determinacy include several transcription factor genes, such as APETALA2 (AP2, AGAMOUS (AG, SUPERMAN (SUP, and CRABSCLAW (CRC, as well as a microRNA (miRNA, miR172, which targets AP2. How the transcription factor and miRNA genes are coordinately regulated to achieve floral determinacy is unknown. A mutation in POWERDRESS (PWR, a previously uncharacterized gene encoding a SANT-domain-containing protein, was isolated in this study as an enhancer of the weakly indeterminate ag-10 allele. PWR was found to promote the transcription of CRC, MIR172a, b, and c and/or enhance Pol II occupancy at their promoters, without affecting MIR172d or e. A mutation in mature miR172d was additionally found to enhance the determinacy defects of ag-10 in an AP2-dependent manner, providing direct evidence that miR172d is functional in repressing AP2 and thereby contributes to floral determinacy. Thus, while PWR promotes floral determinacy by enhancing the expression of three of the five MIR172 members as well as CRC, MIR172d, whose expression is PWR-independent, also functions in floral stem cell termination. Taken together, these findings demonstrate how transcriptional diversification and functional redundancy of a miRNA family along with PWR-mediated co-regulation of miRNA and transcription factor genes contribute to the robustness of the floral determinacy network.

  2. The floral transcriptome of Eucalyptus grandis

    CSIR Research Space (South Africa)

    Vining, KJ

    2015-10-01

    Full Text Available As a step toward functional annotation of genes required for floral initiation and development within the Eucalyptus genome, we used short read sequencing to analyze transcriptomes of floral buds from early and late developmental stages...

  3. Hormonal changes during flower development in floral tissues of Lilium.

    Science.gov (United States)

    Arrom, L; Munné-Bosch, S

    2012-08-01

    Much effort has been focussed on better understanding the key signals that modulate floral senescence. Although ethylene is one of the most important regulators of floral senescence in several species, Lilium flowers show low sensitivity to ethylene; thus their senescence may be regulated by other hormones. In this study we have examined how (1) endogenous levels of hormones in various floral tissues (outer and inner tepals, androecium and gynoecium) vary throughout flower development, (2) endogenous levels of hormones in such tissues change in cut versus intact flowers at anthesis, and (3) spray applications of abscisic acid and pyrabactin alter flower longevity. Results show that floral tissues behave differently in their hormonal changes during flower development. Cytokinin and auxin levels mostly increased in tepals prior to anthesis and decreased later during senescence. In contrast, levels of abscisic acid increased during senescence, but only in outer tepals and the gynoecium, and during the latest stages. In addition, cut flowers at anthesis differed from intact flowers in the levels of abscisic acid and auxins in outer tepals, salicylic acid in inner tepals, cytokinins, gibberellins and jasmonic acid in the androecium, and abscisic acid and salicylic acid in the gynoecium, thus showing a clear differential response between floral tissues. Furthermore, spray applications of abscisic acid and pyrabactin in combination accelerated the latest stages of tepal senescence, yet only when flower senescence was delayed with Promalin. It is concluded that (1) floral tissues differentially respond in their endogenous variations of hormones during flower development, (2) cut flowers have drastic changes in the hormonal balance not only of outer and inner tepals but also of androecium and gynoecium, and (3) abscisic acid may accelerate the progression of tepal senescence in Lilium.

  4. Identification of Genes Associated with Lemon Floral Transition and Flower Development during Floral Inductive Water Deficits: A Hypothetical Model.

    Science.gov (United States)

    Li, Jin-Xue; Hou, Xiao-Jin; Zhu, Jiao; Zhou, Jing-Jing; Huang, Hua-Bin; Yue, Jian-Qiang; Gao, Jun-Yan; Du, Yu-Xia; Hu, Cheng-Xiao; Hu, Chun-Gen; Zhang, Jin-Zhi

    2017-01-01

    Water deficit is a key factor to induce flowering in many woody plants, but reports on the molecular mechanisms of floral induction and flowering by water deficit are scarce. Here, we analyzed the morphology, cytology, and different hormone levels of lemon buds during floral inductive water deficits. Higher levels of ABA were observed, and the initiation of floral bud differentiation was examined by paraffin sections analysis. A total of 1638 differentially expressed genes (DEGs) were identified by RNA sequencing. DEGs were related to flowering, hormone biosynthesis, or metabolism. The expression of some DEGs was associated with floral induction by real-time PCR analysis. However, some DEGs may not have anything to do with flowering induction/flower development; they may be involved in general stress/drought response. Four genes from the phosphatidylethanolamine-binding protein family were further investigated. Ectopic expression of these genes in Arabidopsis changed the flowering time of transgenic plants. Furthermore, the 5' flanking region of these genes was also isolated and sequence analysis revealed the presence of several putative cis -regulatory elements, including basic elements and hormone regulation elements. The spatial and temporal expression patterns of these promoters were investigated under water deficit treatment. Based on these findings, we propose a model for citrus flowering under water deficit conditions, which will enable us to further understand the molecular mechanism of water deficit-regulated flowering in citrus. Based on gene activity during floral inductive water deficits identified by RNA sequencing and genes associated with lemon floral transition, a model for citrus flowering under water deficit conditions is proposed.

  5. FOREVER YOUNG FLOWER Negatively Regulates Ethylene Response DNA-Binding Factors by Activating an Ethylene-Responsive Factor to Control Arabidopsis Floral Organ Senescence and Abscission1

    Science.gov (United States)

    Li, Pei-Fang; Lee, Yung-I; Yang, Chang-Hsien

    2015-01-01

    In this study of Arabidopsis (Arabidopsis thaliana), we investigated the relationship between FOREVER YOUNG FLOWER (FYF) and Ethylene Response DNA-binding Factors (EDFs) and functionally analyzed a key FYF target, an Ethylene-Responsive Factor (ERF), that controls flower senescence/abscission. Ectopic expression of EDF1/2/3/4 caused promotion of flower senescence/abscission and the activation of the senescence-associated genes. The presence of a repressor domain in EDFs and the enhancement of the promotion of senescence/abscission in EDF1/2/3/4+SRDX (converting EDFs to strong repressors by fusion with the ERF-associated amphiphilic repression motif repression domain SRDX) transgenic plants suggested that EDFs act as repressors. The significant reduction of β-glucuronidase (GUS) expression by 35S:FYF in EDF1/2/3/4:GUS plants indicates that EDF1/2/3/4 functions downstream of FYF in regulating flower senescence/abscission. In this study, we also characterized an ERF gene, FOREVER YOUNG FLOWER UP-REGULATING FACTOR1 (FUF1), which is up-regulated by FYF during flower development. Ectopic expression of FUF1 caused similar delayed flower senescence/abscission as seen in 35S:FYF plants. This phenotype was correlated with deficient abscission zone formation, ethylene insensitivity, and down-regulation of EDF1/2/3/4 and abscission-associated genes in 35S:FUF1 flowers. In contrast, significant promotion of flower senescence/abscission and up-regulation of EDF1/2/3/4 were observed in 35S:FUF1+SRDX transgenic dominant-negative plants, in which FUF1 is converted to a potent repressor by fusion to an SRDX-suppressing motif. Thus, FUF1 acts as an activator in suppressing EDF1/2/3/4 function and senescence/abscission of the flowers. Our results reveal that FYF regulates flower senescence/abscission by negatively regulating EDF1/2/3/4, which is the downstream gene in the ethylene response, by activating FUF1 in Arabidopsis. PMID:26063506

  6. Floral organ identity genes in the orchid Dendrobium crumenatum.

    Science.gov (United States)

    Xu, Yifeng; Teo, Lai Lai; Zhou, Jing; Kumar, Prakash P; Yu, Hao

    2006-04-01

    Orchids are members of Orchidaceae, one of the largest families in the flowering plants. Among the angiosperms, orchids are unique in their floral patterning, particularly in floral structures and organ identity. The ABCDE model was proposed as a general model to explain flower development in diverse plant groups, however the extent to which this model is applicable to orchids is still unknown. To investigate the regulatory mechanisms underlying orchid flower development, we isolated candidates for A, B, C, D and E function genes from Dendrobium crumenatum. These include AP2-, PI/GLO-, AP3/DEF-, AG- and SEP-like genes. The expression profiles of these genes exhibited different patterns from their Arabidopsis orthologs in floral patterning. Functional studies showed that DcOPI and DcOAG1 could replace the functions of PI and AG in Arabidopsis, respectively. By using chimeric repressor silencing technology, DcOAP3A was found to be another putative B function gene. Yeast two-hybrid analysis demonstrated that DcOAP3A/B and DcOPI could form heterodimers. These heterodimers could further interact with DcOSEP to form higher protein complexes, similar to their orthologs in eudicots. Our findings suggested that there is partial conservation in the B and C function genes between Arabidopsis and orchid. However, gene duplication might have led to the divergence in gene expression and regulation, possibly followed by functional divergence, resulting in the unique floral ontogeny in orchids.

  7. SR proteins are NXF1 adaptors that link alternative RNA processing to mRNA export.

    Science.gov (United States)

    Müller-McNicoll, Michaela; Botti, Valentina; de Jesus Domingues, Antonio M; Brandl, Holger; Schwich, Oliver D; Steiner, Michaela C; Curk, Tomaz; Poser, Ina; Zarnack, Kathi; Neugebauer, Karla M

    2016-03-01

    Nuclear export factor 1 (NXF1) exports mRNA to the cytoplasm after recruitment to mRNA by specific adaptor proteins. How and why cells use numerous different export adaptors is poorly understood. Here we critically evaluate members of the SR protein family (SRSF1-7) for their potential to act as NXF1 adaptors that couple pre-mRNA processing to mRNA export. Consistent with this proposal, >1000 endogenous mRNAs required individual SR proteins for nuclear export in vivo. To address the mechanism, transcriptome-wide RNA-binding profiles of NXF1 and SRSF1-7 were determined in parallel by individual-nucleotide-resolution UV cross-linking and immunoprecipitation (iCLIP). Quantitative comparisons of RNA-binding sites showed that NXF1 and SR proteins bind mRNA targets at adjacent sites, indicative of cobinding. SRSF3 emerged as the most potent NXF1 adaptor, conferring sequence specificity to RNA binding by NXF1 in last exons. Interestingly, SRSF3 and SRSF7 were shown to bind different sites in last exons and regulate 3' untranslated region length in an opposing manner. Both SRSF3 and SRSF7 promoted NXF1 recruitment to mRNA. Thus, SRSF3 and SRSF7 couple alternative splicing and polyadenylation to NXF1-mediated mRNA export, thereby controlling the cytoplasmic abundance of transcripts with alternative 3' ends. © 2016 Müller-McNicoll et al.; Published by Cold Spring Harbor Laboratory Press.

  8. Floral reward in Ranunculaceae species

    Directory of Open Access Journals (Sweden)

    Bożena Denisow

    2016-04-01

    Full Text Available Floral reward is important in ecological and evolutionary perspectives and essential in pollination biology. For example, floral traits, nectar and pollen features are essential for understanding the functional ecology, the dynamics of pollen transport, competition for pollinator services, and patterns of specialization and generalization in plant–pollinator interactions. We believe to present a synthetic description in the field of floral reward in Ranunculaceae family important in pollination biology and indicating connections between ecological and evolutionary approaches. The links between insect visitors’ behaviour and floral reward type and characteristics exist. Ranunculaceae is a family of aboot 1700 species (aboot 60 genera, distributed worldwide, however the most abundant representatives are in temperate and cool regions of the northern and southern hemispheres. The flowers are usually radially symmetric (zygomorphic and bisexual, but in Aconitum, Aquilegia are bilaterally symmetric (zygomorphic. Most Ranunculaceae flowers offer no nectar, only pollen (e.g., Ranunculus, Adonis vernalis, Thalictrum, but numerous species create trophic niches for different wild pollinators (e.g. Osmia, Megachile, Bombus, Andrena (Denisow et al. 2008. Pollen is a source of protein, vitamins, mineral salts, organic acids and hormones, but the nutritional value varies greatly between different plant species. The pollen production can differ significantly between Ranunculacea species. The mass of pollen produced in anthers differ due to variations in the number of developed anthers. For example, interspecies differences are considerable, 49 anthers are noted in Aquilegia vulgaris, 70 anthers in Ranunculus lanuginosus, 120 in Adonis vernalis. A significant intra-species differences’ in the number of anthers are also noted (e.g. 41 to 61 in Aquilegia vulgaris, 23-45 in Ranunculus cassubicus. Pollen production can be up to 62 kg per ha for Ranunculus acer

  9. Sterility Caused by Floral Organ Degeneration and Abiotic Stresses in Arabidopsis and Cereal Grains

    Directory of Open Access Journals (Sweden)

    Ashley Rae Smith

    2016-10-01

    Full Text Available Natural floral organ degeneration or abortion results in unisexual or fully sterile flowers, while abiotic stresses lead to sterility after initiation of floral reproductive organs. Since normal flower development is essential for plant sexual reproduction and crop yield, it is imperative to have a better understanding of plant sterility under regular and stress conditions. Here, we review the functions of ABC genes together with their downstream genes in floral organ degeneration and the formation of unisexual flowers in Arabidopsis and several agriculturally significant cereal grains. We further explore the roles of hormones, including auxin, brassinosteroids, jasmonic acid, gibberellic acid, and ethylene, in floral organ formation and fertility. We show that alterations in genes affecting hormone biosynthesis, hormone transport and perception cause loss of stamens/carpels, abnormal floral organ development, poor pollen production, which consequently result in unisexual flowers and male/female sterility. Moreover, abiotic stresses, such as heat, cold, and drought, commonly affect floral organ development and fertility. Sterility is induced by abiotic stresses mostly in male floral organ development, particularly during meiosis, tapetum development, anthesis, dehiscence, and fertilization. A variety of genes including those involved in heat shock, hormone signaling, cold tolerance, metabolisms of starch and sucrose, meiosis, and tapetum development are essential for plants to maintain normal fertility under abiotic stress conditions. Further elucidation of cellular, biochemical and molecular mechanisms about regulation of fertility will improve yield and quality for many agriculturally valuable crops.

  10. OsHAL3, a Blue Light-Responsive Protein, Interacts with the Floral Regulator Hd1 to Activate Flowering in Rice.

    Science.gov (United States)

    Su, Lei; Shan, Jun-Xiang; Gao, Ji-Ping; Lin, Hong-Xuan

    2016-02-01

    In flowering plants, photoperiodic flowering is controlled by a complicated network. Light is one of the most important environmental stimuli that control the timing of the transition from vegetative growth to reproductive development. Several photoreceptors, including PHYA, PHYB, CRY2, and FKF1 in Arabidopsis and their homologs (OsPHYA, OsPHYB, OsPHYC, and OsCRY2) in rice, have been identified to be related to flowering. Our previous study suggests that OsHAL3, a flavin mononucleotide-binding protein, may function as a blue-light sensor. Here, we report the identification of OsHAL3 as a positive regulator of flowering in rice. OsHAL3 overexpression lines exhibited an early flowering phenotype, whereas downregulation of OsHAL3 expression by RNA interference delayed flowering under an inductive photoperiod (short-day conditions). The change in flowering time was not accompanied by altered Hd1 expression but rather by reduced accumulation of Hd3a and MADS14 transcripts. OsHAL3 and Hd1 colocalized in the nucleus and physically interacted in vivo under the dark, whereas their interaction was inhibited by white or blue light. Moreover, OsHAL3 directly bound to the promoter of Hd3a, especially before dawn. We conclude that OsHAL3, a novel light-responsive protein, plays an essential role in photoperiodic control of flowering time in rice, which is probably mediated by forming a complex with Hd1. Our findings open up new perspectives on the photoperiodic flowering pathway. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

  11. Evolutionary trends in the floral transcriptome: insights from one of the basalmost angiosperms, the water lily Nuphar advena (Nymphaeaceae).

    Science.gov (United States)

    Yoo, Mi-Jeong; Chanderbali, André S; Altman, Naomi S; Soltis, Pamela S; Soltis, Douglas E

    2010-11-01

    Current understanding of floral developmental genetics comes primarily from the core eudicot model Arabidopsis thaliana. Here, we explore the floral transcriptome of the basal angiosperm, Nuphar advena (water lily), for insights into the ancestral developmental program of flowers. We identify several thousand Nuphar genes with significantly upregulated floral expression, including homologs of the well-known ABCE floral regulators, deployed in broadly overlapping transcriptional programs across floral organ categories. Strong similarities in the expression profiles of different organ categories in Nuphar flowers are shared with the magnoliid Persea americana (avocado), in contrast to the largely organ-specific transcriptional cascades evident in Arabidopsis, supporting the inference that this is the ancestral condition in angiosperms. In contrast to most eudicots, floral organs are weakly differentiated in Nuphar and Persea, with staminodial intermediates between stamens and perianth in Nuphar, and between stamens and carpels in Persea. Consequently, the predominantly organ-specific transcriptional programs that characterize Arabidopsis flowers (and perhaps other eudicots) are derived, and correlate with a shift towards morphologically distinct floral organs, including differentiated sepals and petals, and a perianth distinct from stamens and carpels. Our findings suggest that the genetic regulation of more spatially discrete transcriptional programs underlies the evolution of floral morphology. © 2010 The Authors. The Plant Journal © 2010 Blackwell Publishing Ltd.

  12. UFO: an Arabidopsis gene involved in both floral meristem and floral organ development.

    Science.gov (United States)

    Levin, J Z; Meyerowitz, E M

    1995-05-01

    We describe the role of the UNUSUAL FLORAL ORGANS (UFO) gene in Arabidopsis floral development based on a genetic and molecular characterization of the phenotypes of nine ufo alleles. UFO is required for the proper identity of the floral meristem and acts in three different aspects of the process that distinguishes flowers from shoots. UFO is involved in establishing the whorled pattern of floral organs, controlling the determinacy of the floral meristem, and activating the APETALA3 and PISTILLATA genes required for petal and stamen identity. In many respects, UFO acts in a manner similar to LEAFY, but the ufo mutant phenotype also suggests an additional role for UFO in defining boundaries within the floral primordia or controlling cell proliferation during floral organ growth. Finally, genetic interactions that prevent flower formation and lead to the generation of filamentous structures implicate UFO as a member of a new, large, and diverse class of genes in Arabidopsis necessary for flower formation.

  13. Molecular and regulatory mechanisms controlling floral organ development.

    Science.gov (United States)

    Stewart, Darragh; Graciet, Emmanuelle; Wellmer, Frank

    2016-05-01

    The genetic and molecular mechanisms that underlie the formation of angiosperm flowers have been studied extensively for nearly three decades. This work has led to detailed insights into the gene regulatory networks that control this vital developmental process in plants. Here, we review some of the key findings in the field of flower development and discuss open questions that must be addressed in order to obtain a more comprehensive understanding of flower formation. In particular, we focus on the specification of the different types of floral organs and on how the morphogenesis of these organs is controlled to give rise to mature flowers. Central to this process are the floral organ identity genes, which encode members of the family of MADS-domain transcription factors. We summarize what is currently known about the functions of these master regulators and discuss a working model for the molecular mechanism that may underlie their activities. © 2016 Federation of European Biochemical Societies.

  14. Extreme divergence in floral scent among woodland star species (Lithophragma spp.) pollinated by floral parasites.

    Science.gov (United States)

    Friberg, Magne; Schwind, Christopher; Raguso, Robert A; Thompson, John N

    2013-04-01

    A current challenge in coevolutionary biology is to understand how suites of traits vary as coevolving lineages diverge. Floral scent is often a complex, variable trait that attracts a suite of generalized pollinators, but may be highly specific in plants specialized on attracting coevolved pollinating floral parasites. In this study, floral scent variation was investigated in four species of woodland stars (Lithophragma spp.) that share the same major pollinator (the moth Greya politella, a floral parasite). Three specific hypotheses were tested: (1) sharing the same specific major pollinator favours conservation of floral scent among close relatives; (2) selection favours 'private channels' of rare compounds particularly aimed at the specialist pollinator; or (3) selection from rare, less-specialized co-pollinators mitigates the conservation of floral scent and occurrence of private channels. Dynamic headspace sampling and solid-phase microextraction were applied to greenhouse-grown plants from a common garden as well as to field samples from natural populations in a series of experiments aiming to disentangle the genetic and environmental basis of floral scent variation. Striking floral scent divergence was discovered among species. Only one of 69 compounds was shared among all four species. Scent variation was largely genetically based, because it was consistent across field and greenhouse treatments, and was not affected by visits from the pollinating floral parasite. The strong divergence in floral scents among Lithophragma species contrasts with the pattern of conserved floral scent composition found in other plant genera involved in mutualisms with pollinating floral parasites. Unlike some of these other obligate pollination mutualisms, Lithophragma plants in some populations are occasionally visited by generalist pollinators from other insect taxa. This additional complexity may contribute to the diversification in floral scent found among the Lithophragma

  15. Floral homeotic proteins modulate the genetic program for leaf development to suppress trichome formation in flowers.

    Science.gov (United States)

    Ó'Maoiléidigh, Diarmuid S; Stewart, Darragh; Zheng, Beibei; Coupland, George; Wellmer, Frank

    2018-02-13

    As originally proposed by Goethe in 1790, floral organs are derived from leaf-like structures. The conversion of leaves into different types of floral organ is mediated by floral homeotic proteins, which, as described by the ABCE model of flower development, act in a combinatorial manner. However, how these transcription factors bring about this transformation process is not well understood. We have previously shown that floral homeotic proteins are involved in suppressing the formation of branched trichomes, a hallmark of leaf development, on reproductive floral organs of Arabidopsis Here, we present evidence that the activities of the C function gene AGAMOUS ( AG ) and the related SHATTERPROOF1 / 2 genes are superimposed onto the regulatory network that controls the distribution of trichome formation in an age-dependent manner. We show that AG regulates cytokinin responses and genetically interacts with the organ polarity gene KANADI1 to suppress trichome initiation on gynoecia. Thus, our results show that parts of the genetic program for leaf development remain active during flower formation but have been partially rewired through the activities of the floral homeotic proteins. © 2018. Published by The Company of Biologists Ltd.

  16. Homeotic Genes and the ABCDE Model for Floral Organ Formation in Wheat

    Directory of Open Access Journals (Sweden)

    Koji Murai

    2013-06-01

    Full Text Available Floral organ formation has been the subject of intensive study for over 20 years, particularly in the model dicot species Arabidopsis thaliana. These studies have led to the establishment of a general model for the development of floral organs in higher plants, the so-called ABCDE model, in which floral whorl-specific combinations of class A, B, C, D, or E genes specify floral organ identity. In Arabidopsis, class A, B, C, D, E genes encode MADS-box transcription factors except for the class A gene APETALA2. Mutation of these genes induces floral organ homeosis. In this review, I focus on the roles of these homeotic genes in bread wheat (Triticum aestivum, particularly with respect to the ABCDE model. Pistillody, the homeotic transformation of stamens into pistil-like structures, occurs in cytoplasmic substitution (alloplasmic wheat lines that have the cytoplasm of the related wild species Aegilops crassa. This phenomenon is a valuable tool for analysis of the wheat ABCDE model. Using an alloplasmic line, the wheat ortholog of DROOPING LEAF (TaDL, a member of the YABBY gene family, has been shown to regulate pistil specification. Here, I describe the current understanding of the ABCDE model for floral organ formation in wheat.

  17. Homeotic Genes and the ABCDE Model for Floral Organ Formation in Wheat.

    Science.gov (United States)

    Murai, Koji

    2013-06-25

    Floral organ formation has been the subject of intensive study for over 20 years, particularly in the model dicot species Arabidopsis thaliana. These studies have led to the establishment of a general model for the development of floral organs in higher plants, the so-called ABCDE model, in which floral whorl-specific combinations of class A, B, C, D, or E genes specify floral organ identity. In Arabidopsis, class A, B, C, D, E genes encode MADS-box transcription factors except for the class A gene APETALA2. Mutation of these genes induces floral organ homeosis. In this review, I focus on the roles of these homeotic genes in bread wheat (Triticum aestivum), particularly with respect to the ABCDE model. Pistillody, the homeotic transformation of stamens into pistil-like structures, occurs in cytoplasmic substitution (alloplasmic) wheat lines that have the cytoplasm of the related wild species Aegilops crassa. This phenomenon is a valuable tool for analysis of the wheat ABCDE model. Using an alloplasmic line, the wheat ortholog of DROOPING LEAF (TaDL), a member of the YABBY gene family, has been shown to regulate pistil specification. Here, I describe the current understanding of the ABCDE model for floral organ formation in wheat.

  18. Role of adaptor proteins in motor regulation and membrane transport

    NARCIS (Netherlands)

    M.A. Schlager (Max)

    2010-01-01

    markdownabstract__Abstract__ Active transport along the cytoskeleton is a process essential for proper cellular function. Although much is known about the motor proteins that generate the necessary force and the cytoskeleton that provides the cellular infrastructure, many questions still

  19. Dynamics of DNA methylation and Histone H4 acetylation during floral bud differentiation in azalea

    Directory of Open Access Journals (Sweden)

    Valledor Luis

    2010-01-01

    Full Text Available Abstract Background The ability to control the timing of flowering is a key strategy for planning production in ornamental species such as azalea, however it requires a thorough understanding of floral transition. Floral transition is achieved through a complex genetic network and regulated by multiple environmental and endogenous cues. Dynamic changes between chromatin states facilitating or inhibiting DNA transcription regulate the expression of floral induction pathways in response to environmental and developmental signals. DNA methylation and histone modifications are involved in controlling the functional state of chromatin and gene expression. Results The results of this work indicate that epigenetic mechanisms such as DNA methylation and histone H4 acetylation have opposite and particular dynamics during the transition from vegetative to reproductive development in the apical shoots of azalea. Global levels of DNA methylation and histone H4 acetylation as well as immunodetection of 5-mdC and acetylated H4, in addition to a morphological study have permitted the delimitation of four basic phases in the development of the azalea bud and allowed the identification of a stage of epigenetic reprogramming which showed a sharp decrease of whole DNA methylation similar to that is defined in other developmental processes in plants and in mammals. Conclusion The epigenetic control and reorganization of chromatin seem to be decisive for coordinating floral development in azalea. DNA methylation and H4 deacetylation act simultaneously and co-ordinately, restructuring the chromatin and regulating the gene expression during soot apical meristem development and floral differentiation.

  20. Spiral biasing adaptor for use in Si drift detectors and Si drift detector arrays

    Science.gov (United States)

    Li, Zheng; Chen, Wei

    2016-07-05

    A drift detector array, preferably a silicon drift detector (SDD) array, that uses a low current biasing adaptor is disclosed. The biasing adaptor is customizable for any desired geometry of the drift detector single cell with minimum drift time of carriers. The biasing adaptor has spiral shaped ion-implants that generate the desired voltage profile. The biasing adaptor can be processed on the same wafer as the drift detector array and only one biasing adaptor chip/side is needed for one drift detector array to generate the voltage profiles on the front side and back side of the detector array.

  1. Recruitment of the Mint3 adaptor is necessary for export of the amyloid precursor protein (APP) from the Golgi complex.

    Science.gov (United States)

    Caster, Amanda H; Kahn, Richard A

    2013-10-04

    The amyloid precursor protein (APP) is a ubiquitously expressed single-pass transmembrane protein that undergoes proteolytic processing by secretases to generate the pathogenic amyloid-β peptide, the major component in Alzheimer plaques. The traffic of APP through the cell determines its exposure to secretases and consequently the cleavages that generate the pathogenic or nonpathogenic peptide fragments. Despite the likely importance of APP traffic to Alzheimer disease, we still lack clear models for the routing and regulation of APP in cells. Like the traffic of most transmembrane proteins, the binding of adaptors to its cytoplasmic tail, which is 47 residues long and contains at least four distinct sorting motifs, regulates that of APP. We tested each of these for effects on the traffic of APP from the Golgi by mutating key residues within them and examining adaptor recruitment at the Golgi and traffic to post-Golgi site(s). We demonstrate strict specificity for recruitment of the Mint3 adaptor by APP at the Golgi, a critical role for Tyr-682 (within the YENPTY motif) in Mint3 recruitment and export of APP from the Golgi, and we identify LAMP1(+) structures as the proximal destination of APP after leaving the Golgi. Together, these data provide a detailed view of the first sorting step in its route to the cell surface and processing by secretases and further highlight the critical role played by Mint3.

  2. Recruitment of the Mint3 Adaptor Is Necessary for Export of the Amyloid Precursor Protein (APP) from the Golgi Complex*

    Science.gov (United States)

    Caster, Amanda H.; Kahn, Richard A.

    2013-01-01

    The amyloid precursor protein (APP) is a ubiquitously expressed single-pass transmembrane protein that undergoes proteolytic processing by secretases to generate the pathogenic amyloid-β peptide, the major component in Alzheimer plaques. The traffic of APP through the cell determines its exposure to secretases and consequently the cleavages that generate the pathogenic or nonpathogenic peptide fragments. Despite the likely importance of APP traffic to Alzheimer disease, we still lack clear models for the routing and regulation of APP in cells. Like the traffic of most transmembrane proteins, the binding of adaptors to its cytoplasmic tail, which is 47 residues long and contains at least four distinct sorting motifs, regulates that of APP. We tested each of these for effects on the traffic of APP from the Golgi by mutating key residues within them and examining adaptor recruitment at the Golgi and traffic to post-Golgi site(s). We demonstrate strict specificity for recruitment of the Mint3 adaptor by APP at the Golgi, a critical role for Tyr-682 (within the YENPTY motif) in Mint3 recruitment and export of APP from the Golgi, and we identify LAMP1+ structures as the proximal destination of APP after leaving the Golgi. Together, these data provide a detailed view of the first sorting step in its route to the cell surface and processing by secretases and further highlight the critical role played by Mint3. PMID:23965993

  3. Multimodal floral signals and moth foraging decisions.

    Directory of Open Access Journals (Sweden)

    Jeffrey A Riffell

    Full Text Available Combinations of floral traits - which operate as attractive signals to pollinators - act on multiple sensory modalities. For Manduca sexta hawkmoths, how learning modifies foraging decisions in response to those traits remains untested, and the contribution of visual and olfactory floral displays on behavior remains unclear.Using M. sexta and the floral traits of two important nectar resources in southwestern USA, Datura wrightii and Agave palmeri, we examined the relative importance of olfactory and visual signals. Natural visual and olfactory cues from D. wrightii and A. palmeri flowers permits testing the cues at their native intensities and composition - a contrast to many studies that have used artificial stimuli (essential oils, single odorants that are less ecologically relevant. Results from a series of two-choice assays where the olfactory and visual floral displays were manipulated showed that naïve hawkmoths preferred flowers displaying both olfactory and visual cues. Furthermore, experiments using A. palmeri flowers - a species that is not very attractive to hawkmoths - showed that the visual and olfactory displays did not have synergistic effects. The combination of olfactory and visual display of D. wrightii, however - a flower that is highly attractive to naïve hawkmoths - did influence the time moths spent feeding from the flowers. The importance of the olfactory and visual signals were further demonstrated in learning experiments in which experienced moths, when exposed to uncoupled floral displays, ultimately chose flowers based on the previously experienced olfactory, and not visual, signals. These moths, however, had significantly longer decision times than moths exposed to coupled floral displays.These results highlight the importance of specific sensory modalities for foraging hawkmoths while also suggesting that they learn the floral displays as combinatorial signals and use the integrated floral traits from their memory

  4. Multimodal Floral Signals and Moth Foraging Decisions

    Science.gov (United States)

    Riffell, Jeffrey A.; Alarcón, Ruben

    2013-01-01

    Background Combinations of floral traits – which operate as attractive signals to pollinators – act on multiple sensory modalities. For Manduca sexta hawkmoths, how learning modifies foraging decisions in response to those traits remains untested, and the contribution of visual and olfactory floral displays on behavior remains unclear. Methodology/Principal Findings Using M. sexta and the floral traits of two important nectar resources in southwestern USA, Datura wrightii and Agave palmeri, we examined the relative importance of olfactory and visual signals. Natural visual and olfactory cues from D. wrightii and A. palmeri flowers permits testing the cues at their native intensities and composition – a contrast to many studies that have used artificial stimuli (essential oils, single odorants) that are less ecologically relevant. Results from a series of two-choice assays where the olfactory and visual floral displays were manipulated showed that naïve hawkmoths preferred flowers displaying both olfactory and visual cues. Furthermore, experiments using A. palmeri flowers – a species that is not very attractive to hawkmoths – showed that the visual and olfactory displays did not have synergistic effects. The combination of olfactory and visual display of D. wrightii, however – a flower that is highly attractive to naïve hawkmoths – did influence the time moths spent feeding from the flowers. The importance of the olfactory and visual signals were further demonstrated in learning experiments in which experienced moths, when exposed to uncoupled floral displays, ultimately chose flowers based on the previously experienced olfactory, and not visual, signals. These moths, however, had significantly longer decision times than moths exposed to coupled floral displays. Conclusions/Significance These results highlight the importance of specific sensory modalities for foraging hawkmoths while also suggesting that they learn the floral displays as

  5. A novel role of BELL1-like homeobox genes, PENNYWISE and POUND-FOOLISH, in floral patterning.

    Science.gov (United States)

    Yu, Lifeng; Patibanda, Varun; Smith, Harley M S

    2009-02-01

    Flowers are determinate shoots comprised of perianth and reproductive organs displayed in a whorled phyllotactic pattern. Floral organ identity genes display region-specific expression patterns in the developing flower. In Arabidopsis, floral organ identity genes are activated by LEAFY (LFY), which functions with region-specific co-regulators, UNUSUAL FLORAL ORGANS (UFO) and WUSCHEL (WUS), to up-regulate homeotic genes in specific whorls of the flower. PENNYWISE (PNY) and POUND-FOOLISH (PNF) are redundant functioning BELL1-like homeodomain proteins that are expressed in shoot and floral meristems. During flower development, PNY functions with a co-repressor complex to down-regulate the homeotic gene, AGAMOUS (AG), in the outer whorls of the flower. However, the function of PNY as well as PNF in regulating floral organ identity in the central whorls of the flower is not known. In this report, we show that combining mutations in PNY and PNF enhance the floral patterning phenotypes of weak and strong alleles of lfy, indicating that these BELL1-like homeodomain proteins play a role in the specification of petals, stamens and carpels during flower development. Expression studies show that PNY and PNF positively regulate the homeotic genes, APETALA3 and AG, in the inner whorls of the flower. Moreover, PNY and PNF function in parallel with LFY, UFO and WUS to regulate homeotic gene expression. Since PNY and PNF interact with the KNOTTED1-like homeodomain proteins, SHOOTMERISTEMLESS (STM) and KNOTTED-LIKE from ARABIDOPSIS THALIANA2 (KNAT2) that regulate floral development, we propose that PNY/PNF-STM and PNY/PNF-KNAT2 complexes function in the inner whorls to regulate flower patterning events.

  6. Association of autoimmune hepatitis with Src homology 2 adaptor protein 3 gene polymorphisms in Japanese patients.

    Science.gov (United States)

    Umemura, Takeji; Joshita, Satoru; Hamano, Hideaki; Yoshizawa, Kaname; Kawa, Shigeyuki; Tanaka, Eiji; Ota, Masao

    2017-11-01

    Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease characterized by an autoimmune reaction to hepatocytes. The Src homology 2 adaptor protein 3 (SH2B3) gene is a member of the SH2B family of adaptor proteins that has been implicated in the integration and regulation of multiple signaling events. SH2B3 is involved in cytokine signaling pathways and serves as a negative mediator of T-cell receptor signaling. Genome-wide association analyses in Caucasians have linked a missense mutation at rs3184504 in SH2B3 with AIH. Accordingly, four selected single-nucleotide polymorphisms (SNPs) in the SH2B3 gene were genotyped in 158 patients with AIH, 327 patients with primary biliary cholangitis, 160 patients with autoimmune pancreatitis, and 325 healthy subjects of Japanese descent. Although the functional rs3184504 was non-polymorphic in 952 subjects, the frequency of the minor rs11065904 T allele was significantly decreased in AIH patients compared with healthy controls (odds ratio (OR)=0.68; corrected P=0.025). Haplotype 2 (rs2238154 A, rs11065904 T and rs739496 G) was associated with resistance to AIH (OR 0.67, P=0.021) as well as to autoimmune pancreatitis (OR=0.70, P=0.035). Our findings suggest that an SNP and haplotype in SH2B3 are associated with AIH.

  7. ROS Control Mitochondrial Motility through p38 and the Motor Adaptor Miro/Trak

    Directory of Open Access Journals (Sweden)

    Valentina Debattisti

    2017-11-01

    Full Text Available Mitochondrial distribution and motility are recognized as central to many cellular functions, but their regulation by signaling mechanisms remains to be elucidated. Here, we report that reactive oxygen species (ROS, either derived from an extracellular source or intracellularly generated, control mitochondrial distribution and function by dose-dependently, specifically, and reversibly decreasing mitochondrial motility in both rat hippocampal primary cultured neurons and cell lines. ROS decrease motility independently of cytoplasmic [Ca2+], mitochondrial membrane potential, or permeability transition pore opening, known effectors of oxidative stress. However, multiple lines of genetic and pharmacological evidence support that a ROS-activated mitogen-activated protein kinase (MAPK, p38α, is required for the motility inhibition. Furthermore, anchoring mitochondria directly to kinesins without involvement of the physiological adaptors between the organelles and the motor protein prevents the H2O2-induced decrease in mitochondrial motility. Thus, ROS engage p38α and the motor adaptor complex to exert changes in mitochondrial motility, which likely has both physiological and pathophysiological relevance.

  8. The Adaptor Protein Rai/ShcC Promotes Astrocyte-Dependent Inflammation during Experimental Autoimmune Encephalomyelitis.

    Science.gov (United States)

    Ulivieri, Cristina; Savino, Maria Teresa; Luccarini, Ilaria; Fanigliulo, Emanuela; Aldinucci, Alessandra; Bonechi, Elena; Benagiano, Marisa; Ortensi, Barbara; Pelicci, Giuliana; D'Elios, Mario Milco; Ballerini, Clara; Baldari, Cosima Tatiana

    2016-07-15

    Th17 cells have been casually associated to the pathogenesis of autoimmune disease. We have previously demonstrated that Rai/ShcC, a member of the Shc family of adaptor proteins, negatively regulates Th17 cell differentiation and lupus autoimmunity. In this study, we have investigated the pathogenic outcome of the Th17 bias associated with Rai deficiency on multiple sclerosis development, using the experimental autoimmune encephalomyelitis (EAE) mouse model. We found that, unexpectedly, EAE was less severe in Rai(-/-) mice compared with their wild-type counterparts despite an enhanced generation of myelin-specific Th17 cells that infiltrated into the CNS. Nevertheless, when adoptively transferred into immunodeficient Rai(+/+) mice, these cells promoted a more severe disease compared with wild-type encephalitogenic Th17 cells. This paradoxical phenotype was caused by a dampened inflammatory response of astrocytes, which were found to express Rai, to IL-17. The results provide evidence that Rai plays opposite roles in Th17 cell differentiation and astrocyte activation, with the latter dominant over the former in EAE, highlighting this adaptor as a potential novel target for the therapy of multiple sclerosis. Copyright © 2016 by The American Association of Immunologists, Inc.

  9. The non-motor adaptor HMMR dampens Eg5-mediated forces to preserve the kinetics and integrity of chromosome segregation.

    Science.gov (United States)

    Chen, Helen; Connell, Marisa; Mei, Lin; Reid, Gregor S D; Maxwell, Christopher A

    2018-01-31

    Mitotic spindle assembly and organization require forces generated by motor proteins. The activity of these motors is regulated by non-motor adaptor proteins. However, there are limited studies reporting the functional importance of adaptors on the balance of motor forces and the promotion of faithful and timely cell division. Here, we show that genomic deletion or siRNA silencing of the non-motor adaptor Hmmr/ HMMR disturbs spindle microtubule organization and bipolar chromosome-kinetochore attachments with a consequent elevated occurrence of aneuploidy. Rescue experiments show a conserved motif in HMMR is required to generate inter-kinetochore tension and promote anaphase entry. This motif bears high homology with the kinesin Kif15 and is known to interact with TPX2, a spindle assembly factor. We find that HMMR is required to dampen kinesin Eg5-mediated forces through localizing TPX2 and promoting the formation of inhibitory TPX2-Eg5 complexes. In HMMR-silenced cells, K-fiber stability is reduced while the frequency of unattached chromosomes and the time needed for chromosome segregation are both increased. These defects can be alleviated in HMMR-silenced cells with chemical inhibition of Eg5, but not through the silencing of Kif15. Together, our findings indicate that HMMR balances Eg5-mediated forces to preserve the kinetics and integrity of chromosome segregation. © 2018 by The American Society for Cell Biology.

  10. Floral morphology of Gonocaryum with emphasis on the gynoecium

    Science.gov (United States)

    We investigated the floral development of Gonocaryum, a genus of Cardiopteridaceae that was segregated from Icacinaceae s.l., using scanning electron microscopy to clarify its gynoecial structure and facilitate morphological comparisons of Cardiopteridaceae. The key floral developmental characters i...

  11. Do Plants Eavesdrop on Floral Scent Signals?

    Science.gov (United States)

    Caruso, Christina M; Parachnowitsch, Amy L

    2016-01-01

    Plants emit a diverse array of volatile organic compounds that can function as cues to other plants. Plants can use volatiles emitted by neighbors to gain information about their environment, and respond by adjusting their phenotype. Less is known about whether the many different volatile signals that plants emit are all equally likely to function as cues to other plants. We review evidence for the function of floral volatile signals and conclude that plants are as likely to perceive and respond to floral volatiles as to other, better-studied volatiles. We propose that eavesdropping on floral volatile cues is particularly likely to be adaptive because plants can respond to these cues by adjusting traits that directly affect pollination and mating. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Mutation scanning of peach floral genes

    Directory of Open Access Journals (Sweden)

    Wilde H Dayton

    2011-05-01

    Full Text Available Abstract Background Mutation scanning technology has been used to develop crop species with improved traits. Modifications that improve screening throughput and sensitivity would facilitate the targeted mutation breeding of crops. Technical innovations for high-resolution melting (HRM analysis are enabling the clinic-based screening for human disease gene polymorphism. We examined the application of two HRM modifications, COLD-PCR and QMC-PCR, to the mutation scanning of genes in peach, Prunus persica. The targeted genes were the putative floral regulators PpAGAMOUS and PpTERMINAL FLOWER I. Results HRM analysis of PpAG and PpTFL1 coding regions in 36 peach cultivars found one polymorphic site in each gene. PpTFL1 and PpAG SNPs were used to examine approaches to increase HRM throughput. Cultivars with SNPs could be reliably detected in pools of twelve genotypes. COLD-PCR was found to increase the sensitivity of HRM analysis of pooled samples, but worked best with small amplicons. Examination of QMC-PCR demonstrated that primary PCR products for further analysis could be produced from variable levels of genomic DNA. Conclusions Natural SNPs in exons of target peach genes were discovered by HRM analysis of cultivars from a southeastern US breeding program. For detecting natural or induced SNPs in larger populations, HRM efficiency can be improved by increasing sample pooling and template production through approaches such as COLD-PCR and QMC-PCR. Technical advances developed to improve clinical diagnostics can play a role in the targeted mutation breeding of crops.

  13. Role of SUPERMAN in maintaining Arabidopsis floral whorl boundaries.

    Science.gov (United States)

    Sakai, H; Medrano, L J; Meyerowitz, E M

    1995-11-09

    The Arabidopsis gene SUPERMAN (SUP) is necessary for the proper spatial development of reproductive floral tissues. Recessive mutations cause extra stamens to form interior to the normal third whorl stamens, at the expense of fourth whorl carpel development. The mutant phenotype is associated with the ectopic expression of the B function genes, AP3 and PI, in the altered floral region, closer to the centre of the flower than in the wild type, and ap3 sup and pi sup double mutants exhibit a phenotype similar to ap3 and pi single mutants. These findings led to SUP being interpreted as an upstream negative regulator of the B function organ-identity genes, acting in the fourth whorl, to establish a boundary between stamen and carpel whorls. Here we show, using molecular cloning and analysis, that it is expressed in the third whorl and acts to maintain this boundary in developing flowers. The putative SUPERMAN protein contains one zinc-finger and a region resembling a basic leucine zipper motif, suggesting a function in transcriptional regulation.

  14. Interactions between the Hepatitis C Virus Nonstructural 2 Protein and Host Adaptor Proteins 1 and 4 Orchestrate Virus Release.

    Science.gov (United States)

    Xiao, Fei; Wang, Stanley; Barouch-Bentov, Rina; Neveu, Gregory; Pu, Szuyuan; Beer, Melanie; Schor, Stanford; Kumar, Sathish; Nicolaescu, Vlad; Lindenbach, Brett D; Randall, Glenn; Einav, Shirit

    2018-03-13

    Hepatitis C virus (HCV) spreads via secreted cell-free particles or direct cell-to-cell transmission. Yet, virus-host determinants governing differential intracellular trafficking of cell-free- and cell-to-cell-transmitted virus remain unknown. The host adaptor proteins (APs) AP-1A, AP-1B, and AP-4 traffic in post-Golgi compartments, and the latter two are implicated in basolateral sorting. We reported that AP-1A mediates HCV trafficking during release, whereas the endocytic adaptor AP-2 mediates entry and assembly. We demonstrated that the host kinases AAK1 and GAK regulate HCV infection by controlling these clathrin-associated APs. Here, we sought to define the roles of AP-4, a clathrin-independent adaptor; AP-1A; and AP-1B in HCV infection. We screened for interactions between HCV proteins and the μ subunits of AP-1A, AP-1B, and AP-4 by mammalian cell-based protein fragment complementation assays. The nonstructural 2 (NS2) protein emerged as an interactor of these adaptors in this screening and by coimmunoprecipitations in HCV-infected cells. Two previously unrecognized dileucine-based motifs in the NS2 C terminus mediated AP binding and HCV release. Infectivity and coculture assays demonstrated that while all three adaptors mediate HCV release and cell-free spread, AP-1B and AP-4, but not AP-1A, mediate cell-to-cell spread. Live-cell imaging revealed HCV cotrafficking with AP-1A, AP-1B, and AP-4 and that AP-4 mediates HCV trafficking in a post-Golgi compartment. Lastly, HCV cell-to-cell spread was regulated by AAK1 and GAK and thus susceptible to treatment with AAK1 and GAK inhibitors. These data provide a mechanistic understanding of HCV trafficking in distinct release pathways and reveal a requirement for APs in cell-to-cell viral spread. IMPORTANCE HCV spreads via cell-free infection or cell-to-cell contact that shields it from antibody neutralization, thereby facilitating viral persistence. Yet, factors governing this differential sorting remain unknown

  15. Specialist Osmia bees forage indiscriminately among hybridizing Balsamorhiza floral hosts

    Science.gov (United States)

    James H. Cane

    2011-01-01

    Pollinators, even floral generalists (=polyleges), typically specialize during individual foraging bouts, infrequently switching between floral hosts. Such transient floral constancy restricts pollen flow, and thereby gene flow, to conspecific flowers in mixed plant communities. Where incipient flowering species meet, however, weak cross-fertility and often similar...

  16. Floral development in three species of Impatiens (Balsaminaceae)

    NARCIS (Netherlands)

    Caris, P.L.; Geuten, K.P.; Janssens, S.B.; Smets, E.

    2006-01-01

    The floral morphological and developmental patterns in three species of Impatiens (Balsaminaceae), namely I. columbaria, I. hawkeri, and I. niamniamensis, were studied to contribute to a better understanding of floral evolution in the genus. Strangely enough, the highly diverse floral morphology and

  17. A genetic screen for modifiers of UFO meristem activity identifies three novel FUSED FLORAL ORGANS genes required for early flower development in Arabidopsis.

    Science.gov (United States)

    Levin, J Z; Fletcher, J C; Chen, X; Meyerowitz, E M

    1998-06-01

    In a screen to identify novel genes required for early Arabidopsis flower development, we isolated four independent mutations that enhance the Ufo phenotype toward the production of filamentous structures in place of flowers. The mutants fall into three complementation groups, which we have termed FUSED FLORAL ORGANS (FFO) loci. ffo mutants have specific defects in floral organ separation and/or positioning; thus, the FFO genes identify components of a boundary formation mechanism(s) acting between developing floral organ primordia. FFO1 and FFO3 have specific functions in cauline leaf/stem separation and in first- and third-whorl floral organ separation, with FFO3 likely acting to establish and FFO1 to maintain floral organ boundaries. FFO2 acts at early floral stages to regulate floral organ number and positioning and to control organ separation within and between whorls. Plants doubly mutant for two ffo alleles display additive phenotypes, indicating that the FFO genes may act in separate pathways. Plants doubly mutant for an ffo gene and for ufo, lfy, or clv3 reveal that the FFO genes play roles related to those of UFO and LFY in floral meristem initiation and that FFO2 and FFO3 may act to control cell proliferation late in inflorescence development.

  18. Whole-Transcriptome Analysis of Differentially Expressed Genes in the Vegetative Buds, Floral Buds and Buds of Chrysanthemum morifolium.

    Science.gov (United States)

    Liu, Hua; Sun, Ming; Du, Dongliang; Pan, Huitang; Cheng, Tangren; Wang, Jia; Zhang, Qixiang

    2015-01-01

    Chrysanthemum morifolium is an important floral crop that is cultivated worldwide. However, due to a lack of genomic resources, very little information is available concerning the molecular mechanisms of flower development in chrysanthemum. The transcriptomes of chrysanthemum vegetative buds, floral buds and buds were sequenced using Illumina paired-end sequencing technology. A total of 15.4 Gb of reads were assembled into 91,367 unigenes with an average length of 739 bp. A total of 43,137 unigenes showed similarity to known proteins in the Swissprot or NCBI non-redundant protein databases. Additionally, 25,424, 24,321 and 13,704 unigenes were assigned to 56 gene ontology (GO) categories, 25 EuKaryotic Orthologous Groups (KOG) categories, and 285 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. A total of 1,876 differentially expressed genes (DEGs) (1,516 up-regulated, 360 down-regulated) were identified between vegetative buds and floral buds, and 3,300 DEGs (1,277 up-regulated, 1,706 down-regulated) were identified between floral buds and buds. Many genes encoding important transcription factors (e.g., AP2, MYB, MYC, WRKY, NAC and CRT) as well as proteins involved in carbohydrate metabolism, protein kinase activity, plant hormone signal transduction, and the defense responses, among others, were considerably up-regulated in floral buds. Genes involved in the photoperiod pathway and flower organ determination were also identified. These genes represent important candidate genes for molecular cloning and functional analysis to study flowering regulation in chrysanthemum. This comparative transcriptome analysis revealed significant differences in gene expression and signaling pathway components between the vegetative buds, floral buds and buds of Chrysanthemum morifolium. A wide range of genes was implicated in regulating the phase transition from vegetative to reproductive growth. These results should aid researchers in the study of flower

  19. Brain-derived neurotrophic factor modulation of Kv1.3 channel is disregulated by adaptor proteins Grb10 and nShc

    Directory of Open Access Journals (Sweden)

    Marks David R

    2009-01-01

    Full Text Available Abstract Background Neurotrophins are important regulators of growth and regeneration, and acutely, they can modulate the activity of voltage-gated ion channels. Previously we have shown that acute brain-derived neurotrophic factor (BDNF activation of neurotrophin receptor tyrosine kinase B (TrkB suppresses the Shaker voltage-gated potassium channel (Kv1.3 via phosphorylation of multiple tyrosine residues in the N and C terminal aspects of the channel protein. It is not known how adaptor proteins, which lack catalytic activity, but interact with members of the neurotrophic signaling pathway, might scaffold with ion channels or modulate channel activity. Results We report the co-localization of two adaptor proteins, neuronal Src homology and collagen (nShc and growth factor receptor-binding protein 10 (Grb10, with Kv1.3 channel as demonstrated through immunocytochemical approaches in the olfactory bulb (OB neural lamina. To further explore the specificity and functional ramification of adaptor/channel co-localization, we performed immunoprecipitation and Western analysis of channel, kinase, and adaptor transfected human embryonic kidney 293 cells (HEK 293. nShc formed a direct protein-protein interaction with Kv1.3 that was independent of BDNF-induced phosphorylation of Kv1.3, whereas Grb10 did not complex with Kv1.3 in HEK 293 cells. Both adaptors, however, co-immunoprecipitated with Kv1.3 in native OB. Grb10 was interestingly able to decrease the total expression of Kv1.3, particularly at the membrane surface, and subsequently eliminated the BDNF-induced phosphorylation of Kv1.3. To examine the possibility that the Src homology 2 (SH2 domains of Grb10 were directly binding to basally phosphorylated tyrosines in Kv1.3, we utilized point mutations to substitute multiple tyrosine residues with phenylalanine. Removal of the tyrosines 111–113 and 449 prevented Grb10 from decreasing Kv1.3 expression. In the absence of either adaptor protein

  20. Major transcriptome reprogramming underlies floral mimicry induced by the rust fungus Puccinia monoica in Boechera stricta.

    Directory of Open Access Journals (Sweden)

    Liliana M Cano

    Full Text Available Pucciniamonoica is a spectacular plant parasitic rust fungus that triggers the formation of flower-like structures (pseudoflowers in its Brassicaceae host plant Boecherastricta. Pseudoflowers mimic in shape, color, nectar and scent co-occurring and unrelated flowers such as buttercups. They act to attract insects thereby aiding spore dispersal and sexual reproduction of the rust fungus. Although much ecological research has been performed on P. monoica-induced pseudoflowers, this system has yet to be investigated at the molecular or genomic level. To date, the molecular alterations underlying the development of pseudoflowers and the genes involved have not been described. To address this, we performed gene expression profiling to reveal 256 plant biological processes that are significantly altered in pseudoflowers. Among these biological processes, plant genes involved in cell fate specification, regulation of transcription, reproduction, floral organ development, anthocyanin (major floral pigments and terpenoid biosynthesis (major floral volatile compounds were down-regulated in pseudoflowers. In contrast, plant genes involved in shoot, cotyledon and leaf development, carbohydrate transport, wax biosynthesis, cutin transport and L-phenylalanine metabolism (pathway that results in phenylethanol and phenylacetaldehyde volatile production were up-regulated. These findings point to an extensive reprogramming of host genes by the rust pathogen to induce floral mimicry. We also highlight 31 differentially regulated plant genes that are enriched in the biological processes mentioned above, and are potentially involved in the formation of pseudoflowers. This work illustrates the complex perturbations induced by rust pathogens in their host plants, and provides a starting point for understanding the molecular mechanisms of pathogen-induced floral mimicry.

  1. Lilium floral fragrance: A biochemical and genetic resource for aroma and flavor.

    Science.gov (United States)

    Johnson, Timothy S; Schwieterman, Michael L; Kim, Joo Young; Cho, Keun H; Clark, David G; Colquhoun, Thomas A

    2016-02-01

    Hybrid Lilium (common name lily) cultivars are among the top produced domestic fresh cut flowers and potted plants in the US today. Many hybrid Lilium cultivars produce large and showy flowers that emit copious amounts of volatile molecules, which can negatively affect a consumer's appreciation or limit use of the plant product. There are few publications focused on the biochemistry, genetics, and/or molecular regulation of floral volatile biosynthesis for Lilium cultivars. In an initial pursuit to provide breeders with molecular markers for floral volatile biosynthesis, a total of five commercially available oriental and oriental-trumpet hybrid Lilium cultivars were selected for analytical characterization of floral volatile emission. In total, 66 volatile molecules were qualified and quantitated among all cultivars. Chemical classes of identified volatiles include monoterpene hydrocarbons, monoterpene alcohols and aldehydes, phenylpropanoids, benzenoids, fatty-acid-derived, nitrogen-containing, and amino-acid-derived compounds. In general, the floral volatile profiles of the three oriental-trumpet hybrids were dominated by monoterpene hydrocarbons, monoterpene alcohols and aldehydes, while the two oriental hybrids were dominated by monoterpene alcohols and aldehydes and phenylpropanoids, respectively. Tepal tissues (two petal whirls) emitted the vast majority of total volatile molecules compared to the reproductive organs of the flowers. Tepal volatile profiles were cultivar specific with a high degree of distinction, which indicates the five cultivars chosen will provide an excellent differential genetic environment for gene discovery through comparative transcriptomics in the future. Cloning and assaying transcript accumulation from four floral volatile biosynthetic candidates provided few immediate or obvious trends with floral volatile emission. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Floral structure and ontogeny of Syndiclis (Lauraceae.

    Directory of Open Access Journals (Sweden)

    Gang Zeng

    Full Text Available Generic delimitation in the Beilschmiedia group of the Lauraceae remains ambiguous because flowering specimens of a few genera with confined distribution are poorly represented in herbaria, and a few floral characters important for taxonomy are still poorly known. Syndiclis is sporadically distributed in southwestern China, and is represented in the herbaria by only a few flowering specimens. We conducted field investigations to collect floral materials of four species and observed structures and ontogeny of the tiny flowers using both light microscopy (LM and scanning electron microscopy (SEM. The results show that the genus Syndiclis possesses flowers with huge variation in both merosity and organ number. Flowers of the genus are dimerous, trimerous, or tetramerous, or have mixed merosity with monomerous and dimerous, or dimerous and trimerous, or trimerous and tetramerous whorls. The number of staminodes ranges from two to eight, depending on floral merosity, and on how many stamens of the third androecial whorl are reduced to staminodes. The staminodes of the fourth androecial whorl are comparable to the staminodes in Potameia, but the staminodes of the third androecial whorl of Syndiclis are relatively larger than the staminodes in Potameia. They are erect or curved inwards, covering the ovary. The anthers are usually two-locular, but rarely one-locular or three-locular. Each stamen of the third androecial whorl bears two conspicuous and enlarged glands at the base. The lability of floral merosity and organ number of Syndiclis may have been caused by changes of pollination system and loss of special selective pressures that are present in most Lauraceous plants with fixed floral organ number. This study furthers our understanding of variation and evolution of a few important characters of the Beilschmiedia group and provides essential data for a revised generic classification of the group.

  3. Floral to green: mating switches moth olfactory coding and preference.

    Science.gov (United States)

    Saveer, Ahmed M; Kromann, Sophie H; Birgersson, Göran; Bengtsson, Marie; Lindblom, Tobias; Balkenius, Anna; Hansson, Bill S; Witzgall, Peter; Becher, Paul G; Ignell, Rickard

    2012-06-22

    Mating induces profound physiological changes in a wide range of insects, leading to behavioural adjustments to match the internal state of the animal. Here, we show for the first time, to our knowledge, that a noctuid moth switches its olfactory response from food to egg-laying cues following mating. Unmated females of the cotton leafworm (Spodoptera littoralis) are strongly attracted to lilac flowers (Syringa vulgaris). After mating, attraction to floral odour is abolished and the females fly instead to green-leaf odour of the larval host plant cotton, Gossypium hirsutum. This behavioural switch is owing to a marked change in the olfactory representation of floral and green odours in the primary olfactory centre, the antennal lobe (AL). Calcium imaging, using authentic and synthetic odours, shows that the ensemble of AL glomeruli dedicated to either lilac or cotton odour is selectively up- and downregulated in response to mating. A clear-cut behavioural modulation as a function of mating is a useful substrate for studies of the neural mechanisms underlying behavioural decisions. Modulation of odour-driven behaviour through concerted regulation of odour maps contributes to our understanding of state-dependent choice and host shifts in insect herbivores.

  4. CsTFL1, a constitutive local repressor of flowering, modulates floral initiation by antagonising florigen complex activity in chrysanthemum.

    Science.gov (United States)

    Higuchi, Yohei; Hisamatsu, Tamotsu

    2015-08-01

    Chrysanthemums require repeated cycles of short-day (SD) photoperiod for successful anthesis, but their vegetative state is strictly maintained under long-day (LD) or night-break (NB) conditions. We have previously demonstrated that photoperiodic flowering of a wild diploid chrysanthemum (Chrysanthemum seticuspe f. boreale) is controlled by a pair of systemic floral regulators, florigen (CsFTL3) and anti-florigen (CsAFT), produced in the leaves. Here, we report the functional characterisation of a local floral regulator, CsTFL1, a chrysanthemum orthologue of TERMINAL FLOWER 1 gene in Arabidopsis. Constitutive expression of CsTFL1 in C. seticuspe (CsTFL1-ox) resulted in extremely late flowering under SD and prevented up-regulation of floral meristem identity genes in shoot tips and leaves. Bimolecular fluorescence complementation assay showed that both CsTFL1 and CsFTL3 interacted with CsFDL1, a bZIP transcription factor FD homologue, in the nucleus. The transient gene expression assay indicated that CsTFL1 suppresses flowering by directly antagonising the flower inductive activity of the CsFTL3-CsFDL1 complex. Our results suggest that strict maintenance of vegetative state under non-inductive photoperiod is achieved by the coordinated action of both the systemic floral inhibitor and local floral inhibitor CsTFL1, which is constitutively expressed in shoot tips. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. A Big-Five Personality Profile of the Adaptor and Innovator.

    Science.gov (United States)

    Kwang, Ng Aik; Rodrigues, Daphne

    2002-01-01

    A study explored the relationship between two creative types (adaptor and innovator) and the Big Five personality traits (extraversion, agreeableness, conscientiousness, neuroticism, and openness to experience), in 164 teachers in Singapore. Adaptors were significantly more conscientious than innovators, while innovators were significantly more…

  6. 21 CFR 870.4290 - Cardiopulmonary bypass adaptor, stopcock, manifold, or fitting.

    Science.gov (United States)

    2010-04-01

    ..., or fitting. 870.4290 Section 870.4290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4290 Cardiopulmonary bypass adaptor, stopcock, manifold, or fitting. (a) Identification. A cardiopulmonary bypass adaptor, stopcock, manifold, or fitting is a device used in cardiovascular diagnostic...

  7. Changing MADS-Box Transcription Factor Protein-Protein Interactions as a Mechanism for Generating Floral Morphological Diversity.

    Science.gov (United States)

    Bartlett, Madelaine E

    2017-12-01

    Flowers display fantastic morphological diversity. Despite extreme variability in form, floral organ identity is specified by a core set of deeply conserved proteins-the floral MADS-box transcription factors. This indicates that while core gene function has been maintained, MADS-box transcription factors have evolved to regulate different downstream genes. Thus, the evolution of gene regulation downstream of the MADS-box transcription factors is likely central to the evolution of floral form. Gene regulation is determined by the combination of transcriptional regulators present at a particular cis-regulatory element at a particular time. Therefore, the interactions between transcription factors can be of profound importance in determining patterns of gene regulation. Here, after a short primer on flowers and floral morphology, I discuss the centrality of protein-protein interactions to MADS-box transcription factor function, and review the evidence that the evolution of MADS-box protein-protein interactions is a key driver in the evolution of gene regulation downstream of the MADS-box genes. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  8. An activated form of UFO alters leaf development and produces ectopic floral and inflorescence meristems.

    Directory of Open Access Journals (Sweden)

    Eddy Risseeuw

    Full Text Available Plants are unique in their ability to continuously produce new meristems and organ primordia. In Arabidopsis, the transcription factor LEAFY (LFY functions as a master regulator of a gene network that is important for floral meristem and organ specification. UNUSUAL FLORAL ORGANS (UFO is a co-activator of LEAFY and is required for proper activation of APETALA3 in the floral meristem during the specification of stamens and petals. The ufo mutants display defects in other parts of the flower and the inflorescence, suggestive of additional roles. Here we show that the normal determinacy of the developing Arabidopsis leaves is affected by the expression of a gain-of-function UFO fusion protein with the VP16 transcriptional activator domain. In these lines, the rosette and cauline leaf primordia exhibit reiterated serration, and upon flowering produce ectopic meristems that develop into flowers, bract leaves and inflorescences. These striking phenotypes reveal that developing leaves maintain the competency to initiate flower and inflorescence programs. Furthermore, the gain-of-function phenotypes are dependent on LFY and the SEPALLATA (SEP MADS-box transcription factors, indicative of their functional interactions with UFO. The findings of this study also suggest that UFO promotes the establishment of the lateral meristems and primordia in the peripheral zone of the apical and floral meristems by enhancing the activity of LFY. These novel phenotypes along with the mutant phenotypes of UFO orthologs in other plant species suggest a broader function for UFO in plants.

  9. An activated form of UFO alters leaf development and produces ectopic floral and inflorescence meristems.

    Science.gov (United States)

    Risseeuw, Eddy; Venglat, Prakash; Xiang, Daoquan; Komendant, Kristina; Daskalchuk, Tim; Babic, Vivijan; Crosby, William; Datla, Raju

    2013-01-01

    Plants are unique in their ability to continuously produce new meristems and organ primordia. In Arabidopsis, the transcription factor LEAFY (LFY) functions as a master regulator of a gene network that is important for floral meristem and organ specification. UNUSUAL FLORAL ORGANS (UFO) is a co-activator of LEAFY and is required for proper activation of APETALA3 in the floral meristem during the specification of stamens and petals. The ufo mutants display defects in other parts of the flower and the inflorescence, suggestive of additional roles. Here we show that the normal determinacy of the developing Arabidopsis leaves is affected by the expression of a gain-of-function UFO fusion protein with the VP16 transcriptional activator domain. In these lines, the rosette and cauline leaf primordia exhibit reiterated serration, and upon flowering produce ectopic meristems that develop into flowers, bract leaves and inflorescences. These striking phenotypes reveal that developing leaves maintain the competency to initiate flower and inflorescence programs. Furthermore, the gain-of-function phenotypes are dependent on LFY and the SEPALLATA (SEP) MADS-box transcription factors, indicative of their functional interactions with UFO. The findings of this study also suggest that UFO promotes the establishment of the lateral meristems and primordia in the peripheral zone of the apical and floral meristems by enhancing the activity of LFY. These novel phenotypes along with the mutant phenotypes of UFO orthologs in other plant species suggest a broader function for UFO in plants.

  10. Arabidopsis adaptor protein 1G is critical for pollen development.

    Science.gov (United States)

    Feng, Chong; Wang, Jia-Gang; Liu, Hai-Hong; Li, Sha; Zhang, Yan

    2017-09-01

    Pollen development is a pre-requisite for sexual reproduction of angiosperms, during which various cellular activities are involved. Pollen development accompanies dynamic remodeling of vacuoles through fission and fusion, disruption of which often compromises pollen viability. We previously reported that the Y subunit of adaptor protein 1 (AP1G) mediates synergid degeneration during pollen tube reception. Here, we demonstrate that AP1G is essential for pollen development. AP1G loss-of-function resulted in male gametophytic lethality due to defective pollen development. By ultrastructural analysis and fluorescence labeling, we demonstrate that AP1G loss-of-function compromised dynamic vacuolar remodeling during pollen development and impaired vacuolar acidification of pollen. Results presented here support a key role of vacuoles in gametophytic pollen development. © 2017 Institute of Botany, Chinese Academy of Sciences.

  11. FENOLOGÍA FLORAL Y VISITANTES FLORALES EN Drimys granadensis (WINTERACEAE

    Directory of Open Access Journals (Sweden)

    Xavier Marquínez-Casas

    2009-09-01

    Full Text Available El propósito de este trabajo fue caracterizar las fases fenológicas florales y determinar los visitantes florales en una población natural de Drimys granadensis (Winteraceae ubicada en Altos de Yerbabuena (2850 m, cerros orientales de la Sabana de Bogotá, (Colombia. El desarrollo fenológico floral duró 9.5 días cuando la floración ocurrió en época soleada, 12.5 días en época lluviosa y 16 días cuando se excluyeron a los visitantes florales mediante embolsado. Se realizaron observaciones del recurso utilizado, fase fenólogica de la flor visitada y cargas polínicas en los visitante florales, los cuales correspondieron a 6 órdenes, 21 familias y 29 morfoespecies de insectos. Cuatro especies de coleópteros y dos de dípteros fueron considerados posibles polinizadores por su abundancia y carga de polen. Los resultados obtenidos se discuten en relación con aquellos reportados en otras especies del género Drimys y de la familia Winteraceae.

  12. Dependency on floral resources determines the animals' responses to floral scents.

    Science.gov (United States)

    Junker, Robert R; Blüthgen, Nico

    2010-08-01

    Animal-pollinated angiosperms either depend on cross-pollination or may also reproduce after self-pollination - the former are thus obligately, the latter facultatively dependent on the service of animal-pollinators. Analogously, flower visitors either solely feed on floral resources or complement their diet with these, and are hence dependent or not on the flowers they visit. We assume that obligate flower visitors evolved abilities that enable them to effectively forage on flowers including mechanisms to bypass or tolerate floral defences such as morphological barriers and repellent / deterrent secondary metabolites. Facultative flower visitors, in contrast, are supposed to lack these adaptations and are often prevented to consume floral resources by defence mechanisms. In cases where obligate flower visitors are mutualists and facultative ones are antagonists, this dichotomy provides a solution for the plants' dilemma to attract pollinators and simultaneously repel exploiters. In a meta-analysis, we recently supported this hypothesis: obligate flower visitors are attracted to floral scents, while facultative ones are repelled. Here, we add empirical evidence to these results: bumblebees and ants, obligate and facultative flower visitors, respectively, responded as predicted by the results of the meta-analysis to synthetic floral scent compounds.

  13. Floral Therapy in Occupational Stress Control

    Directory of Open Access Journals (Sweden)

    Maria Aparecida Idalêncio Daniel

    2013-01-01

    Full Text Available The study aimed to know the opinion of the nursing team that acts in motherhood on the therapeutic effects of floral control of occupational stress. This is a survey of qualitative and quantitative approach, the randomized clinical trial. Data analysis was performed by qualitative and quantitative data categorization was based on the evaluation results of the test stress levels proposed by Baccaro. Applied to interview and testing for stress in ten workers before and after use of the flower therapy. Results indicated that 100% of nursing staff were level with moderate to intense stress and 30% had a risk of developing heart disease. The survey results denote that 20% of nursing staff in the control group, with the use of floral, decreased stress levels and moderate to intense high risk of developing heart disease (type "A1", the risk for type "A2 ". From the results of the research suggest motivational strategies and improving quality of life at work.

  14. Floral associations of cyclocephaline scarab beetles.

    Science.gov (United States)

    Moore, Matthew Robert; Jameson, Mary Liz

    2013-01-01

    The scarab beetle tribe Cyclocephalini (Coleoptera: Scarabaeidae: Dynastinae) is the second largest tribe of rhinoceros beetles, with nearly 500 described species. This diverse group is most closely associated with early diverging angiosperm groups (the family Nymphaeaceae, magnoliid clade, and monocots), where they feed, mate, and receive the benefit of thermal rewards from the host plant. Cyclocephaline floral association data have never been synthesized, and a comprehensive review of this ecological interaction was necessary to promote research by updating nomenclature, identifying inconsistencies in the data, and reporting previously unpublished data. Based on the most specific data, at least 97 cyclocephaline beetle species have been reported from the flowers of 58 plant genera representing 17 families and 15 orders. Thirteen new cyclocephaline floral associations are reported herein. Six cyclocephaline and 25 plant synonyms were reported in the literature and on beetle voucher specimen labels, and these were updated to reflect current nomenclature. The valid names of three unavailable plant host names were identified. We review the cyclocephaline floral associations with respect to inferred relationships of angiosperm orders. Ten genera of cyclocephaline beetles have been recorded from flowers of early diverging angiosperm groups. In contrast, only one genus, Cyclocephala, has been recorded from dicot flowers. Cyclocephaline visitation of dicot flowers is limited to the New World, and it is unknown whether this is evolutionary meaningful or the result of sampling bias and incomplete data. The most important areas for future research include: (1) elucidating the factors that attract cyclocephalines to flowers including floral scent chemistry and thermogenesis, (2) determining whether cyclocephaline dicot visitation is truly limited to the New World, and (3) inferring evolutionary relationships within the Cyclocephalini to rigorously test vicarance hypotheses

  15. Disentangling the role of floral sensory stimuli in pollination networks

    DEFF Research Database (Denmark)

    Kantsa, Aphrodite; Raguso, Robert A.; Dyer, Adrian G.

    2018-01-01

    Despite progress in understanding pollination network structure, the functional roles of floral sensory stimuli (visual, olfactory) have never been addressed comprehensively in a community context, even though such traits are known to mediate plant-pollinator interactions. Here, we use...... a comprehensive dataset of floral traits and a novel dynamic data-pooling methodology to explore the impacts of floral sensory diversity on the structure of a pollination network in a Mediterranean scrubland. Our approach tracks transitions in the network behaviour of each plant species throughout its flowering...... period and, despite dynamism in visitor composition, reveals significant links to floral scent, and/or colour as perceived by pollinators. Having accounted for floral phenology, abundance and phylogeny, the persistent association between floral sensory traits and visitor guilds supports a deeper role...

  16. Floral development in three species of Impatiens (Balsaminaceae)

    OpenAIRE

    Caris, Pieter; Geuten, Koen; Janssens, Steven; Smets, Eric

    2006-01-01

    The floral morphological and developmental patterns in three species of Impatiens (Balsaminaceae), namely I. columbaria, I. hawkeri, and I. niamniamensis, were studied to contribute to a better understanding of floral evolution in the genus. Strangely enough, the highly diverse floral morphology and ontogeny of this horticulturally important genus have never been studied thoroughly (e.g., using scanning electron microscopic techniques). We discuss the position and the developmental sequence o...

  17. Floral scent emitted by white and coloured morphs in orchids.

    Science.gov (United States)

    Dormont, L; Delle-Vedove, R; Bessière, J-M; Schatz, B

    2014-04-01

    Polymorphism of floral signals, such as colour and odour, is widespread in flowering plants and often considered to be adaptive, reflecting various pollinator preferences for particular floral traits. Several authors have recently hypothesized that particular associations exist between floral colour and scent, which would result from shared biochemistry between these two floral traits. In this study, we compared the chemical composition of floral volatiles emitted by white- and purple-flowered morphs of three different orchid species, including two food-deceptive species (Orchis mascula and Orchis simia) and a food-rewarding species (Anacamptis coriophora fragrans). We found clear interspecific differences in floral odours. As expected from their pollination strategy, the two deceptive orchids showed high inter-individual variation of floral volatiles, whereas the food-rewarding A. c. fragrans showed low variation of floral scent. Floral volatiles did not differ overall between white- and coloured-flowered morphs in O. mascula and A. c. fragrans, while O. simia exhibited different volatile profiles between the two colour morphs. However, a detailed analysis restricted to benzenoid compounds (which are associated with the production of floral anthocyanin pigments) showed that white inflorescences emitted more volatiles of the shikimic pathway than coloured ones, both for O. mascula and O. simia. These results are consistent with the current hypothesis that shared biochemistry creates pleiotropic links between floral colour and scent. Whether intraspecific variation of floral signals actually affects pollinator attraction and influences the reproductive success of these orchids remains to be determined. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. A spatial dissection of the Arabidopsis floral transcriptome by MPSS

    OpenAIRE

    Sanchez-Leon Nidia; Arteaga-Vazquez Mario; Sakai Hajime; Kaushik Shail; Peiffer Jason A; Ghazal Hassan; Vielle-Calzada Jean-Philippe; Meyers Blake C

    2008-01-01

    Abstract Background We have further characterized floral organ-localized gene expression in the inflorescence of Arabidopsis thaliana by comparison of massively parallel signature sequencing (MPSS) data. Six libraries of RNA sequence tags from immature inflorescence tissues were constructed and matched to their respective loci in the annotated Arabidopsis genome. These signature libraries survey the floral transcriptome of wild-type tissue as well as the floral homeotic mutants, apetala1, ape...

  19. Study on the isothermal forging process of MB26 magnesium alloy adaptor

    Directory of Open Access Journals (Sweden)

    Xu Wenchen

    2015-01-01

    Full Text Available The isothermal forging process is an effective method to manufacture complex-shaped components of hard-to-work materials, such as magnesium alloys. This study investigates the isothermal forging process of an MB26 magnesium alloy adaptor with three branches. The results show that two-step forging process is appropriate to form the adaptor forging, which not only improves the filling quality but also reduces the forging load compared with one-step forging process. Moreover, the flow line is distributed along the contour of the complex-shaped adaptor forging.

  20. The Role of the Clathrin Adaptor AP-1: Polarized Sorting and Beyond

    Directory of Open Access Journals (Sweden)

    Fubito Nakatsu

    2014-11-01

    Full Text Available The selective transport of proteins or lipids by vesicular transport is a fundamental process supporting cellular physiology. The budding process involves cargo sorting and vesicle formation at the donor membrane and constitutes an important process in vesicular transport. This process is particularly important for the polarized sorting in epithelial cells, in which the cargo molecules need to be selectively sorted and transported to two distinct destinations, the apical or basolateral plasma membrane. Adaptor protein (AP-1, a member of the AP complex family, which includes the ubiquitously expressed AP-1A and the epithelium-specific AP-1B, regulates polarized sorting at the trans-Golgi network and/or at the recycling endosomes. A growing body of evidence, especially from studies using model organisms and animals, demonstrates that the AP-1-mediated polarized sorting supports the development and physiology of multi-cellular units as functional organs and tissues (e.g., cell fate determination, inflammation and gut immune homeostasis. Furthermore, a possible involvement of AP-1B in the pathogenesis of human diseases, such as Crohn’s disease and cancer, is now becoming evident. These data highlight the significant contribution of AP-1 complexes to the physiology of multicellular organisms, as master regulators of polarized sorting in epithelial cells.

  1. Mediator subunit18 controls flowering time and floral organ identity in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Zhengui Zheng

    Full Text Available Mediator is a conserved multi-protein complex that plays an important role in regulating transcription by mediating interactions between transcriptional activator proteins and RNA polymerase II. Much evidence exists that Mediator plays a constitutive role in the transcription of all genes transcribed by RNA polymerase II. However, evidence is mounting that specific Mediator subunits may control the developmental regulation of specific subsets of RNA polymerase II-dependent genes. Although the Mediator complex has been extensively studied in yeast and mammals, only a few reports on Mediator function in flowering time control of plants, little is known about Mediator function in floral organ identity. Here we show that in Arabidopsis thaliana, MEDIATOR SUBUNIT 18 (MED18 affects flowering time and floral organ formation through FLOWERING LOCUS C (FLC and AGAMOUS (AG. A MED18 loss-of-function mutant showed a remarkable syndrome of later flowering and altered floral organ number. We show that FLC and AG mRNA levels and AG expression patterns are altered in the mutant. Our results support parallels between the regulation of FLC and AG and demonstrate a developmental role for Mediator in plants.

  2. Evolution of floral meristem identity genes. Analysis of Lolium temulentum genes related to APETALA1 and LEAFY of Arabidopsis

    DEFF Research Database (Denmark)

    Gocal, G.F.W.; King, R.W.; Blundell, C.A.

    2001-01-01

    Flowering (inflorescence formation) of the grass Lolium temulentum is strictly regulated, occurring rapidly on exposure to a single long day (LD). During floral induction, L. temulentum differs significantly from dicot species such as Arabidopsis in the expression, at the shoot apex, of two APETALA......1 (AP1)-like genes, LtMADS1 and LtMADS2, and of L. temulentum LEAFY (LtLFY). As shown by in situ hybridization, LtMADS1 and LtMADS2 are expressed in the vegetative shoot apical meristem, but expression increases strongly within 30 h of LD floral induction. Later in floral development, LtMADS1 and Lt......MADS2 are expressed within spikelet and floret meristems and in the glume and lemma primordia. It is interesting that LtLFY is detected quite late (about 12 d after LD induction) within the spikelet meristems, glumes, and lemma primordia. These patterns contrast with Arabidopsis, where LFY and AP1...

  3. Role of Crk Adaptor Proteins in Cellular Migration and Invasion in Human Breast Cancer

    National Research Council Canada - National Science Library

    Fathers, Kelly E

    2007-01-01

    The Crk adaptor proteins (CrkI, CrkII and CrkL) play an important role during cellular signalling by mediating the formation of protein-protein complexes and are involved in cellular migration, invasion, and adhesion...

  4. Role of Crk Adaptor Proteins in Cellular Migration and Invasion in Human Breast Cancer

    National Research Council Canada - National Science Library

    Fathers, Kelly E

    2008-01-01

    The Crk adaptor proteins (CrkI, CrkII and CrkL) play an important role during cellular signalling by mediating the formation of protein-protein complexes and are involved in cellular migration, invasion, and adhesion...

  5. Floral ontogeny in legume genera Petalostylis, Labichea, and Dialium (Caesalpinioideae: Cassieae), a series in floral reduction.

    Science.gov (United States)

    Tucker, S

    1998-02-01

    Floral ontogeny of taxa of two subtribes (Labicheinae, Dialiinae) of caesalpinioid tribe Cassieae, characterized by reduced number of floral organs, was compared. All three taxa studied are distichous; Petalostylis labicheoides flowers are solitary in leaf axils, Labichea lanceolata has few-flowered racemes, and Dialium guineense has numerous-flowered cymes. The first sepal primordium in each is initiated abaxially and nonmedianly. Order of organogenesis in Petalostylis is: five sepals bidirectionally, five petals and carpel simultaneously, then five stamens bidirectionally, starting abaxially. The order in Labichea is: five sepals helically (one lagging in time), five petals unidirectionally starting abaxially, the carpel and petals concurrently, then two stamens successively, starting laterally. Order in Dialium is: five sepals bidirectionally, the single petal adaxially, and lastly the carpel and two stamens concurrently. Specializations include (1) reduction of the five sepals to four by fusion in Petalostylis and Labichea; (2) reduction of petal number to one in Dialium; (3) reduction of stamen number to two in Labichea and Dialium, and reduction of functional stamens to three in Petalostylis; and (4) an elaborate, late-developing style in Petalostylis. Floral asymmetry, another specialization, characterizes Labichea, expressed by dissimilar stamens, while the other genera have zygomorphic flowers. Floral ontogenies are compared with other taxa of Cassieae.

  6. Overhead irrigation increased winter chilling and floral bud ...

    African Journals Online (AJOL)

    Eucalyptus nitens requires a sufficiently cold winter to produce flower buds. In areas in South Africa where E. nitens commercial plantations as well as breeding and production seed orchards are located, winter chilling is often insufficient for floral bud initiation. Hence, under such conditions, E. nitens floral bud and seed ...

  7. Floral bud distortion in soybean and incidence in Central India ...

    African Journals Online (AJOL)

    Floral bud distortion in soybean and incidence in Central India. V Jadhav Pravin, SS Mane, RS Nandanwar, PB Kale, MS Dudhare, MP Moharil, RG Dani. Abstract. We describe a peculiar and often harmful budding disorder in soybean, leading to huge yield loss in India. To determine the prevalence of floral distortion in ...

  8. Natural selection on floral volatile production in Penstemon digitalis

    Science.gov (United States)

    Parachnowitsch, Amy L.; Burdon, Rosalie C. F.; Raguso, Robert A.; Kessler, André

    2013-01-01

    Natural selection is thought to have shaped the evolution of floral scent; however, unlike other floral characters, we have a rudimentary knowledge of how phenotypic selection acts on scent. We found that floral scent was under stronger selection than corolla traits such as flower size and flower color in weakly scented Penstemon digitalis. Our results suggest that to understand evolution in floral phenotypes, including scent in floral selection, studies are crucial. For P. digitalis, linalool was the direct target of selection in the scent bouquet. Therefore, we determined the enantiomeric configuration of linalool because interacting insects may perceive the enantiomers differentially. We found that P. digitalis produces only (S)-(+)-linalool and, more interestingly, it is also taken up into the nectar. Because the nectar is scented and flavored with (S)-(+)-linalool, it may be an important cue for pollinators visiting P. digitalis flowers. PMID:23221753

  9. The adaptor protein Grb2 is not essential for the establishment of the glomerular filtration barrier.

    Directory of Open Access Journals (Sweden)

    Nicolas Bisson

    Full Text Available The kidney filtration barrier is formed by the combination of endothelial cells, basement membrane and epithelial cells called podocytes. These specialized actin-rich cells form long and dynamic protrusions, the foot processes, which surround glomerular capillaries and are connected by specialized intercellular junctions, the slit diaphragms. Failure to maintain the filtration barrier leads to massive proteinuria and nephrosis. A number of proteins reside in the slit diaphragm, notably the transmembrane proteins Nephrin and Neph1, which are both able to act as tyrosine phosphorylated scaffolds that recruit cytoplasmic effectors to initiate downstream signaling. While association between tyrosine-phosphorylated Neph1 and the SH2/SH3 adaptor Grb2 was shown in vitro to be sufficient to induce actin polymerization, in vivo evidence supporting this finding is still lacking. To test this hypothesis, we generated two independent mouse lines bearing a podocyte-specific constitutive inactivation of the Grb2 locus. Surprisingly, we show that mice lacking Grb2 in podocytes display normal renal ultra-structure and function, thus demonstrating that Grb2 is not required for the establishment of the glomerular filtration barrier in vivo. Moreover, our data indicate that Grb2 is not required to restore podocyte function following kidney injury. Therefore, although in vitro experiments suggested that Grb2 is important for the regulation of actin dynamics, our data clearly shows that its function is not essential in podocytes in vivo, thus suggesting that Grb2 rather plays a secondary role in this process.

  10. Targeting 14-3-3 adaptor protein-protein interactions to stimulate central nervous system repair

    Directory of Open Access Journals (Sweden)

    Andrew Kaplan

    2017-01-01

    Full Text Available The goal of developing treatments for central nervous system (CNS injuries is becoming more attainable with the recent identification of various drugs that can repair damaged axons. These discoveries have stemmed from screening efforts, large expression datasets and an improved understanding of the cellular and molecular biology underlying axon growth. It will be important to continue searching for new compounds that can induce axon repair. Here we describe how a family of adaptor proteins called 14-3-3s can be targeted using small molecule drugs to enhance axon outgrowth and regeneration. 14-3-3s bind to many functionally diverse client proteins to regulate their functions. We highlight the recent discovery of the axon-growth promoting activity of fusicoccin-A, a fungus-derived small molecule that stabilizes 14-3-3 interactions with their client proteins. Here we discuss how fusicoccin-A could serve as a starting point for the development of drugs to induce CNS repair.

  11. Calceolariaceae: floral development and systematic implications.

    Science.gov (United States)

    Mayr, Eva M; Weber, Anton

    2006-03-01

    The recent establishment of the new family Calceolariaceae, separated from Scrophulariaceae on the basis of molecular evidence, is complemented here by a scanning electron microscopy study of floral morphology and development of 12 species encompassing all genera (Calceolaria, Jovellana, and Stemotria [= Porodittia]). All species showed a similar pattern of organ initiation. The slightly zygomorphic, four-merous calyx is the first floral organ series initiated, with the primordia emerging consecutively in a unidirectional (dorso-ventral) succession. The two entire corolla lips in Calceolaria and Jovellana arise as uniform meristematic ridges (sometimes with a central emargination, especially in Jovellana), kept apart by two lateral stamen primordia. Later the margins of the lips fuse across the backs of the young stamens, giving rise to the short corolla tube (late sympetaly). Stemotria stands out by having three stamens instead of two and a bilobed lower lip, resulting in a trimerous corolla. Similar architecture was found in teratological flowers of Calceolaria. The perianth of Calceolariaceae is shown to be derived from a tetramerous condition, not from pentamery as traditionally believed. This is in agreement with the separation of Calceolariaceae from Scrophulariaceae and with their placement in succession of Oleaceae and Tetrachondraceae in the basal Lamiales. The hitherto puzzling molecular evidence is thus supported by morphological-developmental features of the flower.

  12. Floral colleters in Pleurothallidinae (Epidendroideae: Orchidaceae).

    Science.gov (United States)

    Cardoso-Gustavson, Poliana; Campbell, Lisa M; Mazzoni-Viveiros, Solange C; de Barros, Fábio

    2014-04-01

    The term colleter is applied to trichomes or emergences positioned close to developing vegetative and floral meristems that secrete a sticky, mucilaginous, and/or lipophilic exudate. Several ecological functions are attributed to these glands, but none are exclusive to colleters. Patterns of morphology and distribution of colleters may be valuable for systematics and phylogeny, especially concerning problematic and large groups such as the subtribe Pleurothallidinae, and are also essential to understand the evolution of these glands in Orchidaceae as a whole. We used scanning electron and light microscopy to examine the structure and occurrence of trichomes on bracts and sepals and in the invaginations of the external ovary wall (IEOW) in flowers in several developmental stages from species in seven genera. The exudate was composed of polysaccharides, lipophilic, and phenolic compounds. Colleters were secretory only during the development of floral organs, except for the glands in the IEOW that were also active in flowers at anthesis. After the secretory phase, fungal hyphae were found penetrating senescent trichomes. Trichome-like colleters seem to be a widespread character in Epidendroideae, and digitiform colleters are possibly the common type in this subfamily. Mucilage from IEOW colleters may aid in the establishment of symbiotic fungi necessary for seed germination. The presence of colleters in the IEOW may be a case of homeoheterotopy, in which extrafloral nectaries that produce simple sugar-based secretions (as in other orchid species) have changed to glands that produce secretions with complex polysaccharides, as in Pleurothallidinae.

  13. Genetic Deletion of the Clathrin Adaptor GGA3 Reduces Anxiety and Alters GABAergic Transmission.

    Directory of Open Access Journals (Sweden)

    Kendall R Walker

    Full Text Available Golgi-localized γ-ear-containing ARF binding protein 3 (GGA3 is a monomeric clathrin adaptor that has been shown to regulate the trafficking of the Beta-site APP-cleaving enzyme (BACE1, which is required for production of the Alzheimer's disease (AD-associated amyloid βpeptide. Our previous studies have shown that BACE1 is degraded via the lysosomal pathway and that depletion of GGA3 results in increased BACE1 levels and activity owing to impaired lysosomal trafficking and degradation. We further demonstrated the role of GGA3 in the regulation of BACE1 in vivo by showing that BACE1 levels are increased in the brain of GGA3 null mice. We report here that GGA3 deletion results in novelty-induced hyperactivity and decreased anxiety-like behaviors. Given the pivotal role of GABAergic transmission in the regulation of anxiety-like behaviors, we performed electrophysiological recordings in hippocampal slices and found increased phasic and decreased tonic inhibition in the dentate gyrus granule cells (DGGC. Moreover, we found that the number of inhibitory synapses is increased in the dentate gyrus of GGA3 null mice in further support of the electrophysiological data. Thus, the increased GABAergic transmission is a leading candidate mechanism underlying the reduced anxiety-like behaviors observed in GGA3 null mice. All together these findings suggest that GGA3 plays a key role in GABAergic transmission. Since BACE1 levels are elevated in the brain of GGA3 null mice, it is possible that at least some of these phenotypes are a consequence of increased processing of BACE1 substrates.

  14. Genetic Deletion of the Clathrin Adaptor GGA3 Reduces Anxiety and Alters GABAergic Transmission.

    Science.gov (United States)

    Walker, Kendall R; Modgil, Amit; Albrecht, David; Lomoio, Selene; Haydon, Philip G; Moss, Stephen J; Tesco, Giuseppina

    2016-01-01

    Golgi-localized γ-ear-containing ARF binding protein 3 (GGA3) is a monomeric clathrin adaptor that has been shown to regulate the trafficking of the Beta-site APP-cleaving enzyme (BACE1), which is required for production of the Alzheimer's disease (AD)-associated amyloid βpeptide. Our previous studies have shown that BACE1 is degraded via the lysosomal pathway and that depletion of GGA3 results in increased BACE1 levels and activity owing to impaired lysosomal trafficking and degradation. We further demonstrated the role of GGA3 in the regulation of BACE1 in vivo by showing that BACE1 levels are increased in the brain of GGA3 null mice. We report here that GGA3 deletion results in novelty-induced hyperactivity and decreased anxiety-like behaviors. Given the pivotal role of GABAergic transmission in the regulation of anxiety-like behaviors, we performed electrophysiological recordings in hippocampal slices and found increased phasic and decreased tonic inhibition in the dentate gyrus granule cells (DGGC). Moreover, we found that the number of inhibitory synapses is increased in the dentate gyrus of GGA3 null mice in further support of the electrophysiological data. Thus, the increased GABAergic transmission is a leading candidate mechanism underlying the reduced anxiety-like behaviors observed in GGA3 null mice. All together these findings suggest that GGA3 plays a key role in GABAergic transmission. Since BACE1 levels are elevated in the brain of GGA3 null mice, it is possible that at least some of these phenotypes are a consequence of increased processing of BACE1 substrates.

  15. The role of jasmonates in floral nectar secretion.

    Science.gov (United States)

    Radhika, Venkatesan; Kost, Christian; Boland, Wilhelm; Heil, Martin

    2010-02-19

    Plants produce nectar in their flowers as a reward for their pollinators and most of our crops depend on insect pollination, but little is known on the physiological control of nectar secretion. Jasmonates are well-known for their effects on senescence, the development and opening of flowers and on plant defences such as extrafloral nectar. Their role in floral nectar secretion has, however, not been explored so far. We investigated whether jasmonates have an influence on floral nectar secretion in oil-seed rape, Brassica napus. The floral tissues of this plant produced jasmonic acid (JA) endogenously, and JA concentrations peaked shortly before nectar secretion was highest. Exogenous application of JA to flowers induced nectar secretion, which was suppressed by treatment with phenidone, an inhibitor of JA synthesis. This effect could be reversed by additional application of JA. Jasmonoyl-isoleucine and its structural mimic coronalon also increased nectar secretion. Herbivory or addition of JA to the leaves did not have an effect on floral nectar secretion, demonstrating a functional separation of systemic defence signalling from reproductive nectar secretion. Jasmonates, which have been intensively studied in the context of herbivore defences and flower development, have a profound effect on floral nectar secretion and, thus, pollination efficiency in B. napus. Our results link floral nectar secretion to jasmonate signalling and thereby integrate the floral nectar secretion into the complex network of oxylipid-mediated developmental processes of plants.

  16. Disentangling the role of floral sensory stimuli in pollination networks.

    Science.gov (United States)

    Kantsa, Aphrodite; Raguso, Robert A; Dyer, Adrian G; Olesen, Jens M; Tscheulin, Thomas; Petanidou, Theodora

    2018-03-12

    Despite progress in understanding pollination network structure, the functional roles of floral sensory stimuli (visual, olfactory) have never been addressed comprehensively in a community context, even though such traits are known to mediate plant-pollinator interactions. Here, we use a comprehensive dataset of floral traits and a novel dynamic data-pooling methodology to explore the impacts of floral sensory diversity on the structure of a pollination network in a Mediterranean scrubland. Our approach tracks transitions in the network behaviour of each plant species throughout its flowering period and, despite dynamism in visitor composition, reveals significant links to floral scent, and/or colour as perceived by pollinators. Having accounted for floral phenology, abundance and phylogeny, the persistent association between floral sensory traits and visitor guilds supports a deeper role for sensory bias and diffuse coevolution in structuring plant-pollinator networks. This knowledge of floral sensory diversity, by identifying the most influential phenotypes, could help prioritize efforts for plant-pollinator community restoration.

  17. Darwin's beautiful contrivances: evolutionary and functional evidence for floral adaptation.

    Science.gov (United States)

    Harder, Lawrence D; Johnson, Steven D

    2009-08-01

    Although not 'a professed botanist', Charles Darwin made seminal contributions to understanding of floral and inflorescence function while seeking evidence of adaptation by natural selection. This review considers the legacy of Darwin's ideas from three perspectives. First, we examine the process of floral and inflorescence adaptation by surveying studies of phenotypic selection, heritability and selection responses. Despite widespread phenotypic and genetic capacity for natural selection, only one-third of estimates indicate phenotypic selection. Second, we evaluate experimental studies of floral and inflorescence function and find that they usually demonstrate that reproductive traits represent adaptations. Finally, we consider the role of adaptation in floral diversification. Despite different diversification modes (coevolution, divergent use of the same pollen vector, pollinator shifts), evidence of pollination ecotypes and phylogenetic patterns suggests that adaptation commonly contributes to floral diversity. Thus, this review reveals a contrast between the inconsistent occurrence of phenotypic selection and convincing experimental and comparative evidence that floral traits are adaptations. Rather than rejecting Darwin's hypotheses about floral evolution, this contrast suggests that the tempo of creative selection varies, with strong, consistent selection during episodes of diversification, but relatively weak and inconsistent selection during longer, 'normal' periods of relative phenotypic stasis.

  18. The role of jasmonates in floral nectar secretion.

    Directory of Open Access Journals (Sweden)

    Venkatesan Radhika

    Full Text Available Plants produce nectar in their flowers as a reward for their pollinators and most of our crops depend on insect pollination, but little is known on the physiological control of nectar secretion. Jasmonates are well-known for their effects on senescence, the development and opening of flowers and on plant defences such as extrafloral nectar. Their role in floral nectar secretion has, however, not been explored so far. We investigated whether jasmonates have an influence on floral nectar secretion in oil-seed rape, Brassica napus. The floral tissues of this plant produced jasmonic acid (JA endogenously, and JA concentrations peaked shortly before nectar secretion was highest. Exogenous application of JA to flowers induced nectar secretion, which was suppressed by treatment with phenidone, an inhibitor of JA synthesis. This effect could be reversed by additional application of JA. Jasmonoyl-isoleucine and its structural mimic coronalon also increased nectar secretion. Herbivory or addition of JA to the leaves did not have an effect on floral nectar secretion, demonstrating a functional separation of systemic defence signalling from reproductive nectar secretion. Jasmonates, which have been intensively studied in the context of herbivore defences and flower development, have a profound effect on floral nectar secretion and, thus, pollination efficiency in B. napus. Our results link floral nectar secretion to jasmonate signalling and thereby integrate the floral nectar secretion into the complex network of oxylipid-mediated developmental processes of plants.

  19. TIRAP, an Adaptor Protein for TLR2/4, Transduces a Signal from RAGE Phosphorylated upon Ligand Binding

    Science.gov (United States)

    Sakaguchi, Masakiyo; Murata, Hitoshi; Yamamoto, Ken-ichi; Ono, Tomoyuki; Sakaguchi, Yoshihiko; Motoyama, Akira; Hibino, Toshihiko; Kataoka, Ken; Huh, Nam-ho

    2011-01-01

    The receptor for advanced glycation end products (RAGE) is thought to be involved in the pathogenesis of a broad range of inflammatory, degenerative and hyperproliferative diseases. It binds to diverse ligands and activates multiple intracellular signaling pathways. Despite these pivotal functions, molecular events just downstream of ligand-activated RAGE have been surprisingly unknown. Here we show that the cytoplasmic domain of RAGE is phosphorylated at Ser391 by PKCζ upon binding of ligands. TIRAP and MyD88, which are known to be adaptor proteins for Toll-like receptor-2 and -4 (TLR2/4), bound to the phosphorylated RAGE and transduced a signal to downstream molecules. Blocking of the function of TIRAP and MyD88 largely abrogated intracellular signaling from ligand-activated RAGE. Our findings indicate that functional interaction between RAGE and TLRs coordinately regulates inflammation, immune response and other cellular functions. PMID:21829704

  20. Dependency on floral resources determines the animals' responses to floral scents

    OpenAIRE

    Junker, Robert R; Blüthgen, Nico

    2010-01-01

    Animal-pollinated angiosperms either depend on cross-pollination or may also reproduce after self-pollination—the former are thus obligately, the latter facultatively dependent on the service of animal-pollinators. Analogously, flower visitors either solely feed on floral resources or complement their diet with these, and are hence dependent or not on the flowers they visit. We assume that obligate flower visitors evolved abilities that enable them to effectively forage on flowers including m...

  1. Floral adaptation to local pollinator guilds in a terrestrial orchid.

    Science.gov (United States)

    Sun, Mimi; Gross, Karin; Schiestl, Florian P

    2014-01-01

    Studies of local floral adaptation in response to geographically divergent pollinators are essential for understanding floral evolution. This study investigated local pollinator adaptation and variation in floral traits in the rewarding orchid Gymnadenia odoratissima, which spans a large altitudinal gradient and thus may depend on different pollinator guilds along this gradient. Pollinator communities were assessed and reciprocal transfer experiments were performed between lowland and mountain populations. Differences in floral traits were characterized by measuring floral morphology traits, scent composition, colour and nectar sugar content in lowland and mountain populations. The composition of pollinator communities differed considerably between lowland and mountain populations; flies were only found as pollinators in mountain populations. The reciprocal transfer experiments showed that when lowland plants were transferred to mountain habitats, their reproductive success did not change significantly. However, when mountain plants were moved to the lowlands, their reproductive success decreased significantly. Transfers between populations of the same altitude did not lead to significant changes in reproductive success, disproving the potential for population-specific adaptations. Flower size of lowland plants was greater than for mountain flowers. Lowland plants also had significantly higher relative amounts of aromatic floral volatiles, while the mountain plants had higher relative amounts of other floral volatiles. The floral colour of mountain flowers was significantly lighter compared with the lowland flowers. Local pollinator adaptation through pollinator attraction was shown in the mountain populations, possibly due to adaptation to pollinating flies. The mountain plants were also observed to receive pollination from a greater diversity of pollinators than the lowland plants. The different floral phenotypes of the altitudinal regions are likely to be the

  2. Herbivore-Induced DNA Demethylation Changes Floral Signalling and Attractiveness to Pollinators in Brassica rapa.

    Science.gov (United States)

    Kellenberger, Roman T; Schlüter, Philipp M; Schiestl, Florian P

    2016-01-01

    Plants have to fine-tune their signals to optimise the trade-off between herbivore deterrence and pollinator attraction. An important mechanism in mediating plant-insect interactions is the regulation of gene expression via DNA methylation. However, the effect of herbivore-induced DNA methylation changes on pollinator-relevant plant signalling has not been systematically investigated. Here, we assessed the impact of foliar herbivory on DNA methylation and floral traits in the model crop plant Brassica rapa. Methylation-sensitive amplified fragment length polymorphism (MSAP) analysis showed that leaf damage by the caterpillar Pieris brassicae was associated with genome-wide methylation changes in both leaves and flowers of B. rapa as well as a downturn in flower number, morphology and scent. A comparison to plants with jasmonic acid-induced defence showed similar demethylation patterns in leaves, but both the floral methylome and phenotype differed significantly from P. brassicae infested plants. Standardised genome-wide demethylation with 5-azacytidine in five different B. rapa full-sib groups further resulted in a genotype-specific downturn of floral morphology and scent, which significantly reduced the attractiveness of the plants to the pollinator bee Bombus terrestris. These results suggest that DNA methylation plays an important role in adjusting plant signalling in response to changing insect communities.

  3. Why Do Floral Perfumes Become Different? Region-Specific Selection on Floral Scent in a Terrestrial Orchid.

    Science.gov (United States)

    Gross, Karin; Sun, Mimi; Schiestl, Florian P

    2016-01-01

    Geographically structured phenotypic selection can lead to adaptive divergence. However, in flowering plants, such divergent selection has rarely been shown, and selection on floral signals is generally little understood. In this study, we measured phenotypic selection on display size, floral color, and floral scent in four lowland and four mountain populations of the nectar-rewarding terrestrial orchid Gymnadenia odoratissima in two years. We also quantified population differences in these traits and pollinator community composition. Our results show positive selection on display size and positive, negative, or absence of selection on different scent compounds and floral color. Selection on the main scent compounds was consistently stronger in the lowlands than in the mountains, and lowland plants emitted higher amounts of most of these compounds. Pollinator community composition also differed between regions, suggesting different pollinators select for differences in floral volatiles. Overall, our study is the first to document consistent regional differences in selection on floral scent, suggesting this pattern of selection is one of the evolutionary forces contributing to regional divergence in floral chemical signaling.

  4. Why Do Floral Perfumes Become Different? Region-Specific Selection on Floral Scent in a Terrestrial Orchid

    Science.gov (United States)

    Gross, Karin; Sun, Mimi; Schiestl, Florian P.

    2016-01-01

    Geographically structured phenotypic selection can lead to adaptive divergence. However, in flowering plants, such divergent selection has rarely been shown, and selection on floral signals is generally little understood. In this study, we measured phenotypic selection on display size, floral color, and floral scent in four lowland and four mountain populations of the nectar-rewarding terrestrial orchid Gymnadenia odoratissima in two years. We also quantified population differences in these traits and pollinator community composition. Our results show positive selection on display size and positive, negative, or absence of selection on different scent compounds and floral color. Selection on the main scent compounds was consistently stronger in the lowlands than in the mountains, and lowland plants emitted higher amounts of most of these compounds. Pollinator community composition also differed between regions, suggesting different pollinators select for differences in floral volatiles. Overall, our study is the first to document consistent regional differences in selection on floral scent, suggesting this pattern of selection is one of the evolutionary forces contributing to regional divergence in floral chemical signaling. PMID:26886766

  5. Floral Evolution of Philodendron Subgenus Meconostigma (Araceae)

    Science.gov (United States)

    de Oliveira, Letícia Loss; Calazans, Luana Silva Braucks; de Morais, Érica Barroso; Mayo, Simon Joseph; Schrago, Carlos Guerra; Sakuragui, Cassia Mônica

    2014-01-01

    Elucidating the evolutionary patterns of flower and inflorescence structure is pivotal to understanding the phylogenetic relationships of Angiosperms as a whole. The inflorescence morphology and anatomy of Philodendron subgenus Meconostigma, belonging to the monocot family Araceae, has been widely studied but the evolutionary relationships of subgenus Meconostigma and the evolution of its flower characters have hitherto remained unclear. This study examines gynoecium evolution in subgenus Meconostigma in the context of an estimated molecular phylogeny for all extant species of subgenus Meconostigma and analysis of ancestral character reconstructions of some gynoecial structures. The phylogenetic reconstructions of all extant Meconostigma species were conducted under a maximum likelihood approach based on the sequences of two chloroplast (trnk and matK) and two nuclear (ETS and 18S) markers. This topology was used to reconstruct the ancestral states of seven floral characters and to elucidate their evolutionary pattern in the Meconostigma lineage. Our phylogeny shows that Meconostigma is composed of two major clades, one comprising two Amazonian species and the other all the species from the Atlantic Forest and Cerrado biomes with one Amazonian species. The common ancestor of the species of subgenus Meconostigma probably possessed short stylar lobes, long stylar canals, a stylar body, a vascular plexus in the gynoecium and druses in the stylar parenchyma but it is uncertain whether raphide inclusions were present in the parenchyma. The ancestral lineage also probably possessed up to 10 ovary locules. The evolution of these characters seems to have occurred independently in some lineages. We propose that the morphological and anatomical diversity observed in the gynoecial structures of subgenus Meconostigma is the result of an ongoing process of fusion of floral structures leading to a reduction of energy wastage and increase in stigmatic surface. PMID:24586972

  6. Floral evolution of Philodendron subgenus Meconostigma (Araceae).

    Science.gov (United States)

    de Oliveira, Letícia Loss; Calazans, Luana Silva Braucks; de Morais, Érica Barroso; Mayo, Simon Joseph; Schrago, Carlos Guerra; Sakuragui, Cassia Mônica

    2014-01-01

    Elucidating the evolutionary patterns of flower and inflorescence structure is pivotal to understanding the phylogenetic relationships of Angiosperms as a whole. The inflorescence morphology and anatomy of Philodendron subgenus Meconostigma, belonging to the monocot family Araceae, has been widely studied but the evolutionary relationships of subgenus Meconostigma and the evolution of its flower characters have hitherto remained unclear. This study examines gynoecium evolution in subgenus Meconostigma in the context of an estimated molecular phylogeny for all extant species of subgenus Meconostigma and analysis of ancestral character reconstructions of some gynoecial structures. The phylogenetic reconstructions of all extant Meconostigma species were conducted under a maximum likelihood approach based on the sequences of two chloroplast (trnk and matK) and two nuclear (ETS and 18S) markers. This topology was used to reconstruct the ancestral states of seven floral characters and to elucidate their evolutionary pattern in the Meconostigma lineage. Our phylogeny shows that Meconostigma is composed of two major clades, one comprising two Amazonian species and the other all the species from the Atlantic Forest and Cerrado biomes with one Amazonian species. The common ancestor of the species of subgenus Meconostigma probably possessed short stylar lobes, long stylar canals, a stylar body, a vascular plexus in the gynoecium and druses in the stylar parenchyma but it is uncertain whether raphide inclusions were present in the parenchyma. The ancestral lineage also probably possessed up to 10 ovary locules. The evolution of these characters seems to have occurred independently in some lineages. We propose that the morphological and anatomical diversity observed in the gynoecial structures of subgenus Meconostigma is the result of an ongoing process of fusion of floral structures leading to a reduction of energy wastage and increase in stigmatic surface.

  7. Floral evolution of Philodendron subgenus Meconostigma (Araceae.

    Directory of Open Access Journals (Sweden)

    Letícia Loss de Oliveira

    Full Text Available Elucidating the evolutionary patterns of flower and inflorescence structure is pivotal to understanding the phylogenetic relationships of Angiosperms as a whole. The inflorescence morphology and anatomy of Philodendron subgenus Meconostigma, belonging to the monocot family Araceae, has been widely studied but the evolutionary relationships of subgenus Meconostigma and the evolution of its flower characters have hitherto remained unclear. This study examines gynoecium evolution in subgenus Meconostigma in the context of an estimated molecular phylogeny for all extant species of subgenus Meconostigma and analysis of ancestral character reconstructions of some gynoecial structures. The phylogenetic reconstructions of all extant Meconostigma species were conducted under a maximum likelihood approach based on the sequences of two chloroplast (trnk and matK and two nuclear (ETS and 18S markers. This topology was used to reconstruct the ancestral states of seven floral characters and to elucidate their evolutionary pattern in the Meconostigma lineage. Our phylogeny shows that Meconostigma is composed of two major clades, one comprising two Amazonian species and the other all the species from the Atlantic Forest and Cerrado biomes with one Amazonian species. The common ancestor of the species of subgenus Meconostigma probably possessed short stylar lobes, long stylar canals, a stylar body, a vascular plexus in the gynoecium and druses in the stylar parenchyma but it is uncertain whether raphide inclusions were present in the parenchyma. The ancestral lineage also probably possessed up to 10 ovary locules. The evolution of these characters seems to have occurred independently in some lineages. We propose that the morphological and anatomical diversity observed in the gynoecial structures of subgenus Meconostigma is the result of an ongoing process of fusion of floral structures leading to a reduction of energy wastage and increase in stigmatic surface.

  8. Sub-cellular distribution of UNC-104(KIF1A) upon binding to adaptors as UNC-16(JIP3), DNC-1(DCTN1/Glued) and SYD-2(Liprin-α) in C. elegans neurons.

    Science.gov (United States)

    Hsu, C-C; Moncaleano, J D; Wagner, O I

    2011-03-10

    The accumulation of cargo (tau, amyloid precursor protein, neurofilaments etc.) in neurons is a hallmark of various neurodegenerative diseases while we have only little knowledge how axonal transport is regulated. Kinesin-3 UNC-104(KIF1A) is the major transporter of synaptic vesicles and recent reports suggest that a cargo itself can affect the motor's activity. Inspecting an interactome map, we identify three putative UNC-104 interactors, namely UNC-16(JIP3), DNC-1(DCTN1/Glued) and SYD-2(Liprin-α), known to be adaptors in essential neuronal protein complexes. We then employed the novel method bimolecular fluorescence complementation (BiFC) assay to visualize motor-adaptor complexes in the nervous system of living C. elegans. Interestingly, the binding of UNC-104 to each adaptor protein results in different sub-cellular distributions and has distinctive effects on the motor's motility. Specifically, if UNC-104 bound to UNC-16, the motor is primarily localized in the soma of neurons while bound to DNC-1, the motor is basically found in axonal termini. On the other hand, if UNC-104 is bound to SYD-2 we identify motor populations mostly along axons. Therefore, these three adaptors inherit different functions in steering the motor to specific sub-cellular locations in the neuron. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  9. Seneca Valley Virus Suppresses Host Type I Interferon Production by Targeting Adaptor Proteins MAVS, TRIF, and TANK for Cleavage.

    Science.gov (United States)

    Qian, Suhong; Fan, Wenchun; Liu, Tingting; Wu, Mengge; Zhang, Huawei; Cui, Xiaofang; Zhou, Yun; Hu, Junjie; Wei, Shaozhong; Chen, Huanchun; Li, Xiangmin; Qian, Ping

    2017-08-15

    Seneca Valley virus (SVV) is an oncolytic RNA virus belonging to the Picornaviridae family. Its nucleotide sequence is highly similar to those of members of the Cardiovirus genus. SVV is also a neuroendocrine cancer-selective oncolytic picornavirus that can be used for anticancer therapy. However, the interaction between SVV and its host is yet to be fully characterized. In this study, SVV inhibited antiviral type I interferon (IFN) responses by targeting different host adaptors, including mitochondrial antiviral signaling (MAVS), Toll/interleukin 1 (IL-1) receptor domain-containing adaptor inducing IFN-β (TRIF), and TRAF family member-associated NF-κB activator (TANK), via viral 3C protease (3C pro ). SVV 3C pro mediated the cleavage of MAVS, TRIF, and TANK at specific sites, which required its protease activity. The cleaved MAVS, TRIF, and TANK lost the ability to regulate pattern recognition receptor (PRR)-mediated IFN production. The cleavage of TANK also facilitated TRAF6-induced NF-κB activation. SVV was also found to be sensitive to IFN-β. Therefore, SVV suppressed antiviral IFN production to escape host antiviral innate immune responses by cleaving host adaptor molecules. IMPORTANCE Host cells have developed various defenses against microbial pathogen infection. The production of IFN is the first line of defense against microbial infection. However, viruses have evolved many strategies to disrupt this host defense. SVV, a member of the Picornavirus genus, is an oncolytic virus that shows potential functions in anticancer therapy. It has been demonstrated that IFN can be used in anticancer therapy for certain tumors. However, the relationship between oncolytic virus and innate immune response in anticancer therapy is still not well known. In this study, we showed that SVV has evolved as an effective mechanism to inhibit host type I IFN production by using its 3C pro to cleave the molecules MAVS, TRIF, and TANK directly. These molecules are crucial for

  10. Floral scent and pollinators of the holoparasite Pilostyles thurberi (Apodanthaceae

    Directory of Open Access Journals (Sweden)

    Sedonia D Sipes

    2014-02-01

    Full Text Available Floral scent is likely important to the pollination of parasitic plants, despite that it has not been well-studied. We studied the pollination ecology of the North American stem holoparasite Pilostyles thurberi (Apodanthaceae at two field sites in Texas. To identify effective pollinators, we collected floral visitors to P. thurberi flowers, observed their foraging behavior, and looked for P. thurberi pollen on their bodies. Augochloropsis metallica bees (Halictidae and eumenine potter wasps (Vespidae were pollinators. P. thurberi flowers are visually inconspicuous but produce a strong fruity fragrance. GC/MS analysis of whole floral extracts and dynamic headspace samples revealed the fragrance to be an unusually simple bouquet of raspberry ketone and several eugenols. Comparison of scent profiles to those from uninfected host plants (Dalea formosa allowed putative separation of parasite and host volatiles. This is the first report of the constituents of floral fragrance in Apodanthaceae.

  11. Pestalotioid fungi from Restionaceae in the Cape Floral Kingdom.

    NARCIS (Netherlands)

    Lee, S.; Crous, P.W.; Wingfield, M.J.

    2006-01-01

    Eight pestalotioid fungi were isolated from the Restionaceae growing in the Cape Floral Kingdom of South Africa. Sarcostroma restionis, Truncatella megaspora, T. restionacearum and T. spadicea are newly described. New records include Pestalotiopsis matildae, Sarcostroma lomatiae, Truncatella betulae

  12. Pestalotioid fungi from Restionaceae in the Cape Floral Kingdom

    NARCIS (Netherlands)

    Lee, M.J.; Crous, P.W.; Wingfield, M.J.

    2006-01-01

    Eight pestalotioid fungi were isolated from the Restionaceae growing in the Cape Floral Kingdom of South Africa. Sarcostroma restionis, Truncatella megaspora, T. restionacearum and T. spadicea are newly described. New records include Pestalotiopsis matildae, Sarcostroma lomatiae, Truncatella betulae

  13. Floral vasculature and trichomes of common Indian Scrophulariaceae

    Directory of Open Access Journals (Sweden)

    P. C. Datta

    2015-01-01

    Full Text Available The floral anatomy of 24 species of Scrophulariaceae was studied. The results show that although, clear anatomical bases to differentiate taxa are absent, the Pennell classification of subfamilies is strongly supported.

  14. Floral scent and pollinators of the holoparasite Pilostyles thurberi (Apodanthaceae)

    OpenAIRE

    Sedonia D Sipes; Kara E. Huff Hartz; Hardik Amin; Daniel L. Nickrent

    2014-01-01

    Floral scent is likely important to the pollination of parasitic plants, despite that it has not been well-studied. We studied the pollination ecology of the North American stem holoparasite Pilostyles thurberi (Apodanthaceae) at two field sites in Texas. To identify effective pollinators, we collected floral visitors to P. thurberi flowers, observed their foraging behavior, and looked for P. thurberi pollen on their bodies. Augochloropsis metallica bees (Halictidae) and eumenine potter wasps...

  15. Stepping motor adaptor actuator for a commercial uhv linear motion feedthrough

    International Nuclear Information System (INIS)

    Iarocci, M.; Oversluizen, T.

    1989-01-01

    An adaptor coupling has been developed that will allow the attachment of a standard stepping motor to a precision commercial (Varian) uhv linear motion feedthrough. The assembly, consisting of the motor, motor adaptor, limit switches, etc. is clamped to the feedthrough body which can be done under vacuum conditions if necessary. With a 500 step/rev. stepping motor the resolution is 1.27 μm per step. We presently use this assembly in a remote location for the precise positioning of a beam sensing monitor. 2 refs., 3 figs

  16. Similar genetic mechanisms underlie the parallel evolution of floral phenotypes.

    Directory of Open Access Journals (Sweden)

    Wenheng Zhang

    Full Text Available The repeated origin of similar phenotypes is invaluable for studying the underlying genetics of adaptive traits; molecular evidence, however, is lacking for most examples of such similarity. The floral morphology of neotropical Malpighiaceae is distinctive and highly conserved, especially with regard to symmetry, and is thought to result from specialization on oil-bee pollinators. We recently demonstrated that CYCLOIDEA2-like genes (CYC2A and CYC2B are associated with the development of the stereotypical floral zygomorphy that is critical to this plant-pollinator mutualism. Here, we build on this developmental framework to characterize floral symmetry in three clades of Malpighiaceae that have independently lost their oil bee association and experienced parallel shifts in their floral morphology, especially in regard to symmetry. We show that in each case these species exhibit a loss of CYC2B function, and a strikingly similar shift in the expression of CYC2A that is coincident with their shift in floral symmetry. These results indicate that similar floral phenotypes in this large angiosperm clade have evolved via parallel genetic changes from an otherwise highly conserved developmental program.

  17. The TIR-domain containing adaptor TRAM is required for TLR7 mediated RANTES production.

    Directory of Open Access Journals (Sweden)

    Enda Shevlin

    Full Text Available Toll-like receptor 7 (TLR7 plays a vital role in the immune response to ssRNA viruses such as human rhinovirus (HRV and Influenza, against which there are currently no treatments or vaccines with long term efficacy available. Clearly, a more comprehensive understanding of the TLR7 signaling axis will contribute to its molecular targeting. TRIF related adaptor molecule (TRAM plays a vital role in TLR4 signaling by recruiting TRIF to TLR4, followed by endosomal trafficking of the complex and initiation of IRF3 dependent type I interferon production as well as NF-κB dependent pro-inflammatory cytokine production. Towards understanding the molecular mechanisms that regulate TLR7 functionality, we found that TRAM(-/- murine macrophages exhibited a transcriptional and translational impairment in TLR7 mediated RANTES, but not TNFα, production. Suppression of TRAM expression in human macrophages also resulted in an impairment in TLR7 mediated CCL5 and IFN-β, but not TNFα, gene induction. Furthermore, suppression of endogenous human TRAM expression in human macrophages significantly impaired RV16 induced CCL5 and IFNβ, but not TNFα gene induction. Additionally, TRAM-G2A dose-dependently inhibited TLR7 mediated activation of CCL5, IFNβ and IFNα reporter genes. TLR7-mediated phosphorylation and nuclear translocation of IRF3 was impaired in TRAM(-/- cells. Finally, co-immunoprecipitation studies indicated that TRAM physically interacts with MyD88 upon TLR7 stimulation, but not under basal conditions. Our results clearly demonstrate that TRAM plays a, hitherto unappreciated, role in TLR7 signaling through a novel signaling axis containing, but not limited to, MyD88, TRAM and IRF3 towards the activation of anti-viral immunity.

  18. Biologia floral de Virola surinamensis (Rol. Warb. (Myristicaceae Virola surinamensis (Rol. Warb. (Myristicaceae floral biology

    Directory of Open Access Journals (Sweden)

    Mario Augusto Gonçalves Jardim

    2007-12-01

    Full Text Available Neste artigo são apresentadas informações sobre a biologia floral de Virola surinamensis (Rol. Warb. (Myristicaceae, espécie florestal dióica de relevante importância econômica na região amazônica. O estudo foi realizado em uma área de várzea próximo à bacia do igarapé Murutucum, lado direito do rio Guamá, localizada no Campus da Faculdade de Ciências Agrárias do Pará, na cidade de Belém, Estado do Pará, no período de janeiro a dezembro de 2001. Avaliou-se a biologia floral desde o aparecimento dos botões florais até a senescência das flores estaminadas, bem como a formação de frutos nas flores pistiladas. Testes bioquímicos foram aplicados para verificação de odor, pigmentos, osmóforos e receptividade do estigma. A observação no comportamento dos visitantes florais foi realizada durante o período diurno, registrando-se os horários de visitas, tempo de permanência na flor e freqüência; alguns indivíduos foram coletados com rede entomológica e identificados no Departamento de Zoologia do Museu Paraense Emílio Goeldi. A antese ocorreu entre 6 e 16 h nas flores estaminadas e entre 8 e 16 h nas flores pistiladas; a presença de odor foi constatada apenas nas flores estaminadas, enquanto os pigmentos e osmóforos foram encontrados em ambas as flores; o estigma mostrou-se receptivo no período entre 12 e 14 h. Os insetos da ordem diptera foram os visitantes mais freqüentes nas flores estaminadas e pistiladas e as espécies Copestylum sp. e Erystalys sp., as responsáveis pela polinização.Information was obtained on the floral biology of Virola surinamensis (Rol. Warb. (Myristicaceae, a dioecious arboreal species of great importance for the Amazon region economy. The study was carried out in the floodplain area near the Murucutu stream, on the right side of the Guamá River, at the Universidade Federal Rural da Amazônia-UFRA, Belém-Pará , from January to December 2001. Floral biology was assessed from

  19. Adaptor Protein Complex-2 (AP-2) and Epsin-1 Mediate Protease-activated Receptor-1 Internalization via Phosphorylation- and Ubiquitination-dependent Sorting Signals*

    Science.gov (United States)

    Chen, Buxin; Dores, Michael R.; Grimsey, Neil; Canto, Isabel; Barker, Breann L.; Trejo, JoAnn

    2011-01-01

    Signaling by protease-activated receptor-1 (PAR1), a G protein-coupled receptor (GPCR) for thrombin, is regulated by desensitization and internalization. PAR1 desensitization is mediated by β-arrestins, like most classic GPCRs. In contrast, internalization of PAR1 occurs through a clathrin- and dynamin-dependent pathway independent of β-arrestins. PAR1 displays two modes of internalization. Constitutive internalization of unactivated PAR1 is mediated by the clathrin adaptor protein complex-2 (AP-2), where the μ2-adaptin subunit binds directly to a tyrosine-based motif localized within the receptor C-tail domain. However, AP-2 depletion only partially inhibits agonist-induced internalization of PAR1, suggesting a function for other clathrin adaptors in this process. Here, we now report that AP-2 and epsin-1 are both critical mediators of agonist-stimulated PAR1 internalization. We show that ubiquitination of PAR1 and the ubiquitin-interacting motifs of epsin-1 are required for epsin-1-dependent internalization of activated PAR1. In addition, activation of PAR1 promotes epsin-1 de-ubiquitination, which may increase its endocytic adaptor activity to facilitate receptor internalization. AP-2 also regulates activated PAR1 internalization via recognition of distal C-tail phosphorylation sites rather than the canonical tyrosine-based motif. Thus, AP-2 and epsin-1 are both required to promote efficient internalization of activated PAR1 and recognize discrete receptor sorting signals. This study defines a new pathway for internalization of mammalian GPCRs. PMID:21965661

  20. Bioinformatics and expressional analysis of cDNA clones from floral buds

    Science.gov (United States)

    Pawełkowicz, Magdalena Ewa; Skarzyńska, Agnieszka; Cebula, Justyna; Hincha, Dirck; ZiÄ bska, Karolina; PlÄ der, Wojciech; Przybecki, Zbigniew

    2017-08-01

    The application of genomic approaches may serve as an initial step in understanding the complexity of biochemical network and cellular processes responsible for regulation and execution of many developmental tasks. The molecular mechanism of sex expression in cucumber is still not elucidated. A study of differential expression was conducted to identify genes involved in sex determination and floral organ morphogenesis. Herein, we present generation of expression sequence tags (EST) obtained by differential hybridization (DH) and subtraction technique (cDNA-DSC) and their characteristic features such as molecular function, involvement in biology processes, expression and mapping position on the genome.

  1. A spatial dissection of the Arabidopsis floral transcriptome by MPSS

    Directory of Open Access Journals (Sweden)

    Sanchez-Leon Nidia

    2008-04-01

    Full Text Available Abstract Background We have further characterized floral organ-localized gene expression in the inflorescence of Arabidopsis thaliana by comparison of massively parallel signature sequencing (MPSS data. Six libraries of RNA sequence tags from immature inflorescence tissues were constructed and matched to their respective loci in the annotated Arabidopsis genome. These signature libraries survey the floral transcriptome of wild-type tissue as well as the floral homeotic mutants, apetala1, apetala3, agamous, a superman/apetala1 double mutant, and differentiated ovules dissected from the gynoecia of wild-type inflorescences. Comparing and contrasting these MPSS floral expression libraries enabled demarcation of transcripts enriched in the petals, stamens, stigma-style, gynoecia, and those with predicted enrichment within the sepal/sepal-petals, petal-stamens, or gynoecia-stamens. Results By comparison of expression libraries, a total of 572 genes were found to have organ-enriched expression within the inflorescence. The bulk of characterized organ-enriched transcript diversity was noted in the gynoecia and stamens, whereas fewer genes demonstrated sepal or petal-localized expression. Validation of the computational analyses was performed by comparison with previously published expression data, in situ hybridizations, promoter-reporter fusions, and reverse transcription PCR. A number of well-characterized genes were accurately delineated within our system of transcript filtration. Moreover, empirical validations confirm MPSS predictions for several genes with previously uncharacterized expression patterns. Conclusion This extensive MPSS analysis confirms and supplements prior microarray floral expression studies and illustrates the utility of sequence survey-based expression analysis in functional genomics. Spatial floral expression data accrued by MPSS and similar methods will be advantageous in the elucidation of more comprehensive genetic

  2. A spatial dissection of the Arabidopsis floral transcriptome by MPSS.

    Science.gov (United States)

    Peiffer, Jason A; Kaushik, Shail; Sakai, Hajime; Arteaga-Vazquez, Mario; Sanchez-Leon, Nidia; Ghazal, Hassan; Vielle-Calzada, Jean-Philippe; Meyers, Blake C

    2008-04-21

    We have further characterized floral organ-localized gene expression in the inflorescence of Arabidopsis thaliana by comparison of massively parallel signature sequencing (MPSS) data. Six libraries of RNA sequence tags from immature inflorescence tissues were constructed and matched to their respective loci in the annotated Arabidopsis genome. These signature libraries survey the floral transcriptome of wild-type tissue as well as the floral homeotic mutants, apetala1, apetala3, agamous, a superman/apetala1 double mutant, and differentiated ovules dissected from the gynoecia of wild-type inflorescences. Comparing and contrasting these MPSS floral expression libraries enabled demarcation of transcripts enriched in the petals, stamens, stigma-style, gynoecia, and those with predicted enrichment within the sepal/sepal-petals, petal-stamens, or gynoecia-stamens. By comparison of expression libraries, a total of 572 genes were found to have organ-enriched expression within the inflorescence. The bulk of characterized organ-enriched transcript diversity was noted in the gynoecia and stamens, whereas fewer genes demonstrated sepal or petal-localized expression. Validation of the computational analyses was performed by comparison with previously published expression data, in situ hybridizations, promoter-reporter fusions, and reverse transcription PCR. A number of well-characterized genes were accurately delineated within our system of transcript filtration. Moreover, empirical validations confirm MPSS predictions for several genes with previously uncharacterized expression patterns. This extensive MPSS analysis confirms and supplements prior microarray floral expression studies and illustrates the utility of sequence survey-based expression analysis in functional genomics. Spatial floral expression data accrued by MPSS and similar methods will be advantageous in the elucidation of more comprehensive genetic regulatory networks governing floral development.

  3. SCIMP, a transmembrane adaptor protein involved in major histocompatibility complex class II signaling

    Czech Academy of Sciences Publication Activity Database

    Dráber, Peter; Vonková, Ivana; Štěpánek, Ondřej; Hrdinka, Matouš; Kucová, Markéta; Skopcová, Tereza; Otáhal, Pavel; Angelisová, Pavla; Hořejší, Václav; Yeung, M.; Weiss, A.; Brdička, Tomáš

    2011-01-01

    Roč. 31, č. 22 (2011), s. 4550-4562 ISSN 0270-7306 R&D Projects: GA MŠk 1M0506; GA ČR GEMEM/09/E011 Institutional research plan: CEZ:AV0Z50520514 Keywords : SCIMP * transmembrane adaptor protein * MHC II Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.527, year: 2011

  4. NTAL (non-T cell activation linker):a transmembrane adaptor protein involved in immunoreceptor signaling

    Czech Academy of Sciences Publication Activity Database

    Brdička, Tomáš; Imrich, Martin; Angelisová, Pavla; Brdičková, Naděžda; Horváth, Ondřej; Špička, Jiří; Hilgert, Ivan; Lusková, Petra; Dráber, Petr; Novák, P.; Engels, N.; Wienands, J.; Simeoni, L.; Osterreicher, J.; Aguado, E.; Malissen, M.; Schraven, B.; Hořejší, Václav

    2002-01-01

    Roč. 196, č. 12 (2002), s. 16180-16185 ISSN 0022-1007 R&D Projects: GA MŠk LN00A026 Keywords : NTAL * transmembrane adaptor * immunoreceptor signaling Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 15.838, year: 2002

  5. Deletion of the LIME adaptor protein minimally affects T and B cell development and function

    Czech Academy of Sciences Publication Activity Database

    Grégoire, C.; Šímová, Šárka; Wang, Y.; Sansoni, A.; Richelme, S.; Schmidr-Giese, A.; Simeoni, L.; Angelisová, Pavla; Reinhold, D.; Burkhart, S.; Hořejší, Václav; Malissen, B.; Malissen, M.

    2007-01-01

    Roč. 37, č. 11 (2007), s. 3259-3269 ISSN 0014-2980 R&D Projects: GA MŠk 1M0506 Institutional research plan: CEZ:AV0Z50520514 Keywords : LIME * adaptor protein * receptor Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.662, year: 2007

  6. MEMORIA Y APRENDIZAJE EN LA ESCOGENCIA FLORAL DE LAS ABEJAS

    Directory of Open Access Journals (Sweden)

    MARISOL AMAYA

    2009-05-01

    Full Text Available RESUMEN Los polinizadores altamente especializados en su dieta, no hacen escogencias florales, ellos visitan un recurso específico siguiendo el dictado de la información almacenada en sus genes. En contraste, para la abeja social Apis mellifera una escogencia floral implica, la toma de una decisión, usualmente con criterio económico, basada en información aprendida y almacenada en alguna forma de memoria. Aunque existen numerosos estudios y modelos sobre la escogencia floral en abejas, la gran mayoría de éstos, han derivado sus conclusiones a partir de condiciones temporalmente fijas de la interacción. Muy pocos estudios han abordado la dinámica propia del contexto ecológico, en el cual el mercado floral de las abejas cambia con las estaciones del año y con los patrones diarios de antesis floral. Este cambio en la disponibilidad de especies florales enfrenta a los polinizadores, a realizar escogencias secuenciales acerca del alimento a explotar. En este trabajo abordo el tema del forrajeo secuencial en parches florales heterospecíficos, enfocándome en el uso que la abeja melífera hace de la información previamente aprendida en un contexto, cuando se enfrenta a la explotación de alimento en un contexto ecológicamente diferente. He realizado experimentos sobre escogencia floral simulando las condiciones de cambio del paisaje floral, exponiendo abejas individuales de A. mellifera a decidir sobre cuales especies forrajear en cada parche. Los resultados indican que la abeja invierte en procesos de aprendizaje en un muestreo inicial, pero una vez almacenada la información, utiliza una pieza de la información previamente aprendida (color para explotar parches florales heteroespecíficos siguiendo una imagen de búsqueda de color. En esta revisión discuto situaciones biológicas de la interacción planta-abeja, las cuales apoyan la idea que en la naturaleza el uso de imágenes de búsqueda de color por parte de abejas sociales puede

  7. Geraniales flowers revisited: evolutionary trends in floral nectaries.

    Science.gov (United States)

    Jeiter, Julius; Weigend, Maximilian; Hilger, Hartmut H

    2017-02-01

    The detailed relationships in Geraniales in their current circumscription have only recently been clarified. The disparate floral morphologies and especially the nectaries of the corresponding group have consequently not previously been studied in a phylogenetic context. The present study investigates floral and especially nectary morphology and structure for representatives of 12 of the 13 currently accepted genera in the five families of the Geraniales. Flowers were studied using light microscopy and scanning electron microscopy. The data demonstrate the derivation of even the most disparate floral morphologies from a basic pentamerous and pentacyclic organization, with an obdiplostemonous androecium and receptacular nectaries associated with the antesepalous stamens. Divergent morphologies are explained by modifications of merosity (tetramerous flowers), symmetry (several transitions to zygomorphic flowers) and elaboration of the nectaries into variously shaped outgrowths and appendages, especially in Francoaceae. The divergent development of nectar glands ultimately leads to either a reduction in their number (to one in some Geraniaceae and Melianthaceae) or their total loss (some Vivianiaceae). Floral morphology of the Geraniales shows a high degree of similarity, despite the variation in overall floral appearance and nectary morphology. A hypothesis on the transformation of the nectaries within the Geraniales is presented. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Floral visitors of Ananas comosus in Ghana: A preliminary assessment

    Directory of Open Access Journals (Sweden)

    Peter Kwapong

    2010-11-01

    Full Text Available Ananas comosus var comosus (L. Merr. is the third most important tropical fruit in the world production and the leading foreign exchange earner among fresh fruits exported from Ghana. A survey was conducted in pineapple farms in the Central region of Ghana to identify floral visitors and their activities on the flowers. Nectar concentration and energetics and effect of floral visitors on fruit production were determined. Fourteen species of butterflies and one ant species were the main insect floral visitors as well as four species of sunbirds. The mean nectar concentration was 23.3% (± 0.39, SE and pollination limitation did not significantly affect fruit yield (weight: p = 0.285; length: p = 0.056; width: p= 0.268. The study showed that butterflies, ants and sunbirds are the main floral visitors on A. comosus. However their visits did not results in pollination and fruit production was not affected in any way by floral visitation. Still, it was found that A. comosus provides an important nectar resource for its foragers. Even if pollination is not crucial in pineapple cultivation, it is still essential in pineapple breeding programs to promote genetic diversity and conservation.

  9. Composition of the Floral Essential Oil of Brugmansia suaveolens

    Directory of Open Access Journals (Sweden)

    William N. Setzer

    2009-03-01

    Full Text Available The floral essential oils of Brugmansia suaveolens, from Monteverde, Costa Rica, were collected atthree different times of the day by hydrodistillation and the oils analyzed by gas chromatography-massspectrometry (GC-MS. The floral essential oil showed a dramatic change in composition between the freshlyopened night (white blossoms and the rose-colored senescent blossoms the following day. The white blossomswere dominated by 1,8-cineole (72.1%, (E-nerolidol (11.7%, a-terpineol (5.3%, and phenethyl alcohol(3.2%, notably different from headspace analyses of B. suaveolens reported previously. The floral essential oilfrom “rose-colored” senescent blossoms of B. suaveolens showed dramatic decreases in 1,8-cineole (2.0%, (E-nerolidol (1.9%, and phenethyl alcohol (not detected, with concomitant increases in heptanal (10.2%, nonanal(17.4%, terpinen-4-ol (10.5%, and megastigmatrienones (35.5%.

  10. Non-volatile floral oils of Diascia spp. (Scrophulariaceae).

    Science.gov (United States)

    Dumri, Kanchana; Seipold, Lars; Schmidt, Jürgen; Gerlach, Günter; Dötterl, Stefan; Ellis, Allan G; Wessjohann, Ludger A

    2008-04-01

    The floral oils of Diascia purpurea, Diascia vigilis, Diascia cordata, Diascia megathura, Diascia integerrima and Diascia barberae (Scrophulariaceae) were selectively collected from trichome elaiophores. The derivatized floral oils were analyzed by gas chromatography-mass spectrometry (GC-MS), whilst the underivatized samples were analysed by electrospray ionization mass spectrometry (ESI-MS) and Fourier-transform ion cyclotron resonance mass spectrometry (FTICR-MS). The most common constituents of the floral oils investigated are partially acetylated acylglycerols of (3R)-acetoxy fatty acids (C(14), C(16), and C(18)), as was proven with non-racemic synthetic reference samples. The importance of these oils for Rediviva bees is discussed in a co-evolutionary context.

  11. A soybean MADS-box protein modulates floral organ numbers, petal identity and sterility.

    Science.gov (United States)

    Huang, Fang; Xu, Guangli; Chi, Yingjun; Liu, Haicui; Xue, Qian; Zhao, Tuanjie; Gai, Junyi; Yu, Deyue

    2014-04-02

    The MADS-box transcription factors play fundamental roles in reproductive developmental control. Although the roles of many plant MADS-box proteins have been extensively studied, there are almost no functional studies of them in soybean, an important protein and oil crop in the world. In addition, the MADS-box protein orthologs may have species-specific functions. Controlling male fertility is an important goal in plant hybrid breeding but is difficult in some crops like soybean. The morphological structure of soybean flowers prevents the cross-pollination. Understanding the molecular mechanisms for floral development will aid in engineering new sterile materials that could be applied in hybrid breeding programs in soybean. Through microarray analysis, a flower-enriched gene in soybean was selected and designated as GmMADS28. GmMADS28 belongs to AGL9/SEP subfamily of MADS-box proteins, localized in nucleus and showed specific expression patterns in floral meristems as well as stamen and petal primordia. Expression of GmMADS28 in the stamens and petals of a soybean mutant NJS-10Hfs whose stamens are converted into petals was higher than in those of wild-type plants. Constitutive expression of GmMADS28 in tobacco promoted early flowering and converted stamens and sepals to petals. Interestingly, transgenic plants increased the numbers of sepal, petal and stamen from five to six and exhibited male sterility due to the shortened and curly filaments and the failure of pollen release from the anthers. The ectopic expression of GmMADS28 was found to be sufficient to activate expression of tobacco homologs of SOC1, LEAFY, AGL8/FUL, and DEF. In addition, we observed the interactions of GmMADS28 with soybean homologs of SOC1, AP1, and AGL8/FUL proteins. In this study, we observed the roles of GmMADS28 in the regulation of floral organ number and petal identity. Compared to other plant AGL9/SEP proteins, GmMADS28 specifically regulates floral organ number, filament length and

  12. Variations on a theme: changes in the floral ABCs in angiosperms.

    NARCIS (Netherlands)

    Rijpkema, A.S.; Vandenbussche, M.; Koes, R.E.; Heijmans, K.; Gerats, T.

    2009-01-01

    Angiosperms display a huge variety of floral forms. The development of the ABC-model for floral organ identity, almost 20 years ago, has created an excellent basis for comparative floral development (evo-devo) studies. These have resulted in an increasingly more detailed understanding of the

  13. Variations on a theme: changes in the floral ABCs in angiosperms.

    NARCIS (Netherlands)

    Rijpkema, A.S.; Vandenbussche, M.; Koes, R.E.; Heijmans, K.; Gerats, T.

    2010-01-01

    Angiosperms display a huge variety of floral forms. The development of the ABC-model for floral organ identity, almost 20 years ago, has created an excellent basis for comparative floral development (evo-devo) studies. These have resulted in an increasingly more detailed understanding of the

  14. Expression of ethylene biosynthetic and receptor genes in rose floral tissues during ethylene-enhanced flower opening.

    Science.gov (United States)

    Xue, Jingqi; Li, Yunhui; Tan, Hui; Yang, Feng; Ma, Nan; Gao, Junping

    2008-01-01

    Ethylene production, as well as the expression of ethylene biosynthetic (Rh-ACS1-4 and Rh-ACO1) and receptor (Rh-ETR1-5) genes, was determined in five different floral tissues (sepals, petals, stamens, gynoecia, and receptacles) of cut rose (Rosa hybrida cv. Samantha upon treatment with ethylene or the ethylene inhibitor 1-methylcyclopropene (1-MCP). Ethylene-enhanced ethylene production occurred only in gynoecia, petals, and receptacles, with gynoecia showing the greatest enhancement in the early stage of ethylene treatment. However, 1-MCP did not suppress ethylene production in these three tissues. In sepals, ethylene production was highly decreased by ethylene treatment, and increased dramatically by 1-MCP. Ethylene production in stamens remained unchanged after ethylene or 1-MCP treatment. Induction of certain ethylene biosynthetic genes by ethylene in different floral tissues was positively correlated with the ethylene production, and this induction was also not suppressed by 1-MCP. The expression of Rh-ACS2 and Rh-ACS3 was quickly induced by ethylene in gynoecia, but neither Rh-ACS1 nor Rh-ACS4 was induced by ethylene in any of the five tissues. In addition, Rh-ACO1 was induced by ethylene in all floral tissues except sepals. The induced expression of ethylene receptor genes by ethylene was much faster in gynoecia than in petals, and the expression of Rh-ETR3 was strongly suppressed by 1-MCP in all floral tissues. These results indicate that ethylene biosynthesis in gynoecia is regulated developmentally, rather than autocatalytically. The response of rose flowers to ethylene occurs initially in gynoecia, and ethylene may regulate flower opening mainly through the Rh-ETR3 gene in gynoecia.

  15. Role of the epithelial cell-specific clathrin adaptor complex AP-1B in cell polarity

    Science.gov (United States)

    Fölsch, Heike

    2015-01-01

    Epithelial cells are important for organ development and function. To this end, they polarize their plasma membrane into biochemically and physically distinct membrane domains. The apical membrane faces the luminal site of an organ and the basolateral domain is in contact with the basement membrane and neighboring cells. To establish and maintain this polarity it is important that newly synthesized and endocytic cargos are correctly sorted according to their final destinations at either membrane. Sorting takes place at one of 2 major sorting stations in the cells, the trans-Golgi network (TGN) and recycling endosomes (REs). Polarized sorting may involve epithelial cell-specific sorting adaptors like the AP-1B clathrin adaptor complex. AP-1B facilitates basolateral sorting from REs. This review will discuss various aspects of basolateral sorting in epithelial cells with a special emphasis on AP-1B. PMID:27057418

  16. Enhanced Toll-like receptor responses in the absence of signaling adaptor DAP12.

    OpenAIRE

    Hamerman, Jessica A; Tchao, Nadia K; Lowell, Clifford A; Lanier, Lewis L

    2005-01-01

    DAP12 is a signaling adaptor containing an immunoreceptor tyrosine-based activation motif (ITAM) that pairs with receptors on myeloid cells and natural killer cells. We examine here the responses of mice lacking DAP12 to stimulation through Toll-like receptors (TLRs). Unexpectedly, DAP12-deficient macrophages produced higher concentrations of inflammatory cytokines in response to a variety of pathogenic stimuli. Additionally, macrophages deficient in spleen tyrosine kinase (Syk), which signal...

  17. Floral closure induced by pollination in gynodioecious Cyananthus delavayi (Campanulaceae): effects of pollen load and type, floral morph and fitness consequences.

    Science.gov (United States)

    Niu, Yang; Yang, Yang; Zhang, Zhi-Qiang; Li, Zhi-Min; Sun, Hang

    2011-11-01

    Pollination-induced floral changes, which have been widely documented in flowering plants, have been assumed to enhance the plant's reproductive success. However, our understanding of the causes and consequences of these changes is still limited. Using an alpine gynodioecious species, Cyananthus delavayi, we investigated the factors affecting floral closure and estimated the fitness consequences of floral closure. The timings of floral closure and fertilization were determined. The effects of pollen load, pollen type (cross- or self-pollen) and floral morph (female or perfect flower) on the occurrence of floral closure were examined. Ovule fertilization and seed production were examined to investigate the causes and consequences of floral closure. Flowers were manipulated to prevent closing to detect potential benefits for female fitness. Floral closure, which could be induced by a very low pollen load, occurred within 4-7 h after pollination, immediately following fertilization. The proportion of closed flowers was influenced by pollen load and floral morph, but not by pollen type. Floral closure was more likely to occur in flowers with a higher proportion of fertilized ovules, but there was no significant difference in seed production between closed and open flowers. Those flowers in which closure was induced by natural pollination had low fruit set and seed production. Additionally, seed production was not influenced by closing-prevented manipulation when sufficient pollen deposition was received. The occurrence of floral closure may be determined by the proportion of fertilized ovules, but this response can be too sensitive to ensure sufficient pollen deposition and can, to some extent, lead to a cost in female fitness. These results implied that the control of floral receptivity by the recipient flowers does not lead to an optimal fitness gain in C. delavayi.

  18. New Insights to Clathrin and Adaptor Protein 2 for the Design and Development of Therapeutic Strategies

    Directory of Open Access Journals (Sweden)

    Ebbe Toftgaard Poulsen

    2015-12-01

    Full Text Available The Amyloid Precursor Protein (APP has been extensively studied for its role as the precursor of the β-amyloid protein (Aβ in Alzheimer’s disease (AD. However, our understanding of the normal function of APP is still patchy. Emerging evidence indicates that a dysfunction in APP trafficking and degradation can be responsible for neuronal deficits and progressive degeneration in humans. We recently reported that the Y682 mutation in the 682YENPTY687 domain of APP affects its binding to specific adaptor proteins and leads to its anomalous trafficking, to defects in the autophagy machinery and to neuronal degeneration. In order to identify adaptors that influence APP function, we performed pull-down experiments followed by quantitative mass spectrometry (MS on hippocampal tissue extracts of three month-old mice incubated with either the 682YENPTY687 peptide, its mutated form, 682GENPTY687 or its phosphorylated form, 682pYENPTY687. Our experiments resulted in the identification of two proteins involved in APP internalization and trafficking: Clathrin heavy chain (hc and its Adaptor Protein 2 (AP-2. Overall our results consolidate and refine the importance of Y682 in APP normal functions from an animal model of premature aging and dementia. Additionally, they open the perspective to consider Clathrin hc and AP-2 as potential targets for the design and development of new therapeutic strategies.

  19. Multiple regulatory roles of the mouse transmembrane adaptor protein NTAL in gene transcription and mast cell physiology.

    Directory of Open Access Journals (Sweden)

    Iva Polakovicova

    Full Text Available Non-T cell activation linker (NTAL; also called LAB or LAT2 is a transmembrane adaptor protein that is expressed in a subset of hematopoietic cells, including mast cells. There are conflicting reports on the role of NTAL in the high affinity immunoglobulin E receptor (FcεRI signaling. Studies carried out on mast cells derived from mice with NTAL knock out (KO and wild type mice suggested that NTAL is a negative regulator of FcεRI signaling, while experiments with RNAi-mediated NTAL knockdown (KD in human mast cells and rat basophilic leukemia cells suggested its positive regulatory role. To determine whether different methodologies of NTAL ablation (KO vs KD have different physiological consequences, we compared under well defined conditions FcεRI-mediated signaling events in mouse bone marrow-derived mast cells (BMMCs with NTAL KO or KD. BMMCs with both NTAL KO and KD exhibited enhanced degranulation, calcium mobilization, chemotaxis, tyrosine phosphorylation of LAT and ERK, and depolymerization of filamentous actin. These data provide clear evidence that NTAL is a negative regulator of FcεRI activation events in murine BMMCs, independently of possible compensatory developmental alterations. To gain further insight into the role of NTAL in mast cells, we examined the transcriptome profiles of resting and antigen-activated NTAL KO, NTAL KD, and corresponding control BMMCs. Through this analysis we identified several genes that were differentially regulated in nonactivated and antigen-activated NTAL-deficient cells, when compared to the corresponding control cells. Some of the genes seem to be involved in regulation of cholesterol-dependent events in antigen-mediated chemotaxis. The combined data indicate multiple regulatory roles of NTAL in gene expression and mast cell physiology.

  20. Effect of floral display on reproductive success in terrestrial orchids

    Czech Academy of Sciences Publication Activity Database

    Kindlmann, Pavel; Jersáková, Jana

    2006-01-01

    Roč. 41, - (2006), s. 47-60 ISSN 0015-5551 R&D Projects: GA AV ČR(CZ) KJB6141302; GA ČR(CZ) GA206/00/1124 Keywords : deceptivity * floral display * orchid * reproductive success * reward Subject RIV: EF - Botanics Impact factor: 1.033, year: 2005

  1. Floral syndrome and breeding system of Senna (Cassia) corymbosa

    African Journals Online (AJOL)

    微软用户

    2011-06-08

    Jun 8, 2011 ... Senna (Cassia) corymbosa is an ornamental plant with asymmetric flower in which petals and stamens are also involved in floral asymmetry. The pollen number of abaxial lateral stamen (AL), abaxial median stamen (AM) and middle stamen (MI) are descended in sequence. In field, the insects of visiting ...

  2. Research on floral timing by ambient temperature comes into blossom

    NARCIS (Netherlands)

    Verhage, D.S.L.; Angenent, G.C.; Immink, R.G.H.

    2014-01-01

    The floral transition is an essential process in the life cycle of flower-bearing plants, because their reproductive success depends on it. To determine the right moment of flowering, plants respond to many environmental signals, including day length, light quality, and temperature. Small changes in

  3. Genomic Approach to Study Floral Development Genes in Rosa sp.

    Science.gov (United States)

    Chauvet, Aurélie; Maene, Marion; Pécrix, Yann; Yang, Shu-Hua; Jeauffre, Julien; Thouroude, Tatiana; Boltz, Véronique; Martin-Magniette, Marie-Laure; Janczarski, Stéphane; Legeai, Fabrice; Renou, Jean-Pierre; Vergne, Philippe; Le Bris, Manuel; Foucher, Fabrice; Bendahmane, Mohammed

    2011-01-01

    Cultivated for centuries, the varieties of rose have been selected based on a number of flower traits. Understanding the genetic and molecular basis that contributes to these traits will impact on future improvements for this economically important ornamental plant. In this study, we used scanning electron microscopy and sections of meristems and flowers to establish a precise morphological calendar from early rose flower development stages to senescing flowers. Global gene expression was investigated from floral meristem initiation up to flower senescence in three rose genotypes exhibiting contrasted floral traits including continuous versus once flowering and simple versus double flower architecture, using a newly developed Affymetrix microarray (Rosa1_Affyarray) tool containing sequences representing 4765 unigenes expressed during flower development. Data analyses permitted the identification of genes associated with floral transition, floral organs initiation up to flower senescence. Quantitative real time PCR analyses validated the mRNA accumulation changes observed in microarray hybridizations for a selection of 24 genes expressed at either high or low levels. Our data describe the early flower development stages in Rosa sp, the production of a rose microarray and demonstrate its usefulness and reliability to study gene expression during extensive development phases, from the vegetative meristem to the senescent flower. PMID:22194838

  4. Effects of soil moisture stress on floral and pods abortion ...

    African Journals Online (AJOL)

    Experiments were conducted at Ilorin, Nigeria to evaluate the effects of soil moisture stress at different growth stages (vegetative, flowering and pod filling) on floral and pods abortion, reproductive efficiency and grain yields of ten soybean genotypes (TGX 923-2E, TGX 1440-1E, Samsoy- 2, TGX 536 02D, TGX 1019-2E, TGX ...

  5. 36 CFR 12.10 - Floral and commemorative tributes.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Floral and commemorative tributes. 12.10 Section 12.10 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE... of fresh cut or artificial flowers in or on a metal or other non-breakable rod or container...

  6. Aspects of the floral and fruit biology of Allanblackia stuhlmannii ...

    African Journals Online (AJOL)

    Fruit crop was strongly rela ted to tree size, with mean seed number per fruit being 38. Seed quantity per fruit showed a trend to increase with fruit mass, but this relationship was not significant. General physical resemblance of female flowers to male flowers, the latter of which offer multiple floral cues to attract pollinators, ...

  7. Drought and leaf herbivory influence floral volatiles and pollinator attraction

    Science.gov (United States)

    Laura A. Burkle; Justin B. Runyon

    2016-01-01

    The effects of climate change on species interactions are poorly understood. Investigating the mechanisms by which species interactions may shift under altered environmental conditions will help form a more predictive understanding of such shifts. In particular, components of climate change have the potential to strongly influence floral volatile organic...

  8. Pollen diversity, viability and floral structure of some Musa genotypes

    African Journals Online (AJOL)

    This experiment was designed to study the floral structure, pollen morphology and the potential pollen viability of five Musa genotypes obtained from the Musa field germplasm bank at the Faculty of Agriculture & Natural Resources Management farm, Ebonyi State University, Abakaliki. Palynological investigation was carried ...

  9. The co-optimization of floral display and nectar reward

    Indian Academy of Sciences (India)

    Prakash

    2009-12-10

    Dec 10, 2009 ... selective force in the evolution of nectarless flowers. Previous models as well as empirical studies have addressed the problem of optimizing the proportion of nectarless and nectarful flowers. However, there has been no attempt to optimize the investment in nectar production along with that in floral display.

  10. Chemical profiles of honeys originating from different floral sources ...

    African Journals Online (AJOL)

    Chemical profiles of honeys originating from different floral sources and geographic locations examined by a combination of three extraction and analysis techniques. ... The chemical profiles of Tasmanian Leatherwood and Manuka honeys from Tasmania and New Zealand have been compared by a combination of GC-MS ...

  11. Related allopolyploids display distinct floral pigment profiles and transgressive pigments.

    Science.gov (United States)

    McCarthy, Elizabeth W; Berardi, Andrea E; Smith, Stacey D; Litt, Amy

    2017-01-01

    Both polyploidy and shifts in floral color have marked angiosperm evolution. Here, we investigate the biochemical basis of the novel and diverse floral phenotypes seen in allopolyploids in Nicotiana (Solanaceae) and examine the extent to which the merging of distinct genomes alters flavonoid pigment production. We analyzed flavonol and anthocyanin pigments from Nicotiana allopolyploids of different ages (N. tabacum, 0.2 million years old; several species from Nicotiana section Repandae, 4.5 million years old; and five lines of first-generation synthetic N. tabacum) as well as their diploid progenitors. Allopolyploid floral pigment profiles tend not to overlap with their progenitors or related allopolyploids, and allopolyploids produce transgressive pigments that are not present in either progenitor. Differences in floral color among N. tabacum accessions seems mainly to be due to variation in cyanidin concentration, but changes in flavonol concentrations among accessions are also present. Competition for substrates within the flavonoid biosynthetic pathway to make either flavonols or anthocyanins may drive the differences seen among related allopolyploids. Some of the pigment differences observed in allopolyploids may be associated with making flowers more visible to nocturnal pollinators. © 2017 Botanical Society of America.

  12. Differential expressions of putative genes in various floral organs of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... Full Length Research Paper. Differential expressions of putative genes in various floral organs of the Pigeon orchid (Dendrobium crumenatum) using GeneFishing. Faridah, Q. Z.1, 2, Ng, B. Z.3, Raha, A. R.4, Umi, K. A. B.5 and Khosravi, A. R.2*. 1Department of Biology, Faculty Science, University Putra ...

  13. Floral morphology of the Polystachya Hook. (Orchidaceae) in Nigeria.

    African Journals Online (AJOL)

    A study of the floral morphology of the 32 Polystachya Hook. species in Nigeria, all occurring in the wild, was undertaken in search of simple, non-technical characters for their identification. The study has revealed that each lip is distinctive and can be recognized on the basis of their macroscopical and microscopical ...

  14. Cytological behaviour of floral organs and in silico characterization ...

    Indian Academy of Sciences (India)

    1Biotechnology Centre, 2Nagarjuna Medicinal Garden, 4Department of Agricultural Botany, and 5Department of Plant. Pathology, Post ... Abstract. An attempt was made to understand the 'floral bud distortion' (FBD), an unexplored disorder prevailing in soybean. Cyto- .... USA) image processing software. Amplicons derived ...

  15. Kyllinga mbitheana (Cyperaceae)—description, floral ontogeny and ...

    African Journals Online (AJOL)

    The spikelet has an indeterminate rachilla with distichously arranged glumes, and the floral ontogenetic pattern is similar to that of other Cyperoideae. The diagnostic laterally compressed nutlets can be observed in the ontogenetic phase, where the dorsiventrally orientated stigma primordia give rise to a laterally flattened ...

  16. Flavonoids patterns of French honeys with different floral origin

    NARCIS (Netherlands)

    Soler, C.; Gil, M.I.; Garcia-Viguera, C.; Tomás-Barberán, F.A.

    1995-01-01

    The flavonoid profiles of 12 different unifloral French honey samples were analysed by HPLC to evaluate if these substances could be used as markers of the floral origin of honey. In this analysis, the characteristic flavonoids from propolis and/or beeswax (chrysin, galangin, tectochrysin,

  17. Lilium longiflorum and molecular floral development: the ABCDE model

    NARCIS (Netherlands)

    Benedito, V.A.; Angenent, G.C.; Tuyl, van J.M.; Krens, F.A.

    2004-01-01

    Because lily (Lilium longiflorum Thunb.) is an important cut-flower crop, molecular characterisation of genes that are involved in flower morphology could help breeders to develop novel floral architectures in this species. The early ABC model for flower development emerged more than 10 years ago

  18. Bias in ligation-based small RNA sequencing library construction is determined by adaptor and RNA structure.

    Directory of Open Access Journals (Sweden)

    Ryan T Fuchs

    Full Text Available High-throughput sequencing (HTS has become a powerful tool for the detection of and sequence characterization of microRNAs (miRNA and other small RNAs (sRNA. Unfortunately, the use of HTS data to determine the relative quantity of different miRNAs in a sample has been shown to be inconsistent with quantitative PCR and Northern Blot results. Several recent studies have concluded that the major contributor to this inconsistency is bias introduced during the construction of sRNA libraries for HTS and that the bias is primarily derived from the adaptor ligation steps, specifically where single stranded adaptors are sequentially ligated to the 3' and 5'-end of sRNAs using T4 RNA ligases. In this study we investigated the effects of ligation bias by using a pool of randomized ligation substrates, defined mixtures of miRNA sequences and several combinations of adaptors in HTS library construction. We show that like the 3' adaptor ligation step, the 5' adaptor ligation is also biased, not because of primary sequence, but instead due to secondary structures of the two ligation substrates. We find that multiple secondary structural factors influence final representation in HTS results. Our results provide insight about the nature of ligation bias and allowed us to design adaptors that reduce ligation bias and produce HTS results that more accurately reflect the actual concentrations of miRNAs in the defined starting material.

  19. Polimorfismo floral em Valeriana scandens L. (Valerianaceae Floral polymorphism in Valeriana scandens L. (Valerianaceae

    Directory of Open Access Journals (Sweden)

    Erica Duarte-Silva

    2010-09-01

    Full Text Available Foram encontrados três morfos florais em Valeriana scandens L.: flor perfeita, flor pistilada 1 e flor pistilada 2. A perfeita possui corola maior que a dos demais morfos, com lobos reflexos na antese, giba proeminente e localizada na porção proximal do tubo floral; anteras maiores que as dos demais morfos, com pólen viável; estilete curto e estigma incluso, o menor ovário e saco embrionário estruturalmente normal, semelhante ao dos demais morfos. A pistilada 1 possui a giba menos proeminente, corola de tamanho intermediário em relação aos demais morfos, lobos radiais na antese; anteras pequenas, sem pólen e estilete longo e estigma exserto. A pistilada 2 possui lobos radiais na antese, anteras de comprimento semelhante às da perfeita, mas de menor largura, com pólen inviável; estilete mais curto, tal como o da flor perfeita, e estigma exserto, tal como o da flor pistilada 1. Nos três morfos, o nectário é formado por tricomas secretores unicelulares situados na epiderme da face interna da giba, e suas sementes são viáveis. As flores pistilada 2 e perfeita apresentam um septo que isola a giba do restante do tubo floral, formando uma câmara nectarífera. V. scandens L. é ginomonóica-ginodióica, expressão sexual inédita em Valerianaceae.Three floral morphs were found in Valeriana scandens L.: perfect, pistillate 1, and pistillate 2. In perfect flowers, the corolla is longer than in the other morphs, with reflexed lobes at anthesis and a prominent gibbus at the tube base; anthers are longer and contain viable pollen grains; the pistil has a short included style/stigma and the smallest ovary, but a structurally normal embryo sac similar to that of the other morphs. In pistillate 1 flowers, the corolla is intermediate in size, and has radially displayed lobes at anthesis, and a softly prominent gibbus; anthers are small and devoid of pollen; the pistil shows a long exerted style/stigma. In pistillate 2 flowers, the corolla

  20. Characterizing Floral Symmetry in the Core Goodeniaceae with Geometric Morphometrics.

    Science.gov (United States)

    Gardner, Andrew G; Fitz Gerald, Jonathan N; Menz, John; Shepherd, Kelly A; Howarth, Dianella G; Jabaily, Rachel S

    2016-01-01

    Core Goodeniaceae is a clade of ~330 species primarily distributed in Australia. Considerable variation in flower morphology exists within this group and we aim to use geometric morphometrics to characterize this variation across the two major subclades: Scaevola sensu lato (s.l.) and Goodenia s.l., the latter of which was hypothesized to exhibit greater variability in floral symmetry form. We test the hypothesis that floral morphological variation can be adequately characterized by our morphometric approach, and that discrete groups of floral symmetry morphologies exist, which broadly correlate with subjectively determined groups. From 335 images of 44 species in the Core Goodeniaceae, two principal components were computed that describe >98% of variation in all datasets. Increasing values of PC1 ventralize the dorsal petals (increasing the angle between them), whereas increasing values of PC2 primarily ventralize the lateral petals (decreasing the angle between them). Manipulation of these two morphological "axes" alone was sufficient to recreate any of the general floral symmetry patterns in the Core Goodeniaceae. Goodenia s.l. exhibits greater variance than Scaevola s.l. in PC1 and PC2, and has a significantly lower mean value for PC1. Clustering clearly separates fan-flowers (with dorsal petals at least 120° separated) from the others, whereas the distinction between pseudo-radial and bilabiate clusters is less clear and may form a continuum rather than two distinct groups. Transitioning from the average fan-flower to the average non-fan-flower is described almost exclusively by PC1, whereas PC2 partially describes the transition between bilabiate and pseudo-radial morphologies. Our geometric morphometric method accurately models Core Goodeniaceae floral symmetry diversity.

  1. Transcription Factor Interplay between LEAFY and APETALA1/CAULIFLOWER during Floral Initiation.

    Science.gov (United States)

    Goslin, Kevin; Zheng, Beibei; Serrano-Mislata, Antonio; Rae, Liina; Ryan, Patrick T; Kwaśniewska, Kamila; Thomson, Bennett; Ó'Maoiléidigh, Diarmuid S; Madueño, Francisco; Wellmer, Frank; Graciet, Emmanuelle

    2017-06-01

    The transcription factors LEAFY (LFY) and APETALA1 (AP1), together with the AP1 paralog CAULIFLOWER (CAL), control the onset of flower development in a partially redundant manner. This redundancy is thought to be mediated, at least in part, through the regulation of a shared set of target genes. However, whether these genes are independently or cooperatively regulated by LFY and AP1/CAL is currently unknown. To better understand the regulatory relationship between LFY and AP1/CAL and to obtain deeper insights into the control of floral initiation, we monitored the activity of LFY in the absence of AP1/CAL function. We found that the regulation of several known LFY target genes is unaffected by AP1/CAL perturbation, while others appear to require AP1/CAL activity. Furthermore, we obtained evidence that LFY and AP1/CAL control the expression of some genes in an antagonistic manner. Notably, these include key regulators of floral initiation such as TERMINAL FLOWER1 ( TFL1 ), which had been previously reported to be directly repressed by both LFY and AP1. We show here that TFL1 expression is suppressed by AP1 but promoted by LFY. We further demonstrate that LFY has an inhibitory effect on flower formation in the absence of AP1/CAL activity. We propose that LFY and AP1/CAL act as part of an incoherent feed-forward loop, a network motif where two interconnected pathways or transcription factors act in opposite directions on a target gene, to control the establishment of a stable developmental program for the formation of flowers. © 2017 American Society of Plant Biologists. All Rights Reserved.

  2. High Constitutive Overexpression of Glycosyl Hydrolase Family 17 Delays Floral Transition by Enhancing FLC Expression in Transgenic Arabidopsis

    Science.gov (United States)

    Enoki, Shinichi; Fujimori, Nozomi; Yamaguchi, Chiho; Hattori, Tomoki

    2017-01-01

    Vitis vinifera glycosyl hydrolase family 17 (VvGHF17) is a grape apoplasmic β-1,3-glucanase, which belongs to glycosyl hydrolase family 17 in grapevines. β-1,3-glucanase is not only involved in plant defense response but also has various physiological functions in plants. Although VvGHF17 expression is negatively related to the length of inflorescence in grapevines, the physiological functions of VvGHF17 are still uncertain. To clarify the physiological functions of VvGHF17, we conducted a phenotypic analysis of VvGHF17-overexpressing Arabidopsis plants. VvGHF17-overexpressing Arabidopsis plants showed short inflorescence, similar to grapevines. These results suggested that VvGHF17 might negatively regulate the length of inflorescence in plants. VvGHF17 expression induced a delay of floral transition in Arabidopsis plants. The expression level of FLOWERING LOCUS C (FLC), known as a floral repressor gene, in inflorescence meristem of transgenic plants were increased by approximately 10-fold as compared with wild plants. These results suggest that VvGHF17 induces a delay of floral transition by enhancing FLC expression and concomitantly decreases the length of plant inflorescence. PMID:28757594

  3. Suppression of systemic autoimmunity by the innate immune adaptor STING

    Science.gov (United States)

    Sharma, Shruti; Campbell, Allison M.; Chan, Jennie; Schattgen, Stefan A.; Orlowski, Gregory M.; Nayar, Ribhu; Huyler, Annie H.; Nündel, Kerstin; Mohan, Chandra; Berg, Leslie J.; Shlomchik, Mark J.; Marshak-Rothstein, Ann; Fitzgerald, Katherine A.

    2015-01-01

    Cytosolic DNA-sensing pathways that signal via Stimulator of interferon genes (STING) mediate immunity to pathogens and also promote autoimmune pathology in DNaseII- and DNaseIII-deficient mice. In contrast, we report here that STING potently suppresses inflammation in a model of systemic lupus erythematosus (SLE). Lymphoid hypertrophy, autoantibody production, serum cytokine levels, and other indicators of immune activation were markedly increased in STING-deficient autoimmune-prone mice compared with STING-sufficient littermates. As a result, STING-deficient autoimmune-prone mice had significantly shorter lifespans than controls. Importantly, Toll-like receptor (TLR)-dependent systemic inflammation during 2,6,10,14-tetramethylpentadecane (TMPD)-mediated peritonitis was similarly aggravated in STING-deficient mice. Mechanistically, STING-deficient macrophages failed to express negative regulators of immune activation and thus were hyperresponsive to TLR ligands, producing abnormally high levels of proinflammatory cytokines. This hyperreactivity corresponds to dramatically elevated numbers of inflammatory macrophages and granulocytes in vivo. Collectively these findings reveal an unexpected negative regulatory role for STING, having important implications for STING-directed therapies. PMID:25646421

  4. Photoperiod-insensitive floral transition in chrysanthemum induced by constitutive expression of chimeric repressor CsLHY-SRDX.

    Science.gov (United States)

    Oda, Atsushi; Higuchi, Yohei; Hisamatsu, Tamotsu

    2017-06-01

    A wide variety of physiological processes including flowering are controlled by the circadian clock in plants. In Arabidopsis, LATE ELONGATED HYPOCOTYL (LHY) and CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) constitute the central oscillator, and their gain of function and loss of function disrupt the circadian clock and affect flowering time through FLOWERING LOCUS T (FT), a gene encoding a florigen. Chrysanthemum is a typical short-day (SD) plant and responds to shortening of day length by the transition from the vegetative to reproductive phase. We identified FLOWERING LOCUS T-LIKE 3 (FTL3) and ANTI-FLORIGENIC FT/TFL1 FAMILY PROTEIN (AFT) as a florigen and antiflorigen, respectively, in a wild diploid chrysanthemum (Chrysanthemum seticuspe f. boreale). CsFTL3 and CsAFT are induced under SD or a noninductive photoperiod, respectively, and their balance determines the floral transition and anthesis. Meanwhile, the time-keeping mechanism that regulates the photoperiodic flowering in chrysanthemum is poorly understood. Here, we focused on a LHY/CCA1-like gene called CsLHY in chrysanthemum. We fused CsLHY to a gene encoding short transcriptional repressor domain (SRDX) and constitutively expressed it in chrysanthemum. Although the transcription of clock-related genes was conditionally affected, circadian rhythm was not completely disrupted in CsLHY-SRDX transgenic plants. These plants formed almost the same number of leaves before floral transition under SD and long-day conditions. Thus, CsLHY-SRDX chrysanthemum showed photoperiod-insensitive floral transition, but further development of the capitulum was arrested, and anthesis was not observed. Simultaneously with the flowering phenotype, CsFTL3 and CsAFT were downregulated in CsLHY-SRDX transgenic plants. These results suggest that CsLHY-SRDX affects CsFTL3 and CsAFT expression and causes photoperiod-insensitive floral transition without a severe defect in the circadian clock. Copyright © 2017 Elsevier B.V. All rights

  5. Developmentally regulated expression of the transmembrane adaptor protein TRIM in fetal and adult T cells

    Czech Academy of Sciences Publication Activity Database

    Huynh, T.; Wurch, A.; Bruyns, E.; Kořínek, Vladimír; Schraven, B.; Eichmann, K.

    2001-01-01

    Roč. 54, 1-2 (2001), s. 146-154 ISSN 0300-9475 Institutional research plan: CEZ:AV0Z5052915 Keywords : TCR * TRIM * thymocytes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.739, year: 2001

  6. Adaptor protein sorting nexin 17 regulates amyloid precursor protein trafficking and processing in the early endosomes

    NARCIS (Netherlands)

    Lee, Jiyeon; Retamal, Claudio; Cuitino, Loreto; Caruano-Yzermans, Amy; Shin, Jung-Eun; van Kerkhof, Peter; Marzolo, Maria-Paz; Bu, Guojun

    2008-01-01

    Accumulation of extracellular amyloid beta peptide (A beta), generated from amyloid precursor protein (APP) processing by beta- and gamma-secretases, is toxic to neurons and is central to the pathogenesis of Alzheimer disease. Production of A beta from APP is greatly affected by the subcellular

  7. Negative regulation of mast cell signaling and function by the adaptor LAB/NTAL

    Czech Academy of Sciences Publication Activity Database

    Lusková, Petra; Lebduška, Pavel; Dráberová, Lubica; Šímová, Šárka; Heneberg, Petr; Boubelík, Michael; Bugajev, V.; Mallisen, B.; Wilson, B. S.; Hořejší, Václav; Mallisen, M.; Dráber, Petr

    2004-01-01

    Roč. 200, č. 8 (2004), s. 1001-1013 ISSN 0022-1007 R&D Projects: GA MŠk LN00A026; GA ČR GA204/03/0594; GA ČR GA301/03/0596; GA AV ČR IAA5052310 Institutional research plan: CEZ:AV0Z5052915 Keywords : mast cell * LAB/NTAL * cell signaling Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 14.588, year: 2004

  8. U1 Adaptor Oligonucleotides Targeting BCL2 and GRM1 Suppress Growth of Human Melanoma Xenografts In Vivo

    Directory of Open Access Journals (Sweden)

    Rafal Goraczniak

    2013-01-01

    Full Text Available U1 Adaptor is a recently discovered oligonucleotide-based gene-silencing technology with a unique mechanism of action that targets nuclear pre-mRNA processing. U1 Adaptors have two distinct functional domains, both of which must be present on the same oligonucleotide to exert their gene-silencing function. Here, we present the first in vivo use of U1 Adaptors by targeting two different human genes implicated in melanomagenesis, B-cell lymphoma 2 (BCL2 and metabotropic glutamate receptor 1 (GRM1, in a human melanoma cell xenograft mouse model system. Using a newly developed dendrimer delivery system, anti-BCL2 U1 Adaptors were very potent and suppressed tumor growth at doses as low as 34 µg/kg with twice weekly intravenous (iv administration. Anti-GRM1 U1 Adaptors suppressed tumor xenograft growth with similar potency. Mechanism of action was demonstrated by showing target gene suppression in tumors and by observing that negative control U1 Adaptors with just one functional domain show no tumor suppression activity. The anti-BCL2 and anti-GRM1 treatments were equally effective against cell lines harboring either wild-type or a mutant V600E B-RAF allele, the most common mutation in melanoma. Treatment of normal immune-competent mice (C57BL6 indicated no organ toxicity or immune stimulation. These proof-of-concept studies represent an in-depth (over 800 mice in ~108 treatment groups validation that U1 Adaptors are a highly potent gene-silencing therapeutic and open the way for their further development to treat other human diseases.

  9. TRAM is involved in IL-18 signaling and functions as a sorting adaptor for MyD88.

    Directory of Open Access Journals (Sweden)

    Hidenori Ohnishi

    Full Text Available MyD88, a Toll/interleukin-1 receptor homology (TIR domain-containing adaptor protein, mediates signals from the Toll-like receptors (TLR or IL-1/IL-18 receptors to downstream kinases. In MyD88-dependent TLR4 signaling, the function of MyD88 is enhanced by another TIR domain-containing adaptor, Mal/TIRAP, which brings MyD88 to the plasma membrane and promotes its interaction with the cytosolic region of TLR4. Hence, Mal is recognized as the "sorting adaptor" for MyD88. In this study, a direct interaction between MyD88-TIR and another membrane-sorting adaptor, TRAM/TICAM-2, was demonstrated in vitro. Cell-based assays including RNA interference experiments and TRAM deficient mice revealed that the interplay between MyD88 and TRAM in cells is important in mediating IL-18 signal transduction. Live cell imaging further demonstrated the co-localized accumulation of MyD88 and TRAM in the membrane regions in HEK293 cells. These findings suggest that TRAM serves as the sorting adaptor for MyD88 in IL-18 signaling, which then facilitates the signal transduction. The binding sites for TRAM are located in the TIR domain of MyD88 and actually overlap with the binding sites for Mal. MyD88, the multifunctional signaling adaptor that works together with most of the TLR members and with the IL-1/IL-18 receptors, can interact with two distinct sorting adaptors, TRAM and Mal, in a conserved manner in a distinct context.

  10. Epigenetic imbalance and the floral developmental abnormality of the in vitro-regenerated oil palm Elaeis guineensis

    Science.gov (United States)

    Jaligot, Estelle; Adler, Sophie; Debladis, Émilie; Beulé, Thierry; Richaud, Frédérique; Ilbert, Pascal; Finnegan, E. Jean; Rival, Alain

    2011-01-01

    Background The large-scale clonal propagation of oil palm (Elaeis guineensis) is being stalled by the occurrence of the mantled somaclonal variation. Indeed, this abnormality which presents a homeotic-like conversion of male floral organs into carpelloid structures, hampers oil production since the supernumerary female organs are either sterile or produce fruits with poor oil yields. Scope In the last 15 years, the prevailing point of view on the origin of the mantled floral phenotype has evolved from a random mutation event triggered by in vitro culture to a hormone-dependent dysfunction of gene regulation processes. In this review, we retrace the history of the research on the mantled variation in the light of the parallel advances made in the understanding of plant development regulation in model systems and more specifically in the role of epigenetic mechanisms. An overview of the current state of oil palm genomic and transcriptomic resources, which are key to any comparison with model organisms, is given. We show that, while displaying original characteristics, the mantled phenotype of oil palm is morphologically, and possibly molecularly, related to MADS-box genes mutants described in model plants. We also discuss the occurrence of comparable floral phenotypes in other palm species. Conclusions Beyond its primary interest in the search for discriminating markers against an economically crippling phenotype, the study of the mantled abnormality also provides a unique opportunity to investigate the regulation of reproductive development in a perennial tropical palm. On the basis of recent results, we propose that future efforts should concentrate on the epigenetic regulation targeting MADS-box genes and transposable elements of oil palm, since both types of sequences are most likely to be involved in the mantled variant phenotype. PMID:21224269

  11. Aromas florales y su interacción con los insectos polinizadores Floral scents and their interaction with insect pollinators

    Directory of Open Access Journals (Sweden)

    Julieta Grajales-Conesa

    2011-12-01

    Full Text Available Las plantas emplean diversas señales visuales y olfativas con la finalidad de atraer a los polinizadores que en su mayoría son insectos. Algunas plantas han desarrollado mecanismos, basándose en mensajes olfativos que los hacen únicos para sus polinizadores específicos. Estos mecanismos, así como las variaciones intra- e interespecíficas en el perfil de los aromas florales han evolucionado para determinadas especies. Los aromas florales son un conjunto de compuestos volátiles orgánicos y para su estudio hay varios métodos que requieren de técnicas que cada vez son más eficientes. El uso de estos aromas podría ser una opción en determinados sistemas de polinización, utilizándolos como atrayente de polinizadores o de depredadores y/o herbívoro para incrementar la producción y disminuir los daños por plagas. En este trabajo se revisan las distintas interacciones de los insectos y los aromas florales, los sistemas específicos planta-polinizador, los métodos de análisis, así como algunos patrones o tendencias de estas interacciones y su aplicación e importancia.Plants use visual and olfactory cues to attract pollinators and to allow them to detect the presence of flowers, which most of them are insects. Some plants have evolved with their pollinators, based on the olfactory messages, which make them unique for their specific pollinators. These mechanisms have evolved in certain plants in relation to their pollinators, and there are also inter and intra-specific variation in fragrance cues which show specific chemical profile for each plant species, so insects attracted are specific to them. Most of the floral scents are organic compounds identified with techniques and methodologies which become more specific and efficient along the time. The application of floral scent could be used as a tool in pollination and pest management. In these studies, insect interaction with floral scent is reviewed and specificity of plant

  12. Floral flavonoids and ultraviolet patterns in Viguiera (Compositae)

    International Nuclear Information System (INIS)

    Rieseberg, L.H.; Schilling, E.E.

    1985-01-01

    Variation occurs among species of Viguiera series Viguiera for ultraviolet (UV) absorption/reflection patterns of ligules. Floral flavonoids that cause UV absorption occur in epidermal papillae. Flavonoids are further localized to the proximal portion of the ligule in the seven taxa that have only proximal UV absorption. Floral flavonoids involved in UV absorption consist of flavone, flavonol, and anthochlor (chalcone/aurone) glycosides. Quercetin 3-methyl ether glycosides characterize the ligules of 10 taxa occurring in Baja California, Mexico, and nearby areas, and these taxa appear to form one taxonomic group. The anthochlor pair, marein/maritimein, characterizes V. dentata, and the lack of ligule flavonoids distinguishes V. potosina from the remaining taxa. The presence of the anthochlor pair, marein/maritimein, only in V. dentata and the lack of ligule flavonoids in V. potosina concur with other data to indicate that these species are not correctly placed with each other or with the other species currently included in series Viguiera. (author)

  13. Floral glands in asclepiads: structure, diversity and evolution

    Directory of Open Access Journals (Sweden)

    Diego Demarco

    Full Text Available ABSTRACT Species of Apocynaceae stand out among angiosperms in having very complex flowers, especially those of asclepiads, which belong to the most derived subfamily (Asclepiadoideae. These flowers are known to represent the highest degree of floral synorganization of the eudicots, and are comparable only to orchids. This morphological complexity may also be understood by observing their glands. Asclepiads have several protective and nuptial secretory structures. Their highly specific and specialized pollination systems are associated with the great diversity of glands found in their flowers. This review gathers data regarding all types of floral glands described for asclepiads and adds three new types (glandular trichome, secretory idioblast and obturator, for a total of 13 types of glands. Some of the species reported here may have dozens of glands of up to 11 types on a single flower, corresponding to the largest diversity of glands recorded to date for a single structure.

  14. Caffeine in floral nectar enhances a pollinator's memory of reward.

    Science.gov (United States)

    Wright, G A; Baker, D D; Palmer, M J; Stabler, D; Mustard, J A; Power, E F; Borland, A M; Stevenson, P C

    2013-03-08

    Plant defense compounds occur in floral nectar, but their ecological role is not well understood. We provide evidence that plant compounds pharmacologically alter pollinator behavior by enhancing their memory of reward. Honeybees rewarded with caffeine, which occurs naturally in nectar of Coffea and Citrus species, were three times as likely to remember a learned floral scent as were honeybees rewarded with sucrose alone. Caffeine potentiated responses of mushroom body neurons involved in olfactory learning and memory by acting as an adenosine receptor antagonist. Caffeine concentrations in nectar did not exceed the bees' bitter taste threshold, implying that pollinators impose selection for nectar that is pharmacologically active but not repellent. By using a drug to enhance memories of reward, plants secure pollinator fidelity and improve reproductive success.

  15. Photoperiodic control of sugar release during the floral transition: What is the role of sugars in the florigenic signal?

    Science.gov (United States)

    Ortiz-Marchena, M Isabel; Romero, José M; Valverde, Federico

    2015-01-01

    Florigen is a mobile signal released by the leaves that reaching the shoot apical meristem (SAM), changes its developmental program from vegetative to reproductive. The protein FLOWERING LOCUS T (FT) constitutes an important element of the florigen, but other components such as sugars, have been also proposed to be part of this signal. (1-5) We have studied the accumulation and composition of starch during the floral transition in Arabidopsis thaliana in order to understand the role of carbon mobilization in this process. In A. thaliana and Antirrhinum majus the gene coding for the Granule-Bound Starch Synthase (GBSS) is regulated by the circadian clock (6,7) while in the green alga Chlamydomonas reinhardtii the homolog gene CrGBSS is controlled by photoperiod and circadian signals. (8,9) In a recent paper(10) we described the role of the central photoperiodic factor CONSTANS (CO) in the regulation of GBSS expression in Arabidopsis. This regulation is in the basis of the change in the balance between starch and free sugars observed during the floral transition. We propose that this regulation may contribute to the florigenic signal and to the increase in sugar transport required during the flowering process.

  16. Quantitative trait loci for floral morphology in Arabidopsis thaliana.

    OpenAIRE

    Juenger, T; Purugganan, M; Mackay, T F

    2000-01-01

    A central question in biology is how genes control the expression of quantitative variation. We used statistical methods to estimate genetic variation in eight Arabidopsis thaliana floral characters (fresh flower mass, petal length, petal width, sepal length, sepal width, long stamen length, short stamen length, and pistil length) in a cosmopolitan sample of 15 ecotypes. In addition, we used genome-wide quantitative trait locus (QTL) mapping to evaluate the genetic basis of variation in these...

  17. Anatomia floral de espécies de Cyperaceae (Poales)

    OpenAIRE

    Monteiro, Mariana Maciel [UNESP

    2015-01-01

    Cyperaceae comprises about 5000 species with a worldwide distribution. The family is divided into two subfamilies: Mapanioideae (earlier divergent) and Cyperoideae that are distinguished from each other by the structure of their reproductive units. There is no consensus on whether these units are flowers or reduced inflorescences in Mapanioideae. In Cyperoideae, the reproductive units correspond to a spikelet whose structural variation difficults the understanding of the floral evolution in t...

  18. Pestalotioid fungi from Restionaceae in the Cape Floral Kingdom

    OpenAIRE

    Lee, Seonju; Crous, Pedro W.; Wingfield, Michael J.

    2006-01-01

    Eight pestalotioid fungi were isolated from the Restionaceae growing in the Cape Floral Kingdom of South Africa. Sarcostroma restionis, Truncatella megaspora, T. restionacearum and T. spadicea are newly described. New records include Pestalotiopsis matildae, Sarcostroma lomatiae, Truncatella betulae and T. hartigii. To resolve generic affiliations, phylogenetic analyses were performed on ITS (ITS1, 5.8S, ITS2) and part of 28S rDNA. DNA data support the original generic concept of Truncatella,...

  19. Study on the Development of Yunnan Floral E-commerce

    OpenAIRE

    Kuang, Yulan; Li, Qifang; Ning, Wangyun

    2013-01-01

    Cut flower production in Yunnan accounts for 80% nationwide. In order to expand the Yunnan Flower sales channels, the promotion of the development of e-commerce is necessary. In 2012 China's online shopping users reached 247 million people, but e-commerce of fresh flowers lagged behind due to the constraints of preservation facilities and logistics cost. The analysis of the factors restricting the development of floral e-commerce and the proposition of solutions to this problem can promote fa...

  20. Morphology of floral papillae in Maxillaria Ruiz & Pav. (Orchidaceae).

    Science.gov (United States)

    Davies, K L; Turner, M P

    2004-01-01

    The labellar papillae and trichomes of Maxillaria Ruiz & Pav. show great diversity. Although papillae also occur upon other parts of the flower (e.g. column and anther cap), these have not yet been studied. Labellar trichomes of Maxillaria are useful in taxonomy, but hitherto the taxonomic value of floral papillae has not been assessed. The aim of this paper is to describe the range of floral papillae found in Maxillaria and to determine whether papillae are useful as taxonomic characters. Light microscopy, histochemistry, low-vacuum scanning and transmission electron microscopy. A total of 75 taxa were studied. Conical papillae with rounded or pointed tips were the most common. The column and anther cap usually bear conical, obpyriform or villiform papillae, whereas those around the stigmatic surface and at the base of the anther are often larger and swollen. Labellar papillae show greater diversity, and may be conical, obpyriform, villiform, fusiform or clavate. Papillae may also occur on multiseriate trichomes that perhaps function as pseudostamens. Labellar papillae contain protein but most lack lipid. The occurrence of starch, however, is more variable. Many papillae contain pigment or act as osmophores, thereby attracting insects. Rewards such as nectar or a protein-rich, wax-like, lipoidal substance may be secreted by papillae onto the labellar surface. Some papillae may have a protective role in preventing desiccation. Species of diverse vegetative morphology may have identical floral papillae, whereas others of similar vegetative morphology may not. Generally, floral papillae in Maxillaria have little taxonomic value. Nevertheless, the absence of papillae from members of the M. cucullata alliance, the occurrence of clavate papillae with distended apices in the M. rufescens alliance and the presence of papillose trichomes in some species may yet prove to be useful.

  1. Profiling Histone Modifications in Synchronized Floral Tissues for Quantitative Resolution of Chromatin and Transcriptome Dynamics.

    Science.gov (United States)

    Engelhorn, Julia; Wellmer, Frank; Carles, Cristel C

    2018-01-01

    Covalent histone modifications and their effects on chromatin state and accessibility play a key role in the regulation of gene expression in eukaryotes. To gain insights into their functions during plant growth and development, the distribution of histone modifications can be analyzed at a genome-wide scale through chromatin immunoprecipitation assays followed by sequencing of the isolated genomic DNA. Here, we present a protocol for systematic analysis of the distribution and dynamic changes of selected histone modifications, during flower development in the model plant Arabidopsis thaliana. This protocol utilizes a previously established floral induction system to synchronize flower development, which allows the collection of sufficient plant material for analysis by genomic technologies. In this chapter, we describe how to use this system to study, from the same set of samples, chromatin and transcriptome dynamics during early stages of flower formation.

  2. The Role of Crk Adaptor Proteins in Breast Tumorigenesis and Bone Metastasis

    Science.gov (United States)

    2012-09-01

    points indicated. Treatments included DMSO control or inhibition of Met (0.2uM PHA-665752), Abl (4uM Imatinib ), PI3K (20uM LY-294002), mTOR (0.1uM...CrkL over CrkII, Nat Chem Biol 8, 590–596 (2012). RESEARCH ARTICLE Open Access Crk adaptor proteins act as key signaling integrators for breast...R74 http://breast-cancer-research.com/content/14/3/R74 © 2012 Fathers et al.; licensee BioMed Central Ltd. This is an open access article distributed

  3. Transmembrane adaptor proteins in the high-affinity IgE receptor signaling

    Czech Academy of Sciences Publication Activity Database

    Dráber, Petr; Hálová, Ivana; Levi-Schaffer, F.; Dráberová, Lubica

    2012-01-01

    Roč. 2, 11.1. (2012), s. 95 ISSN 1664-3224 R&D Projects: GA MŠk 1M0506; GA ČR GA301/09/1826; GA ČR GAP302/10/1759; GA AV ČR KAN200520701 Grant - others:AV ČR(CZ) M200520901 Institutional research plan: CEZ:AV0Z50520514 Institutional support: RVO:68378050 Keywords : IgE receptor * LAT/LAT1 * LAX * NTAL/Lab/LAT2 * PAG/Cbp * mast cells * plasma membrane * transmembrane adaptor proteins Subject RIV: EB - Genetics ; Molecular Biology

  4. Correlation between number and position of floral organs in Arabidopsis.

    Science.gov (United States)

    Penin, Aleksey A; Logacheva, Maria D

    2011-07-01

    The study of variation in number, position and type of floral organs may serve as a key to understanding the mechanisms underlying their variation, and will make it possible to improve the analysis of gene function in model plant species by means of a more accurate characterization of mutant phenotypes. The present analysis was carried out in order to understand the correlation between number and position of floral organs in Arabidopsis thaliana. An analysis of number and position of organs in flowers of wild type as well as in a series of mutations with floral organ position alterations was carried out, using light and electron microscopy. Variation common to different genotypes was analysed by means of individual diagrams, upon which generalized diagrams depicting variation in number and position of organs, were built by superimposition. It is shown that in the Arabidopsis flower a correlation exists between positions of petals and sepals, as well as between positions of stamens and carpels, whereas the position of carpels does not seem to depend on number and position of petals and stamens. This suggests that the position of organs in the basal (sepals) and apical (carpels) parts of the flower are determined before that in the intermediate zone. This assumption is consistent with the results of mathematical modelling and is supposed to be the consequence of stem-cell activity in the flower.

  5. VIS/NIR imaging application for honey floral origin determination

    Science.gov (United States)

    Minaei, Saeid; Shafiee, Sahameh; Polder, Gerrit; Moghadam-Charkari, Nasrolah; van Ruth, Saskia; Barzegar, Mohsen; Zahiri, Javad; Alewijn, Martin; Kuś, Piotr M.

    2017-11-01

    Nondestructive methods are of utmost importance for honey characterization. This study investigates the potential application of VIS-NIR hyperspectral imaging for detection of honey flower origin using machine learning techniques. Hyperspectral images of 52 honey samples were taken in transmittance mode in the visible/near infrared (VIS-NIR) range (400-1000 nm). Three different machine learning algorithms were implemented to predict honey floral origin using honey spectral images. These methods, included radial basis function (RBF) network, support vector machine (SVM), and random forest (RF). Principal component analysis (PCA) was also exploited for dimensionality reduction. According to the obtained results, the best classifier (RBF) achieved a precision of 94% in a fivefold cross validation experiment using only the first two PCs. Mapping of the classifier results to the test set images showed 90% accuracy for honey images. Three types of honey including buckwheat, rapeseed and heather were classified with 100% accuracy. The proposed approach has great potential for honey floral origin detection. As some other honey properties can also be predicted using image features, in addition to floral origin detection, this method may be applied to predict other honey characteristics.

  6. The evolution of floral biology in basal angiosperms

    Science.gov (United States)

    Endress, Peter K.

    2010-01-01

    In basal angiosperms (including ANITA grade, magnoliids, Choranthaceae, Ceratophyllaceae) almost all bisexual flowers are dichogamous (with male and female functions more or less separated in time), and nearly 100 per cent of those are protogynous (with female function before male function). Movements of floral parts and differential early abscission of stamens in the male phase are variously associated with protogyny. Evolution of synchronous dichogamy based on the day/night rhythm and anthesis lasting 2 days is common. In a few clades in Magnoliales and Laurales heterodichogamy has also evolved. Beetles, flies and thrips are the major pollinators, with various degrees of specialization up to large beetles and special flies in some large-flowered Nymphaeaceae, Magnoliaceae, Annonaceae and Aristolochiaceae. Unusual structural specializations are involved in floral biological adaptations (calyptras, inner staminodes, synandria and food bodies, and secretory structures on tepals, stamens and staminodes). Numerous specializations that are common in monocots and eudicots are absent in basal angiosperms. Several families are poorly known in their floral biology. PMID:20047868

  7. Accessibility, constraint, and repetition in adaptive floral evolution.

    Science.gov (United States)

    Wessinger, Carolyn A; Hileman, Lena C

    2016-11-01

    Adaptive phenotypic evolution is shaped by natural selection on multiple organismal traits as well as by genetic correlations among traits. Genetic correlations can arise through pleiotropy and can bias the production of phenotypic variation to certain combinations of traits. This phenomenon is referred to as developmental bias or constraint. Developmental bias may accelerate or constrain phenotypic evolution, depending on whether selection acts parallel or in opposition to genetic correlations among traits. We discuss examples from floral evolution where genetic correlations among floral traits contribute to rapid, coordinated evolution in multiple floral organ phenotypes and suggest future research directions that will explore the relationship between the genetic basis of adaptation and the pre-existing structure of genetic correlations. On the other hand, natural selection may act perpendicular to a strong genetic correlation, for example when two traits are encoded by a subset of the same genes and natural selection favors change in one trait and stability in the second trait. In such cases, adaptation is constrained by the availability of genetic variation that can influence the focal trait with minimal pleiotropic effects. Examples from plant diversification suggest that the origin of certain adaptations depends on the prior evolution of a gene copy with reduced pleiotropic effects, generated through the process of gene duplication followed by subfunctionalization or neofunctionalization. A history of gene duplication in some developmental pathways appears to have allowed particular flowering plant linages to have repeatedly evolved adaptations that might otherwise have been developmentally constrained. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Floral homeotic C function genes repress specific B function genes in the carpel whorl of the basal eudicot California poppy (Eschscholzia californica

    Directory of Open Access Journals (Sweden)

    Yellina Aravinda L

    2010-12-01

    Full Text Available Abstract Background The floral homeotic C function gene AGAMOUS (AG confers stamen and carpel identity and is involved in the regulation of floral meristem termination in Arabidopsis. Arabidopsis ag mutants show complete homeotic conversions of stamens into petals and carpels into sepals as well as indeterminacy of the floral meristem. Gene function analysis in model core eudicots and the monocots rice and maize suggest a conserved function for AG homologs in angiosperms. At the same time gene phylogenies reveal a complex history of gene duplications and repeated subfunctionalization of paralogs. Results EScaAG1 and EScaAG2, duplicate AG homologs in the basal eudicot Eschscholzia californica show a high degree of similarity in sequence and expression, although EScaAG2 expression is lower than EScaAG1 expression. Functional studies employing virus-induced gene silencing (VIGS demonstrate that knock down of EScaAG1 and 2 function leads to homeotic conversion of stamens into petaloid structures and defects in floral meristem termination. However, carpels are transformed into petaloid organs rather than sepaloid structures. We also show that a reduction of EScaAG1 and EScaAG2 expression leads to significantly increased expression of a subset of floral homeotic B genes. Conclusions This work presents expression and functional analysis of the two basal eudicot AG homologs. The reduction of EScaAG1 and 2 functions results in the change of stamen to petal identity and a transformation of the central whorl organ identity from carpel into petal identity. Petal identity requires the presence of the floral homeotic B function and our results show that the expression of a subset of B function genes extends into the central whorl when the C function is reduced. We propose a model for the evolution of B function regulation by C function suggesting that the mode of B function gene regulation found in Eschscholzia is ancestral and the C-independent regulation as

  9. UFO in the Arabidopsis inflorescence apex is required for floral-meristem identity and bract suppression.

    Science.gov (United States)

    Hepworth, Shelley R; Klenz, Jennifer E; Haughn, George W

    2006-03-01

    The UNUSUAL FLORAL ORGANS (UFO) gene of Arabidopsis encodes an F-box protein required for the determination of floral-organ and floral-meristem identity. Mutation of UFO leads to dramatic changes in floral-organ type which are well-characterized whereas inflorescence defects are more subtle and less understood. These defects include an increase in the number of secondary inflorescences, nodes that alternate between forming flowers and secondary inflorescences, and nodes in which a single flower is subtended by a bract. Here, we show how inflorescence defects correlate with the abnormal development of floral primordia and establish a temporal requirement for UFO in this process. At the inflorescence apex of ufo mutants, newly formed primordia are initially bract-like. Expression of the floral-meristem identity genes LFY and AP1 are confined to a relatively small adaxial region of these primordia with expression of the bract-identity marker FIL observed in cells that comprise the balance of the primordia. Proliferation of cells in the adaxial region of these early primordia is delayed by several nodes such that primordia appear "chimeric" at several nodes, having visible floral and bract components. However, by late stage 2 of floral development, growth of the bract generally ceases and is overtaken by development of the floral primordium. This abnormal pattern of floral meristem development is not rescued by expression of UFO from the AP1 promoter, indicating that UFO is required prior to AP1 activation for normal development of floral primordia. We propose that UFO and LFY are jointly required in the inflorescence meristem to both promote floral meristem development and inhibit, in a non-cell autonomous manner, growth of the bract.

  10. Floral polymorphism and the fitness implications of attracting pollinating and florivorous insects.

    Science.gov (United States)

    de Jager, Marinus L; Ellis, Allan G

    2014-01-01

    Floral polymorphism is frequently attributed to pollinator-mediated selection. Multiple studies, however, have revealed the importance of non-pollinating visitors in floral evolution. Using the polymorphic annual daisy Ursinia calenduliflora, this study investigated the importance of different insect visitors, and their effects on fitness, in the maintenance of floral polymorphism. The spatial structure of a discrete floral polymorphism was characterized based on the presence/absence of anthocyanin floret spots in U. calenduliflora. A 3-year observational study was then conducted in polymorphic populations to investigate differences in visitation rates of dominant visitors to floral morphs. Experiments were performed to explore the floral preference of male and female Megapalpus capensis (the dominant insect visitor) and their effectiveness as pollinators. Next, floral damage by antagonistic florivores and the reproductive success of the two floral morphs were surveyed in multiple populations and years. Floral polymorphism in U. calenduliflora was structured spatially, as were insect visitation patterns. Megapalpus capensis males were the dominant visitors and exhibited strong preference for the spotted morph in natural and experimental observations. While this may indicate potential fitness benefits for the spotted morph, female fitness did not differ between floral morphs. However, as M. capensis males are very efficient at exporting U. calenduliflora pollen, their preference may likely increase the reproductive fitness of the spotted morph through male fitness components. The spotted morph, however, also suffered significantly greater costs due to ovule predation by florivores than the spotless morph. The results suggest that pollinators and florivores may potentially exert antagonistic selection that could contribute to the maintenance of floral polymorphism across the range of U. calenduliflora. The relative strength of selection imposed by each agent is

  11. Comparison of Different Methods for RNA Extraction from Floral Buds of Tree Peony (Paeonia suffruticosa Andr.)

    OpenAIRE

    Yan GAO; Guangqi ZHAO; Changhua JIANG; Yao SONG; Kang YE; Shucheng FENG

    2016-01-01

    Tree peony (Paeonia suffruticosa Andr.), a species native to China, is one of the most important ornamental and medicinal plants. Like other tree species in temperate and boreal zones, the dormancy-activity transition of floral buds is critical for blooming time and fruit production. However, floral buds contain high levels of secondary metabolites, making the isolation of high quality RNA difficult. To obtain a method suitable for extracting RNA from floral buds of tree peony, we evaluated f...

  12. The adaptor-like protein ROG-1 is required for activation of the Ras-MAP kinase pathway and meiotic cell cycle progression in Caenorhabditis elegans.

    Science.gov (United States)

    Matsubara, Yosuke; Kawasaki, Ichiro; Urushiyama, Seiichi; Yasuda, Tomoharu; Shirakata, Masaki; Iino, Yuichi; Shibuya, Hiroshi; Yamanashi, Yuji

    2007-03-01

    The Ras-MAP kinase pathway regulates varieties of fundamental cellular events. In Caenorhabditis elegans, this pathway is required for oocyte development; however, the nature of its up-stream regulators has remained elusive. Here, we identified a C. elegans gene, rog-1, which encodes the only protein having the IRS-type phosphotyrosine-binding (PTB) domain in the worms. ROG-1 has no obvious domain structure aside from the PTB domain, suggesting that it could serve as an adaptor down-stream of protein-tyrosine kinases (PTKs). RNA interference (RNAi)-mediated down-regulation of rog-1 mRNA significantly decreased brood size. rog-1(tm1031) truncation mutants showed a severe disruption in progression of developing oocytes from pachytene to diakinesis, as was seen in worms carrying a loss-of-function mutation in the let-60 Ras or mpk-1 MAP kinase gene. Furthermore, let-60 Ras-regulated activation of MPK-1 in the gonad is undetectable in rog-1(tm1031) mutants. Conversely, a gain-of-function mutation in the let-60 Ras gene rescues the brood size reduction and germ cell abnormality in rog-1(tm1031) worms. Consistently, rog-1 is preferentially expressed in the germ cells and its expression in the gonad is essential for oocyte development. Thus, ROG-1 is a key positive regulator of the Ras-MAP kinase pathway that permits germ cells to exit from pachytene.

  13. Floral gene resources from basal angiosperms for comparative genomics research

    Directory of Open Access Journals (Sweden)

    Zhang Xiaohong

    2005-03-01

    Full Text Available Abstract Background The Floral Genome Project was initiated to bridge the genomic gap between the most broadly studied plant model systems. Arabidopsis and rice, although now completely sequenced and under intensive comparative genomic investigation, are separated by at least 125 million years of evolutionary time, and cannot in isolation provide a comprehensive perspective on structural and functional aspects of flowering plant genome dynamics. Here we discuss new genomic resources available to the scientific community, comprising cDNA libraries and Expressed Sequence Tag (EST sequences for a suite of phylogenetically basal angiosperms specifically selected to bridge the evolutionary gaps between model plants and provide insights into gene content and genome structure in the earliest flowering plants. Results Random sequencing of cDNAs from representatives of phylogenetically important eudicot, non-grass monocot, and gymnosperm lineages has so far (as of 12/1/04 generated 70,514 ESTs and 48,170 assembled unigenes. Efficient sorting of EST sequences into putative gene families based on whole Arabidopsis/rice proteome comparison has permitted ready identification of cDNA clones for finished sequencing. Preliminarily, (i proportions of functional categories among sequenced floral genes seem representative of the entire Arabidopsis transcriptome, (ii many known floral gene homologues have been captured, and (iii phylogenetic analyses of ESTs are providing new insights into the process of gene family evolution in relation to the origin and diversification of the angiosperms. Conclusion Initial comparisons illustrate the utility of the EST data sets toward discovery of the basic floral transcriptome. These first findings also afford the opportunity to address a number of conspicuous evolutionary genomic questions, including reproductive organ transcriptome overlap between angiosperms and gymnosperms, genome-wide duplication history, lineage

  14. Terrestrial floral change during the ETM2 hyperthermal

    Science.gov (United States)

    Wing, S. L.; Currano, E. D.

    2017-12-01

    Hyperthermal events during the Eocene are defined by negative shifts in carbon isotope composition, global temperature increase and carbonate dissolution in marine settings. These features suggest repeated releases of large amounts of carbon followed by increasing concentration of CO2in the atmosphere and ocean, climate change, and biotic responses such as rapid evolution and changes in geographic range and trophic relationships. The Paleocene-Eocene Thermal Maximum (PETM, 56.0 Ma) is the largest Eocene hyperthermal in terms of carbon cycle, climate and biotic effects, including dwarfing of mammalian lineages. Terrestrial floral turnover at the PETM documented in the Bighorn Basin, Wyoming, USA, is very high. Almost all late Paleocene species, most belonging to mesic, warm-temperate lineages, disappeared during the PETM. The PETM flora was composed of species belonging to dry tropical lineages present only during the body of the PETM. Most mesic, warm-temperate species returned to the area immediately after the PETM. Such extreme change in floral composition makes it difficult to assess how much floral turnover is associated with how much change in temperature. The ETM2 hyperthermal event ( 53.7 Ma) is characterized by a carbon isotope excursion and warming about half as great as during the PETM, and by half as much mammalian dwarfing. Here we report on a new fossil flora from ETM2 that demonstrates the magnitude of floral change was also less than during the PETM. Some characteristic PETM plant species reappeared in the Bighorn Basin during ETM2, including species of Fabaceae that dominate PETM assemblages but are less common during ETM2. Many stratigraphically long-ranging plant species that preferred mesic climates remain common in the ETM2 flora. We conclude that warm climate during ETM2 shifted ranges of plant species such that some PETM species returned to northern Wyoming, but was not so severe as to cause local extirpation of species preferring 'background

  15. The role of small adaptor proteins in the control of oncogenic signaling driven by tyrosine kinases in human cancer

    Science.gov (United States)

    Naudin, Cécile; Chevalier, Clément; Roche, Serge

    2016-01-01

    Protein phosphorylation on tyrosine (Tyr) residues has evolved as an important mechanism to coordinate cell communication in multicellular organisms. The importance of this process has been revealed by the discovery of the prominent oncogenic properties of tyrosine kinases (TK) upon deregulation of their physiological activities, often due to protein overexpression and/or somatic mutation. Recent reports suggest that TK oncogenic signaling is also under the control of small adaptor proteins. These cytosolic proteins lack intrinsic catalytic activity and signal by linking two functional members of a catalytic pathway. While most adaptors display positive regulatory functions, a small group of this family exerts negative regulatory functions by targeting several components of the TK signaling cascade. Here, we review how these less studied adaptor proteins negatively control TK activities and how their loss of function induces abnormal TK signaling, promoting tumor formation. We also discuss the therapeutic consequences of this novel regulatory mechanism in human oncology. PMID:26788993

  16. The role of small adaptor proteins in the control of oncogenic signalingr driven by tyrosine kinases in human cancer.

    Science.gov (United States)

    Naudin, Cécile; Chevalier, Clément; Roche, Serge

    2016-03-08

    Protein phosphorylation on tyrosine (Tyr) residues has evolved as an important mechanism to coordinate cell communication in multicellular organisms. The importance of this process has been revealed by the discovery of the prominent oncogenic properties of tyrosine kinases (TK) upon deregulation of their physiological activities, often due to protein overexpression and/or somatic mutation. Recent reports suggest that TK oncogenic signaling is also under the control of small adaptor proteins. These cytosolic proteins lack intrinsic catalytic activity and signal by linking two functional members of a catalytic pathway. While most adaptors display positive regulatory functions, a small group of this family exerts negative regulatory functions by targeting several components of the TK signaling cascade. Here, we review how these less studied adaptor proteins negatively control TK activities and how their loss of function induces abnormal TK signaling, promoting tumor formation. We also discuss the therapeutic consequences of this novel regulatory mechanism in human oncology.

  17. Floral biology of Stachytarpheta maximiliani Scham. (Verbenaceae and its floral visitors Biologia floral de Stachytarpheta maximiliani Scham. (Verbenaceae e seus visitantes florais

    Directory of Open Access Journals (Sweden)

    Ivana de Freitas Barbola

    2006-12-01

    Full Text Available This study describes the reproductive system of Stachytarpheta maximiliani (Verbenaceae, including its floral biology, nectar and pollen availability and insect foraging patterns, identifying whose species act as pollinators. It was carried out in a Brazilian Atlantic rain forest site. Observations on the pollination biology of the Verbenaceae S. maximiliani indicate that their flowering period extends from September through May. Anthesis occurs from 5:30 a.m. to 5:00 p.m. and nectar and pollen are available during all the anthesis. Many species of beetles, hemipterans, flies, wasps, bees and butterflies visit their flowers, but bees and butterflies are the most frequent visitors. The flowers are generally small, gathered in dense showy inflorescences. A complex of floral characteristcs, such as violet-blue color of flowers, long floral tubes, without scents, nectar not exposed, high concentration of sugar in nectar (about 32%, allowed identification of floral syndromes (melittophily and psicophily and function for each visitor. The bees, Bombus morio, B. atratus, Trigonopedia ferruginea, Xylocopa brasilianorum and Apis mellifera and the butterflies Corticea mendica mendica, Corticea sp., Vehilius clavicula, Urbanus simplicius, U. teleus and Heraclides thoas brasiliensis, are the most important pollinators.Este estudo descreve alguns aspectos do sistema reprodutivo de Stachytarpheta maximiliani (Verbenaceae, incluindo características da flor, disponibilidade de néctar e pólen e o padrão de forrageio dos insetos visitantes florais, em uma área de Floresta Atlântica, no sul do Brasil. Observações sobre sua biologia floral indicam que esta espécie tem um período de floração que se estende de setembro a maio, antese diurna (das 5:30h às 17:00h e oferta de néctar e pólen praticamente durante todo o período de antese. Suas flores são visitadas por diferentes espécies de coleópteros, dípteros, hemípteros, himenópteros e lepid

  18. ÉVOLUTION DU RÔLE ET DES PROPRIÉTÉS BIOCHIMIQUES DE LEAFY : Un régulateur central du développement floral

    OpenAIRE

    Moyroud, Edwige

    2010-01-01

    Flowers are a key innovation in plant evolution and their origin remains a mystery. LEAFY(LFY) is a unique plant transcription factor regulating floral development, but this genepredates flowers. My thesis work aimed to understand how the evolution of LFY biochemicalproperties could help explaining flower origins.First, I took part in the structural characterization of LFY DNA-binding domain, revealing anovel protein fold bound to DNA as a cooperative dimer (Hamès et al., 2009). Toexhaustivel...

  19. The Cytoplasmic Adaptor Protein Dok7 Activates the Receptor Tyrosine Kinase MuSK via Dimerization

    Energy Technology Data Exchange (ETDEWEB)

    Bergamin, E.; Hallock, P; Burden, S; Hubbard, S

    2010-01-01

    Formation of the vertebrate neuromuscular junction requires, among others proteins, Agrin, a neuronally derived ligand, and the following muscle proteins: LRP4, the receptor for Agrin; MuSK, a receptor tyrosine kinase (RTK); and Dok7 (or Dok-7), a cytoplasmic adaptor protein. Dok7 comprises a pleckstrin-homology (PH) domain, a phosphotyrosine-binding (PTB) domain, and C-terminal sites of tyrosine phosphorylation. Unique among adaptor proteins recruited to RTKs, Dok7 is not only a substrate of MuSK, but also an activator of MuSK's kinase activity. Here, we present the crystal structure of the Dok7 PH-PTB domains in complex with a phosphopeptide representing the Dok7-binding site on MuSK. The structure and biochemical data reveal a dimeric arrangement of Dok7 PH-PTB that facilitates trans-autophosphorylation of the kinase activation loop. The structure provides the molecular basis for MuSK activation by Dok7 and for rationalizing several Dok7 loss-of-function mutations found in patients with congenital myasthenic syndromes.

  20. Pertussis toxin targets the innate immunity through DAP12, FcRγ, and MyD88 adaptor proteins.

    Science.gov (United States)

    Phongsisay, Vongsavanh; Iizasa, Ei'ichi; Hara, Hiromitsu; Yoshida, Hiroki

    2017-04-01

    Activation of the innate immunity by adjuvants, such as pertussis toxin (PTX), in the presence of autoreactive lymphocytes and antigen mimicry is sufficient to trigger autoimmunity. Toll-like, C-type lectin, and immunglobulin-like receptors play an important role in the innate immunity by sensing a variety of microbial products through several adaptor proteins, including MyD88, DAP12, and FcRγ. This study investigated the interaction between PTX and innate immune components. The direct interactions between coated PTX and receptor-fusion proteins were examined using ELISA-based binding assays. Functionally, PTX-binding receptors could be classified into two groups: inhibition (DAP12-coupled TREM2, ITIM-bearing SIRPα, SIGNR1/SIGNR3/DCSIGN) and activation (MyD88-associated TLR4, DAP12-coupled LMIR5/CD300b, FcRγ-coupled LMIR8/CD300c, CLEC9A, MGL-1). DAP12, MyD88, and FcRγ were selected for further investigation. A comprehensive analysis of gene transcription showed that PTX up-regulated the expression of various inflammatory mediators. DAP12 deficiency resulted in reduction or enhancement of inflammatory responses in a cytokine-specific manner. PTX was able to activate the TREM2-DAP12 signalling pathway. PTX induced lower expression of inflammatory mediators in the absence of FcRγ alone and substantially lost its inflammatory capacity in the absence of both FcRγ and MyD88. PTX was able to activate the MyD88-NF-κB signalling pathway in the presence of TLR2 or TLR4. The inflammatory activity of PTX was completely lost by heating. These results demonstrate that PTX targets the innate immunity through DAP12, FcRγ, and MyD88 providing new insights into the immunobiology of PTX. Copyright © 2016 Elsevier GmbH. All rights reserved.

  1. Plasticity of floral longevity and floral display in the self-compatible biennial Sabatia angularis (Gentianaceae): untangling the role of multiple components of pollination.

    Science.gov (United States)

    Spigler, Rachel B

    2017-01-01

    Plasticity of floral traits in response to pollination can enable plants to maximize opportunities for pollen import and export under poor pollination conditions, while minimizing costs under favourable ones. Both floral longevity and display are key traits influencing pollination. While pollination-induced flower wilting is widely documented, we lack an understanding of the multifactorial complexity of this response, including the influence of other pollination components, costs of extended longevity and subsequent impacts on floral display. Plasticity of floral longevity was experimentally evaluated in Sabatia angularis in response to multiple pollination factors: pollen addition, removal, and source (self, single-donor outcross, multiple-donor outcross) and timing of pollination. Effects of pollen quantity were further evaluated by exploiting variation in autonomous self-pollen deposition. Delayed pollination costs were tested comparing seed set from early versus late pollinations. Finally, I compared floral display metrics (peak floral display, time to peak flower, flowering duration, mean flowering rate) between experimentally pollinated and control plants. Floral longevity was highly plastic in response to pollen addition and its timing, and the response was dose-dependent but insensitive to pollen source. Pollen removal tended to extend floral longevity, but only insofar as it precluded pollination-induced wilting via autonomous self-pollination. Under delayed pollination, the wilting response was faster and no cost was detected. Pollination further led to reduced peak floral displays and condensed flowering periods. Floral longevity and display plasticity could optimize fitness in S. angularis, a species prone to pollen limitation and high inbreeding depression. Under pollinator scarcity, extended floral longevities offer greater opportunities for pollen receipt and export at no cost to seed set, reproductive assurance via autonomous self-pollination and

  2. Role of vernalization-mediated demethylation in the floral transition of Brassica rapa.

    Science.gov (United States)

    Duan, Weike; Zhang, Huijun; Zhang, Bei; Wu, Xiaoting; Shao, Shuaixu; Li, Ying; Hou, Xilin; Liu, Tongkun

    2017-01-01

    Vernalization-mediated demethylation of BrCKA2 (casein kinase II α-subunit) and BrCKB4 (casein kinase II β-subunit) shorten the period of the clock gene BrCCA1 (circadian clock associated 1) in Brassica rapa. Photoperiod and vernalization are two environmental cues involved in the regulation of floral transition, but the ways in which they interact remain unclear. DNA methylation is one of the main mechanisms involved in controlling the functional state of chromatin and gene expression in response to environmental signals. To study the interaction between photoperiod and vernalization in floral transition, we carried out a comparative genomic analysis of genome-wide DNA methylation profiles in normal (CK) and vernalized (CA) leaves from Brassica rapa using methylated-DNA immunoprecipitation sequencing (MeDIP-seq). Two subunits of casein kinase II (CK2), BrCKA2 (catalytic α-subunit of CK2) and BrCKB4 (regulatory β-subunit of CK2), exhibited gradual DNA demethylation and increased expression in vernalized B. rapa. DNA methylation-defective plants demonstrated the causal link between DNA demethylation changes and changes in gene expression. Virus-induced gene silencing (VIGS) of BrCKA2 and BrCKB4 in B. rapa resulted in no change to the period of BrCCA1 (circadian clock associated 1) and a 1-week late flowering time. Finally, we demonstrated that increased levels of BrCKA2 and BrCKB4 in vernalized B. rapa confer elevated CK2 activity, resulting in a shortened period of the clock gene BrCCA1, which plays an important role in perceiving photoperiod in plants. Thus, our results suggest that there is a direct interaction between photoperiod and vernalization through DNA methylation mechanisms.

  3. Biología floral de Passiflora foetida (Passifloraceae

    Directory of Open Access Journals (Sweden)

    María T. Amela García

    1998-06-01

    Full Text Available Un experimento reproductivo muestra que Passiflora foetida es autocompatible. Observaciones de las características florales y de los visitantes durante la antesis, más el análisis del polen transportado, permitieron identificar el síndrome floral (melitofilia y las funciones de cada visitante. La antesis ocurre desde las 6 hasta las 11 hs. Se identificaron 3 fases florales: 1 estigmas por encima de las anteras, 2 estigmas a la altura de las anteras, 3 estigmas por encima de las anteras; los radii, los pétalos y los sépalos se incurvan. Los estigmas están receptivos durante toda la antesis. La concentración de azúcares del néctar es 34 %. El color predominante en el espectro visible es el blanco. En el espectro UV, los estambres y el gineceo contrastan con el limen y el androginóforo; pueden ser una guía de néctar. Tres especies de himenópteros fueron los visitantes más frecuentes y constantes: Ptiloglossa tarsata (Colletidae siempre contactan las anteras y los estigmas cuando liban, transportan un alto porcentaje de polen de P. foetida y visitan flores en fase 1 y 2; pueden ser considerados los principales polinizadores. Pseudaugochloropsis sp. (Halictidae raramente contactan las anteras o los estigmas cuando perforan el limen para acceder al néctar y visitan flores en fase 2 y 3; son ladrones de néctar que raramente polinizan. Augochlorella sp. (Halictidae recolectan polen sin tocar los estigmas y visitan flores en fase 2 y 3; son hurtadores de polen.A reproductive experiment shows that Passiflora foetida is autocompatible. Observations of floral characteristics and visitors during anthesis, plus the analysis of pollen allowed identification of floral syndrome (melittophily and functions for each visitor. Anthesis occurs from 6 to 11 AM. Three floral phases were identified: 1 stigmas above anthers, 2 stigmas at anther level, 3 stigmas above anthers; radii, petals and sepals become incurved. The stigmas are receptive during the

  4. Decision Support Methods for Supply Processes in the Floral Industry

    Directory of Open Access Journals (Sweden)

    Kutyba Agata

    2017-12-01

    Full Text Available The aim of this paper was to show the application of the ABC and AHP (multi-criteria method for hierarchical analysis of decision processes as an important part of decision making in supply processes which are realized in the floral industry. The ABC analysis was performed in order to classify the product mix from the perspective of the demand values. This in consequence enabled us to identify the most important products which were then used as a variant in the AHP method.

  5. In vitro direct organogenesis in response to floral reversion in lily ...

    African Journals Online (AJOL)

    Our previous study indicated that the tiger lily (Lilium lancifolium var. Flore Pleno) has a great ability to produce inflorescence bulbils in nature as a form of natural phenomenon of floral reversion in plants. This present research was carried out to investigate the artificial floral reversion in in vitro culture of two lilies (Asiatic ...

  6. Receptor tyrosine phosphatase R-PTP-alpha is tyrosine-phosphorylated and associated with the adaptor protein Grb2

    DEFF Research Database (Denmark)

    Su, J; Batzer, A; Sap, J

    1994-01-01

    Receptor tyrosine phosphatases (R-PTPases) have generated interest because of their suspected involvement in cellular signal transduction. The adaptor protein Grb2 has been implicated in coupling receptor tyrosine kinases to Ras. We report that a ubiquitous R-PTPase, R-PTP-alpha, is tyrosine-phos...

  7. Design and Calibration of a Dispersive Imaging Spectrometer Adaptor for a Fast IR Camera on NSTX-U

    Science.gov (United States)

    Reksoatmodjo, Richard; Gray, Travis; Princeton Plasma Physics Laboratory Team

    2017-10-01

    A dispersive spectrometer adaptor was designed, constructed and calibrated for use on a fast infrared camera employed to measure temperatures on the lower divertor tiles of the NSTX-U tokamak. This adaptor efficiently and evenly filters and distributes long-wavelength infrared photons between 8.0 and 12.0 microns across the 128x128 pixel detector of the fast IR camera. By determining the width of these separated wavelength bands across the camera detector, and then determining the corresponding average photon count for each photon wavelength, a very accurate measurement of the temperature, and thus heat flux, of the divertor tiles can be calculated using Plank's law. This approach of designing an exterior dispersive adaptor for the fast IR camera allows accurate temperature measurements to be made of materials with unknown emissivity. Further, the relative simplicity and affordability of this adaptor design provides an attractive option over more expensive, slower, dispersive IR camera systems. This work was made possible by funding from the Department of Energy for the Summer Undergraduate Laboratory Internship (SULI) program. This work is supported by the US DOE Contract No. DE-AC02-09CH11466.

  8. Terapia floral: una alternativa de tratamiento para la mujer de edad mediana Floral therapy: an alternative treatment for the middle-age

    Directory of Open Access Journals (Sweden)

    Margeris Yanes Calderón

    2005-04-01

    Full Text Available Se realizó un trabajo dirigido a los Médicos de Familia sobre la aplicación de los remedios (esencias, elíxires florales de Bach durante la etapa climatérica. Se describen los 5 elíxires florales que han tenido mayor indicación en la consulta de climaterio del Policlínico Docente "Ana Betancourt," en el municipio Playa de la Ciudad de La Habana, así como su forma de preparación y administración. Se citan algunas esencias florales de nueva generación, que por su vibración y calidad podrían indicarse en esta etapa de la vida femenina. En aquellas mujeres de edad mediana (climatéricas, donde predominen los síntomas psicológicos sobre los circulatorios, genitourinarios y generales, la terapia floral se impone como una alternativa de tratamiento para mejorar su calidad de vida.A paper directed to the family physicians on the application of Bach's floral remedies (essence oils and elixirs during the climateric period was made. The 5 floral elixirs that have been prescribed the most at the climacteric office of "Ana Betancourt" Teaching Polyclinic, in Playa municipality, Havana City, as well as their mode of preparation and administration are described. Some new generation floral essences that due to their vibration and quality may be indicated at this stage of females' life, are mentioned. In those middle-aged women (climacteric among whom the psychological symptoms prevailed over the circulatory, genitourinary and general symptoms, the floral therapy constitutes an alternative treatment to improve their quality of life.

  9. Self-pollination rate and floral-display size in Asclepias syriaca (Common Milkweed) with regard to floral-visitor taxa

    OpenAIRE

    Howard, Aaron F; Barrows, Edward M

    2014-01-01

    Background Animals fertilize thousands of angiosperm species whose floral-display sizes can significantly influence pollinator behavior and plant reproductive success. Many studies have measured the interactions among pollinator behavior, floral-display size, and plant reproductive success, but few studies have been able to separate the effects of pollinator behavior and post-pollination processes on angiosperm sexual reproduction. In this study, we utilized the highly self-incompatible polli...

  10. Isolation and characterization of a floral homeotic gene in Fraxinus nigra causing earlier flowering and homeotic alterations in transgenic Arabidopsis

    Science.gov (United States)

    Jun Hyung Lee; Paula M. Pijut

    2017-01-01

    Reproductive sterility, which can be obtained by manipulating floral organ identity genes, is an important tool for gene containment of genetically engineered trees. In Arabidopsis, AGAMOUS (AG) is the only C-class gene responsible for both floral meristem determinacy and floral organ identity, and its mutations produce...

  11. Behavior and postharvest evaluation criteria of Vriesea incurvata Gaudich. (Bromeliaceae floral scapes

    Directory of Open Access Journals (Sweden)

    Edwin Pulido

    2017-10-01

    Full Text Available Genus Vriesea of the Bromeliaceae family are highly appreciated to use as ornamental plant due to their floral morphological characteristics, color and the beauty of inflorescences. V. incurvata has been commercialized as a potted ornamental plant. The morphological features of its floral scape may also indicate it for use as a cut flower. However, there are no information available to use of this bromeliad as a cut flower. The aim of this study was to determine quantitative and qualitative criteria in order to evaluate the postharvest behavior of V. incurvata floral scapes. It was observed that V. incurvata floral scapes has great potential to use as cut flower, which has an average of vase-life of 14.9 ± 1.5 days. Quantitative and qualitative characteristics such as color (L*, C*, H°, brightness, turgidity, stiffness, presence of injuries, relative fresh weight, water uptake and loss can be indicated as postharvest evaluation criteria of V. incurvata floral scapes.

  12. A floral induction system for the study of early Arabidopsis flower development.

    Science.gov (United States)

    O'Maoiléidigh, Diarmuid Seosamh; Wellmer, Frank

    2014-01-01

    Assessing the molecular changes that occur over the course of flower development is hampered by difficulties in isolating sufficient amounts of floral tissue at specific developmental stages. This is especially problematic when investigating molecular events at very early stages of Arabidopsis flower development, as the floral buds are minute and are initiated sequentially such that a single flower on an inflorescence is at a given developmental stage. Moreover, young floral buds are hidden by older buds, which present an additional challenge for dissection. To circumvent these issues, a floral induction system that allows the simultaneous induction of a large number of flowers on the inflorescence of a single plant was generated. To allow the plant community to avail of the full benefits of this system, we address some common problems that can be encountered when growing these plants and collecting floral buds for analysis.

  13. Interactions between bee foraging and floral resource phenology shape bee populations and communities.

    Science.gov (United States)

    Ogilvie, Jane E; Forrest, Jessica Rk

    2017-06-01

    Flowers are ephemeral, yet bees rely on them for food throughout their lives. Floral resource phenology - which can be altered by changes in climate and land-use - is therefore key to bee fitness and community composition. Here, we discuss the interactions between floral resource phenology, bee foraging behaviour, and traits such as diet breadth, sociality, and body size. Recent research on bumble bees has examined behavioural responses to local floral turnover and effects of landscape-scale floral resource phenology on fitness, abundance, and foraging distances. Comparable studies are needed on non-social, pollen-specialist species. We also encourage greater use of information contained in museum collections on bee phenologies and floral hosts to test how phenology has shaped the evolution of bee-plant associations. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Alternatively spliced short and long isoforms of adaptor protein intersectin 1 form complexes in mammalian cells

    Directory of Open Access Journals (Sweden)

    Rynditch A. V.

    2012-12-01

    Full Text Available Intersectin 1 (ITSN1 is an adaptor protein involved in membrane trafficking and cell signaling. Long and short isoforms of ITSN1 (ITSN1-L and ITSN1-S are produced by alternative splicing. The aim of our study was to investigate whether ITSN1-L and ITSN1-S could interact in mammalian cells. Methods. During this study we employed immunoprecipitation and confocal microscopy. Results. We have shown that endogenous ITSN1-S co-precipitates with overexpressed ITSN1-L in PC12, 293 and 293T cells. Long and short isoforms of ITSN1 also co-localize in 293T cells. Conclusions. ITSN1-L and ITSN1-S form complexes in mammalian cells.

  15. Specification of reproductive meristems requires the combined function of SHOOT MERISTEMLESS and floral integrators FLOWERING LOCUS T and FD during Arabidopsis inflorescence development.

    Science.gov (United States)

    Smith, Harley M S; Ung, Nolan; Lal, Shruti; Courtier, Jennifer

    2011-01-01

    In Arabidopsis floral meristems are specified on the periphery of the inflorescence meristem by the combined activities of the FLOWERING LOCUS T (FT)-FD complex and the flower meristem identity gene LEAFY. The floral specification activity of FT is dependent upon two related BELL1-like homeobox (BLH) genes PENNYWISE (PNY) and POUND-FOOLISH (PNF) which are required for floral evocation. PNY and PNF interact with a subset of KNOTTED1-LIKE homeobox proteins including SHOOT MERISTEMLESS (STM). Genetic analyses show that these BLH proteins function with STM to specify flowers and internodes during inflorescence development. In this study, experimental evidence demonstrates that the specification of flower and coflorescence meristems requires the combined activities of FT-FD and STM. FT and FD also regulate meristem maintenance during inflorescence development. In plants with reduced STM function, ectopic FT and FD promote the formation of axillary meristems during inflorescence development. Lastly, gene expression studies indicate that STM functions with FT-FD and AGAMOUS-LIKE 24 (AGL24)-SUPPRESSOR OF OVEREXPRESSION OF CONTANS1 (SOC1) complexes to up-regulate flower meristem identity genes during inflorescence development.

  16. Loss of the adaptor protein ShcA in endothelial cells protects against monocyte macrophage adhesion, LDL-oxydation, and atherosclerotic lesion formation.

    Science.gov (United States)

    Jaoude, Antoine Abou; Badiqué, Lise; Mlih, Mohamed; Awan, Sara; Guo, Sunning; Lemle, Alexandre; Abboud, Clauda; Foppolo, Sophie; Host, Lionel; Terrand, Jérôme; Justiniano, Hélène; Herz, Joachim; Matz, Rachel L; Boucher, Philippe

    2018-03-14

    ShcA is an adaptor protein that binds to the cytoplasmic tail of receptor tyrosine kinases and of the Low Density Lipoprotein-related receptor 1 (LRP1), a trans-membrane receptor that protects against atherosclerosis. Here, we examined the role of endothelial ShcA in atherosclerotic lesion formation. We found that atherosclerosis progression was markedly attenuated in mice deleted for ShcA in endothelial cells, that macrophage content was reduced at the sites of lesions, and that adhesion molecules such as the intercellular adhesion molecule-1 (ICAM-1) were severely reduced. Our data indicate that transcriptional regulation of ShcA by the zinc-finger E-box-binding homeobox 1 (ZEB1) and the Hippo pathway effector YAP, promotes ICAM-1 expression independently of p-NF-κB, the primary driver of adhesion molecules expressions. In addition, ShcA suppresses endothelial Akt and nitric oxide synthase (eNOS) expressions. Thus, through down regulation of eNOS and ZEB1-mediated ICAM-1 up regulation, endothelial ShcA promotes monocyte-macrophage adhesion and atherosclerotic lesion formation. Reducing ShcA expression in endothelial cells may represent an obvious therapeutic approach to prevent atherosclerosis.

  17. Effectiveness of Needles Vial Adaptors and Blunt Cannulas for Drug Administration in a Microgravity Environment

    Science.gov (United States)

    Hailey, Melinda; Bayuse, Tina

    2009-01-01

    The need for a new system of injectable medications aboard the International Space Station (ISS) was identified. It is desired that this system fly medications in their original manufacturer's packaging, allowing the system to comply with United States Pharmacopeia (USP) guidelines while minimizing the resupply frequency due to medication expiration. Pre-filled syringes are desired, however, the evolving nature of the healthcare marketplace requires flexibility in the redesign. If medications must be supplied in a vial, a system is required that allows for the safe withdrawal of medication from the vial into a syringe for administration in microgravity. During two reduced gravity flights, the effectiveness of two versions of a blunt cannula and needleless vial adaptors was evaluated to facilitate the withdrawal of liquid medication from a vial into a syringe for injection. Other parameters assessed included the ability to withdraw the required amount of medication and whether this is dependent on vial size, liquid, or the total volume of fluid within the vial. Injectable medications proposed for flight on ISS were used for this evaluation. Due to differing sizes of vials and the fluid properties of the medications, the needleless vial adaptors proved to be too cumbersome to recommend for use on the ISS. The blunt cannula, specifically the plastic version, proved to be more effective at removing medication from the various sizes of vials and are the recommended hardware for ISS. Fluid isolation within the vials and syringes is an important step in preparing medication for injection regardless of the hardware used. Although isolation is a challenge in the relatively short parabolas during flight, it is not an obstacle for sustained microgravity. This presentation will provide an overview of the products tested as well as the challenges identified during the microgravity flights.

  18. The effect of polyploidy and hybridization on the evolution of floral colour in Nicotiana (Solanaceae).

    Science.gov (United States)

    McCarthy, Elizabeth W; Arnold, Sarah E J; Chittka, Lars; Le Comber, Steven C; Verity, Robert; Dodsworth, Steven; Knapp, Sandra; Kelly, Laura J; Chase, Mark W; Baldwin, Ian T; Kovařík, Aleš; Mhiri, Corinne; Taylor, Lin; Leitch, Andrew R

    2015-06-01

    Speciation in angiosperms can be accompanied by changes in floral colour that may influence pollinator preference and reproductive isolation. This study investigates whether changes in floral colour can accompany polyploid and homoploid hybridization, important processes in angiosperm evolution. Spectral reflectance of corolla tissue was examined for 60 Nicotiana (Solanaceae) accessions (41 taxa) based on spectral shape (corresponding to pigmentation) as well as bee and hummingbird colour perception in order to assess patterns of floral colour evolution. Polyploid and homoploid hybrid spectra were compared with those of their progenitors to evaluate whether hybridization has resulted in floral colour shifts. Floral colour categories in Nicotiana seem to have arisen multiple times independently during the evolution of the genus. Most younger polyploids displayed an unexpected floral colour, considering those of their progenitors, in the colour perception of at least one pollinator type, whereas older polyploids tended to resemble one or both of their progenitors. Floral colour evolution in Nicotiana is weakly constrained by phylogeny, and colour shifts do occur in association with both polyploid and homoploid hybrid divergence. Transgressive floral colour in N. tabacum has arisen by inheritance of anthocyanin pigmentation from its paternal progenitor while having a plastid phenotype like its maternal progenitor. Potentially, floral colour evolution has been driven by, or resulted in, pollinator shifts. However, those polyploids that are not sympatric (on a regional scale) with their progenitor lineages are typically not divergent in floral colour from them, perhaps because of a lack of competition for pollinators. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Disruption of a belowground mutualism alters interactions between plants and their floral visitors.

    Science.gov (United States)

    Cahill, James F; Elle, Elizabeth; Smith, Glen R; Shore, Bryon H

    2008-07-01

    Plants engage in diverse and intimate interactions with unrelated taxa. For example, aboveground floral visitors provide pollination services, while belowground arbuscular mycorrhizal fungi (AMF) enhance nutrient capture. Traditionally in ecology, these processes were studied in isolation, reinforcing the prevailing assumption that these above- and belowground processes were also functionally distinct. More recently, there has been a growing realization that the soil surface is not a barrier to many ecological interactions, particularly those involving plants (who live simultaneously above and below ground). Because of the potentially large impact that mycorrhizae and floral visitors can have on plant performance and community dynamics, we designed an experiment to test whether these multi-species mutualisms were interdependent under field conditions. Using benomyl, a widely used fungicide, we suppressed AMF in a native grassland, measuring plant, fungal, and floral-visitor responses after three years of fungal suppression. AMF suppression caused a shift in the community of floral visitors from large-bodied bees to small-bodied bees and flies, and reduced the total number of floral visits per flowering stem 67% across the 23 flowering species found in the plots. Fungal suppression has species-specific effects on floral visits for the six most common flowering plants in this experiment. Exploratory analyses suggest these results were due to changes in floral-visitor behavior due to altered patch-level floral display, rather than through direct effects of AMF suppression on floral morphology. Our findings indicate that AMF are an important, and overlooked, driver of floral-visitor community structure with the potential to affect pollination services. These results support the growing body of research indicating that interactions among ecological interactions can be of meaningful effect size under natural field conditions and may influence individual performance

  20. Evolution of the process underlying floral zygomorphy development in pentapetalous angiosperms.

    Science.gov (United States)

    Bukhari, Ghadeer; Zhang, Jingbo; Stevens, Peter F; Zhang, Wenheng

    2017-12-01

    Observations of floral ontogeny indicated that floral organ initiation in pentapetalous flowers most commonly results in a median-abaxial (MAB) petal during early development, a median-adaxial (MAD) petal being less common. Such different patterns of floral organ initiation might be linked with different morphologies of floral zygomorphy that have evolved in Asteridae. Here, we provide the first study of zygomorphy in pentapetalous angiosperms placed in a phylogenetic framework, the goal being to find if the different patterns of floral organ initiation are connected with particular patterns of zygomorphy. We analyzed patterns of floral organ initiation and displays of zygomorphy, extracted from floral diagrams representing 405 taxa in 330 genera, covering 83% of orders (30 out of 36) and 37% of families (116 out of 313) in core eudicots in the context of a phylogeny using ancestral state reconstructions. The MAB petal initiation is the ancestral state of the pattern of floral organ initiation in pentapetalous angiosperms. Taxa with MAD petal initiation represent ∼30 independent origins from the ancestral MAB initiation. There are distinct developmental processes that give rise to zygomorphy in different lineages of pentapetalous angiosperms, closely related lineages being likely to share similar developmental processes. We have demonstrated that development indeed constrains the processes that give rise to floral zygomorphy, while phylogenetic distance allows relaxation of these constraints, which provides novel insights on the role that development plays in the evolution of floral zygomorphy. © 2017 Bukhari et al. Published by the Botanical Society of America. This work is licensed under a Creative Commons Attribution License (CC-BY-NC).

  1. Identification of major quantitative trait loci underlying floral pollination syndrome divergence in Penstemon.

    Science.gov (United States)

    Wessinger, Carolyn A; Hileman, Lena C; Rausher, Mark D

    2014-08-05

    Distinct floral pollination syndromes have emerged multiple times during the diversification of flowering plants. For example, in western North America, a hummingbird pollination syndrome has evolved more than 100 times, generally from within insect-pollinated lineages. The hummingbird syndrome is characterized by a suite of floral traits that attracts and facilitates pollen movement by hummingbirds, while at the same time discourages bee visitation. These floral traits generally include large nectar volume, red flower colour, elongated and narrow corolla tubes and reproductive organs that are exerted from the corolla. A handful of studies have examined the genetic architecture of hummingbird pollination syndrome evolution. These studies find that mutations of relatively large effect often explain increased nectar volume and transition to red flower colour. In addition, they suggest that adaptive suites of floral traits may often exhibit a high degree of genetic linkage, which could facilitate their fixation during pollination syndrome evolution. Here, we explore these emerging generalities by investigating the genetic basis of floral pollination syndrome divergence between two related Penstemon species with different pollination syndromes--bee-pollinated P. neomexicanus and closely related hummingbird-pollinated P. barbatus. In an F2 mapping population derived from a cross between these two species, we characterized the effect size of genetic loci underlying floral trait divergence associated with the transition to bird pollination, as well as correlation structure of floral trait variation. We find the effect sizes of quantitative trait loci for adaptive floral traits are in line with patterns observed in previous studies, and find strong evidence that suites of floral traits are genetically linked. This linkage may be due to genetic proximity or pleiotropic effects of single causative loci. Interestingly, our data suggest that the evolution of floral traits

  2. Floral traits and pollination ecology of European Arum hybrids.

    Science.gov (United States)

    Chartier, Marion; Liagre, Suzanne; Weiss-Schneeweiss, Hanna; Kolano, Bozena; Bessière, Jean-Marie; Schönenberger, Jürg; Gibernau, Marc

    2016-02-01

    Hybridisation is common in plants and can affect the genetic diversity and ecology of sympatric parental populations. Hybrids may resemble the parental species in their ecology, leading to competition and/or gene introgression; alternatively, they may diverge from the parental phenotypes, possibly leading to the colonisation of new ecological niches and to speciation. Here, we describe inflorescence morphology, ploidy levels, pollinator attractive scents, and pollinator guilds of natural hybrids of Arum italicum and A. maculatum (Araceae) from a site with sympatric parental populations in southern France to determine how these traits affect the hybrid pollination ecology. Hybrids were characterised by inflorescences with a size and a number of flowers more similar to A. italicum than to A. maculatum. In most cases, hybrid stamens were purple, as in A. maculatum, and spadix appendices yellow, as in A. italicum. Hybrid floral scent was closer to that of A. italicum, but shared some compounds with A. maculatum and comprised unique compounds. Also, the pollinator guild of the hybrids was similar to that of A. italicum. Nevertheless, the hybrids attracted a high proportion of individuals of the main pollinator of A. maculatum. We discuss the effects of hybridisation in sympatric parental zones in which hybrids exhibit low levels of reproductive success, the establishment of reproductive barriers between parental species, the role of the composition of floral attractive scents in the differential attraction of pollinators and in the competition between hybrids and their parental species, and the potential of hybridisation to give rise to new independent lineages.

  3. Natural selection on floral morphology can be influenced by climate.

    Science.gov (United States)

    Campbell, Diane R; Powers, John M

    2015-06-07

    Climate has the potential to influence evolution, but how it influences the strength or direction of natural selection is largely unknown. We quantified the strength of selection on four floral traits of the subalpine herb Ipomopsis sp. in 10 years that differed in precipitation, causing extreme temporal variation in the date of snowmelt in the Colorado Rocky Mountains. The chosen floral traits were under selection by hummingbird and hawkmoth pollinators, with hawkmoth abundance highly variable across years. Selection for flower length showed environmental sensitivity, with stronger selection in years with later snowmelt, as higher water resources can allow translation of pollination success into fitness based on seed production. Selection on corolla width also varied across years, favouring narrower corolla tubes in two unusual years with hawkmoths, and wider corollas in another late snowmelt year. Our results illustrate how changes in climate could alter natural selection even when the primary selective agent is not directly influenced. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  4. Heat stress differentially modifies ethylene biosynthesis and signaling in pea floral and fruit tissues.

    Science.gov (United States)

    Savada, Raghavendra P; Ozga, Jocelyn A; Jayasinghege, Charitha P A; Waduthanthri, Kosala D; Reinecke, Dennis M

    2017-10-01

    Ethylene biosynthesis is regulated in reproductive tissues in response to heat stress in a manner to optimize resource allocation to pollinated fruits with developing seeds. High temperatures during reproductive development are particularly detrimental to crop fruit/seed production. Ethylene plays vital roles in plant development and abiotic stress responses; however, little is known about ethylene's role in reproductive tissues during development under heat stress. We assessed ethylene biosynthesis and signaling regulation within the reproductive and associated tissues of pea during the developmental phase that sets the stage for fruit-set and seed development under normal and heat-stress conditions. The transcript abundance profiles of PsACS [encode enzymes that convert S-adenosyl-L-methionine to 1-aminocyclopropane-1-carboxylic acid (ACC)] and PsACO (encode enzymes that convert ACC to ethylene), and ethylene evolution were developmentally, environmentally, and tissue-specifically regulated in the floral/fruit/pedicel tissues of pea. Higher transcript abundance of PsACS and PsACO in the ovaries, and PsACO in the pedicels was correlated with higher ethylene evolution and ovary senescence and pedicel abscission in fruits that were not pollinated under control temperature conditions. Under heat-stress conditions, up-regulation of ethylene biosynthesis gene expression in pre-pollinated ovaries was also associated with higher ethylene evolution and lower retention of these fruits. Following successful pollination and ovule fertilization, heat-stress modified PsACS and PsACO transcript profiles in a manner that suppressed ovary ethylene evolution. The normal ethylene burst in the stigma/style and petals following pollination was also suppressed by heat-stress. Transcript abundance profiles of ethylene receptor and signaling-related genes acted as qualitative markers of tissue ethylene signaling events. These data support the hypothesis that ethylene biosynthesis is

  5. Herbivory by a Phloem-feeding insect inhibits floral volatile production.

    Directory of Open Access Journals (Sweden)

    Martin Pareja

    Full Text Available There is extensive knowledge on the effects of insect herbivory on volatile emission from vegetative tissue, but little is known about its impact on floral volatiles. We show that herbivory by phloem-feeding aphids inhibits floral volatile emission in white mustard Sinapis alba measured by gas chromatographic analysis of headspace volatiles. The effect of the Brassica specialist aphid Lipaphis erysimi was stronger than the generalist aphid Myzus persicae and feeding by chewing larvae of the moth Plutella xylostella caused no reduction in floral volatile emission. Field observations showed no effect of L. erysimi-mediated floral volatile emission on the total number of flower visits by pollinators. Olfactory bioassays suggested that although two aphid natural enemies could detect aphid inhibition of floral volatiles, their olfactory orientation to infested plants was not disrupted. This is the first demonstration that phloem-feeding herbivory can affect floral volatile emission, and that the outcome of interaction between herbivory and floral chemistry may differ depending on the herbivore's feeding mode and degree of specialisation. The findings provide new insights into interactions between insect herbivores and plant chemistry.

  6. Convergent evolution of floral signals underlies the success of Neotropical orchids.

    Science.gov (United States)

    Papadopulos, Alexander S T; Powell, Martyn P; Pupulin, Franco; Warner, Jorge; Hawkins, Julie A; Salamin, Nicolas; Chittka, Lars; Williams, Norris H; Whitten, W Mark; Loader, Deniz; Valente, Luis M; Chase, Mark W; Savolainen, Vincent

    2013-08-22

    The great majority of plant species in the tropics require animals to achieve pollination, but the exact role of floral signals in attraction of animal pollinators is often debated. Many plants provide a floral reward to attract a guild of pollinators, and it has been proposed that floral signals of non-rewarding species may converge on those of rewarding species to exploit the relationship of the latter with their pollinators. In the orchid family (Orchidaceae), pollination is almost universally animal-mediated, but a third of species provide no floral reward, which suggests that deceptive pollination mechanisms are prevalent. Here, we examine floral colour and shape convergence in Neotropical plant communities, focusing on certain food-deceptive Oncidiinae orchids (e.g. Trichocentrum ascendens and Oncidium nebulosum) and rewarding species of Malpighiaceae. We show that the species from these two distantly related families are often more similar in floral colour and shape than expected by chance and propose that a system of multifarious floral mimicry--a form of Batesian mimicry that involves multiple models and is more complex than a simple one model-one mimic system--operates in these orchids. The same mimetic pollination system has evolved at least 14 times within the species-rich Oncidiinae throughout the Neotropics. These results help explain the extraordinary diversification of Neotropical orchids and highlight the complexity of plant-animal interactions.

  7. Herbivory by a Phloem-feeding insect inhibits floral volatile production.

    Science.gov (United States)

    Pareja, Martin; Qvarfordt, Erika; Webster, Ben; Mayon, Patrick; Pickett, John; Birkett, Michael; Glinwood, Robert

    2012-01-01

    There is extensive knowledge on the effects of insect herbivory on volatile emission from vegetative tissue, but little is known about its impact on floral volatiles. We show that herbivory by phloem-feeding aphids inhibits floral volatile emission in white mustard Sinapis alba measured by gas chromatographic analysis of headspace volatiles. The effect of the Brassica specialist aphid Lipaphis erysimi was stronger than the generalist aphid Myzus persicae and feeding by chewing larvae of the moth Plutella xylostella caused no reduction in floral volatile emission. Field observations showed no effect of L. erysimi-mediated floral volatile emission on the total number of flower visits by pollinators. Olfactory bioassays suggested that although two aphid natural enemies could detect aphid inhibition of floral volatiles, their olfactory orientation to infested plants was not disrupted. This is the first demonstration that phloem-feeding herbivory can affect floral volatile emission, and that the outcome of interaction between herbivory and floral chemistry may differ depending on the herbivore's feeding mode and degree of specialisation. The findings provide new insights into interactions between insect herbivores and plant chemistry.

  8. First evidence of putrescine involvement in mitigating the floral malformation in mangoes: a scanning electron microscope study.

    Science.gov (United States)

    Singh, Archana; Ansari, Mohammad W; Rani, Varsha; Singh, C P; Shukla, Alok; Pant, Ramesh C; Tuteja, Narendra; Bains, Gurdeep

    2014-09-01

    Floral malformation is the most destructive disease in mangoes. To date, the etiology of this disease has not been resolved. There are indications that stress-stimulated ethylene production might be responsible for the disease. Putrescine mediates various physiological processes for normal functioning and cellular metabolism. Here, the effect of putrescine in concentration ranging from 10(-1) to 10(-3) M was evaluated on disease incidence during mango flowering seasons of 2012 and 2013. In a scanning electron microscopy (SEM) study, putrescine (10(-2) M)-treated malformed floral buds bloomed into opened flowers with separated sepals and/or petals like healthy, whereas the untreated (control) malformed buds remained deformed. Further, malformed flowers recovered upon putrescine treatment, displaying clearly bilobed anthers, enclosing a large number of normal pollen grains and functional ovary with broad stigmatic surface as compared to control. The present findings provide the first report to demonstrate the role of putrescine in reducing various adverse effects of stress ethylene via decelerating the higher pace of its biosynthesis. It stabilizes the normal morphology, development, and functions of malformed reproductive organs to facilitate successful pollination, fertilization, and, thereby, fruit set in mango flowers. However, putrescine-ethylene-mediated cell signaling network, involving various genes to trigger the response, which regulates a wide range of developmental and physiological processes leading to normal cell physiology, needs to be investigated further.

  9. Jasmonoyl-L-isoleucine coordinates metabolic networks required for anthesis and floral attractant emission in wild tobacco (Nicotiana attenuata).

    Science.gov (United States)

    Stitz, Michael; Hartl, Markus; Baldwin, Ian T; Gaquerel, Emmanuel

    2014-10-01

    Jasmonic acid and its derivatives (jasmonates [JAs]) play central roles in floral development and maturation. The binding of jasmonoyl-L-isoleucine (JA-Ile) to the F-box of CORONATINE INSENSITIVE1 (COI1) is required for many JA-dependent physiological responses, but its role in anthesis and pollinator attraction traits remains largely unexplored. Here, we used the wild tobacco Nicotiana attenuata, which develops sympetalous flowers with complex pollination biology, to examine the coordinating function of JA homeostasis in the distinct metabolic processes that underlie flower maturation, opening, and advertisement to pollinators. From combined transcriptomic, targeted metabolic, and allometric analyses of transgenic N. attenuata plants for which signaling deficiencies were complemented with methyl jasmonate, JA-Ile, and its functional homolog, coronatine (COR), we demonstrate that (1) JA-Ile/COR-based signaling regulates corolla limb opening and a JA-negative feedback loop; (2) production of floral volatiles (night emissions of benzylacetone) and nectar requires JA-Ile/COR perception through COI1; and (3) limb expansion involves JA-Ile-induced changes in limb fresh mass and carbohydrate metabolism. These findings demonstrate a master regulatory function of the JA-Ile/COI1 duet for the main function of a sympetalous corolla, that of advertising for and rewarding pollinator services. Flower opening, by contrast, requires JA-Ile signaling-dependent changes in primary metabolism, which are not compromised in the COI1-silenced RNA interference line used in this study. © 2014 American Society of Plant Biologists. All rights reserved.

  10. Floral humidity as a reliable sensory cue for profitability assessment by nectar-foraging hawkmoths

    Science.gov (United States)

    von Arx, Martin; Goyret, Joaquín; Davidowitz, Goggy; Raguso, Robert A.

    2012-01-01

    Most research on plant–pollinator communication has focused on sensory and behavioral responses to relatively static cues. Floral rewards such as nectar, however, are dynamic, and foraging animals will increase their energetic profit if they can make use of floral cues that more accurately indicate nectar availability. Here we document such a cue—transient humidity gradients—using the night blooming flowers of Oenothera cespitosa (Onagraceae). The headspace of newly opened flowers reaches levels of about 4% above ambient relative humidity due to additive evapotranspirational water loss through petals and water-saturated air from the nectar tube. Floral humidity plumes differ from ambient levels only during the first 30 min after anthesis (before nectar is depleted in wild populations), whereas other floral traits (scent, shape, and color) persist for 12–24 h. Manipulative experiments indicated that floral humidity gradients are mechanistically linked to nectar volume and therefore contain information about energy rewards to floral visitors. Behavioral assays with Hyles lineata (Sphingidae) and artificial flowers with appropriate humidity gradients suggest that these hawkmoth pollinators distinguish between subtle differences in relative humidity when other floral cues are held constant. Moths consistently approached and probed flowers with elevated humidity over those with ambient humidity levels. Because floral humidity gradients are largely produced by the evaporation of nectar itself, they represent condition-informative cues that facilitate remote sensing of floral profitability by discriminating foragers. In a xeric environment, this level of honest communication should be adaptive when plant reproductive success is pollinator limited, due to intense competition for the attention of a specialized pollinator. PMID:22645365

  11. Insight into Phosphatidylinositol-Dependent Membrane Localization of the Innate Immune Adaptor Protein Toll/Interleukin 1 Receptor Domain-Containing Adaptor Protein

    Science.gov (United States)

    Patra, Mahesh Chandra; Choi, Sangdun

    2018-01-01

    The toll/interleukin 1 receptor (TIR) domain-containing adaptor protein (TIRAP) plays an important role in the toll-like receptor (TLR) 2, TLR4, TLR7, and TLR9 signaling pathways. TIRAP anchors to phosphatidylinositol (PI) 4,5-bisphosphate (PIP2) on the plasma membrane and PI (3,4,5)-trisphosphate (PIP3) on the endosomal membrane and assists in recruitment of the myeloid differentiation primary response 88 protein to activated TLRs. To date, the structure and mechanism of TIRAP’s membrane association are only partially understood. Here, we modeled an all-residue TIRAP dimer using homology modeling, threading, and protein–protein docking strategies. Molecular dynamics simulations revealed that PIP2 creates a stable microdomain in a dipalmitoylphosphatidylcholine bilayer, providing TIRAP with its physiologically relevant orientation. Computed binding free energy values suggest that the affinity of PI-binding domain (PBD) for PIP2 is stronger than that of TIRAP as a whole for PIP2 and that the short PI-binding motif (PBM) contributes to the affinity between PBD and PIP2. Four PIP2 molecules can be accommodated by distinct lysine-rich surfaces on the dimeric PBM. Along with the known PI-binding residues (K15, K16, K31, and K32), additional positively charged residues (K34, K35, and R36) showed strong affinity toward PIP2. Lysine-to-alanine mutations at the PI-binding residues abolished TIRAP’s affinity for PIP2; however, K34, K35, and R36 consistently interacted with PIP2 headgroups through hydrogen bond (H-bond) and electrostatic interactions. TIRAP exhibited a PIP2-analogous intermolecular contact and binding affinity toward PIP3, aided by an H-bond network involving K34, K35, and R36. The present study extends our understanding of TIRAP’s membrane association, which could be helpful in designing peptide decoys to block TLR2-, TLR4-, TLR7-, and TLR9-mediated autoimmune diseases. PMID:29434596

  12. Insight into Phosphatidylinositol-Dependent Membrane Localization of the Innate Immune Adaptor Protein Toll/Interleukin 1 Receptor Domain-Containing Adaptor Protein

    Directory of Open Access Journals (Sweden)

    Mahesh Chandra Patra

    2018-01-01

    Full Text Available The toll/interleukin 1 receptor (TIR domain-containing adaptor protein (TIRAP plays an important role in the toll-like receptor (TLR 2, TLR4, TLR7, and TLR9 signaling pathways. TIRAP anchors to phosphatidylinositol (PI 4,5-bisphosphate (PIP2 on the plasma membrane and PI (3,4,5-trisphosphate (PIP3 on the endosomal membrane and assists in recruitment of the myeloid differentiation primary response 88 protein to activated TLRs. To date, the structure and mechanism of TIRAP’s membrane association are only partially understood. Here, we modeled an all-residue TIRAP dimer using homology modeling, threading, and protein–protein docking strategies. Molecular dynamics simulations revealed that PIP2 creates a stable microdomain in a dipalmitoylphosphatidylcholine bilayer, providing TIRAP with its physiologically relevant orientation. Computed binding free energy values suggest that the affinity of PI-binding domain (PBD for PIP2 is stronger than that of TIRAP as a whole for PIP2 and that the short PI-binding motif (PBM contributes to the affinity between PBD and PIP2. Four PIP2 molecules can be accommodated by distinct lysine-rich surfaces on the dimeric PBM. Along with the known PI-binding residues (K15, K16, K31, and K32, additional positively charged residues (K34, K35, and R36 showed strong affinity toward PIP2. Lysine-to-alanine mutations at the PI-binding residues abolished TIRAP’s affinity for PIP2; however, K34, K35, and R36 consistently interacted with PIP2 headgroups through hydrogen bond (H-bond and electrostatic interactions. TIRAP exhibited a PIP2-analogous intermolecular contact and binding affinity toward PIP3, aided by an H-bond network involving K34, K35, and R36. The present study extends our understanding of TIRAP’s membrane association, which could be helpful in designing peptide decoys to block TLR2-, TLR4-, TLR7-, and TLR9-mediated autoimmune diseases.

  13. Floral diversity and pollination strategies of three rheophytic Schismatoglottideae (Araceae).

    Science.gov (United States)

    Low, S L; Wong, S Y; Ooi, I H; Hesse, M; Städler, Y; Schönenberger, J; Boyce, P C

    2016-01-01

    Homoplastic evolution of 'unique' morphological characteristics in the Schismatoglottideae - many previously used to define genera - prompted this study to compare morphology and function in connection with pollination biology for Aridarum nicolsonii, Phymatarum borneense and Schottarum sarikeense. Aridarum nicolsonii and P. borneense extrude pollen through a pair of horned thecae while S. sarikeense sheds pollen through a pair of pores on the thecae. Floral traits of spathe constriction, presence and movement of sterile structures on the spadix, the comparable role of horned thecae and thecae pores, the presence of stamen-associated calcium oxalate packages, and the timing of odour emission are discussed in the context of their roles in pollinator management. Pollinators for all investigated species were determined to be species of Colocasiomyia (Diptera: Drosophilidae). © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  14. Floral guidance of learning a preference for symmetry by bumblebees.

    Science.gov (United States)

    Plowright, Catherine M S; Bridger, Jeremy J M; Xu, Vicki; Herlehy, Racheal A; Collin, Charles A

    2017-11-01

    This study examines the mechanism underlying one way in which bumblebees are known to develop a preference for symmetric patterns: through prior non-differential reinforcement on simple patterns (black discs and white discs). In three experiments, bees were given a choice among symmetric and asymmetric black-and-white non-rewarding patterns presented at the ends of corridors in a radial maze. Experimental groups had prior rewarded non-discrimination training on white patterns and black patterns, while control groups had no pre-test experience outside the colony. No preference for symmetry was obtained for any of the control groups. Prior training with circular patterns highlighting a horizontal axis of symmetry led to a specific subsequent preference for horizontal over vertical symmetry, while training with a vertical axis abolished this effect. Circles highlighting both axes created a general avoidance of asymmetry in favour of symmetric patterns with vertical, horizontal or both axes of symmetry. Training with plain circles, but not with deformed circles, led to a preference for symmetry: there was no evidence that the preference emerged just by virtue of having attention drawn away from irrelevant pattern differences. Our results point to a preference for symmetry developing gradually through first learning to extract an axis of symmetry from simple patterns and subsequently recognizing that axis in new patterns. They highlight the importance of continued learning through non-differential reinforcement by skilled foragers. Floral guides can function not only to guide pollinators to the source of reward but also to highlight an axis of symmetry for use in subsequent floral encounters.

  15. The genetic architecture of UV floral patterning in sunflower.

    Science.gov (United States)

    Moyers, Brook T; Owens, Gregory L; Baute, Gregory J; Rieseberg, Loren H

    2017-07-01

    The patterning of floral ultraviolet (UV) pigmentation varies both intra- and interspecifically in sunflowers and many other plant species, impacts pollinator attraction, and can be critical to reproductive success and crop yields. However, the genetic basis for variation in UV patterning is largely unknown. This study examines the genetic architecture for proportional and absolute size of the UV bullseye in Helianthus argophyllus , a close relative of the domesticated sunflower. A camera modified to capture UV light (320-380 nm) was used to phenotype floral UV patterning in an F 2 mapping population, then quantitative trait loci (QTL) were identified using genotyping-by-sequencing and linkage mapping. The ability of these QTL to predict the UV patterning of natural population individuals was also assessed. Proportional UV pigmentation is additively controlled by six moderate effect QTL that are predictive of this phenotype in natural populations. In contrast, UV bullseye size is controlled by a single large effect QTL that also controls flowerhead size and co-localizes with a major flowering time QTL in Helianthus . The co-localization of the UV bullseye size QTL, flowerhead size QTL and a previously known flowering time QTL may indicate a single highly pleiotropic locus or several closely linked loci, which could inhibit UV bullseye size from responding to selection without change in correlated characters. The genetic architecture of proportional UV pigmentation is relatively simple and different from that of UV bullseye size, and so should be able to respond to natural or artificial selection independently. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  16. De novo sequencing and comparative transcriptome analysis of white petals and red labella in Phalaenopsis for discovery of genes related to flower color and floral differentation

    Directory of Open Access Journals (Sweden)

    Yuxia Yang

    2014-09-01

    Full Text Available Phalaenopsis is one of the world’s most popular and important epiphytic monopodial orchids. The extraordinary floral diversity of Phalaenopsis is a reflection of its evolutionary success. As a consequence of this diversity, and of the complexity of flower color development in Phalaenopsis, this species is a valuable research material for developmental biology studies. Nevertheless, research on the molecular mechanisms underlying flower color and floral organ formation in Phalaenopsis is still in the early phases. In this study, we generated large amounts of data from Phalaenopsis flowers by combining Illumina sequencing with differentially expressed gene (DEG analysis. We obtained 37 723 and 34 020 unigenes from petals and labella, respectively. A total of 2736 DEGs were identified, and the functions of many DEGs were annotated by BLAST-searching against several public databases. We mapped 837 up-regulated DEGs (432 from petals and 405 from labella to 102 Kyoto Encyclopedia of Genes and Genomes pathways. Almost all pathways were represented in both petals (102 pathways and labella (99 pathways. DEGs involved in energy metabolism were significantly differentially distributed between labella and petals, and various DEGs related to flower color and floral differentiation were found in the two organs. Interestingly, we also identified genes encoding several key enzymes involved in carotenoid synthesis. These genes were differentially expressed between petals and labella, suggesting that carotenoids may influence Phalaenopsis flower color. We thus conclude that a combination of anthocyanins and/or carotenoids determine flower color formation in Phalaenopsis. These results broaden our understanding of the mechanisms controlling flower color and floral organ differentiation in Phalaenopsis and other orchids.

  17. Highly pathogenic avian influenza virus nucleoprotein interacts with TREX complex adaptor protein Aly/REF.

    Directory of Open Access Journals (Sweden)

    Vinod R M T Balasubramaniam

    Full Text Available We constructed a novel chicken (Gallus gallus lung cDNA library fused inside yeast acting domain vector (pGADT7. Using yeast two-hybrid screening with highly pathogenic avian influenza (HPAI nucleoprotein (NP from the strain (A/chicken/Malaysia/5858/2004(H5N1 as bait, and the Gallus gallus lung cDNA library as prey, a novel interaction between the Gallus gallus cellular RNA export adaptor protein Aly/REF and the viral NP was identified. This interaction was confirmed and validated with mammalian two hybrid studies and co-immunoprecipitation assay. Cellular localization studies using confocal microscopy showed that NP and Aly/REF co-localize primarily in the nucleus. Further investigations by mammalian two hybrid studies into the binding of NP of other subtypes of influenza virus such as the swine A/New Jersey/1976/H1N1 and pandemic A/Malaysia/854/2009(H1N1 to human Aly/REF, also showed that the NP of these viruses interacts with human Aly/REF. Our findings are also supported by docking studies which showed tight and favorable binding between H5N1 NP and human Aly/REF, using crystal structures from Protein Data Bank. siRNA knockdown of Aly/REF had little effect on the export of HPAI NP and other viral RNA as it showed no significant reduction in virus titer. However, UAP56, another component of the TREX complex, which recruits Aly/REF to mRNA was found to interact even better with H5N1 NP through molecular docking studies. Both these proteins also co-localizes in the nucleus at early infection similar to Aly/REF. Intriguingly, knockdown of UAP56 in A549 infected cells shows significant reduction in viral titer (close to 10 fold reduction. Conclusively, our study have opened new avenues for research of other cellular RNA export adaptors crucial in aiding viral RNA export such as the SRSF3, 9G8 and ASF/SF2 that may play role in influenza virus RNA nucleocytoplasmic transport.

  18. LIME: a new membrane raft-associated adaptor protein involved in CD4 and CD8 coreceptor signaling

    Czech Academy of Sciences Publication Activity Database

    Brdičková, Naděžda; Brdička, Tomáš; Angelisová, Pavla; Horváth, Ondřej; Špička, Jiří; Hilgert, Ivan; Pačes, Jan; Simeoni, L.; Kliche, S.; Merten, C.; Schraven, B.; Hořejší, Václav

    2003-01-01

    Roč. 198, č. 10 (2003), s. 1453-1462 ISSN 0022-1007 R&D Projects: GA MŠk LN00A079; GA MŠk LN00A026 Grant - others:Wellcome Trust(GB) J1116W24Z Institutional research plan: CEZ:AV0Z5052915 Keywords : immunology * T-lymphocyte * adaptor protein Subject RIV: EC - Immunology Impact factor: 15.302, year: 2003

  19. APS, an adaptor molecule containing PH and SH2 domains, has a negative regulatory role in B cell proliferation

    International Nuclear Information System (INIS)

    Iseki, Masanori; Kubo-Akashi, Chiyomi; Kwon, Sang-Mo; Yamaguchi, Akiko; Takatsu, Kiyoshi; Takaki, Satoshi

    2005-01-01

    Adaptor molecule containing PH and SH2 domains (APS) is an intracellular adaptor protein that forms part of an adaptor family along with Lnk and SH2-B. APS transcripts are expressed in various tissues including brain, kidney, and muscle, as well as in splenic B cells but not in T cells. We investigated the functions of APS in B cell development and activation by generating APS-transgenic (APS-Tg) mice that overexpressed APS in lymphocytes. The number of B-1 cells in the peritoneal cavity was reduced in APS-Tg mice, as were B-2 cells in the spleen. B cell development in the bone marrow was partially impaired at the transition stage from proliferating large pre-B to small pre-B cells. B cell proliferation induced by B cell receptor (BCR) crosslinking but not by other B cell mitogens was also impaired in APS-Tg mice. APS co-localized with BCR complexes and filamentous actin in activated APS-Tg B cells. Thus, APS appears to play novel negative regulatory roles in BCR signaling, actin reorganization pathways, and control of compartment sizes of B-lineage cells

  20. Nrf2 reduces levels of phosphorylated tau protein by inducing autophagy adaptor protein NDP52

    Science.gov (United States)

    Jo, Chulman; Gundemir, Soner; Pritchard, Susanne; Jin, Youngnam N.; Rahman, Irfan; Johnson, Gail V. W.

    2014-03-01

    Nuclear factor erythroid 2-related factor 2 (Nrf2) is a pivotal transcription factor in the defence against oxidative stress. Here we provide evidence that activation of the Nrf2 pathway reduces the levels of phosphorylated tau by induction of an autophagy adaptor protein NDP52 (also known as CALCOCO2) in neurons. The expression of NDP52, which we show has three antioxidant response elements (AREs) in its promoter region, is strongly induced by Nrf2, and its overexpression facilitates clearance of phosphorylated tau in the presence of an autophagy stimulator. In Nrf2-knockout mice, phosphorylated and sarkosyl-insoluble tau accumulates in the brains concurrent with decreased levels of NDP52. Moreover, NDP52 associates with phosphorylated tau from brain cortical samples of Alzheimer disease cases, and the amount of phosphorylated tau in sarkosyl-insoluble fractions is inversely proportional to that of NDP52. These results suggest that NDP52 plays a key role in autophagy-mediated degradation of phosphorylated tau in vivo.

  1. Neuronal adaptor FE65 stimulates Rac1-mediated neurite outgrowth by recruiting and activating ELMO1.

    Science.gov (United States)

    Li, Wen; Tam, Ka Ming Vincent; Chan, Wai Wan Ray; Koon, Alex Chun; Ngo, Jacky Chi Ki; Chan, Ho Yin Edwin; Lau, Kwok-Fai

    2018-04-03

    Neurite outgrowth is a crucial process in developing neurons for neural network formation. Understanding the regulatory mechanisms of neurite outgrowth is essential for developing strategies to stimulate neurite regeneration after nerve injury and in neurodegenerative disorders. FE65 is a brain-enriched adaptor that stimulates Rac1-mediated neurite elongation. However, the precise mechanism by which FE65 promotes the process remains elusive. Here, we show that ELMO1, a subunit of ELMO1-DOCK180 bipartite Rac1 GEF, interacts with the FE65 N-terminal region. Overexpression of FE65 and/or ELMO1 enhances whereas knockdown of FE65 or ELMO1 inhibits neurite outgrowth and Rac1 activation. The effect of FE65 alone or together with ELMO1 is attenuated by an FE65 double mutation that disrupts FE65-ELMO1 interaction. Notably, FE65 is found to activate ELMO1 by diminishing ELMO1 intramolecular autoinhibitory interaction and to promote the targeting of ELMO1 to the plasma membrane where Rac1 is activated. We also show that FE65, ELMO1 and DOCK180 form a tripartite complex. Knockdown of DOCK180 reduces the stimulatory effect of FE65-ELMO1 on Rac1 activation and neurite outgrowth. Thus, we identify a novel mechanism that FE65 stimulates Rac1-mediated neurite outgrowth by recruiting and activating of ELMO1. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

  2. The adaptor molecule SAP plays essential roles during invariant NKT cell cytotoxicity and lytic synapse formation.

    Science.gov (United States)

    Das, Rupali; Bassiri, Hamid; Guan, Peng; Wiener, Susan; Banerjee, Pinaki P; Zhong, Ming-Chao; Veillette, André; Orange, Jordan S; Nichols, Kim E

    2013-04-25

    The adaptor molecule signaling lymphocytic activation molecule-associated protein (SAP) plays critical roles during invariant natural killer T (iNKT) cell ontogeny. As a result, SAP-deficient humans and mice lack iNKT cells. The strict developmental requirement for SAP has made it difficult to discern its possible involvement in mature iNKT cell functions. By using temporal Cre recombinase-mediated gene deletion to ablate SAP expression after completion of iNKT cell development, we demonstrate that SAP is essential for T-cell receptor (TCR)-induced iNKT cell cytotoxicity against T-cell and B-cell leukemia targets in vitro and iNKT-cell-mediated control of T-cell leukemia growth in vivo. These findings are not restricted to the murine system: silencing RNA-mediated suppression of SAP expression in human iNKT cells also significantly impairs TCR-induced cytolysis. Mechanistic studies reveal that iNKT cell killing requires the tyrosine kinase Fyn, a known SAP-binding protein. Furthermore, SAP expression is required within iNKT cells to facilitate their interaction with T-cell targets and induce reorientation of the microtubule-organizing center to the immunologic synapse (IS). Collectively, these studies highlight a novel and essential role for SAP during iNKT cell cytotoxicity and formation of a functional IS.

  3. Development of STEP-NC Adaptor for Advanced Web Manufacturing System

    Science.gov (United States)

    Ajay Konapala, Mr.; Koona, Ramji, Dr.

    2017-08-01

    Information systems play a key role in the modern era of Information Technology. Rapid developments in IT & global competition calls for many changes in basic CAD/CAM/CAPP/CNC manufacturing chain of operations. ‘STEP-NC’ an enhancement to STEP for operating CNC machines, creating new opportunities for collaborative, concurrent, adaptive works across the manufacturing chain of operations. Schemas and data models defined by ISO14649 in liaison with ISO10303 standards made STEP-NC file rich with feature based, rather than mere point to point information of G/M Code format. But one needs to have a suitable information system to understand and modify these files. Various STEP-NC information systems are reviewed to understand the suitability of STEP-NC for web manufacturing. Present work also deals with the development of an adaptor which imports STEP-NC file, organizes its information, allowing modifications to entity values and finally generates a new STEP-NC file to export. The system is designed and developed to work on web to avail additional benefits through the web and also to be part of a proposed ‘Web based STEP-NC manufacturing platform’ which is under development and explained as future scope.

  4. Dengue Virus Targets the Adaptor Protein MITA to Subvert Host Innate Immunity

    Science.gov (United States)

    Yu, Chia-Yi; Chang, Tsung-Hsien; Liang, Jian-Jong; Chiang, Ruei-Lin; Lee, Yi-Ling; Liao, Ching-Len; Lin, Yi-Ling

    2012-01-01

    Dengue is one of the most important arboviral diseases caused by infection of four serotypes of dengue virus (DEN). We found that activation of interferon regulatory factor 3 (IRF3) triggered by viral infection and by foreign DNA and RNA stimulation was blocked by DEN-encoded NS2B3 through a protease-dependent mechanism. The key adaptor protein in type I interferon pathway, human mediator of IRF3 activation (MITA) but not the murine homologue MPYS, was cleaved in cells infected with DEN-1 or DEN-2 and with expression of the enzymatically active protease NS2B3. The cleavage site of MITA was mapped to LRR↓96G and the function of MITA was suppressed by dengue protease. DEN replication was reduced with overexpression of MPYS but not with MITA, while DEN replication was enhanced by MPYS knockdown, indicating an antiviral role of MITA/MPYS against DEN infection. The involvement of MITA in DEN-triggered innate immune response was evidenced by reduction of IRF3 activation and IFN induction in cells with MITA knockdown upon DEN-2 infection. NS2B3 physically interacted with MITA, and the interaction and cleavage of MITA could be further enhanced by poly(dA:dT) stimulation. Thus, we identified MITA as a novel host target of DEN protease and provide the molecular mechanism of how DEN subverts the host innate immunity. PMID:22761576

  5. Artificial Neural Network for the Prediction of Tyrosine-Based Sorting Signal Recognition by Adaptor Complexes

    Directory of Open Access Journals (Sweden)

    Debarati Mukherjee

    2012-01-01

    Full Text Available Sorting of transmembrane proteins to various intracellular compartments depends on specific signals present within their cytosolic domains. Among these sorting signals, the tyrosine-based motif (YXXØ is one of the best characterized and is recognized by μ-subunits of the four clathrin-associated adaptor complexes (AP-1 to AP-4. Despite their overlap in specificity, each μ-subunit has a distinct sequence preference dependent on the nature of the X-residues. Moreover, combinations of these residues exert cooperative or inhibitory effects towards interaction with the various APs. This complexity makes it impossible to predict a priori, the specificity of a given tyrosine-signal for a particular μ-subunit. Here, we describe the results obtained with a computational approach based on the Artificial Neural Network (ANN paradigm that addresses the issue of tyrosine-signal specificity, enabling the prediction of YXXØ-μ interactions with accuracies over 90%. Therefore, this approach constitutes a powerful tool to help predict mechanisms of intracellular protein sorting.

  6. Role of the AP-5 adaptor protein complex in late endosome-to-Golgi retrieval.

    Science.gov (United States)

    Hirst, Jennifer; Itzhak, Daniel N; Antrobus, Robin; Borner, Georg H H; Robinson, Margaret S

    2018-01-01

    The AP-5 adaptor protein complex is presumed to function in membrane traffic, but so far nothing is known about its pathway or its cargo. We have used CRISPR-Cas9 to knock out the AP-5 ζ subunit gene, AP5Z1, in HeLa cells, and then analysed the phenotype by subcellular fractionation profiling and quantitative mass spectrometry. The retromer complex had an altered steady-state distribution in the knockout cells, and several Golgi proteins, including GOLIM4 and GOLM1, were depleted from vesicle-enriched fractions. Immunolocalisation showed that loss of AP-5 led to impaired retrieval of the cation-independent mannose 6-phosphate receptor (CIMPR), GOLIM4, and GOLM1 from endosomes back to the Golgi region. Knocking down the retromer complex exacerbated this phenotype. Both the CIMPR and sortilin interacted with the AP-5-associated protein SPG15 in pull-down assays, and we propose that sortilin may act as a link between Golgi proteins and the AP-5/SPG11/SPG15 complex. Together, our findings suggest that AP-5 functions in a novel sorting step out of late endosomes, acting as a backup pathway for retromer. This provides a mechanistic explanation for why mutations in AP-5/SPG11/SPG15 cause cells to accumulate aberrant endolysosomes, and highlights the role of endosome/lysosome dysfunction in the pathology of hereditary spastic paraplegia and other neurodegenerative disorders.

  7. Dengue virus targets the adaptor protein MITA to subvert host innate immunity.

    Science.gov (United States)

    Yu, Chia-Yi; Chang, Tsung-Hsien; Liang, Jian-Jong; Chiang, Ruei-Lin; Lee, Yi-Ling; Liao, Ching-Len; Lin, Yi-Ling

    2012-01-01

    Dengue is one of the most important arboviral diseases caused by infection of four serotypes of dengue virus (DEN). We found that activation of interferon regulatory factor 3 (IRF3) triggered by viral infection and by foreign DNA and RNA stimulation was blocked by DEN-encoded NS2B3 through a protease-dependent mechanism. The key adaptor protein in type I interferon pathway, human mediator of IRF3 activation (MITA) but not the murine homologue MPYS, was cleaved in cells infected with DEN-1 or DEN-2 and with expression of the enzymatically active protease NS2B3. The cleavage site of MITA was mapped to LRR↓(96)G and the function of MITA was suppressed by dengue protease. DEN replication was reduced with overexpression of MPYS but not with MITA, while DEN replication was enhanced by MPYS knockdown, indicating an antiviral role of MITA/MPYS against DEN infection. The involvement of MITA in DEN-triggered innate immune response was evidenced by reduction of IRF3 activation and IFN induction in cells with MITA knockdown upon DEN-2 infection. NS2B3 physically interacted with MITA, and the interaction and cleavage of MITA could be further enhanced by poly(dA:dT) stimulation. Thus, we identified MITA as a novel host target of DEN protease and provide the molecular mechanism of how DEN subverts the host innate immunity.

  8. Dengue virus targets the adaptor protein MITA to subvert host innate immunity.

    Directory of Open Access Journals (Sweden)

    Chia-Yi Yu

    Full Text Available Dengue is one of the most important arboviral diseases caused by infection of four serotypes of dengue virus (DEN. We found that activation of interferon regulatory factor 3 (IRF3 triggered by viral infection and by foreign DNA and RNA stimulation was blocked by DEN-encoded NS2B3 through a protease-dependent mechanism. The key adaptor protein in type I interferon pathway, human mediator of IRF3 activation (MITA but not the murine homologue MPYS, was cleaved in cells infected with DEN-1 or DEN-2 and with expression of the enzymatically active protease NS2B3. The cleavage site of MITA was mapped to LRR↓(96G and the function of MITA was suppressed by dengue protease. DEN replication was reduced with overexpression of MPYS but not with MITA, while DEN replication was enhanced by MPYS knockdown, indicating an antiviral role of MITA/MPYS against DEN infection. The involvement of MITA in DEN-triggered innate immune response was evidenced by reduction of IRF3 activation and IFN induction in cells with MITA knockdown upon DEN-2 infection. NS2B3 physically interacted with MITA, and the interaction and cleavage of MITA could be further enhanced by poly(dA:dT stimulation. Thus, we identified MITA as a novel host target of DEN protease and provide the molecular mechanism of how DEN subverts the host innate immunity.

  9. The adaptor protein MITA links virus-sensing receptors to IRF3 transcription factor activation.

    Science.gov (United States)

    Zhong, Bo; Yang, Yan; Li, Shu; Wang, Yan-Yi; Li, Ying; Diao, Feici; Lei, Caoqi; He, Xiao; Zhang, Lu; Tien, Po; Shu, Hong-Bing

    2008-10-17

    Viral infection triggers activation of transcription factors such as NF-kappaB and IRF3, which collaborate to induce type I interferons (IFNs) and elicit innate antiviral response. Here, we identified MITA as a critical mediator of virus-triggered type I IFN signaling by expression cloning. Overexpression of MITA activated IRF3, whereas knockdown of MITA inhibited virus-triggered activation of IRF3, expression of type I IFNs, and cellular antiviral response. MITA was found to localize to the outer membrane of mitochondria and to be associated with VISA, a mitochondrial protein that acts as an adaptor in virus-triggered signaling. MITA also interacted with IRF3 and recruited the kinase TBK1 to the VISA-associated complex. MITA was phosphorylated by TBK1, which is required for MITA-mediated activation of IRF3. Our results suggest that MITA is a critical mediator of virus-triggered IRF3 activation and IFN expression and further demonstrate the importance of certain mitochondrial proteins in innate antiviral immunity.

  10. Role of the AP-5 adaptor protein complex in late endosome-to-Golgi retrieval.

    Directory of Open Access Journals (Sweden)

    Jennifer Hirst

    2018-01-01

    Full Text Available The AP-5 adaptor protein complex is presumed to function in membrane traffic, but so far nothing is known about its pathway or its cargo. We have used CRISPR-Cas9 to knock out the AP-5 ζ subunit gene, AP5Z1, in HeLa cells, and then analysed the phenotype by subcellular fractionation profiling and quantitative mass spectrometry. The retromer complex had an altered steady-state distribution in the knockout cells, and several Golgi proteins, including GOLIM4 and GOLM1, were depleted from vesicle-enriched fractions. Immunolocalisation showed that loss of AP-5 led to impaired retrieval of the cation-independent mannose 6-phosphate receptor (CIMPR, GOLIM4, and GOLM1 from endosomes back to the Golgi region. Knocking down the retromer complex exacerbated this phenotype. Both the CIMPR and sortilin interacted with the AP-5-associated protein SPG15 in pull-down assays, and we propose that sortilin may act as a link between Golgi proteins and the AP-5/SPG11/SPG15 complex. Together, our findings suggest that AP-5 functions in a novel sorting step out of late endosomes, acting as a backup pathway for retromer. This provides a mechanistic explanation for why mutations in AP-5/SPG11/SPG15 cause cells to accumulate aberrant endolysosomes, and highlights the role of endosome/lysosome dysfunction in the pathology of hereditary spastic paraplegia and other neurodegenerative disorders.

  11. Expression of the Rai (Shc C) adaptor protein in the human enteric nervous system.

    Science.gov (United States)

    Villanacci, V; Bassotti, G; Ortensi, B; Fisogni, S; Cathomas, G; Maurer, C A; Galletti, A; Salerni, B; Pelicci, G

    2008-03-01

    The adaptor protein Rai (ShcC/N-Shc) is almost exclusively present in the nervous system, although little is documented about its expression in the gut and the enteric nervous system (ENS). As Rai is a physiological substrate of Ret, an important factor for the development of ENS, we have evaluated the expression of Rai in the ENS in various segments of the human gastrointestinal tract. The expression of Rai was assessed by immunohistochemistry in disease-free human gut samples (oesophagus, stomach, small bowel and colon) obtained from subjects undergoing surgical procedures. Rai was not expressed in the epithelia or lymphoid tissue, whereas a moderate level of expression was observed in the endothelial cells of blood vessels and on the outer membrane of smooth muscle cells in both the muscularis mucosae and the muscularis propria. In the ENS, strong positivity was observed only in enteric glial cells, overlapping with GFAP and S100. In conclusion, Rai is expressed in the human gut, especially in the enteric glial cells. We conclude that Rai may provide an additional marker for this cell type.

  12. Floral heterochrony promotes flexibility of reproductive strategies in the morphologically homogeneous genus Eugenia (Myrtaceae).

    Science.gov (United States)

    Vasconcelos, Thais N C; Lucas, Eve J; Faria, Jair E Q; Prenner, Gerhard

    2018-01-25

    Comparative floral ontogeny represents a valuable tool to understand angiosperm evolution. Such an approach may elucidate subtle changes in development that discretely modify floral architecture and underlie reproductive lability in groups with superficial homogeneous morphology. This study presents a comparative survey of floral development in Eugenia (Myrtaceae), one of the largest genera of angiosperms, and shows how previously undocumented ontogenetic trends help to explain the evolution of its megadiversity in contrast to its apparent flower uniformity. Using scanning electron microscopy, selected steps of the floral ontogeny of a model species (Eugenia punicifolia) are described and compared with 20 further species representing all ten major clades in the Eugenia phylogenetic tree. Additional floral trait data are contrasted for correlation analysis and character reconstructions performed against the Myrtaceae phylogenetic tree. Eugenia flowers show similar organ arrangement patterns: radially symmetrical, (most commonly) tetramerous flowers with variable numbers of stamens and ovules. Despite a similar general organization, heterochrony is evident from size differences between tissues and structures at similar developmental stages. These differences underlie variable levels of investment in protection, subtle modifications to symmetry, herkogamic effects and independent androecium and gynoecium variation, producing a wide spectrum of floral display and contributing to fluctuations in fitness. During Eugenia's bud development, the hypanthium (as defined here) is completely covered by stamen primordia, unusual in other Myrtaceae. This is the likely plesiomorphic state for Myrteae and may have represented a key evolutionary novelty in the tribe. Floral evolution in Eugenia depends on heterochronic patterns rather than changes in complexity to promote flexibility in floral strategies. The successful early establishment of Myrteae, previously mainly linked to the

  13. EVALUATION OF FLORAL CHARACTERISTICS OF MELON HYBRIDS (Cucumis melo L.) IN POLLINATOR ATTRACTIVENESS

    OpenAIRE

    KIILL,LÚCIA HELENA PIEDADE; FEITOZA,EDSÂNGELA DE ARAÚJO; SIQUEIRA,KÁTIA MARIA MEDEIROS DE; RIBEIRO,MÁRCIA DE FÁTIMA; SILVA,EVA MÔNICA SARMENTO DA

    2016-01-01

    ABSTRACT Floral morphology and biology are important characteristics for plant-pollinator interactions and may influence the behavior of these agents. This study aimed to determine which floral attributes of different melon hybrids influence this interaction and, consequently, their attractiveness in simultaneous crops. The study was conducted in the region of Petrolina, State of Pernambuco (PE)/Juazeiro, State of Bahia (BA) and Mossoró, State of Rio Grande do Norte (RN), in areas with the f...

  14. Antagonistic effects of floral scent in an insect–plant interaction

    OpenAIRE

    Reisenman, Carolina E.; Riffell, Jeffrey A.; Bernays, Elizabeth A.; Hildebrand, John G.

    2010-01-01

    In southwestern USA, the jimsonweed Datura wrightii and the nocturnal moth Manduca sexta form a pollinator–plant and herbivore–plant association. Because the floral scent is probably important in mediating this interaction, we investigated the floral volatiles that might attract M. sexta for feeding and oviposition. We found that flower volatiles increase oviposition and include small amounts of both enantiomers of linalool, a common component of the scent of hawkmoth-pollinated flowers. Beca...

  15. Floral longevity and autonomous selfing are altered by pollination and water availability in Collinsia heterophylla.

    Science.gov (United States)

    Jorgensen, Rachael; Arathi, H S

    2013-09-01

    A plant investing in reproduction partitions resources between flowering and seed production. Under resource limitation, altered allocations may result in floral trait variations, leading to compromised fecundity. Floral longevity and timing of selfing are often the traits most likely to be affected. The duration of corolla retention determines whether fecundity results from outcrossing or by delayed selfing-mediated reproductive assurance. In this study, the role of pollination schedules and soil water availability on floral longevity and seed production is tested in Collinsia heterophylla (Plantaginaceae). Using three different watering regimes and pollination schedules, effects on floral longevity and seed production were studied in this protandrous, flowering annual. The results reveal that soil water status and pollination together influence floral longevity with low soil water and hand-pollinations early in the floral lifespan reducing longevity. However, early pollinations under excess water did not extend longevity, implying that resource surplus does not lengthen the outcrossing period. The results also indicate that pollen receipt, a reliable cue for fecundity, accelerates flower drop. Early corolla abscission under drought stress could potentially exacerbate sexual conflict in this protandrous, hermaphroditic species by ensuring self-pollen paternity and enabling male control of floral longevity. While pollination schedules did not affect fecundity, water stress reduced per-capita seed numbers. Unmanipulated flowers underwent delayed autonomous selfing, producing very few seeds, suggesting that inbreeding depression may limit benefits of selfing. In plants where herkogamy and dichogamy facilitate outcrossing, floral longevity determines reproductive success and mating system. Reduction in longevity under drought suggests a strong environmental effect that could potentially alter the preferred breeding mode in this mixed-mated species. Extrapolating the

  16. High embryogenic ability and regeneration from floral axis of Amorphophallus konjac (Araceae)

    OpenAIRE

    Zhong Lin; Liu Erxi; Yang Chaozhu; Jin Surong; Diao Ying; Hu Zhongli

    2017-01-01

    Amorphophallus konjac (Araceae) a perennial herb, it has high medicinal and industrial value. In this study, a simple and efficient system for direct somatic embryogenesis and plantlet regeneration of Amorphophallus konjac was developed. The floral axis was used as the experimental material. The primary callus, developed from the floral axis grown on Murashige and Skoog (MS) medium supplemented with different hormone combination at different concentrations. The highest rate of embryogenic cal...

  17. Floral scent composition predicts bee pollination system in five butterfly bush (Buddleja, Scrophulariaceae) species.

    Science.gov (United States)

    Gong, W-C; Chen, G; Vereecken, N J; Dunn, B L; Ma, Y-P; Sun, W-B

    2015-01-01

    Traditionally, plant-pollinator interactions have been interpreted as pollination syndrome. However, the validity of pollination syndrome has been widely doubted in modern studies of pollination ecology. The pollination ecology of five Asian Buddleja species, B. asiatica, B. crispa, B. forrestii, B. macrostachya and B. myriantha, in the Sino-Himalayan region in Asia, flowering in different local seasons, with scented inflorescences were investigated during 2011 and 2012. These five species exhibited diverse floral traits, with narrow and long corolla tubes and concealed nectar. According to their floral morphology, larger bees and Lepidoptera were expected to be the major pollinators. However, field observations showed that only larger bees (honeybee/bumblebee) were the primary pollinators, ranging from 77.95% to 97.90% of total visits. In this study, floral scents of each species were also analysed using coupled gas chromatography and mass spectrometry (GC-MS). Although the five Buddleja species emitted differentiated floral scent compositions, our results showed that floral scents of the five species are dominated by substances that can serve as attractive signals to bees, including species-specific scent compounds and principal compounds with larger relative amounts. This suggests that floral scent compositions are closely associated with the principal pollinator assemblages in these five species. Therefore, we conclude that floral scent compositions rather than floral morphology traits should be used to interpret plant-pollinator interactions in these Asian Buddleja species. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  18. The relationship between nectaries and floral architecture: a case study in Geraniaceae and Hypseocharitaceae.

    Science.gov (United States)

    Jeiter, Julius; Hilger, Hartmut H; Smets, Erik F; Weigend, Maximilian

    2017-11-10

    Flowers of Geraniaceae and Hypseocharitaceae are generally considered as morphologically simple. However, previous studies indicated complex diversity in floral architecture including tendencies towards synorganization. Most of the species have nectar-rewarding flowers which makes the nectaries a key component of floral organization and architecture. Here, the development of the floral nectaries is studied and placed into the context of floral architecture. Seven species from Geraniaceae and one from Hypseocharitaceae were investigated using scanning electron microscopy and light microscopy. Samples were prepared and processed using standard protocols. The development of the nectary glands follows the same trajectory in all species studied. Minor differences occur in the onset of nectarostomata development. The most striking finding is the discovery that a short anthophore develops via intercalary growth at the level of the nectary glands. This anthophore lifts up the entire flower apart from the nectary gland itself and thus plays an important role in floral architecture, especially in the flowers of Pelargonium. Here, the zygomorphic flowers show a particularly extensive receptacular growth, resulting in the formation of a spur-like receptacular cavity ('inner spur'). The nectary gland is hidden at the base of the cavity. Various forms of compartmentalization, culminating in the 'revolver flower' of Geranium maderense, are described. Despite the superficial similarity of the flowers in Geraniaceae and Hypseocharitaceae, there is broad diversity in floral organization and floral architecture. While the receptacular origin of the spur-like cavity in Pelargonium had already been described, anthophore formation via intercalary growth of the receptacle in the other genera had not been previously documented. In the context of the most recent phylogenies of the families, an evolutionary series for the floral architecture is proposed, underscoring the importance of

  19. Molecular basis for the specification of floral organs by APETALA3 and PISTILLATA.

    Science.gov (United States)

    Wuest, Samuel E; O'Maoileidigh, Diarmuid S; Rae, Liina; Kwasniewska, Kamila; Raganelli, Andrea; Hanczaryk, Katarzyna; Lohan, Amanda J; Loftus, Brendan; Graciet, Emmanuelle; Wellmer, Frank

    2012-08-14

    How different organs are formed from small sets of undifferentiated precursor cells is a key question in developmental biology. To understand the molecular mechanisms underlying organ specification in plants, we studied the function of the homeotic selector genes APETALA3 (AP3) and PISTILLATA (PI), which control the formation of petals and stamens during Arabidopsis flower development. To this end, we characterized the activities of the transcription factors that AP3 and PI encode throughout flower development by using perturbation assays as well as transcript profiling and genomewide localization studies, in combination with a floral induction system that allows a stage-specific analysis of flower development by genomic technologies. We discovered considerable spatial and temporal differences in the requirement for AP3/PI activity during flower formation and show that they control different sets of genes at distinct phases of flower development. The genomewide identification of target genes revealed that AP3/PI act as bifunctional transcription factors: they activate genes involved in the control of numerous developmental processes required for organogenesis and repress key regulators of carpel formation. Our results imply considerable changes in the composition and topology of the gene network controlled by AP3/PI during the course of flower development. We discuss our results in light of a model for the mechanism underlying sex-determination in seed plants, in which AP3/PI orthologues might act as a switch between the activation of male and the repression of female development.

  20. Carbohydrate metabolism in floral structures of Lilium pumilum in different development stages

    Directory of Open Access Journals (Sweden)

    Mirelle Nayana de Sousa Santos

    2016-01-01

    Full Text Available ABSTRACT: Lilium pumilum is a species that stands out in floriculture for presenting orange inflorescences that attract the consumer. This study thus aimed at characterizing the carbohydrate metabolism of floral structures of L. pumilum in different development stages. For this purpose, carbohydrate levels (total soluble sugars, reducing sugars, non-reducing sugars, and starch, at different floral stages (E0 - bud with no color; E1 - bud at early coloring; E2 - orange bud; E3 - open flower; E4 - senescent flower were quantified after extraction with ethanol. Lilium pumilum flowers showed high energy potential during floral opening and senescence; total soluble sugars were the main carbohydrates present in the species, reducing with the floral development, and the same occurred with the non-reducing sugar and starch contents. The reducing-sugar content increased with the floral stages. Therefore, this species presents great mobilization of compounds, which are utilized in the production of energy that is employed in floral opening.

  1. Multiple strong postmating and intrinsic postzygotic reproductive barriers isolate florally diverse species of Jaltomata (Solanaceae).

    Science.gov (United States)

    Kostyun, Jamie L; Moyle, Leonie C

    2017-06-01

    Divergence in phenotypic traits often contributes to premating isolation between lineages, but could also promote isolation at postmating stages. Phenotypic differences could directly result in mechanical isolation or hybrids with maladapted traits; alternatively, when alleles controlling these trait differences pleiotropically affect other components of development, differentiation could indirectly produce genetic incompatibilities in hybrids. Here, we determined the strength of nine postmating and intrinsic postzygotic reproductive barriers among 10 species of Jaltomata (Solanaceae), including species with highly divergent floral traits. To evaluate the relative importance of floral trait diversification for the strength of these postmating barriers, we assessed their relationship to floral divergence, genetic distance, geographical context, and ecological differences, using conventional tests and a new linear-mixed modeling approach. Despite close evolutionary relationships, all species pairs showed moderate to strong isolation. Nonetheless, floral trait divergence was not a consistent predictor of the strength of isolation; instead this was best explained by genetic distance, although we found evidence for mechanical isolation in one species, and a positive relationship between floral trait divergence and fruit set isolation across species pairs. Overall, our data indicate that intrinsic postzygotic isolation is more strongly associated with genome-wide genetic differentiation, rather than floral divergence. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  2. Diversity and evolution of floral structure among early diverging lineages in the Ericales.

    Science.gov (United States)

    Schönenberger, Jürg; von Balthazar, Maria; Sytsma, Kenneth J

    2010-02-12

    This is a combination of review and original data on floral structure and diversity in the two earliest diverging lineages of the Ericales, i.e. the balsaminoids, comprising Balsaminaceae, Marcgraviaceae and Tetrameristaceae, and the polemonioids, comprising Fouquieriaceae and Polemoniaceae. Each clade is strongly supported in molecular studies, while structural synapomorphies have largely been lacking. For the balsaminoid families, we compare floral morphology, anatomy and histology among selected taxa and find that the entire clade is strongly supported by the shared presence of nectariferous tissue in the floral periphery, thread-like structures on anthers, truncate stigmas, secretion in the ovary, as well as mucilage cells, raphides and tannins in floral tissues. A possible sister group relationship between Balsaminaceae and Tetrameristaceae is supported by the shared presence of post-genital fusion of filaments and ovary and a star-shaped stylar canal. For polemonioids, we document unexpected diversity of floral features in Polemoniaceae, partly providing structural links to Fouquieriaceae. Features include cochlear and quincuncial corolla aestivation, connective protrusions, ventrifixed anthers and nectariferous tissue in the base of the ovary. In addition, we outline future directions for research on floral structure in the Ericales and briefly discuss the general importance of structural studies for our understanding of plant phylogeny and evolution.

  3. A Stretch of Negatively Charged Amino Acids of Linker for Activation of T-Cell Adaptor Has a Dual Role in T-Cell Antigen Receptor Intracellular Signaling

    Directory of Open Access Journals (Sweden)

    Mikel M. Arbulo-Echevarria

    2018-02-01

    Full Text Available The adaptor protein linker for activation of T cells (LAT has an essential role transducing activatory intracellular signals coming from the TCR/CD3 complex. Previous reports have shown that upon T-cell activation, LAT interacts with the tyrosine kinase Lck, leading to the inhibition of its kinase activity. LAT–Lck interaction seemed to depend on a stretch of negatively charged amino acids in LAT. Here, we have substituted this segment of LAT between amino acids 113 and 126 with a non-charged segment and expressed the mutant LAT (LAT-NIL in J.CaM2 cells in order to analyze TCR signaling. Substitution of this segment in LAT prevented the activation-induced interaction with Lck. Moreover, cells expressing this mutant form of LAT showed a statistically significant increase of proximal intracellular signals such as phosphorylation of LAT in tyrosine residues 171 and 191, and also enhanced ZAP70 phosphorylation approaching borderline statistical significance (p = 0.051. Nevertheless, downstream signals such as Ca2+ influx or MAPK pathways were partially inhibited. Overall, our data reveal that LAT–Lck interaction constitutes a key element regulating proximal intracellular signals coming from the TCR/CD3 complex.

  4. Identification and Characterization of KCASH2 and KCASH3, 2 Novel Cullin3 Adaptors Suppressing Histone Deacetylase and Hedgehog Activity in Medulloblastoma

    Directory of Open Access Journals (Sweden)

    Enrico De Smaele

    2011-04-01

    Full Text Available Medulloblastoma is the most common pediatric malignant brain tumor, arising from aberrant cerebellar precursors' development, a process mainly controlled by Hedgehog (Hh signaling pathway. Histone deacetylase HDAC1 has been recently shown to modulate Hh signaling, deacetylating its effectors Gli1/2 and enhancing their transcriptional activity. Therefore, HDAC may represent a potential therapeutic target for Hh-dependent tumors, but still little information is available on the physiological mechanisms of HDAC regulation. The putative tumor suppressor RENKCTD11 acts through ubiquitination-dependent degradation of HDAC1, thereby affecting Hh activity and medulloblastoma growth. We identify and characterize here two RENKCTD11 homologues, defining a new family of proteins named KCASH, as “KCTD containing, Cullin3 adaptor, suppressor of Hedgehog.” Indeed, the novel genes (KCASH2KCTD21 and KCASH3KCTD6 share with RENKCTD11 a number of features, such as a BTB domain required for the formation of a Cullin3 ubiquitin ligase complex and HDAC1 ubiquitination and degradation capability, suppressing the acetylation-dependent Hh/Gli signaling. Expression of KCASH2 and -3 is observed in cerebellum, whereas epigenetic silencing and allelic deletion are observed in human medulloblastoma. Rescuing KCASHs expression reduces the Hedgehog-dependent medulloblastoma growth, suggesting that loss of members of this novel family of native HDAC inhibitors is crucial in sustaining Hh pathway-mediated tumorigenesis. Accordingly, they might represent a promising class of endogenous “agents” through which this pathway may be targeted.

  5. Dual role of the Toxoplasma gondii clathrin adaptor AP1 in the sorting of rhoptry and microneme proteins and in parasite division.

    Directory of Open Access Journals (Sweden)

    Kannan Venugopal

    2017-04-01

    Full Text Available Toxoplasma gondii possesses a highly polarized secretory system, which efficiently assembles de novo micronemes and rhoptries during parasite replication. These apical secretory organelles release their contents into host cells promoting parasite invasion and survival. Using a CreLox-based inducible knock-out strategy and the ddFKBP over-expression system, we unraveled novel functions of the clathrin adaptor complex TgAP1. First, our data indicate that AP1 in T. gondii likely functions as a conserved heterotetrameric complex composed of the four subunits γ, β, μ1, σ1 and interacts with known regulators of clathrin-mediated vesicular budding such as the unique ENTH-domain containing protein, which we named Epsin-like protein (TgEpsL. Disruption of the μ1 subunit resulted in the mis-sorting of microneme proteins at the level of the Trans-Golgi-Network (TGN. Furthermore, we demonstrated that TgAP1 regulates rhoptry biogenesis by activating rhoptry protein exit from the TGN, but also participates in the post-Golgi maturation process of preROP compartments into apically anchored club-shaped mature organelles. For this latter activity, our data indicate a specific functional relationship between TgAP1 and the Rab5A-positive endosome-like compartment. In addition, we unraveled an original role for TgAP1 in the regulation of parasite division. APμ1-depleted parasites undergo normal daughter cell budding and basal complex assembly but fail to segregate at the end of cytokinesis.

  6. Floral organ abscission peptide IDA and its HAE/HSL2 receptors control cell separation during lateral root emergence.

    Science.gov (United States)

    Kumpf, Robert P; Shi, Chun-Lin; Larrieu, Antoine; Stø, Ida Myhrer; Butenko, Melinka A; Péret, Benjamin; Riiser, Even Sannes; Bennett, Malcolm J; Aalen, Reidunn B

    2013-03-26

    Throughout their life cycle, plants produce new organs, such as leaves, flowers, and lateral roots. Organs that have served their purpose may be shed after breakdown of primary cell walls between adjacent cell files at the site of detachment. In Arabidopsis, floral organs abscise after pollination, and this cell separation event is controlled by the peptide INFLORESCENCE DEFICIENT IN ABSCISSION (IDA), which signals through the leucine-rich repeat receptor-like kinases HAESA (HAE) and HAESA-LIKE2 (HSL2). Emergence of new lateral root primordia, initiated deep inside the root under the influence of auxin, is similarly dependent on cell wall dissolution between cells in the overlaying endodermal, cortical, and epidermal tissues. Here we show that this process requires IDA, HAE, and HSL2. Mutation in these genes constrains the passage of the growing lateral root primordia through the overlaying layers, resulting in altered shapes of the lateral root primordia and of the overlaying cells. The HAE and HSL2 receptors are redundant in function during floral organ abscission, but during lateral root emergence they are differentially involved in regulating cell wall remodeling genes. In the root, IDA is strongly auxin-inducible and dependent on key regulators of lateral root emergence--the auxin influx carrier LIKE AUX1-3 and AUXIN RESPONSE FACTOR7. The expression levels of the receptor genes are only transiently induced by auxin, suggesting they are limiting factors for cell separation. We conclude that elements of the same cell separation signaling module have been adapted to function in different developmental programs.

  7. A potential role for the clathrin adaptor GGA in Drosophila spermatogenesis

    Directory of Open Access Journals (Sweden)

    Carmichael Jenny

    2011-05-01

    Full Text Available Abstract Background GGAs (Golgi-localised, γ-ear containing, ADP ribosylation factor-binding are a family of clathrin adaptors that sort a number of biologically important transmembrane proteins into clathrin-coated vesicles. Knockout and knockdown studies to determine GGA function are confounded by the fact that there are 3 GGA genes in mammalian cells. Thus Drosophila melanogaster is a useful model system to study tissue expression profiles and knockdown phenotypes as there is a single GGA ortholog. Results Here we have quantified protein expression in Drosophila and show that there is >3-fold higher expression of GGA in male flies relative to female flies. In female flies the majority of GGA expression is in the head. In male flies GGA is not only expressed at high levels in the head but there is a gender specific increased expression which is due to the abundant expression of GGA in the testes. Using a highly specific antibody we have localised endogenous GGA protein in testes squashes, and visualised it in somatic and germ line cells. We show that GGA is expressed during multiple stages of sperm development, and co-stains with a marker of the trans-Golgi Network. This is most striking at the acroblast of early spermatids. In spite of the high expression of GGA in testes, knocking down its expression by >95% using transgenic RNAi fly lines did not affect male fertility. Therefore spermatogenesis in the male flies appears to progress normally with Conclusion In Drosophila we have uncovered a potential role for GGA in the testes of male flies. The gender specific higher expression of GGA, its specific enrichment in testes and its localisation to developing spermatocytes and at the acroblast of spermatids supports a role for GGA function in Drosophila spermatogenesis, even though spermatogenesis still occurs when GGA expression is depleted to

  8. Hydrological Modeling Reproducibility Through Data Management and Adaptors for Model Interoperability

    Science.gov (United States)

    Turner, M. A.

    2015-12-01

    Because of a lack of centralized planning and no widely-adopted standards among hydrological modeling research groups, research communities, and the data management teams meant to support research, there is chaos when it comes to data formats, spatio-temporal resolutions, ontologies, and data availability. All this makes true scientific reproducibility and collaborative integrated modeling impossible without some glue to piece it all together. Our Virtual Watershed Integrated Modeling System provides the tools and modeling framework hydrologists need to accelerate and fortify new scientific investigations by tracking provenance and providing adaptors for integrated, collaborative hydrologic modeling and data management. Under global warming trends where water resources are under increasing stress, reproducible hydrological modeling will be increasingly important to improve transparency and understanding of the scientific facts revealed through modeling. The Virtual Watershed Data Engine is capable of ingesting a wide variety of heterogeneous model inputs, outputs, model configurations, and metadata. We will demonstrate one example, starting from real-time raw weather station data packaged with station metadata. Our integrated modeling system will then create gridded input data via geostatistical methods along with error and uncertainty estimates. These gridded data are then used as input to hydrological models, all of which are available as web services wherever feasible. Models may be integrated in a data-centric way where the outputs too are tracked and used as inputs to "downstream" models. This work is part of an ongoing collaborative Tri-state (New Mexico, Nevada, Idaho) NSF EPSCoR Project, WC-WAVE, comprised of researchers from multiple universities in each of the three states. The tools produced and presented here have been developed collaboratively alongside watershed scientists to address specific modeling problems with an eye on the bigger picture of

  9. Floral ecology and insect visitation in riparian Tamarix sp. (saltcedar)

    Science.gov (United States)

    Andersen, D.C.; Nelson, S.M.

    2013-01-01

    Climate change projections for semiarid and arid North America include reductions in stream discharge that could adversely affect riparian plant species dependent on stream-derived ground water. In order to better understand this potential impact, we used a space-for-time substitution to test the hypotheses that increasing depth-to-groundwater (DGW) is inversely related to Tamarix sp. (saltcedar) flower abundance (F) and nectar production per flower (N). We also assessed whether DGW affected the richness or abundance of insects visiting flowers. We examined Tamarix floral attributes and insect visitation patterns during 2010 and 2011 at three locations along a deep DWG gradient (3.2–4.1 m) on a floodplain terrace adjacent to Las Vegas Wash, an effluent-dominated Mojave Desert stream. Flower abundance and insect visitation patterns differed between years, but no effect from DGW on either F or N was detected. An eruption of a novel non-native herbivore, the splendid tamarisk weevil (Coniatus splendidulus), likely reduced flower production in 2011.

  10. Disorder in convergent floral nanostructures enhances signalling to bees

    Science.gov (United States)

    Moyroud, Edwige; Wenzel, Tobias; Middleton, Rox; Rudall, Paula J.; Banks, Hannah; Reed, Alison; Mellers, Greg; Killoran, Patrick; Westwood, M. Murphy; Steiner, Ullrich; Vignolini, Silvia; Glover, Beverley J.

    2017-10-01

    Diverse forms of nanoscale architecture generate structural colour and perform signalling functions within and between species. Structural colour is the result of the interference of light from approximately regular periodic structures; some structural disorder is, however, inevitable in biological organisms. Is this disorder functional and subject to evolutionary selection, or is it simply an unavoidable outcome of biological developmental processes? Here we show that disordered nanostructures enable flowers to produce visual signals that are salient to bees. These disordered nanostructures (identified in most major lineages of angiosperms) have distinct anatomies but convergent optical properties; they all produce angle-dependent scattered light, predominantly at short wavelengths (ultraviolet and blue). We manufactured artificial flowers with nanoscale structures that possessed tailored levels of disorder in order to investigate how foraging bumblebees respond to this optical effect. We conclude that floral nanostructures have evolved, on multiple independent occasions, an effective degree of relative spatial disorder that generates a photonic signature that is highly salient to insect pollinators.

  11. Floral odor learning within the hive affects honeybees' foraging decisions

    Science.gov (United States)

    Arenas, Andrés; Fernández, Vanesa M.; Farina, Walter M.

    2007-03-01

    Honeybees learn odor cues quickly and efficiently when visiting rewarding flowers. Memorization of these cues facilitates the localization and recognition of food sources during foraging flights. Bees can also use information gained inside the hive during social interactions with successful foragers. An important information cue that can be learned during these interactions is food odor. However, little is known about how floral odors learned in the hive affect later decisions of foragers in the field. We studied the effect of food scent on foraging preferences when this learning is acquired directly inside the hive. By using in-hive feeders that were removed 24 h before the test, we showed that foragers use the odor information acquired during a 3-day stimulation period with a scented solution during a food-choice situation outside the nest. This bias in food preference is maintained even 24 h after the replacement of all the hive combs. Thus, without being previously collected outside by foragers, food odors learned within the hive can be used during short-range foraging flights. Moreover, correct landings at a dual-choice device after replacing the storing combs suggests that long-term memories formed within the colony can be retrieved while bees search for food in the field.

  12. Interspecific and Intersexual Differences in the Chemical Composition of Floral Scent in Glochidion Species (Phyllanthaceae in South China

    Directory of Open Access Journals (Sweden)

    Daihong Huang

    2015-01-01

    Full Text Available Plants of the Glochidion (Phyllanthaceae genus are pollinated exclusively by host-specific Epicephala (Gracillariidae moths. Floral scent has been thought to play key role in the obligate pollination mutualism between Glochidion plants and Epicephala moths, but few studies have been reported about chemical variation in floral volatiles of Glochidion species in China. Floral volatiles of male and female flowers of five Glochidion species in south China were collected by dynamic headspace absorption technique and then were chemically analyzed by using gas chromatography-mass spectrometry. A total of 69 compounds were identified from floral scents of five investigated species. Glochidion hirsutum and G. zeylanicum showed no qualitative differences in floral scent, whereas there were clear variations of floral scent among other species (G. eriocarpum, G. daltonii, and G. sphaerogynum and also they distinctly differed from these two species. Male flowers emitted significantly more scent than female flowers. Glochidion plants exhibited qualitative and quantitative differences in floral scent between two sexes of flowers. The findings suggest that the volatile variation of floral scent among Glochidion species reflects adaptations to specific pollinators. Sexual dimorphism in floral scent has evolved to signal alternative rewards provided by each sex to Epicephala moths.

  13. Global gene expression analysis of apple fruit development from the floral bud to ripe fruit

    Directory of Open Access Journals (Sweden)

    McArtney Steve

    2008-02-01

    Full Text Available Abstract Background Apple fruit develop over a period of 150 days from anthesis to fully ripe. An array representing approximately 13000 genes (15726 oligonucleotides of 45–55 bases designed from apple ESTs has been used to study gene expression over eight time points during fruit development. This analysis of gene expression lays the groundwork for a molecular understanding of fruit growth and development in apple. Results Using ANOVA analysis of the microarray data, 1955 genes showed significant changes in expression over this time course. Expression of genes is coordinated with four major patterns of expression observed: high in floral buds; high during cell division; high when starch levels and cell expansion rates peak; and high during ripening. Functional analysis associated cell cycle genes with early fruit development and three core cell cycle genes are significantly up-regulated in the early stages of fruit development. Starch metabolic genes were associated with changes in starch levels during fruit development. Comparison with microarrays of ethylene-treated apple fruit identified a group of ethylene induced genes also induced in normal fruit ripening. Comparison with fruit development microarrays in tomato has been used to identify 16 genes for which expression patterns are similar in apple and tomato and these genes may play fundamental roles in fruit development. The early phase of cell division and tissue specification that occurs in the first 35 days after pollination has been associated with up-regulation of a cluster of genes that includes core cell cycle genes. Conclusion Gene expression in apple fruit is coordinated with specific developmental stages. The array results are reproducible and comparisons with experiments in other species has been used to identify genes that may play a fundamental role in fruit development.

  14. Dosage-dependent impacts of a floral volatile compound on pollinators, larcenists, and the potential for floral evolution in the alpine skypilot Polemonium viscosum.

    Science.gov (United States)

    Galen, Candace; Kaczorowski, Rainee; Todd, Sadie L; Geib, Jennifer; Raguso, Robert A

    2011-02-01

    All volatile organic compounds (VOCs) vary quantitatively, yet how such variation affects their ecological roles is unknown. Because floral VOCs are cues for both pollinators and floral antagonists, variation in emission may have major consequences for costs and benefits in plant-pollinator interactions. In Polemonium viscosum, the emission rate for the floral VOC 2-phenylethanol (2PE) spans more than two orders of magnitude. We investigated the ecological and evolutionary impacts of this immense phenotypic variation. The emission rate of 2PE varies independently of nectar rewards and thus is uninformative of profitability. Emission is elevated in flowers that are morphologically vulnerable to ant larcenists, suggesting that chemical deterrence may compensate for weak physical barriers. In nature, plants emitting more 2PE than their neighbors escape ant damage. Flower-damaging ants die when exposed to 2PE in the laboratory, and they avoid high 2PE emitters in the field. High 2PE also reduces bumblebee visitation and pollination, suggesting an ecological cost of defense in pollinator service. However, at more moderate emission rates, 2PE enhances the amount of nectar left in flowers, at no pollination cost. In conclusion, repellency of 2PE is highly sensitive to dosage, giving it a key role in shaping ecological interactions between skypilot plants and their floral visitors.

  15. Strong phylogenetic effects on floral scent variation of oil-secreting orchids in South Africa.

    Science.gov (United States)

    Steiner, Kim E; Kaiser, Roman; Dötterl, Stefan

    2011-10-01

    Evolution involves the interplay between natural selection and phylogenetic constraint. This is particularly evident among the flowering plants where form and diversity of flowers attest to the importance of both pollinator-mediated selection and phylogenetic constraint. Although this has been studied mostly using visible floral characters, invisible volatile chemicals emitted by the flowers should be subject to these same evolutionary forces. Unfortunately, most analyses of floral volatiles have over-emphasized the importance of natural selection and underplayed phylogenetic constraint without quantifying their respective roles in the evolution and composition of floral scents. We used multivariate analyses to test the relative importance of pollinators vs. phylogeny in determining the composition of floral scents among oil-secreting orchids in southern Africa. Floral scents of 42 oil-secreting taxa/ecotypes distributed among 12 subclades in the tribe Diseae were sampled using headspace adsorption and gas chromatography-mass spectroscopy. We identified 257 scent compounds distributed over nine different compound classes, with the majority of scents dominated by aliphatic or benzenoid compounds. The only significant predictor of floral scent among these orchids above the species level was phylogeny. Nevertheless, in two of the clades there were differences in scent profiles at the species and ecotype level that corresponded to different pollinators and were thus suggestive of pollinator-mediated selection. Scent variation was greater than expected and phylogeny was more important than pollinator-mediated selection in predicting the composition of floral scents of oil-secreting orchids, despite the specialized nature of the pollinator reward system.

  16. Synchronicity of thermogenic activity, alternative pathway respiratory flux, AOX protein content, and carbohydrates in receptacle tissues of sacred lotus during floral development.

    Science.gov (United States)

    Grant, Nicole M; Miller, Rebecca E; Watling, Jennifer R; Robinson, Sharon A

    2008-01-01

    The relationships between heat production, alternative oxidase (AOX) pathway flux, AOX protein, and carbohydrates during floral development in Nelumbo nucifera (Gaertn.) were investigated. Three distinct physiological phases were identified: pre-thermogenic, thermogenic, and post-thermogenic. The shift to thermogenic activity was associated with a rapid, 10-fold increase in AOX protein. Similarly, a rapid decrease in AOX protein occurred post-thermogenesis. This synchronicity between AOX protein and thermogenic activity contrasts with other thermogenic plants where AOX protein increases some days prior to heating. AOX protein in thermogenic receptacles was significantly higher than in post-thermogenic and leaf tissues. Stable oxygen isotope measurements confirmed that the increased respiratory flux supporting thermogenesis was largely via the AOX, with little or no contribution from the cytochrome oxidase pathway. During the thermogenic phase, no significant relationship was found between AOX protein content and either heating or AOX flux, suggesting that regulation is likely to be post-translational. Further, no evidence of substrate limitation was found; starch accumulated during the early stages of floral development, peaking in thermogenic receptacles, before declining by 89% in post-thermogenic receptacles. Whilst coarse regulation of AOX flux occurs via protein synthesis, the ability to thermoregulate probably involves precise regulation of AOX protein, most probably by effectors such as alpha-keto acids.

  17. Pollination systems and floral traits in cerrado woody species of the Upper Taquari region (central Brazil

    Directory of Open Access Journals (Sweden)

    F. Q. Martins

    Full Text Available Plant species present flowers with varied morphological and functional features, which may be associated to pollination systems, including species pollinated by wind, beetles, moths, bees, small insects, birds, or bats. We calculated the frequencies of the pollination systems among woody species in five cerrado fragments in central-western Brazil and tested whether the pollination systems were indeed related to floral traits. We sampled 2,280 individuals, belonging to 121 species, ninety-nine of which were described in relation to all floral traits. Most species had diurnal anthesis, pale colors, and open flowers. The most frequent groups were those composed by the species pollinated by bees, small insects, and moths. A Principal Component Analysis of the species and floral traits showed that there was a grouping among species with some pollination systems, such as those pollinated mainly by beetles, moths, birds, and bats, for which inferences based on the floral traits are recommended in cerrado sites. For the species pollinated mainly by bees or small insects, inferences based on the floral traits are not recommended, due to the large dispersion of the species scores and overlapping between these two groups, which probably occurred due to the specificity absence in plant-pollinator relationships.

  18. Floral development in the tribe Cedreleae (Meliaceae, sub-family Swietenioideae): Cedrela and Toona.

    Science.gov (United States)

    Gouvêa, Cantídio Fernando; Dornelas, Marcelo Carnier; Rodriguez, Adriana Pinheiro Martinelli

    2008-01-01

    Floral development of Cedrela and Toona, the genera comprising the basal tribe Cedreleae of the sub-family Swietenioideae of Meliaceae, is described. The focus was on three endangered, ecologically and economically important species: Cedrela fissilis, Cedrela odorata and Toona ciliata. The aims of the study were to characterize the patterns of floral development in the tribe and to establish apomorphic and plesiomorphic floral characters in relation to other taxa within the family based on the current molecular phylogeny of Meliaceae. A detailed floral structural and developmental study was completed using both scanning electron microscopy and visualization of microtome sections with a light microscope. Twelve floral developmental stages were identified. The initial development of the pentamerous flowers of both Toona and Cedrela is strikingly similar. The morphological differences observed between them are due to differential patterns of organ elongation and adnation/connation occurring late in development. Additionally, the formation of functionally male and female flowers was found to occur at specific positions within the inflorescence. Due to the basal position of the tribe Cedreleae in the phylogeny of Meliaceae, functionally either male or female pentamerous flowers and the presence of (at least partially) free stamens may be considered plesiomorphic traits within the family. In contrast, sympetaly and the absence of nectaries in Cedrela species are synapomorphies.

  19. Is floral specialization an evolutionary dead-end? Pollination system transitions in Ruellia (Acanthaceae).

    Science.gov (United States)

    Tripp, Erin A; Manos, Paul S

    2008-07-01

    Pollination systems frequently reflect adaptations to particular groups of pollinators. Such systems are indicative of evolutionary specialization and have been important in angiosperm diversification. We studied the evolution of pollination systems in the large genus Ruellia. Phylogenetic analyses, morphological ordinations, ancestral state reconstructions, and a character mapping simulation were conducted to reveal key patterns in the direction and lability of floral characters associated with pollination. We found significant floral morphological differences among species that were generally associated with different groups of floral visitors. Floral evolution has been highly labile and also directional. Some specialized systems such as hawkmoth or bat pollination are likely evolutionary dead-ends. In contrast, specialized pollination by hummingbirds is clearly not a dead-end. We found evidence for multiple reverse transitions from presumed ancestral hummingbird pollination to more derived bee or insect pollination. These repeated origins of insect pollination from hummingbird-pollinated ancestors have not evolved without historical baggage. Flowers of insect-pollinated species derived from hummingbird-pollinated ancestors are morphologically more similar to hummingbird flowers than they are to other more distantly related insect-pollinated flowers. Finally, some pollinator switches were concomitant with changes in floral morphology that are associated with those pollinators. These observations are consistent with the hypothesis that some transitions have been adaptive in the evolution of Ruellia.

  20. Separable roles of UFO during floral development revealed by conditional restoration of gene function.

    Science.gov (United States)

    Laufs, Patrick; Coen, Enrico; Kronenberger, Jocelyne; Traas, Jan; Doonan, John

    2003-02-01

    The UNUSUAL FLORAL ORGANS (UFO) gene is required for several aspects of floral development in Arabidopsis including specification of organ identity in the second and third whorls and the proper pattern of primordium initiation in the inner three whorls. UFO is expressed in a dynamic pattern during the early phases of flower development. Here we dissect the role of UFO by ubiquitously expressing it in ufo loss-of-function flowers at different developmental stages and for various durations using an ethanol-inducible expression system. The previously known functions of UFO could be separated and related to its expression at specific stages of development. We show that a 24- to 48-hour period of UFO expression from floral stage 2, before any floral organs are visible, is sufficient to restore normal petal and stamen development. The earliest requirement for UFO is during stage 2, when the endogenous UFO gene is transiently expressed in the centre of the wild-type flower and is required to specify the initiation patterns of petal, stamen and carpel primordia. Petal and stamen identity is determined during stages 2 or 3, when UFO is normally expressed in the presumptive second and third whorl. Although endogenous UFO expression is absent from the stamen whorl from stage 4 onwards, stamen identity can be restored by UFO activation up to stage 6. We also observed floral phenotypes not observed in loss-of-function or constitutive gain-of-function backgrounds, revealing additional roles of UFO in outgrowth of petal primordia.

  1. BIOLOGÍA FLORAL Y REPRODUCTIVA DE LA GULUPA PASSIFLORA EDULIS SIMS F. EDULIS

    Directory of Open Access Journals (Sweden)

    Angel-Coca Catalina

    2011-12-01

    Full Text Available Se estudió la biología floral y reproductiva de Passiflora edulis f. edulis en cultivos ubicados en la Cordillera Oriental en los Andes colombianos (Buenavista, Boyacá. La flor presentó antesis entre las 6 y las 8 hrs, la longevidad floral promedio fue de 25 hrs. Se reconocieron cuatro fases fenológicas: (1 Femenina con hercogamia (2 Homógama con hercogamia (3 Homógama sin hercogamia y (4 Senescente. Aunque el estigma está receptivo durante todas las fases florales, se obtuvo mayor producción de frutos en las fases segunda y tercera. La donación del polen, en su mayoría ocurrió en la fase dos con una viabilidad del 96%. El néctar mostró una tendencia ascendente durante la vida floral. Los experimentos de polinización indican que la gulupa es una variedad altamente autocompatible, pero requiere de los polinizadores para producir una buena cosecha, pues sólo el 33% de los frutos se forma sin el acceso de éstos. Los resultados sugieren que la gulupa tiene una estrategia floral mixta con el potencial para promover endogamia y entrecruzamiento genético, y que la conservación de las abejas polinizadoras es crucial en la productividad de este frutal.

  2. Floral Development in the Tribe Cedreleae (Meliaceae, Sub-family Swietenioideae): Cedrela and Toona

    Science.gov (United States)

    Gouvêa, Cantídio Fernando; Dornelas, Marcelo Carnier; Rodriguez, Adriana Pinheiro Martinelli

    2008-01-01

    Background and Aims Floral development of Cedrela and Toona, the genera comprising the basal tribe Cedreleae of the sub-family Swietenioideae of Meliaceae, is described. The focus was on three endangered, ecologically and economically important species: Cedrela fissilis, Cedrela odorata and Toona ciliata. The aims of the study were to characterize the patterns of floral development in the tribe and to establish apomorphic and plesiomorphic floral characters in relation to other taxa within the family based on the current molecular phylogeny of Meliaceae. Methods A detailed floral structural and developmental study was completed using both scanning electron microscopy and visualization of microtome sections with a light microscope. Key Results Twelve floral developmental stages were identified. The initial development of the pentamerous flowers of both Toona and Cedrela is strikingly similar. The morphological differences observed between them are due to differential patterns of organ elongation and adnation/connation occurring late in development. Additionally, the formation of functionally male and female flowers was found to occur at specific positions within the inflorescence. Conclusions Due to the basal position of the tribe Cedreleae in the phylogeny of Meliaceae, functionally either male or female pentamerous flowers and the presence of (at least partially) free stamens may be considered plesiomorphic traits within the family. In contrast, sympetaly and the absence of nectaries in Cedrela species are synapomorphies. PMID:17981877

  3. Floral Scent Chemistry of Luculia yunnanensis (Rubiaceae), a Species Endemic to China with Sweetly Fragrant Flowers.

    Science.gov (United States)

    Li, Yuying; Wan, Youming; Sun, Zhenghai; Li, Taiqiang; Liu, Xiongfang; Ma, Hong; Liu, Xiuxian; He, Rui; Ma, Yan; Li, Zhenghong

    2017-05-25

    Luculia plants are famed ornamentals with sweetly fragrant flowers. Luculia yunnanensis Hu is an endemic plant from Yunnan Province, China. Headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to identify the volatile organic compounds (VOCs) of the different flower development stages of L. yunnanensis for the evaluation of floral volatile polymorphism. The results showed that a total of 40 compounds were identified at four different stages. The main aroma-active compounds were 3-carene, α-cubebene, α-copaene, δ-cadinene, and isoledene. Floral scent emission had the tendency to ascend first and descend in succession, reaching its peak level at the initial-flowering stage. The richest diversity of floral volatiles was detected at the full-flowering stage. Principal component analysis (PCA) indicated that the composition and its relative content of floral scent differed at the whole flower development stage. In comparison with the other two species of Luculia ( L. pinceana and L. gratissima ), the composition and its relative content of floral scent were also different among the tree species.

  4. Morpho-anatomical and morphometric studies of the floral structures of the distylous Oldenlandia salzmannii (Rubiaceae

    Directory of Open Access Journals (Sweden)

    Mariela Nuñez Florentin

    Full Text Available ABSTRACT The genus Oldenlandia (Rubiaceae has a conflicting generic delimitation, with representatives that show different floral syndromes. Oldenlandia salzmannii is a marshy herb that is widespread in South America. It is heterostylous, specifically distylous, and self-compatible. Recent molecular phylogenetic studies found that this species forms a clade that is isolated from the remaining described taxa of Oldenlandia. Information about the floral anatomy and reproductive biology of genera in the Spermacoceae tribe, particularly Oldenlandia, is insufficient, especially among the neotropical species. Accordingly, the present study aimed at contributing information on the reproductive biology of Oldenlandia salzmannii by analyzing its floral morpho-anatomy, morphometrics and phenology of both floral morphs. These analyses were conducted with natural, cultivated and fixed material using optical and scanning electron microscopes. Morphologically, the species is typically heterostylous with two floral morphs, long-styled and short-styled, the main difference being the indument of the corolla. The short-styled flowers have larger anthers and pollen grains. Morphometrics show a high degree of herkogamic reciprocity. The mature ovules have a hemitropous position, which is the first record of this position for the Spermacoceae tribe. This study represents the first comprehensive morphological study of Oldenlandia salzmannii.

  5. Pollinator responses to floral colour change, nectar, and scent promote reproductive fitness in Quisqualis indica (Combretaceae).

    Science.gov (United States)

    Yan, Juan; Wang, Gang; Sui, Yi; Wang, Menglin; Zhang, Ling

    2016-04-13

    Floral colour change is visual signals for pollinators to avoid old flowers and increase pollination efficiency. Quisqualis indica flowers change colour from white to pink to red may be associated with a shift from moth to butterfly pollination. To test this hypothesis, we investigated Q. indica populations in Southwest China. Flowers secreted nectar continuously from the evening of anthesis until the following morning, then decreased gradually with floral colour change. The scent compounds in the three floral colour stages were similar; however, the scent composition was different, and the scent emission rate decreased from the white to red stage. Dichogamy in Q. indica prevents self-pollination and interference of male and female functions. Controlled pollinations demonstrated that this species is self-incompatible and needs pollinators for seed production. Different pollinators were attracted in each floral colour stage; mainly moths at night and bees and butterflies during the day. Observations of open-pollinated inflorescences showed that white flowers had a higher fruit set than pink or red flowers, indicating the high contribution of moths to reproductive success. We concluded that the nectar and scent secretion are related to floral colour change in Q. indica, in order to attract different pollinators and promote reproductive fitness.

  6. Pollen sensitivity to ultraviolet-B (UV-B) suggests floral structure evolution in alpine plants.

    Science.gov (United States)

    Zhang, Chan; Yang, Yong-Ping; Duan, Yuan-Wen

    2014-03-31

    Various biotic and abiotic factors are known to exert selection pressures on floral traits, but the influence of ultraviolet-B (UV-B) light on the evolution of flower structure remains relatively unexplored. We have examined the effectiveness of flower structure in blocking radiation and the effects of UV-B on pollen viability in 42 species of alpine plants in the Hengduan Mountains, China. Floral forms were categorized as either protecting or exposing pollen grains to UV-B. The floral materials of plants with exposed and protected pollen grains were able to block UV-B at similar levels. Exposure to UV-B radiation in vitro resulted in a significantly greater loss of viability in pollen from plant species with protective floral structures. The pronounced sensitivity of protected pollen to UV-B radiation was associated with the type of flower structure. These findings demonstrate that UV-B plays an important role in the evolution of protective floral forms in alpine plants.

  7. Floral neighborhood influences pollinator assemblages and effective pollination in a native plant.

    Science.gov (United States)

    Bruckman, Daniela; Campbell, Diane R

    2014-10-01

    Pollinators represent an important intermediary by which different plant species can influence each other's reproductive fitness. Floral neighbors can modify the quantity of pollinator visits to a focal species but may also influence the composition of visitor assemblages that plants receive leading to potential changes in the average effectiveness of floral visits. We explored how the heterospecific floral neighborhood (abundance of native and non-native heterospecific plants within 2 m × 2 m) affects pollinator visitation and composition of pollinator assemblages for a native plant, Phacelia parryi. The relative effectiveness of different insect visitors was also assessed to interpret the potential effects on plant fitness of shifts in pollinator assemblage composition. Although the common non-native Brassica nigra did not have a significant effect on overall pollinator visitation rate to P. parryi, the proportion of flower visits that were made by native pollinators increased with increasing abundance of heterospecific plant species in the floral neighborhood other than B. nigra. Furthermore, native pollinators deposited twice as many P. parryi pollen grains per visit as did the nonnative Apis mellifera, and visits by native bees also resulted in more seeds than visits by A. mellifera. These results indicate that the floral neighborhood can influence the composition of pollinator assemblages that visit a native plant and that changes in local flower communities have the potential to affect plant reproductive success through shifts in these assemblages towards less effective pollinators.

  8. CONSTITUTIVE PHOTOMORPHOGENIC 10 (COP10 Contributes to Floral Repression under Non-Inductive Short Days in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Min-Young Kang

    2015-11-01

    Full Text Available In Arabidopsis, CONSTITUTIVE PHOTOMORPHOGENIC/DE-ETIOLATED/FUSCA (COP/DET/FUS genes act in repression of photomorphogenesis in darkness, and recent reports revealed that some of these genes, such as COP1 and DET1, also have important roles in controlling flowering time and circadian rhythm. The COP/DET/FUS protein COP10 interacts with DET1 and DNA DAMAGE-BINDING PROTEIN 1 (DDB1 to form a CDD complex and represses photomorphogenesis in darkness. The cop10-4 mutants flower normally in inductive long days (LD but early in non-inductive short days (SD compared with wild type (WT; however, the role of COP10 remains unknown. Here, we investigate the role of COP10 in SD-dependent floral repression. Reverse transcription-quantitative PCR revealed that in SD, expression of the LD-dependent floral inducers GI, FKF1, and FT significantly increased in cop10-4 mutants, compared with WT. This suggests that COP10 mainly regulates FT expression in a CO-independent manner. We also show that COP10 interacts with GI in vitro and in vivo, suggesting that COP10 could also affect GI function at the posttranslational level. Moreover, FLC expression was repressed drastically in cop10-4 mutants and COP10 interacts with MULTICOPY SUPPRESSOR OF IRA1 4 (MSI4/FVE (MSI4/FVE, which epigenetically inhibits FLC expression. These data suggest that COP10 contributes to delaying flowering in the photoperiod and autonomous pathways by downregulating FT expression under SD.

  9. Floral markers of strawberry tree (Arbutus unedo L.) honey.

    Science.gov (United States)

    Tuberoso, Carlo I G; Bifulco, Ersilia; Caboni, Pierluigi; Cottiglia, Filippo; Cabras, Paolo; Floris, Ignazio

    2010-01-13

    Strawberry tree honey, due to its characteristic bitter taste, is one of the most typical Mediterranean honeys, with Sardinia being one of the largest producers. According to specific chemical studies, homogentisic acid was identified as a possible marker of this honey. This work, based on HPLC-DAD-MS/MS analysis of strawberry tree (Arbutus unedo L.) honeys, previously selected by sensory evaluation and melissopalynological analysis, showed that, in addition to the above-mentioned acid, there were other high levels of substances useful for the botanical classification of this unifloral honey. Two of these compounds were isolated and identified as (+/-)-2-cis,4-trans-abscisic acid (c,t-ABA) and (+/-)-2-trans,4-trans-abscisic acid (t,t-ABA). A third compound, a new natural product named unedone, was characterized as an epoxidic derivative of the above-mentioned acids. Structures of c,t-ABA, t,t-ABA, and unedone were elucidated on the basis of extensive 1D and 2D NMR experiments, as well as HPLC-MS/MS and Q-TOF analysis. In selected honeys the average amounts of c,t-ABA, t,t-ABA, and unedone were 176.2+/-25.4, 162.3+/-21.1, and 32.9+/-7.1 mg/kg, respectively. Analysis of the A. unedo nectar confirmed the floral origin of these compounds found in the honey. Abscisic acids were found in other unifloral honeys but not in such high amount and with a constant ratio of about 1:1. For this reason, besides homogentisic acid, these compounds could be used as complementary markers of strawberry tree honey.

  10. Studies on floral biology of passion fruit (passiflora spp.)

    International Nuclear Information System (INIS)

    Kishore, K.; Pathak, K.A.; Shukla, R.; Bharali, R.

    2010-01-01

    Floral biology of purple, yellow, giant and Passiflora foetida was studied at the ICAR Research Complex, Mizoram Centre, Kolasib, Mizoram, India during 2005-07. Purple, giant and P. foetida had major bloom during March-April, July-August and September-October. While major bloom in yellow was mainly during May-June and September-October. Purple, giant and P. foetida had the maximum duration of bloom of 42.4, 22.5 and 32.6 days, respectively during March-April with the maximum duration of effective bloom of 12.5 8.6 and 10.4 days in purple, giant and P. foetida, respectively. Yellow had the maximum duration of bloom for 28.4 days and effective bloom of 10.5 days during May-June. Most of the flowers of purple (54.5%) and giant (58.5%) opened between 6-7 hrs, while the maximum per cent of anthesis in yellow (70%) took place between 12-13 hrs. Pollen dehiscence and pollination in purple and giant mainly occurred between 7-8 hrs, while 13-14 hrs was the major period of pollen dehiscence and pollination in yellow. The earliest anthesis (5-6 hrs), anther dehiscence (6-7 hrs) and pollination (6-7 hrs) were recorded in P. foetida. The maximum stigma receptivity was recorded on the day of anthesis in all the passion fruits. Completely curved style was more common in all passion fruits that gave the maximum fruit set. The maximum number of bees observed between 7-8 hrs in purple and giant and between 13-14 hrs in yellow. The most common pollinating bee in purple, giant and yellow was Apis mellifera, while A. cerena was in P. foetida. (author)

  11. Biosurfactant production by Pseudomonas strains isolated from floral nectar.

    Science.gov (United States)

    Ben Belgacem, Z; Bijttebier, S; Verreth, C; Voorspoels, S; Van de Voorde, I; Aerts, G; Willems, K A; Jacquemyn, H; Ruyters, S; Lievens, B

    2015-06-01

    To screen and identify biosurfactant-producing Pseudomonas strains isolated from floral nectar; to characterize the produced biosurfactants; and to investigate the effect of different carbon sources on biosurfactant production. Four of eight nectar Pseudomonas isolates were found to produce biosurfactants. Phylogenetic analysis based on three housekeeping genes (16S rRNA gene, rpoB and gyrB) classified the isolates into two groups, including one group closely related to Pseudomonas fluorescens and another group closely related to Pseudomonas fragi and Pseudomonas jessenii. Although our nectar pseudomonads were able to grow on a variety of water-soluble and water-immiscible carbon sources, surface active agents were only produced when using vegetable oil as sole carbon source, including olive oil, sunflower oil or waste frying sunflower oil. Structural characterization based on thin layer chromatography (TLC) and ultra high performance liquid chromatography-accurate mass mass spectrometry (UHPLC-amMS) revealed that biosurfactant activity was most probably due to the production of fatty acids (C16:0; C18:0; C18:1 and C18:2), and mono- and diglycerides thereof. Four biosurfactant-producing nectar pseudomonads were identified. The active compounds were identified as fatty acids (C16:0; C18:0; C18:1 and C18:2), and mono- and diglycerides thereof, produced by hydrolysis of triglycerides of the feedstock. Studies on biosurfactant-producing micro-organisms have mainly focused on microbes isolated from soils and aquatic environments. Here, for the first time, nectar environments were screened as a novel source for biosurfactant producers. As nectars represent harsh environments with high osmotic pressure and varying pH levels, further screening of nectar habitats for biosurfactant-producing microbes may lead to the discovery of novel biosurfactants with broad tolerance towards different environmental conditions. © 2015 The Society for Applied Microbiology.

  12. Yeast identification in floral nectar of Mimulus aurantiacus (Invited)

    Science.gov (United States)

    Kyauk, C.; Belisle, M.; Fukami, T.

    2009-12-01

    Nectar is such a sugar-rich resource that serves as a natural habitat in which microbes thrive. As a result, yeasts arrive to nectar on the bodies of pollinators such as hummingbirds and bees. Yeasts use the sugar in nectar for their own needs when introduced. This research focuses on the identification of different types of yeast that are found in the nectar of Mimulus aurantiacus (commonly known as sticky monkey-flower). Unopened Mimulus aurantiacus flower buds were tagged at Jasper Ridge and bagged three days later. Floral nectar was then extracted and plated on potato dextrose agar. Colonies on the plates were isolated and DNA was extracted from each sample using QIAGEN DNeasy Plant Mini Kit. The DNA was amplified through PCR and ran through gel electrophoresis. The PCR product was used to clone the nectar samples into an E.coli vector. Finally, a phylogenetic tree was created by BLAST searching sequences in GenBank using the Internal Transcribed Space (ITS) locus. It was found that 18 of the 50 identified species were Candida magnifica, 14 was Candida rancensis, 6 were Crytococcus albidus and there were 3 or less of the following: Starmella bombicola, Candida floricola, Aureobasidium pullulans, Pichia kluyvera, Metschnikowa cibodaserisis, Rhodotorua colostri, and Malassezia globosa. The low diversity of the yeast could have been due to several factors: time of collection, demographics of Jasper Ridge, low variety of pollinators, and sugar concentration of the nectar. The results of this study serve as a necessary first step for a recently started research project on ecological interactions between plants, pollinators, and nectar-living yeast. More generally, this research studies the use of the nectar-living yeast community as a natural microcosm for addressing basic questions about the role of dispersal and competitive and facilitative interactions in ecological succession.

  13. A Dictyostelium SH2 adaptor protein required for correct DIF-1 signaling and pattern formation.

    Science.gov (United States)

    Sugden, Christopher; Ross, Susan; Annesley, Sarah J; Cole, Christian; Bloomfield, Gareth; Ivens, Alasdair; Skelton, Jason; Fisher, Paul R; Barton, Geoffrey; Williams, Jeffrey G

    2011-05-15

    phototaxis defect, implying that the early and late functions of LrrB are affected in different ways. These observations, coupled with its domain structure, suggest that LrrB is an SH2 adaptor protein active in diverse developmental signaling pathways. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Downstream Toll-like receptor signaling mediates adaptor-specific cytokine expression following focal cerebral ischemia

    Directory of Open Access Journals (Sweden)

    Bolanle Famakin

    2012-07-01

    Full Text Available Abstract Background Deletion of some Toll-like receptors (TLRs affords protection against cerebral ischemia, but disruption of their known major downstream adaptors does not. To determine whether compensation in the production of downstream effectors by one pathway when the other is disrupted can explain these findings, we examined cytokine/chemokine expression and inflammatory infiltrates in wild-type (WT, MyD88−/− and TRIF-mutant mice following permanent middle cerebral artery occlusion (pMCAO. Methods Cytokine/chemokine expression was measured with a 25-plex bead array in the serum and brains of all three groups of mice at baseline (no surgery/naïve and at 3 hours and 24 hours following pMCAO. Brain inflammatory and neutrophil infiltrates were examined 24 hours following pMCAO. Results IL-6, keratinocyte chemoattractant (KC, granulocyte colony-stimulating factor (G-CSF and IL-10 were significantly decreased in MyD88−/− mice compared to WT mice following pMCAO. Significantly, decreased levels of the neutrophil chemoattractants KC and G-CSF corresponded with a trend toward fewer neutrophils in the brains of MyD88−/− mice. IP-10 was significantly decreased when either pathway was disrupted. MIP-1α was significantly decreased in TRIF-mutant mice, consistent with TRIF-dependent production. MyD88−/− mice showed elevations of a number of Th2 cytokines, such as IL-13, at baseline, which became significantly decreased following pMCAO. Conclusions Both MyD88 and TRIF mediate pathway-specific cytokine production following focal cerebral ischemia. Our results also suggest a compensatory Th2-type skew at baseline in MyD88−/− mice and a paradoxical switch to a Th1 phenotype following focal cerebral ischemia. The MyD88 pathway directs the expression of neutrophil chemoattractants following cerebral ischemia.

  15. [In vitro regeneration and callogenesis in tissue culture of floral organs of the genus Iris (Iridaceae)].

    Science.gov (United States)

    Boltenkov, E V; Zarembo, E V

    2005-01-01

    We tested the differentiation and morphogenetic capacity of floral organs of Iris ensata, I. setosa, and I. sanguinea cultured in vitro. Organogenesis through direct formation of shoots from explants, callogenesis, and floral organogenesis were demonstrated in I. ensata callus culture in vitro. These processes depended on the plant species and on the content of phytohormones in the medium. Adventitious shoots proved to develop on the basal part of the perianth tube and on the apical part of the ovary, while roots were not formed. Direct organogenesis was induced by the following phytohormones: alpha-naphthylacetic acid and 6-benzylaminopurine for I. ensata and 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine for I. setosa and I. sanguinea; while callogenesis was induced by 2,4-dichlorophenoxyacetic acid. The obtained data indicate that development of adventitious structures from iris floral organs requires the presence of 6-benzylaminopurine in the growth medium.

  16. A quantitative review of pollination syndromes: do floral traits predict effective pollinators?

    Science.gov (United States)

    Rosas-Guerrero, Víctor; Aguilar, Ramiro; Martén-Rodríguez, Silvana; Ashworth, Lorena; Lopezaraiza-Mikel, Martha; Bastida, Jesús M; Quesada, Mauricio

    2014-03-01

    The idea of pollination syndromes has been largely discussed but no formal quantitative evaluation has yet been conducted across angiosperms. We present the first systematic review of pollination syndromes that quantitatively tests whether the most effective pollinators for a species can be inferred from suites of floral traits for 417 plant species. Our results support the syndrome concept, indicating that convergent floral evolution is driven by adaptation to the most effective pollinator group. The predictability of pollination syndromes is greater in pollinator-dependent species and in plants from tropical regions. Many plant species also have secondary pollinators that generally correspond to the ancestral pollinators documented in evolutionary studies. We discuss the utility and limitations of pollination syndromes and the role of secondary pollinators to understand floral ecology and evolution. © 2014 John Wiley & Sons Ltd/CNRS.

  17. Floral scent of brazilian Passiflora: five species analised by dynamic headspace

    Directory of Open Access Journals (Sweden)

    DANIEL A.V. MONTERO

    2016-01-01

    Full Text Available ABSTRACT This study describes for the first time the chemical composition and olfactive description of floral scent from Brazilian Passiflora (Passiflora edulis Sim, Passiflora alata Curtis, Passiflora cincinnata Mast., Passiflora coccinea Aubl. and Passiflora quadrangularis L.. Five species were grown in greenhouse at the Agronomic Institute (IAC, São Paulo, Brazil. Volatile compounds were collected using dynamic headspace. Analyses of scent composition were performed by gas chromatograph coupled to mass spectrometer. Identification of chemical constituents was conducted through of retention index followed by comparative analysis of mass spectra with specialized databases. The olfactive descriptions of floral scent from each species was evaluated for a professional perfumer. High interspecific diversity was found between chemical compositions of floral scent within Passiflora and different bouquets were observed amount the studied species. Mayor constituents were linalool (P. alata, geraniol (P. quadrangularis, 1,4-dimethoxybenzene (P. edulis, benzaldehyde (P. cincinnata and 2-methyl-3-pentanone (P. coccinea.

  18. More lessons from linalool: insights gained from a ubiquitous floral volatile.

    Science.gov (United States)

    Raguso, Robert A

    2016-08-01

    Linalool (3,7-dimethyl-1,6-octadien-3-ol) is a common floral volatile with two distinct enantiomers and related metabolites involved in the full spectrum of plant-pollinator interactions. Recent studies reveal a complex interplay between pollinator attraction and plant defense mediated by linalool and its derivatives, from the smallest (Arabidopsis, Mitella) to the largest (Datura) flowers studied. Accordingly, fig wasps, fungus gnats and moths of all sizes show remarkable electrophysiological, neural and behavioral sensitivity to different enantiomers and quantitative ratios of linalool in floral bouquets. The diverse functions of linalool, ranging from toxin to long distance pollinator attractant are discussed in the broader context of floral volatile ecology and evolution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Floral scent of brazilian Passiflora: five species analised by dynamic headspace.

    Science.gov (United States)

    Montero, Daniel A V; Marques, Marcia Ortiz M; Meletti, Laura M M; Kampen, Maria H VAN; Polozzi, Sandra C

    2016-09-01

    This study describes for the first time the chemical composition and olfactive description of floral scent from Brazilian Passiflora (Passiflora edulis Sim, Passiflora alata Curtis, Passiflora cincinnata Mast., Passiflora coccinea Aubl. and Passiflora quadrangularis L.). Five species were grown in greenhouse at the Agronomic Institute (IAC), São Paulo, Brazil. Volatile compounds were collected using dynamic headspace. Analyses of scent composition were performed by gas chromatograph coupled to mass spectrometer. Identification of chemical constituents was conducted through of retention index followed by comparative analysis of mass spectra with specialized databases. The olfactive descriptions of floral scent from each species was evaluated for a professional perfumer. High interspecific diversity was found between chemical compositions of floral scent within Passiflora and different bouquets were observed amount the studied species. Mayor constituents were linalool (P. alata), geraniol (P. quadrangularis), 1,4-dimethoxybenzene (P. edulis), benzaldehyde (P. cincinnata) and 2-methyl-3-pentanone (P. coccinea).

  20. Ethylene-Dependent and -Independent Processes Associated with Floral Organ Abscission in Arabidopsis1

    Science.gov (United States)

    Patterson, Sara E.; Bleecker, Anthony B.

    2004-01-01

    Abscission is an important developmental process in the life cycle of the plant, regulating the detachment of organs from the main body of the plant. This mechanism can be initiated in response to environmental cues such as disease or pathogen, or it can be a programmed shedding of organs that no longer provide essential functions to the plant. We have identified five novel dab (delayed floral organ abscission) mutants (dab1-1, dab2-1, dab3-1, dab3-2, and dab3-3) in Arabidopsis. These mutants each display unique anatomical and physiological characteristics and are governed by three independent loci. Scanning electron microscopy shows delayed development of the flattened fracture plane in some mutants and irregular elongation in the cells of the fracture plane in other mutants. The anatomical observations are also supported by breakstrength measurements that show high breakstrength associated with broken cells, moderate levels for the flattened fracture plane, and low levels associated with the initial rounding of cells. In addition, observations on the expression patterns in the abscission zone of cell wall hydrolytic enzymes, chitinase and cellulose, show altered patterns in the mutants. Last, we have compared these mutants with the ethylene-insensitive mutants etr1-1 and ein2-1 to determine if ethylene is an essential component of the abscission process and find that although ethylene can accelerate abscission under many conditions, the perception of ethylene is not essential. The role of the dab genes and the ethylene response genes during the abscission process is discussed. PMID:14701913

  1. Acceleration of flowering in Arabidopsis thaliana by Cape Verde Islands alleles of FLOWERING H is dependent on the floral promoter FD.

    Science.gov (United States)

    Seedat, Noorina; Dinsdale, Adrian; Ong, Eng Kok; Gendall, Anthony Richard

    2013-07-01

    Flowering time in the model plant Arabidopsis thaliana is regulated by both external environmental signals and internal developmental pathways. Natural variation at the FLOWERING H (FLH) locus has previously been described, with alleles present in the Cape Verde Islands accession causing early flowering, particularly after vernalization. The mechanism of FLH-induced early flowering is not understood. Here, the integration of FLH activity into the known flowering time pathways is described using molecular and genetic approaches. The identification of molecular markers that co-segregated with the FLH locus allowed the generation of multiple combinations of FLH alleles with mutations in flowering time genes in different flowering pathways. Combining an early flowering FLH allele with mutations in vernalization pathway genes that regulate FLC expression revealed that FLH appears to act in parallel to FLC. Surprisingly, the early flowering allele of FLH requires the floral integrator FD, but not FT, to accelerate flowering. This suggests a model in which some alleles of FLH are able to affect the FD-dependent activity of the floral activator complex.

  2. Phosphorylation-dependent regulation of T-cell activation by PAG/Cbp, a lipid raft-associated transmembrane adaptor

    Czech Academy of Sciences Publication Activity Database

    Davidson, D.; Bakinowski, M.; Thomas, M. L.; Hořejší, Václav; Veillette, A.

    2003-01-01

    Roč. 23, č. 6 (2003), s. 2017-2028 ISSN 0270-7306 R&D Projects: GA MŠk LN00A026 Institutional research plan: CEZ:AV0Z5052915 Keywords : PAG * Csk * T cell activation Subject RIV: EC - Immunology Impact factor: 8.142, year: 2003

  3. Transmembrane Adaptor Protein PAG/CBP Is Involved in both Positive and Negative Regulation of Mast Cell Signaling

    Czech Academy of Sciences Publication Activity Database

    Dráberová, Lubica; Bugajev, Viktor; Potůčková, Lucie; Hálová, Ivana; Bambousková, Monika; Polakovičová, Iva; Xavier, R.J.; Seed, B.; Dráber, Petr

    2014-01-01

    Roč. 34, č. 23 (2014), s. 4285-4300 ISSN 0270-7306 R&D Projects: GA ČR GA301/09/1826; GA ČR GAP302/10/1759; GA ČR(CZ) GBP302/12/G101; GA ČR(CZ) GD204/09/H084; GA MŠk LD12073; GA ČR(CZ) GA14-00703S; GA ČR(CZ) GA14-09807S Institutional support: RVO:68378050 Keywords : plasma membrane * cel signaling * IgE receptor Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.777, year: 2014

  4. Lessons from Red Data Books: Plant Vulnerability Increases with Floral Complexity.

    Directory of Open Access Journals (Sweden)

    Anastasia Stefanaki

    Full Text Available The architectural complexity of flower structures (hereafter referred to as floral complexity may be linked to pollination by specialized pollinators that can increase the probability of successful seed set. As plant-pollinator systems become fragile, a loss of such specialized pollinators could presumably result in an increased likelihood of pollination failure. This is an issue likely to be particularly evident in plants that are currently rare. Using a novel index describing floral complexity we explored whether this aspect of the structure of flowers could be used to predict vulnerability of plant species to extinction. To do this we defined plant vulnerability using the Red Data Book of Rare and Threatened Plants of Greece, a Mediterranean biodiversity hotspot. We also tested whether other intrinsic (e.g. life form, asexual reproduction or extrinsic (e.g. habitat, altitude, range-restrictedness factors could affect plant vulnerability. We found that plants with high floral complexity scores were significantly more likely to be vulnerable to extinction. Among all the floral complexity components only floral symmetry was found to have a significant effect, with radial-flower plants appearing to be less vulnerable. Life form was also a predictor of vulnerability, with woody perennial plants having significantly lower risk of extinction. Among the extrinsic factors, both habitat and maximum range were significantly associated with plant vulnerability (coastal plants and narrow-ranged plants are more likely to face higher risk. Although extrinsic and in particular anthropogenic factors determine plant extinction risk, intrinsic traits can indicate a plant's proneness to vulnerability. This raises the potential threat of declining global pollinator diversity interacting with floral complexity to increase the vulnerability of individual plant species. There is potential scope for using plant-pollinator specializations to identify plant species

  5. Microbial diversity in the floral nectar of Linaria vulgaris along an urbanization gradient.

    Science.gov (United States)

    Bartlewicz, Jacek; Lievens, Bart; Honnay, Olivier; Jacquemyn, Hans

    2016-03-30

    Microbes are common inhabitants of floral nectar and are capable of influencing plant-pollinator interactions. All studies so far investigated microbial communities in floral nectar in plant populations that were located in natural environments, but nothing is known about these communities in nectar of plants inhabiting urban environments. However, at least some microbes are vectored into floral nectar by pollinators, and because urbanization can have a profound impact on pollinator communities and plant-pollinator interactions, it can be expected that it affects nectar microbes as well. To test this hypothesis, we related microbial diversity in floral nectar to the degree of urbanization in the late-flowering plant Linaria vulgaris. Floral nectar was collected from twenty populations along an urbanization gradient and culturable bacteria and yeasts were isolated and identified by partially sequencing the genes coding for small and large ribosome subunits, respectively. A total of seven yeast and 13 bacterial operational taxonomic units (OTUs) were found at 3 and 1% sequence dissimilarity cut-offs, respectively. In agreement with previous studies, Metschnikowia reukaufii and M. gruessi were the main yeast constituents of nectar yeast communities, whereas Acinetobacter nectaris and Rosenbergiella epipactidis were the most frequently found bacterial species. Microbial incidence was high and did not change along the investigated urbanization gradient. However, microbial communities showed a nested subset structure, indicating that species-poor communities were a subset of species-rich communities. The level of urbanization was putatively identified as an important driver of nestedness, suggesting that environmental changes related to urbanization may impact microbial communities in floral nectar of plants growing in urban environments.

  6. Lessons from Red Data Books: Plant Vulnerability Increases with Floral Complexity.

    Science.gov (United States)

    Stefanaki, Anastasia; Kantsa, Aphrodite; Tscheulin, Thomas; Charitonidou, Martha; Petanidou, Theodora

    2015-01-01

    The architectural complexity of flower structures (hereafter referred to as floral complexity) may be linked to pollination by specialized pollinators that can increase the probability of successful seed set. As plant-pollinator systems become fragile, a loss of such specialized pollinators could presumably result in an increased likelihood of pollination failure. This is an issue likely to be particularly evident in plants that are currently rare. Using a novel index describing floral complexity we explored whether this aspect of the structure of flowers could be used to predict vulnerability of plant species to extinction. To do this we defined plant vulnerability using the Red Data Book of Rare and Threatened Plants of Greece, a Mediterranean biodiversity hotspot. We also tested whether other intrinsic (e.g. life form, asexual reproduction) or extrinsic (e.g. habitat, altitude, range-restrictedness) factors could affect plant vulnerability. We found that plants with high floral complexity scores were significantly more likely to be vulnerable to extinction. Among all the floral complexity components only floral symmetry was found to have a significant effect, with radial-flower plants appearing to be less vulnerable. Life form was also a predictor of vulnerability, with woody perennial plants having significantly lower risk of extinction. Among the extrinsic factors, both habitat and maximum range were significantly associated with plant vulnerability (coastal plants and narrow-ranged plants are more likely to face higher risk). Although extrinsic and in particular anthropogenic factors determine plant extinction risk, intrinsic traits can indicate a plant's proneness to vulnerability. This raises the potential threat of declining global pollinator diversity interacting with floral complexity to increase the vulnerability of individual plant species. There is potential scope for using plant-pollinator specializations to identify plant species particularly at

  7. Hybrid floral scent novelty drives pollinator shift in sexually deceptive orchids

    Directory of Open Access Journals (Sweden)

    Cozzolino Salvatore

    2010-04-01

    Full Text Available Abstract Background Sexually deceptive orchids of the genus Ophrys attract their pollinators, male insects, on a highly specific basis through the emission of odour blends that mimic the female sex pheromone of the targeted species. In this study, we have investigated a contact site between Ophrys arachnitiformis and O. lupercalis, two sympatric orchid species that are usually reproductively isolated via the exploitation of different pollinator "niches", but occasionally hybridise despite their apparent combination of ethological and mechanical isolation barriers. In particular, we have investigated the extent to which these Ophrys hybrids generate "emergent" combinations (i.e. novel and unpredictable from the parents' phenotypes of floral traits, and how these phenotypic novelties, particularly the odour blends emitted by the flower, could facilitate the invasion of a novel pollinator "niche" and induce the rapid formation of reproductive isolation, a prerequisite for adaptive evolutionary divergence. Results Our chemical analyses of floral scents show that the Ophrys F1 hybrids investigated here produce more compounds, significantly different ratios (% of odour compounds in the total blend, as well as new compounds in their floral odour compared to their progenitors. When tested for their attractiveness to the pollinator of each parent orchid species, we found that floral scent extracts of the hybrids triggered less inspecting flights and contacts by the male bees with the scented dummy than those of the parental orchid species. However, a series of additional behavioural bioassays revealed that the novel floral scent of the hybrids was significantly more attractive than either of the two parents to a pollinator species not initially involved in the pollination of any of the parent Ophrys species. Conclusions Collectively, our results illustrate that the process of hybridisation can lead to the generation of evolutionary novelties, and that

  8. EVALUATION OF FLORAL CHARACTERISTICS OF MELON HYBRIDS (Cucumis melo L. IN POLLINATOR ATTRACTIVENESS

    Directory of Open Access Journals (Sweden)

    LÚCIA HELENA PIEDADE KIILL

    2016-01-01

    Full Text Available ABSTRACT Floral morphology and biology are important characteristics for plant-pollinator interactions and may influence the behavior of these agents. This study aimed to determine which floral attributes of different melon hybrids influence this interaction and, consequently, their attractiveness in simultaneous crops. The study was conducted in the region of Petrolina, State of Pernambuco (PE/Juazeiro, State of Bahia (BA and Mossoró, State of Rio Grande do Norte (RN, in areas with the following melon hybrids: Yellow type, Piel de Sapo, Cantaloupe and Galia. For studies on floral morphology and biology, hermaphrodites and male flowers of each hybrid were analyzed for their size and nectar chamber size, pollen and nectar production, anthesis time and flower lifespan. Floral visitors were observed simultaneously in hybrids of three types of melon, from 5:00 a.m. to 6:00 p.m., in the two study sites. Evaluations of the corolla diameter and flower height indicated that the hermaphrodite flowers were larger in size than male flowers in all types of melon investigated, in both study sites. As for nectar chamber, male flowers are larger in width, but smaller in height, compared to hermaphrodite flowers. Regarding the volume of nectar, differences were found between floral types for the hybrids evaluated, in the two study sites; the hermaphrodite flowers produced 2-7 times more nectar than male flowers in all studied hybrids. Observations of visits of Apis mellifera to areas with simultaneous flowering of the three types of melon demonstrated differences in the frequency of visits between hybrids, floral type and foraged resource. Flowers of the hybrids Piel de Sapo and Cantaloupe exhibited larger corolla diameter, larger dimensions of the nectar chamber and greater supply of resources for foraging, which could explain the higher number of visits of bees to their flowers in the sites studied.

  9. Floral symmetry genes and the origin and maintenance of zygomorphy in a plant-pollinator mutualism.

    Science.gov (United States)

    Zhang, Wenheng; Kramer, Elena M; Davis, Charles C

    2010-04-06

    The evolution of floral zygomorphy is an important innovation in flowering plants and is thought to arise principally from specialization on various insect pollinators. Floral morphology of neotropical Malpighiaceae is distinctive and highly conserved, especially with regard to symmetry, and is thought to be caused by selection by its oil-bee pollinators. We sought to characterize the genetic basis of floral zygomorphy in Malpighiaceae by investigating CYCLOIDEA2-like (CYC2-like) genes, which are required for establishing symmetry in diverse core eudicots. We identified two copies of CYC2-like genes in Malpighiaceae, which resulted from a gene duplication in the common ancestor of the family. A likely role for these loci in the development of floral zygomorphy in Malpighiaceae is demonstrated by the conserved pattern of dorsal gene expression in two distantly related neotropical species, Byrsonima crassifolia and Janusia guaranitica. Further evidence for this function is observed in a Malpighiaceae species that has moved to the paleotropics and experienced coincident shifts in pollinators, floral symmetry, and CYC2-like gene expression. The dorsal expression pat-tern observed in Malpighiaceae contrasts dramatically with their actinomorphic-flowered relatives, Centroplacaceae (Bhesa paniculata) and Elatinaceae (Bergia texana). In particular, B. texana exhibits a previously undescribed pattern of uniform CYC2 expression, suggesting that CYC2 expression among the actinomorphic ancestors of zygomorphic lineages may be much more complex than previously thought. We consider three evolutionary models that may have given rise to this patterning, including the hypothesis that floral zygomorphy in Malpighiaceae arose earlier than standard morphology-based character reconstructions suggest.

  10. Floral traits driving reproductive isolation of two co-flowering taxa that share vertebrate pollinators

    Science.gov (United States)

    Queiroz, Joel A.; Quirino, Zelma G. M.; Machado, Isabel C.

    2015-01-01

    Floral attributes evolve in response to frequent and efficient pollinators, which are potentially important drivers of floral diversification and reproductive isolation. In this context, we asked, how do flowers evolve in a bat–hummingbird pollination system? Hence, we investigated the pollination ecology of two co-flowering Ipomoea taxa (I. marcellia and I. aff. marcellia) pollinated by bats and hummingbirds, and factors favouring reproductive isolation and pollinator sharing in these plants. To identify the most important drivers of reproductive isolation, we compared the flowers of the two Ipomoea taxa in terms of morphometry, anthesis and nectar production. Pollinator services were assessed using frequency of visits, fruit set and the number of seeds per fruit after visits. The studied Ipomoea taxa differed in corolla size and width, beginning and duration of anthesis, and nectar attributes. However, they shared the same diurnal and nocturnal visitors. The hummingbird Heliomaster squamosus was more frequent in I. marcellia (1.90 visits h−1) than in I. aff. marcellia (0.57 visits h−1), whereas glossophagine bats showed similar visit rates in both taxa (I. marcellia: 0.57 visits h−1 and I. aff. marcellia: 0.64 visits h−1). Bat pollination was more efficient in I. aff. marcellia, whereas pollination by hummingbirds was more efficient in I. marcellia. Differences in floral attributes between Ipomoea taxa, especially related to the anthesis period, length of floral parts and floral arrangement in the inflorescence, favour reproductive isolation from congeners through differential pollen placement on pollinators. This bat–hummingbird pollination system seems to be advantageous in the study area, where the availability of pollinators and floral resources changes considerably throughout the year, mainly as a result of rainfall seasonality. This interaction is beneficial for both sides, as it maximizes the number of potential pollen vectors for plants and

  11. A dimer of the Toll-like receptor 4 cytoplasmic domain provides a specific scaffold for the recruitment of signalling adaptor proteins.

    Directory of Open Access Journals (Sweden)

    Ricardo Núñez Miguel

    2007-08-01

    Full Text Available The Toll-like receptor 4 (TLR4 is a class I transmembrane receptor expressed on the surface of immune system cells. TLR4 is activated by exposure to lipopolysaccharides derived from the outer membrane of Gram negative bacteria and forms part of the innate immune response in mammals. Like other class 1 receptors, TLR4 is activated by ligand induced dimerization, and recent studies suggest that this causes concerted conformational changes in the receptor leading to self association of the cytoplasmic Toll/Interleukin 1 receptor (TIR signalling domain. This homodimerization event is proposed to provide a new scaffold that is able to bind downstream signalling adaptor proteins. TLR4 uses two different sets of adaptors; TRAM and TRIF, and Mal and MyD88. These adaptor pairs couple two distinct signalling pathways leading to the activation of interferon response factor 3 (IRF-3 and nuclear factor kappaB (NFkappaB respectively. In this paper we have generated a structural model of the TLR4 TIR dimer and used molecular docking to probe for potential sites of interaction between the receptor homodimer and the adaptor molecules. Remarkably, both the Mal and TRAM adaptors are strongly predicted to bind at two symmetry-related sites at the homodimer interface. This model of TLR4 activation is supported by extensive functional studies involving site directed mutagenesis, inhibition by cell permeable peptides and stable protein phosphorylation of receptor and adaptor TIR domains. Our results also suggest a molecular mechanism for two recent findings, the caspase 1 dependence of Mal signalling and the protective effects conferred by the Mal polymorphism Ser180Leu.

  12. High floral bud abscission and lack of open flower abscission in Dendrobium cv. Miss Teen: rapid reduction of ethylene sensitivity in the abscission zone

    NARCIS (Netherlands)

    Bunya-atichart, K.; Ketsa, S.; Doorn, van W.G.

    2006-01-01

    We studied the abscission of floral buds and open flowers in cut Dendrobium inflorescences. Abscission of floral buds was high and sensitive to ethylene in all cultivars studied. Many open flowers abscised in most cultivars, but cv. Willie exhibited only small amount of floral fall and cv. Miss Teen

  13. Comparative GC analyses of ripe fruits, leaves and floral buds essential oils of Tunisian Myrtus communis L.

    Directory of Open Access Journals (Sweden)

    Ahmed Snoussi

    2014-07-01

    Full Text Available The chemical composition of essential oils obtained by hydrodistillation from Tunisian wild growing myrtle ripe fruits, leaves and floral buds was examined by GC and GC-MS. The yields of hydrodistilled oils obtained from different plant parts were: leaves 0.5%, floral buds 0.2% and ripe fruits 0.02%. Significant differences were found in the concentration of main constituents of the oils: α-pinene [48.9% (floral buds, 34.3% (fruits, 23.7% (leaves], 1,8-cineole [15.3% (floral buds, 26.6% (fruits, 61.0% (leaves]. The leaves oil contained less linalool than floral buds and ripe fruits oils. Tunisian myrtle is characterized by the absence of myrtenyl acetate.

  14. Aspectos de biologia floral de cajueiros anão precoce e comum

    OpenAIRE

    Sousa,Larissa Barbosa de; Feitoza,Lidiane de Lima; Gomes,Regina Lucia Ferreira; Lopes,Ângela Celis de Almeida; Soares,Edson Basílio; Silva,Eduardo Magno Pereira da

    2007-01-01

    O conhecimento da biologia floral é de suma importância para o desenvolvimento da cultura do cajueiro (Anacardium occidentale L.). Com relação aos aspectos botânicos, as características morfológicas das flores contribuíram efetivamente para a determinação das espécies do gênero Anacarduim conhecidas. No presente trabalho, objetivou-se estudar a biologia floral dos cajueiros anão precoce e comum. A pesquisa foi desenvolvida na área experimental do Departamento de Fitotecnia, Centro de Ciências...

  15. Total control - pollen presentation and floral longevity in Loasaceae (blazing star family are modulated by light, temperature and pollinator visitation rates.

    Directory of Open Access Journals (Sweden)

    Tilo Henning

    Full Text Available Stamen movements can be understood as a mechanism influencing pollen presentation and increasing outbreeding success of hermaphroditic flowers via optimized male function. In this study we experimentally analyzed the factors regulating autonomous and thigmonastic (triggered by flower visitors stamen movements in eight species of Loasaceae. Both types of stamen movements are positively influenced by light and temperature and come to a virtual standstill in the dark and at low temperatures (12°C. Pollen presentation is thus discontinued during periods where pollinators are not active. Overall stamen presentation increases with increasing flower age. Contrary to expectation, no geometrical correlation between the floral scale stimulated and the stamen fascicle reacting exists, indicating that the stimulus is transmitted over the receptacle and stamen maturation dictates which and how many stamens react. Thigmonastic stamen presentation is dramatically accelerated compared to autonomous movement (3-37 times, indicating that the rate of stamen maturation can be adjusted to different visitation schedules. Flowers can react relatively uniformly down to stimulation intervals of 10-15 min., consistently presenting comparable numbers of stamens in the flower c. 5 min. after the stimulus and can thus keep the amount of pollen presented relatively constant even under very high visitation frequencies of 4-6 visits/h. Thigmonastic pollen presentation dramatically reduces the overall duration of the staminate phase (to 1/3(rd in Nasa macrothyrsa. Similarly, the carpellate phase is dramatically reduced after pollination, down to 1 d from 4 d. Overall flower longevity is reduced by more than 2/3(rds under high visitation rates (<3 d versus 10 d under visitor exclusion and depleted and pollinated flowers are rapidly removed from the pool. Complex floral behaviour in Loasaceae thus permits a near-total control over pollen dispensation schedules and floral

  16. Evidence that a herbivore tolerance response affects selection on floral traits and inflorescence architecture in purple loosestrife (Lythrum salicaria).

    Science.gov (United States)

    Thomsen, Christina J M; Sargent, Risa D

    2017-06-01

    The study of the evolution of floral traits has generally focused on pollination as the primary driver of selection. However, herbivores can also impose selection on floral traits through a variety of mechanisms, including florivory and parasitism. Less well understood is whether floral and inflorescence architecture traits that influence a plant's tolerance to herbivory, such as compensatory regrowth, alter pollinator-mediated selection. Because herbivore damage to Lythrum salicaria meristems typically leads to an increase in the number of inflorescences and the size of the floral display, an experiment was conducted to test whether simulated herbivory (i.e. clipping the developing meristem) could alter the magnitude or direction of pollinator-mediated selection on a suite of floral and inflorescence architecture traits. Using a pollen supplementation protocol, pollen limitation was compared in the presence and absence of meristem damage in order to quantify any interaction between pollinator and herbivore-mediated selection on floral traits. Surprisingly, in spite of an obvious impact on floral display and architecture, with clipped plants producing more inflorescences and more flowers, there was no difference in pollen limitation between clipped and unclipped plants. Correspondingly, there was no evidence that imposing herbivore damage altered pollinator-mediated selection in this system. Rather, the herbivory treatment alone was found to alter direct selection on floral display, with clipped plants experiencing greater selection for earlier flowering and weaker selection for number of inflorescences when compared with unclipped plants. These findings imply that herbivory on its own can drive selection on plant floral traits and inflorescence architecture in this species, even more so than pollinators. Specifically, herbivory can impose selection on floral traits if such traits influence a plant's tolerance to herbivory, such as through the timing of flowering

  17. Lentiviral Vpx accessory factor targets VprBP/DCAF1 substrate adaptor for cullin 4 E3 ubiquitin ligase to enable macrophage infection.

    Directory of Open Access Journals (Sweden)

    Smita Srivastava

    2008-05-01

    Full Text Available Vpx is a small virion-associated adaptor protein encoded by viruses of the HIV-2/SIVsm lineage of primate lentiviruses that enables these viruses to transduce monocyte-derived cells. This probably reflects the ability of Vpx to overcome an as yet uncharacterized block to an early event in the virus life cycle in these cells, but the underlying mechanism has remained elusive. Using biochemical and proteomic approaches, we have found that Vpx protein of the pathogenic SIVmac 239 strain associates with a ternary protein complex comprising DDB1 and VprBP subunits of Cullin 4-based E3 ubiquitin ligase, and DDA1, which has been implicated in the regulation of E3 catalytic activity, and that Vpx participates in the Cullin 4 E3 complex comprising VprBP. We further demonstrate that the ability of SIVmac as well as HIV-2 Vpx to interact with VprBP and its associated Cullin 4 complex is required for efficient reverse transcription of SIVmac RNA genome in primary macrophages. Strikingly, macrophages in which VprBP levels are depleted by RNA interference resist SIVmac infection. Thus, our observations reveal that Vpx interacts with both catalytic and regulatory components of the ubiquitin proteasome system and demonstrate that these interactions are critical for Vpx ability to enable efficient SIVmac replication in primary macrophages. Furthermore, they identify VprBP/DCAF1 substrate receptor for Cullin 4 E3 ubiquitin ligase and its associated protein complex as immediate downstream effector of Vpx for this function. Together, our findings suggest a model in which Vpx usurps VprBP-associated Cullin 4 ubiquitin ligase to enable efficient reverse transcription and thereby overcome a block to lentivirus replication in monocyte-derived cells, and thus provide novel insights into the underlying molecular mechanism.

  18. Identification of Atg2 and ArfGAP1 as Candidate Genetic Modifiers of the Eye Pigmentation Phenotype of Adaptor Protein-3 (AP-3) Mutants in Drosophila melanogaster.

    Science.gov (United States)

    Rodriguez-Fernandez, Imilce A; Dell'Angelica, Esteban C

    2015-01-01

    The Adaptor Protein (AP)-3 complex is an evolutionary conserved, molecular sorting device that mediates the intracellular trafficking of proteins to lysosomes and related organelles. Genetic defects in AP-3 subunits lead to impaired biogenesis of lysosome-related organelles (LROs) such as mammalian melanosomes and insect eye pigment granules. In this work, we have performed a forward screening for genetic modifiers of AP-3 function in the fruit fly, Drosophila melanogaster. Specifically, we have tested collections of large multi-gene deletions--which together covered most of the autosomal chromosomes-to identify chromosomal regions that, when deleted in single copy, enhanced or ameliorated the eye pigmentation phenotype of two independent AP-3 subunit mutants. Fine-mapping led us to define two non-overlapping, relatively small critical regions within fly chromosome 3. The first critical region included the Atg2 gene, which encodes a conserved protein involved in autophagy. Loss of one functional copy of Atg2 ameliorated the pigmentation defects of mutants in AP-3 subunits as well as in two other genes previously implicated in LRO biogenesis, namely Blos1 and lightoid, and even increased the eye pigment content of wild-type flies. The second critical region included the ArfGAP1 gene, which encodes a conserved GTPase-activating protein with specificity towards GTPases of the Arf family. Loss of a single functional copy of the ArfGAP1 gene ameliorated the pigmentation phenotype of AP-3 mutants but did not to modify the eye pigmentation of wild-type flies or mutants in Blos1 or lightoid. Strikingly, loss of the second functional copy of the gene did not modify the phenotype of AP-3 mutants any further but elicited early lethality in males and abnormal eye morphology when combined with mutations in Blos1 and lightoid, respectively. These results provide genetic evidence for new functional links connecting the machinery for biogenesis of LROs with molecules implicated in

  19. Self-pollination rate and floral-display size in Asclepias syriaca (Common Milkweed) with regard to floral-visitor taxa.

    Science.gov (United States)

    Howard, Aaron F; Barrows, Edward M

    2014-06-23

    Animals fertilize thousands of angiosperm species whose floral-display sizes can significantly influence pollinator behavior and plant reproductive success. Many studies have measured the interactions among pollinator behavior, floral-display size, and plant reproductive success, but few studies have been able to separate the effects of pollinator behavior and post-pollination processes on angiosperm sexual reproduction. In this study, we utilized the highly self-incompatible pollinium-pollination system of Asclepias syriaca (Common Milkweed) to quantify how insect visitors influenced male reproductive success measured as pollen removal, female reproductive success measured as pollen deposition, and self-pollination rate. We also determined how floral-display size impacts both visitor behavior and self-pollination rate. Four insect taxonomic orders visited A. syriaca: Coleoptera, Diptera, Hymenoptera, and Lepidoptera. We focused on three groups of visitor taxa within two orders (Hymenoptera and Lepidoptera) with sample sizes large enough for quantitative analysis: Apis mellifera (Western Honey Bee), Bombus spp. (bumble bees) and lepidopterans (butterflies and moths). Qualitatively, lepidopterans had the highest pollinator importance values, but the large variability in the lepidopteran data precluded meaningful interpretation of much of their behavior. The introduced A. mellifera was the most effective and most important diurnal pollinator with regard to both pollen removal and pollen deposition. However, when considering the self-incompatibility of A. syriaca, A. mellifera was not the most important pollinator because of its high self-pollination rate as compared to Bombus spp. Additionally, the rate of self-pollination increased more rapidly with the number of flowers per inflorescence in A. mellifera than in the native Bombus spp. Apis mellifera's high rate of self-pollination may have significant negative effects on both male and female reproductive successes

  20. Floral biology and breeding system of three Ipomoea weeds Biologia floral e sistema reprodutivo de três espécies daninhas de Ipomoea

    Directory of Open Access Journals (Sweden)

    R.C.S. Maimoni-Rodella

    2007-03-01

    Full Text Available The floral biology of three weeds, Ipomoea cairica, I. grandifolia and I. nil (Convolvulaceae, was studied in Botucatu and Jaboticabal, São Paulo, in southeastern Brazil. The three species are melittophilous, with a varied set of floral visitors, but with some overlapping. Cluster analysis using Jacquard similarity index indicated a greater similarity among different plant species in the same locality than among the populations at different places, in relation to floral visitor sets. The promiscuous and opportunistic features of the flowers were shown, with such type of adaptation to pollination being advantageous to weeds since pollinator availability is unpredictable at ruderal environments.A biologia floral de Ipomoea cairica, I. grandifolia e I. nil - plantas daninhas da família Convolvulaceae - foi estudada em Botucatu e Jaboticabal, Estado de São Paulo, Brasil. As três espécies são melitófilas, apresentando conjuntos de visitantes florais bastante diversificados, embora haja alguma sobreposição entre eles. Com relação aos visitantes florais, a análise de agrupamento, empregando-se o índice de similaridade de Jaccard, indicou maior similaridade entre diferentes espécies de Ipomoea ocorrentes no mesmo local do que entre populações da mesma espécie em diferentes localidades. O caráter promíscuo e oportunista da adaptação à polinização, presente nessas espécies, foi demonstrado, sendo essa adaptação vantajosa para plantas daninhas, uma vez que em ambientes ruderais a disponibilidade de polinizadores é imprevisível.

  1. Sequential multisite phospho-regulation of KNL1-BUB3 interfaces at mitotic kinetochores

    NARCIS (Netherlands)

    Vleugel, Mathijs; Omerzu, Manja; Groenewold, Vincent; Hadders, Michael A; Lens, Susanne M A; Kops, Geert J P L

    2015-01-01

    Regulated recruitment of the kinase-adaptor complex BUB1/BUB3 to kinetochores is crucial for correcting faulty chromosome-spindle attachments and for spindle assembly checkpoint (SAC) signaling. BUB1/BUB3 localizes to kinetochores by binding phosphorylated MELT motifs (MELpT) in the kinetochore

  2. Visitantes florales diurnos del girasol (Helianthus annuus, Asterales: Asteraceae en la Argentina Diurnal floral visitors of sunflower (Helianthus annuus, Asterales: Asteraceae in Argentina

    Directory of Open Access Journals (Sweden)

    Juan P. Torretta

    2010-06-01

    Full Text Available El girasol (Helianthus annuus L. es un importante cultivo oleaginoso en la Argentina. Durante tres campañas agrícolas, se determinaron la diversidad y la abundancia del elenco de los visitantes florales diurnos de capítulos de girasol, en ocho sitios que cubren gran parte del área cultivada en Argentina. Setenta y seis morfo-especies de visitantes florales, pertenecientes a ocho órdenes, fueron capturados sobre capítulos de este cultivo. El principal orden fue Hymenoptera, con 37 especies o morfoespecies, de las cuales 32 fueron abejas (Apoidea. Las familias de abejas más representadas fueron Apidae (13, Megachilidae (11 y Halictidae (7. La abeja doméstica (Apis mellifera L. realizó el 93% de las visitas. La composición del elenco de visitantes no mostró un patrón de variación identificable a lo largo del día, ni con respecto a la distancia al borde del cultivo, pero varió entre sitios de muestreo. Se concluye que la abeja doméstica es el principal polinizador del girasol en la Argentina, aunque varias especies nativas de abejas (Melissodes tintinnans (Holmberg, M. rufithorax Brèthes, Melissoptila tandilensis Holmberg, y Megachile spp. podrían ser consideradas como potenciales polinizadores del cultivo.Sunflower (Helianthus annuus L. is an important oilseed crop in Argentina. During three agricultural years, the diversity and abundance of diurnal floral visitors of sunflower heads were determined in eight sites spanning much of this crop's cultivation area in Argentina. Seventysix morpho-species of floral visitors, belonging to eight orders, were captured on sunflower. The principal order was Hymenoptera, with 37 species or morpho-species, of which 32 were bees (Apoidea. The most represented bee families were Apidae (13, Megachilidae (11 and Halictidae (7. The domestic bee (Apis mellifera L. accounted for 93% of the visits. Floral visitor composition did not show an identifiable variation pattern either throughout the day or

  3. How to be sweet? Extra floral nectar allocation by Gossypium hirsutum fits optimal defense theory predictions

    NARCIS (Netherlands)

    Wäckers, F.L.; Bonifay, C.

    2004-01-01

    Plants employ nectar for two distinct functions. Floral nectar has traditionally been viewed in the context of pollination. Extrafloral nectar on the other hand, can act as an indirect defense, allowing the plant to recruit predators and parasitoids. Whereas this makes for a clear-cut

  4. Assessing risks and benefits of floral supplements in conservation biological control

    NARCIS (Netherlands)

    Winkler, K.; Wackers, F.L.; Termorshuizen, A.J.; Lenteren, van J.C.

    2010-01-01

    The use of flowering field margins is often proposed as a method to support biological control in agro-ecosystems. In addition to beneficial insects, many herbivores depend on floral food as well. The indiscriminate use of flowering species in field margins can therefore lead to higher pest numbers.

  5. Setaria viridis floral-dip: A simple and rapid Agrobacterium-mediated transformation method

    Directory of Open Access Journals (Sweden)

    Polyana Kelly Martins

    2015-06-01

    Full Text Available Setaria viridis was recently described as a new monocotyledonous model species for C4 photosynthesis research and genetic transformation. It has biological attributes (rapid life cycle, small genome, diploid, short stature and simple growth requirements that make it suitable for use as a model plant. We report an alternative method of S. viridis transformation using floral dip to circumvent the necessity of tissue culture phase for transgenic plant regeneration. S. viridis spikes at boot stage were selected to be immersed in Agrobacterium suspension. T1 seeds could be identified in 1.5–2 months after floral dipping. We demonstrated through molecular analysis and RFP expression that seeds and resulting plants from dipped inflorescences were transformed. Our results suggest the feasibility of S. viridis floral dip transformation as a time-saving and cost-effective compared with traditional methods. To our knowledge, this is the first report using floral dip in S. viridis as an Agrobacterium-mediated transformation method.

  6. Access, labor, and wild floral greens management in western Washington's forests.

    Science.gov (United States)

    Kathryn A. Lynch; Rebecca J. McLain

    2003-01-01

    This report compares the changes that took place between 1994 and 2002 in the nontimber forest product (NTFP) management regime that governed access to floral greens and other NTFPs in western coastal Washington. A rapid rural appraisal approach was used to gather data from 24 NTFP stakeholders during phase I (1994) and from 37 NTFP stakeholders during phase II (2002...

  7. Study of the chemical composition of essential oils and floral waters ...

    African Journals Online (AJOL)

    This work aimed to study the chemical composition of essential oils and floral waters of Cymbopogon citratus (DC.) Stapf (Poaceae) from Senegal. The plants were collected in two different localities, Dakar and. Kaolack. The extracts were obtained by steam distillation from both fresh and dried plants and analyses carried.

  8. Study of the chemical composition of essential oils and floral waters ...

    African Journals Online (AJOL)

    This work aimed to study the chemical composition of essential oils and floral waters of Cymbopogon citratus (DC.) Stapf (Poaceae) from Senegal. The plants were collected in two different localities, Dakar and Kaolack. The extracts were obtained by steam distillation from both fresh and dried plants and analyses carried ...

  9. TRL1 gene expression in tomato (Solanum lycopersicum) floral organs after γ-irradiation

    International Nuclear Information System (INIS)

    Bondarenco, V.S.; Barbacar, N.I.

    2009-01-01

    The article describes the expression patterns of a novel RAD16-like TRL1 (tomato RAD16-like 1) gene in the floral organs of tomato during anther meiosis and mature flower stages. The data on the induction of the TRL1 expression as a result of γ-irradiation is discussed. (authors)

  10. How to be an attractive male: floral dimorphism and attractiveness to pollinators in a dioecious plant

    Directory of Open Access Journals (Sweden)

    Waelti Marc O

    2009-08-01

    Full Text Available Abstract Background Sexual selection theory predicts that males are limited in their reproductive success by access to mates, whereas females are more limited by resources. In animal-pollinated plants, attraction of pollinators and successful pollination is crucial for reproductive success. In dioecious plant species, males should thus be selected to increase their attractiveness to pollinators by investing more than females in floral traits that enhance pollinator visitation. We tested the prediction of higher attractiveness of male flowers in the dioecious, moth-pollinated herb Silene latifolia, by investigating floral signals (floral display and fragrance and conducting behavioral experiments with the pollinator-moth, Hadena bicruris. Results As found in previous studies, male plants produced more but smaller flowers. Male flowers, however, emitted significantly larger amounts of scent than female flowers, especially of the pollinator-attracting compounds. In behavioral tests we showed that naïve pollinator-moths preferred male over female flowers, but this preference was only significant for male moths. Conclusion Our data suggest the evolution of dimorphic floral signals is shaped by sexual selection and pollinator preferences, causing sexual conflict in both plants and pollinators.

  11. Teaching Flower Structure & Floral Formulae--A Mix of the Real & Virtual Worlds

    Science.gov (United States)

    Burrows, Geoff

    2010-01-01

    The study of flower structure is essential in plant identification and in understanding sexual reproduction in plants, pollination syndromes, plant breeding, and fruit structure. Thus, study of flower structure and construction of floral formulae are standard parts of first-year university botany and biology courses. These activities involve…

  12. Phénologie florale et production fruitière de Syzygium guineense ...

    African Journals Online (AJOL)

    A total of 85% of trees and shrubs having bloomed during the dry season despite fire stress. These individuals in the state of reproduction have diameters between 2.07 and 42.04 cm and heights ranging from 1.50 to 11.50 m. Four stages of flowering (floral initiation, developed bud, open flower and senescent flowers) and ...

  13. The emergence of core eudicots: new floral evidence from the earliest Late Cretaceous.

    Science.gov (United States)

    Friis, Else Marie; Pedersen, Kaj Raunsgaard; Crane, Peter R

    2016-12-28

    Eudicots, the most diverse of the three major clades of living angiosperms, are first recognized in the latest Barremian-earliest Aptian. All Early Cretaceous forms appear to be related to species-poor lineages that diverged before the rise of core eudicots, which today comprise more than 70% of angiosperm species. Here, we report the discovery of a well-preserved flower, Caliciflora mauldinensis, from the earliest Late Cretaceous, with unequivocal core eudicot features, including five sepals, five petals and two whorls of stamens borne on the rim of a floral cup containing three free carpels. Pollen is tricolporate. Carpels mature into follicular fruitlets. This character combination suggests a phylogenetic position among rosids, but more specific assignment is precluded by complex patterns of character evolution among the very large number of potentially relevant extant taxa. The whorled floral organization is consistent with ideas that this stable pattern evolved early and was a prerequisite for more integrated patterns of floral architecture that evolved later. However, limited floral synorganization in Caliciflora and all earlier eudicot flowers recognized so far, calls into question hypotheses that substantial diversification of core eudicots had already occurred by the end of the Early Cretaceous. © 2016 The Authors.

  14. Floral Biology of Fluted Pumpkin (Telfairia occidentalis Hook. F.

    Directory of Open Access Journals (Sweden)

    Lawrence Stephen FAYEUN

    2016-12-01

    Full Text Available Knowledge of floral biology is essential to crop improvement. Ten genotypes of fluted pumpkin (Telfairia occidentalis were observed for floral morphology, phenology and insect visitation for two consecutive years. Functional dioecy of fluted pumpkin was confirmed, whereas none of the studied genotypes was monoecious. Floral structures differed significantly among the genotypes. Both male and female flowers were symmetrical, pentasepalous, fimbriate and non-bright pentapetalous, but male flowers were more numerous. Male inflorescences emerged from 11 to 14 weeks after planting and the female flower buds appeared about 4 weeks later. The flowering period of the male flowers was longer than that of female flowers and both gender flowering periods coincided for a specific interval. It took between 11 to 14 days from bud initiation to anthesis and flowering ceased when there were occurrences of successful fruits set. In both gender flowers petals started unfurling at around 6.00 pm and full bloom was achieved by dawn, while petal shrivelled at sun set (between 6.30 pm to 7.30 pm. The anthers dehisced at anthesis of the male flowers; the pollen grains were whitish and sticky. Only the male flowers have nectar and pollen and this may explain infrequent female flowers visitation. Hover flies (Cheilosia species were the major floral visitors observed.

  15. What shapes amino acid and sugar composition in Mediterranean floral nectars?

    NARCIS (Netherlands)

    Petanidou, T.; Van Laere, A.; Ellis, W.; Smets, E.

    2006-01-01

    We studied the amino acid (AA) composition of the floral nectars of 73 plant species occurring in a phryganic (East Mediterranean garrigue) community and investigated whether AA and sugar composition is shaped by evolutionary (plant phylogeny), ecological (flowering time as a direct effect of summer

  16. Floral diversity in the wetlands of Ibeju-Lekki Area, Lagos, Nigeria ...

    African Journals Online (AJOL)

    Site A has the highest number of species (35), Simpson's, Shannon-Wienners and Margalef index values of 0.9385, 3.057 and 5.225 respectively. The sites ... The high floral diversity found in the undisturbed site (site C) indicates that the wetlands are correlated with their functions in biodiversity and other indirect benefits.

  17. Genetic control of floral morph in tristylous Pickerelweed (Pontederia cordata L.).

    Science.gov (United States)

    Gettys, Lyn A; Wofford, David S

    2008-01-01

    Pickerelweed (Pontederia cordata L.) is a diploid (2n = 2x = 16) tristylous aquatic perennial. Populations usually contain 3 floral morphs that differ reciprocally in style length and anther height (referred to as the long-, mid-, and short-styled morphs, hereafter L-, M-, and S-morphs). The floral polymorphism promotes disassortative mating among the 3 floral morphs and is maintained in populations by negative frequency-dependent selection. The objective of this study was to determine the number of loci, number of alleles, and gene action controlling floral morph in pickerelweed. Three parental lines (one each of the L-, M-, and S-morph) were used to create S1 and F1 populations. F2 populations were produced through self-pollination of F1 plants. Progeny ratios of S1, F1, and F2 generations revealed that tristyly is controlled by 2 diallelic loci (S and M) with dominant gene action. The S locus is epistatic to the M locus, with the S-morph produced by plants with the dominant S allele (genotype S _ _ _). Plants with recessive alleles at the S locus were either L-morph (ssmm) or M-morph (ssM_). The results of this experiment demonstrate that the inheritance of tristyly in pickerelweed is the same as previously reported for several tristylous species in the Lythraceae and Oxalidaceae.

  18. Selection by pollinators on floral traits in generalized Trollius ranunculoides (Ranunculaceae along altitudinal gradients.

    Directory of Open Access Journals (Sweden)

    Zhi-Gang Zhao

    Full Text Available Abundance and visitation of pollinator assemblages tend to decrease with altitude, leading to an increase in pollen limitation. Thus increased competition for pollinators may generate stronger selection on attractive traits of flowers at high elevations and cause floral adaptive evolution. Few studies have related geographically variable selection from pollinators and intraspecific floral differentiation. We investigated the variation of Trollius ranunculoides flowers and its pollinators along an altitudinal gradient on the eastern Qinghai-Tibet Plateau, and measured phenotypic selection by pollinators on floral traits across populations. The results showed significant decline of visitation rate of bees along altitudinal gradients, while flies was unchanged. When fitness is estimated by the visitation rate rather than the seed number per plant, phenotypic selection on the sepal length and width shows a significant correlation between the selection strength and the altitude, with stronger selection at higher altitudes. However, significant decreases in the sepal length and width of T. ranunculoides along the altitudinal gradient did not correspond to stronger selection of pollinators. In contrast to the pollinator visitation, mean annual precipitation negatively affected the sepal length and width, and contributed more to geographical variation in measured floral traits than the visitation rate of pollinators. Therefore, the sepal size may have been influenced by conflicting selection pressures from biotic and abiotic selective agents. This study supports the hypothesis that lower pollinator availability at high altitude can intensify selection on flower attractive traits, but abiotic selection is preventing a response to selection from pollinators.

  19. Abiotic conditions affect floral antagonists and mutualists of Impatiens capensis (Balsaminaceae).

    Science.gov (United States)

    Soper Gorden, Nicole L; Adler, Lynn S

    2013-04-01

    While the effect of abiotic factors on leaf herbivory is well known, the relative importance of abiotic conditions influencing both mutualists and antagonists is less well understood. Species interactions could enhance or reduce the direct effects of abiotic factors, depending on how mutualists and antagonists respond to abiotic conditions. We manipulated soil nutrients and shade in a factorial design and measured soil moisture in the annual Impatiens capensis. We then measured interactions with mutualists (two pollinating species) and antagonists (herbivores, florivores, nectar thieves, and flower bud gallers), as well as plant growth, floral rewards, and plant reproduction. Fertilizer increased plant growth, floral attractiveness, mutualist and antagonist interactions, and plant reproduction. Shade had no effects, and soil moisture was negatively associated with plant growth and reproduction. All effects were additive. Mutualist and antagonist floral interactions both increased on fertilized plants, but antagonists increased at a greater rate, leading to a larger ratio of antagonist to mutualist interactions on fertilized plants. Despite having more antagonists, fertilized plants still had significantly higher reproduction, suggesting higher tolerance to antagonists. Abiotic effects can have consistent effects on antagonists and mutualists, and on both floral and leaf antagonists. However, tolerance to antagonisms increased in favorable conditions. Thus, the direct positive effects of favorable abiotic conditions on plants outweighed negative indirect effects via increased antagonisms, which may lead to selection to grow in high-nutrient microsites in spite of increased herbivory.

  20. Genetic variation of inbreeding depression among floral and fitness traits in Silene nutans

    DEFF Research Database (Denmark)

    Thiele, Jan; Hansen, Thomas Møller; Siegismund, Hans Redlef

    2010-01-01

    The magnitude and variation of inbreeding depression (ID) within populations is important for the evolution and maintenance of mixed mating systems. We studied ID and its genetic variation in a range of floral and fitness traits in a small and large population of the perennial herb Silene nutans,...

  1. Aphid Sex Pheromone Compounds Interfere with Attraction of Common Green Lacewings to Floral Bait.

    Science.gov (United States)

    Koczor, Sándor; Szentkirályi, Ferenc; Pickett, John A; Birkett, Michael A; Tóth, Miklós

    2015-06-01

    Common green lacewings (Chrysoperla carnea complex) form a group of generalist predators important for biological control. Several reports show attraction of these insects to plant volatiles, and a highly attractive ternary compound floral bait has been developed. With aphids being a preferred prey of larvae, one might expect these lacewings to be attracted to aphid semiochemicals, for instance, to aphid sex pheromones, as found for several other green lacewing species. However, in a previous study, we found that traps containing aphid sex pheromone compounds (1R,4aS,7S,7aR)-nepetalactol (NEPOH), (4aS,7S,7aR)-nepetalactone (NEPONE), and a ternary floral bait attracted fewer individuals than those containing the ternary floral bait alone. In the present study, possible causes for this effect of NEPOH and NEPONE on trap capture were studied. We established that C. carnea complex catches in traps with a ternary floral lure were not influenced by the presence of Chrysopa formosa individuals in traps (attracted by NEPOH and NEPONE) or by synthetic skatole (a characteristic component of Chrysopa defense secretion). A direct negative effect of NEPOH and NEPONE on attraction of C. carnea complex was found, suggesting active avoidance of these aphid sex pheromone components. This finding is surprising as the larvae of these lacewings prey preferentially on aphids. Possible mechanisms underlying this phenomenon are discussed.

  2. Minor modifications in agricultural landscapes for promoting biodiversity through floral provisioning

    Science.gov (United States)

    There is growing interest in IPM programs and habitat management to combat the decline in diversity of beneficial arthropods in agricultural landscapes caused by habitat simplification and intensive management practices. Addition of floral resources to the landscape can help offset these effects. We...

  3. Extraction optimization and characterization of water soluble red purple pigment from floral bracts of Bougainvillea glabra

    Directory of Open Access Journals (Sweden)

    Shiv Narayan Amit Kumar

    2017-05-01

    Full Text Available Recently, natural dyes and pigments gain more importance in food and textile industries because of their non toxic and eco friendly characteristics. Bougainvillea glabra floral bracts are rich in betalain pigments which can be used as a dye in sensitized solar cells, medicinal and food applications. The aim of this study was to optimize the natural pigment extraction from the floral bracts by response surface methodology. Central composite design (CCD of response surface methodology (RSM was applied to evaluate the optimal conditions of three process variables namely mass of floral bracts (g, extraction time (h and temperature (°C studied at five levels. Mass of bracts and extraction time were found statistically significant in the process and correlation coefficient (R2 value of 0.96 showed that model was well fitted with the experimental values. The optimum process conditions were found to be mass of floral bracts: 3 g, contact time: 6 h and extraction temperature: 22.5 °C with maximum absorbance of 9.18. Response surface methodology was performed well to identify the optimal levels of extraction process variables and the validation of predicted model was fitted 99.76% with the experimental results conducted at the optimum conditions. Fourier Transform Infrared Spectroscopy was also confirmed the presence of betalain pigment by identifying the major functional groups.

  4. The smell of environmental change: Using floral scent to explain shifts in pollinator attraction

    Science.gov (United States)

    Laura A. Burkle; Justin B. Runyon

    2017-01-01

    As diverse environmental changes continue to influence the structure and function of plant-pollinator interactions across spatial and temporal scales, we will need to enlist numerous approaches to understand these changes. Quantitative examination of floral volatile organic compounds (VOCs) is one approach that is gaining popularity, and recent work suggests that...

  5. The potential role of B-function gene involved in floral development ...

    African Journals Online (AJOL)

    Camellia changii Ye, a rare and endangered species, has a phenotype that sepals frequently transform into petals. We assumed that this change would cause single C. changii Ye turned double flowers and this was confirmed by the double flowers we found in grafted C. changii Ye. The microstructure of floral organs ...

  6. Evolution of resistance to single and combined floral phytochemicals by a bumble bee parasite.

    Science.gov (United States)

    Palmer-Young, E C; Sadd, B M; Adler, L S

    2017-02-01

    Repeated exposure to inhibitory compounds can drive the evolution of resistance, which weakens chemical defence against antagonists. Floral phytochemicals in nectar and pollen have antimicrobial properties that can ameliorate infection in pollinators, but evolved resistance among parasites could diminish the medicinal efficacy of phytochemicals. However, multicompound blends, which occur in nectar and pollen, present simultaneous chemical challenges that may slow resistance evolution. We assessed evolution of resistance by the common bumble bee gut parasite Crithidia bombi to two floral phytochemicals, singly and combined, over 6 weeks (~100 generations) of chronic exposure. Resistance of C. bombi increased under single and combined phytochemical exposure, without any associated costs of reduced growth under phytochemical-free conditions. After 6 weeks' exposure, phytochemical concentrations that initially inhibited growth by > 50%, and exceeded concentrations in floral nectar, had minimal effects on evolved parasite lines. Unexpectedly, the phytochemical combination did not impede resistance evolution compared to single compounds. These results demonstrate that repeated phytochemical exposure, which could occur in homogeneous floral landscapes or with therapeutic phytochemical treatment of managed hives, can cause rapid evolution of resistance in pollinator parasites. We discuss possible explanations for submaximal phytochemical resistance in natural populations. Evolved resistance could diminish the antiparasitic value of phytochemical ingestion, weakening an important natural defence against infection. © 2016 The Authors. Journal of Evolutionary Biology Published by John Wiley & Sons ltd on behalf of European Society for Evolutionary Biology.

  7. Effect of floral bud reduction on flower longevity in Asiatic hybrids lilies.

    NARCIS (Netherlands)

    Meulen-Muisers, van der J.J.M.; Oeveren, van J.C.; Sandbrink, J.M.; Tuyl, van J.M.

    1995-01-01

    Floral bud abortion was found to be an undesirable source of non-genetic variation in breeding trials directed on the improvement of individual flower longevity in Asiatic hybrid lilies. It increased the longevity of the remaining flowers of the inflorescence. A similar response was found after

  8. Floral biology and the effects of plant-pollinator interaction on ...

    African Journals Online (AJOL)

    Reproductive biology and patterns of plant-pollinator interaction are fundamental to gene flow, diversity and evolutionary success of plants. Consequently, we examined the magnitude of insect-plant interaction based on the dynamics of breeding systems and floral biology and their effects on pollination intensity, fruit and ...

  9. Floral resources and habitat affect the composition of hummingbirds at the local scale in tropical mountaintops

    Directory of Open Access Journals (Sweden)

    LC Rodrigues

    Full Text Available Hummingbird communities tend to respond to variation in resources, having a positive relationship between abundance and diversity of food resources and the abundance and/or diversity of hummingbirds. Here we examined the influence of floral resource availability, as well as seasonality and type of habitat on the composition of hummingbird species. The study was carried out in two habitats of eastern Brazilian mountaintops. A gradient representative of the structure of hummingbird community, based on species composition, was obtained by the ordination of samples using the method of non-metric multidimensional scaling. The composition of hummingbird species was influenced by the type of habitat and floral resource availability, but not by seasonality. Hummingbird communities differ between habitats mainly due to the relative abundance of hummingbird species. The variation in composition of hummingbird species with the variation in floral resource availability may be related to differences in feeding habits of hummingbirds. Hummingbird species with the longest bills visited higher proportions of ornithophilous species, while hummingbirds with shorter bills visited higher proportions of non-ornithophilous species. The results demonstrate that at local-scale the composition of hummingbird species is affected by the type of habitat and floral resources availability, but not by seasonality.

  10. Floral resources and habitat affect the composition of hummingbirds at the local scale in tropical mountaintops.

    Science.gov (United States)

    Rodrigues, L C; Rodrigues, M

    2015-01-01

    Hummingbird communities tend to respond to variation in resources, having a positive relationship between abundance and diversity of food resources and the abundance and/or diversity of hummingbirds. Here we examined the influence of floral resource availability, as well as seasonality and type of habitat on the composition of hummingbird species. The study was carried out in two habitats of eastern Brazilian mountaintops. A gradient representative of the structure of hummingbird community, based on species composition, was obtained by the ordination of samples using the method of non-metric multidimensional scaling. The composition of hummingbird species was influenced by the type of habitat and floral resource availability, but not by seasonality. Hummingbird communities differ between habitats mainly due to the relative abundance of hummingbird species. The variation in composition of hummingbird species with the variation in floral resource availability may be related to differences in feeding habits of hummingbirds. Hummingbird species with the longest bills visited higher proportions of ornithophilous species, while hummingbirds with shorter bills visited higher proportions of non-ornithophilous species. The results demonstrate that at local-scale the composition of hummingbird species is affected by the type of habitat and floral resources availability, but not by seasonality.

  11. Supporting crop pollinators with floral resources: network-based phenological matching.

    Science.gov (United States)

    Russo, Laura; Debarros, Nelson; Yang, Suann; Shea, Katriona; Mortensen, David

    2013-09-01

    The production of diverse and affordable agricultural crop species depends on pollination services provided by bees. Indeed, the proportion of pollinator-dependent crops is increasing globally. Agriculture relies heavily on the domesticated honeybee; the services provided by this single species are under threat and becoming increasingly costly. Importantly, the free pollination services provided by diverse wild bee communities have been shown to be sufficient for high agricultural yields in some systems. However, stable, functional wild bee communities require floral resources, such as pollen and nectar, throughout their active season, not just when crop species are in flower. To target floral provisioning efforts to conserve and support native and managed bee species, we apply network theoretical methods incorporating plant and pollinator phenologies. Using a two-year dataset comprising interactions between bees (superfamily Apoidea, Anthophila) and 25 native perennial plant species in floral provisioning habitat, we identify plant and bee species that provide a key and central role to the stability of the structure of this community. We also examine three specific case studies: how provisioning habitat can provide temporally continuous support for honeybees (Apis mellifera) and bumblebees (Bombus impatiens), and how resource supplementation strategies might be designed for a single genus of important orchard pollinators (Osmia). This framework could be used to provide native bee communities with additional, well-targeted floral resources to ensure that they not only survive, but also thrive.

  12. Expression of heterosis in floral traits and fruit size in tomato ...

    African Journals Online (AJOL)

    A modified three way cross between the advanced generation of the tomato hybrids and an exotic variety with giant fruit size was initiated. The resulting hybrids were evaluated to determine the magnitude of heterosis in floral traits and fruit size. Highly significant differences were observed among the genotypes in all the ...

  13. Analysis of MADS-Box Gene Family Reveals Conservation in Floral Organ ABCDE Model of Moso Bamboo (Phyllostachys edulis).

    Science.gov (United States)

    Cheng, Zhanchao; Ge, Wei; Li, Long; Hou, Dan; Ma, Yanjun; Liu, Jun; Bai, Qingsong; Li, Xueping; Mu, Shaohua; Gao, Jian

    2017-01-01

    Mini chromosome maintenance 1, agamous, deficiens, and serum response factor (MADS)-box genes are transcription factors which play fundamental roles in flower development and regulation of floral organ identity. However, till date, identification and functions of MADS-box genes remain largely unclear in Phyllostachys edulis . In view of this, we performed a whole-genome survey and identified 34 MADS-box genes in P. edulis , and based on phylogeny, they were classified as MIKC C , MIKC ∗ , Mα, and Mβ. The detailed analysis about gene structure and motifs, phylogenetic classification, comparison of gene divergence and duplication are provided. Interestingly, expression patterns for most genes were found similar to those of Arabidopsis and rice, indicating that the well-established ABCDE model can be applied to P. edulis . Moreover, we overexpressed PheMADS15 , an AP1 -like gene, in Arabidopsis , and found that the transgenic plants have early flowering phenotype, suggesting that PheMADS15 might be a regulator of flowering transition in P. edulis . Taken together, this study provides not only insightful comprehension but also useful information for understanding the functions of MADS-box genes in P. edulis .

  14. Analysis of MADS-Box Gene Family Reveals Conservation in Floral Organ ABCDE Model of Moso Bamboo (Phyllostachys edulis

    Directory of Open Access Journals (Sweden)

    Zhanchao Cheng

    2017-05-01

    Full Text Available Mini chromosome maintenance 1, agamous, deficiens, and serum response factor (MADS-box genes are transcription factors which play fundamental roles in flower development and regulation of floral organ identity. However, till date, identification and functions of MADS-box genes remain largely unclear in Phyllostachys edulis. In view of this, we performed a whole-genome survey and identified 34 MADS-box genes in P. edulis, and based on phylogeny, they were classified as MIKCC, MIKC∗, Mα, and Mβ. The detailed analysis about gene structure and motifs, phylogenetic classification, comparison of gene divergence and duplication are provided. Interestingly, expression patterns for most genes were found similar to those of Arabidopsis and rice, indicating that the well-established ABCDE model can be applied to P. edulis. Moreover, we overexpressed PheMADS15, an AP1-like gene, in Arabidopsis, and found that the transgenic plants have early flowering phenotype, suggesting that PheMADS15 might be a regulator of flowering transition in P. edulis. Taken together, this study provides not only insightful comprehension but also useful information for understanding the functions of MADS-box genes in P. edulis.

  15. Temporal stability of pollinator preference in an alpine plant community and its implications for the evolution of floral traits.

    Science.gov (United States)

    Gong, Yan-Bing; Huang, Shuang-Quan

    2011-07-01

    A traditional view of diverse floral traits is that they reflect differences in foraging preferences of pollinators. The role of pollinators in the evolution of floral traits has been questioned recently by broad community surveys, especially studies concerning variation in pollinator assemblages and visitation frequency, which suggest a diminished role of pollinators in floral evolution. Here, we investigate the relationships between six categories of floral traits of 29 species and 10 pollinator functional groups in an alpine meadow in the Hengduan Mountains of China, over three consecutive years. Simpson's diversity index was used to estimate the level of pollinator generalization of each plant species by considering both pollinator groups and their relative visitation frequencies. Multivariate analyses indicated that eight of the ten pollinator groups showed constant preferences for at least two floral traits, leading to a relatively stable level of ecological generalization for most floral traits (two out of three categories), despite the fact that the level of generalization of the entire community varied across years. Shape preferences of butterflies, honeybees and beeflies varied such that open flowers exhibited a lower level of ecological generalization in 2007 than closed flowers, in contrast with the other 2 years. These results suggest that temporally stabilized preferences of diverse pollinators may contribute to the evolution of specialized versus generalized floral traits; however, their role may be moderated by variation in community structure, including both the composition and abundance of plants and pollinators.

  16. LAT--an important raft-associated transmembrane adaptor protein. Delivered on 6 July 2009 at the 34th FEBS Congress in Prague, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Hořejší, Václav; Otáhal, Pavel; Brdička, Tomáš

    2010-01-01

    Roč. 277, č. 21 (2010), s. 4383-4397 ISSN 1742-464X R&D Projects: GA ČR GEMEM/09/E011; GA MŠk 1M0506 Institutional research plan: CEZ:AV0Z50520514 Keywords : LAT * transmembrane adaptor protein * membrane rafts Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.129, year: 2010

  17. Kit- and Fc epsilonRI-induced differential phosphorylation of the transmembrane adaptor molecule NTAL/LAB/LAT2 allows flexibility in its scaffolding function in mast cells

    DEFF Research Database (Denmark)

    Iwaki, Shoko; Spicka, Jiri; Tkaczyk, Christine

    2008-01-01

    The transmembrane adaptor protein (TRAP), NTAL, is phosphorylated in mast cells following FcvarepsilonRI aggregation whereby it cooperates with LAT to induce degranulation. The Kit ligand, stem cell factor (SCF), enhances antigen-induced degranulation and this also appears to be NTAL-dependent. H...

  18. Genetic architecture of male floral traits required for hybrid wheat breeding.

    Science.gov (United States)

    Boeven, Philipp H G; Longin, C Friedrich H; Leiser, Willmar L; Kollers, Sonja; Ebmeyer, Erhard; Würschum, Tobias

    2016-12-01

    This study revealed a complex genetic architecture of male floral traits in wheat, and Rht-D1 was identified as the only major QTL. Genome-wide prediction approaches but also phenotypic recurrent selection appear promising to increase outcrossing ability required for hybrid wheat seed production. Hybrid wheat breeding is a promising approach to increase grain yield and yield stability. However, the identification of lines with favorable male floral characteristics required for hybrid seed production currently poses a severe bottleneck for hybrid wheat breeding. This study therefore aimed to unravel the genetic architecture of floral traits and to assess the potential of genomic approaches to accelerate their improvement. To this end, we employed a panel of 209 diverse winter wheat lines assessed for male floral traits and genotyped with genome-wide markers as well as for Rht-B1 and Rht-D1. We found the highest proportion of explained genotypic variance for the Rht-D1 locus (11-24 %), for which the dwarfing allele Rht-D1b had a negative effect on anther extrusion, visual anther extrusion and pollen mass. The genome-wide scan detected only few QTL with small or medium effects, indicating a complex genetic architecture. Consequently, marker-assisted selection yielded only moderate prediction abilities (0.44-0.63), mainly relying on Rht-D1. Genomic selection based on weighted ridge-regression best linear unbiased prediction achieved higher prediction abilities of up to 0.70 for anther extrusion. In conclusion, recurrent phenotypic selection appears most cost-effective for the initial improvement of floral traits in wheat, while genome-wide prediction approaches may be worthwhile when complete marker profiles are already available in a hybrid wheat breeding program.

  19. Semen-Like Floral Scents and Pollination Biology of a Sapromyophilous Plant Stemona japonica (Stemonaceae).

    Science.gov (United States)

    Chen, Gao; Jürgens, Andreas; Shao, Lidong; Liu, Yang; Sun, Weibang; Xia, Chengfeng

    2015-03-01

    By emitting scent resembling that of organic material suitable for oviposition and/or consumption by flies, sapromyophilous flowers use these flies as pollinators. To date, intensive scent analyses of such flowers have been restricted to Apocynaceae, Annonaceae, and Araceae. Recent studies have suggested that the wide range of volatile organic compounds (VOCs) from sapromyophilous flowers play an important role in attracting saprophagous flies by mimicking different types of decomposing substrates (herbivore and carnivore feces, carrion, and the fruiting bodies of fungi, etc.). In this study, we report the flower visitors and the floral VOCs of Stemona japonica (Blume) Miquel, a species native to China. The flowers do not produce rewards, and pollinators were not observed consuming pollen, thus suggesting a deceptive pollination system. Headspace samples of the floral scent were collected via solid-phase micro-extraction and analysed by gas chromatography coupled with mass spectrometry. Main floral scent compounds were 1-pyrroline (59.2%), 2-methyl-1-butanol (27.2%), and 3-methyl-1-butanol (8.8%), and resulted in a semen-like odor of blooming flowers. The floral constituents of S. japonica were significantly different from those found in previous sapromyophilous plants. An olfaction test indicated that 1-pyrroline is responsible for the semen-like odor in S. japonica flowers. Main flower visitors were shoot flies of the genus Atherigona (Muscidae). Bioassays using a mixture of all identified floral volatiles revealed that the synthetic volatiles can attract Atherigona flies in natural habitats. Our results suggest that the foul-smelling flowers of S. japonica may represent a new type of sapromyophily through scent mimicry.

  20. Evolution of pollination niches and floral divergence in the generalist plant Erysimum mediohispanicum.

    Science.gov (United States)

    Gómez, J M; Muñoz-Pajares, A J; Abdelaziz, M; Lorite, J; Perfectti, F

    2014-01-01

    How generalist plants diverge in response to pollinator selection without becoming specialized is still unknown. This study explores this question, focusing on the evolution of the pollination system in the pollination generalist Erysimum mediohispanicum (Brassicaceae). Pollinator assemblages were surveyed from 2001 to 2010 in 48 geo-referenced populations covering the entire geographic distribution of E. mediohispanicum. Bipartite modularity, a complex network tool, was used to find the pollination niche of each population. Evolution of the pollination niches and the correlated evolution of floral traits and pollination niches were explored using within-species comparative analyses. Despite being generalists, the E. mediohispanicum populations studied can be classified into five pollination niches. The boundaries between niches were not sharp, the niches differing among them in the relative frequencies of the floral visitor functional groups. The absence of spatial autocorrelation and phylogenetic signal indicates that the niches were distributed in a phylogeographic mosaic. The ancestral E. mediohispanicum populations presumably belonged to the niche defined by a high number of beetle and ant visits. A correlated evolution was found between pollination niches and some floral traits, suggesting the existence of generalist pollination ecotypes. It is conjectured that the geographic variation in pollination niches has contributed to the observed floral divergence in E. mediohispanicum. The process mediating this floral divergence presumably has been adaptive wandering, but the adaptation to the local pollinator faunas has been not universal. The outcome is a landscape where a few populations locally adapted to their pollination environment (generalist pollination ecotypes) coexist with many populations where this local adaptation has failed and where the plant phenotype is not primarily shaped by pollinators.

  1. Floral scent and species divergence in a pair of sexually deceptive orchids.

    Science.gov (United States)

    Gervasi, Daniel D L; Selosse, Marc-Andre; Sauve, Mathieu; Francke, Wittko; Vereecken, Nicolas J; Cozzolino, Salvatore; Schiestl, Florian P

    2017-08-01

    Speciation is typically accompanied by the formation of isolation barriers between lineages. Commonly, reproductive barriers are separated into pre- and post-zygotic mechanisms that can evolve with different speed. In this study, we measured the strength of different reproductive barriers in two closely related, sympatric orchids of the Ophrys insectifera group, namely Ophrys insectifera and Ophrys aymoninii to infer possible mechanisms of speciation. We quantified pre- and post-pollination barriers through observation of pollen flow, by performing artificial inter- and intraspecific crosses and analyzing scent bouquets. Additionally, we investigated differences in mycorrhizal fungi as a potential extrinsic factor of post-zygotic isolation. Our results show that floral isolation mediated by the attraction of different pollinators acts apparently as the sole reproductive barrier between the two orchid species, with later-acting intrinsic barriers seemingly absent. Also, the two orchids share most of their fungal mycorrhizal partners in sympatry, suggesting little or no importance of mycorrhizal symbiosis in reproductive isolation. Key traits underlying floral isolation were two alkenes and wax ester, present predominantly in the floral scent of O. aymoninii . These compounds, when applied to flowers of O. insectifera , triggered attraction and a copulation attempt of the bee pollinator of O. aymoninii and thus led to the (partial) breakdown of floral isolation. Based on our results, we suggest that adaptation to different pollinators, mediated by floral scent, underlies species isolation in this plant group. Pollinator switches may be promoted by low pollination success of individuals in dense patches of plants, an assumption that we also confirmed in our study.

  2. More than euglossines: the diverse pollinators and floral scents of Zygopetalinae orchids.

    Science.gov (United States)

    Nunes, Carlos E P; Wolowski, Marina; Pansarin, Emerson Ricardo; Gerlach, Günter; Aximoff, Izar; Vereecken, Nicolas J; Salvador, Marcos José; Sazima, Marlies

    2017-10-13

    Floral volatile organic compounds (VOCs) play important roles in plant-pollinator interactions. We investigated the reproductive ecology and floral VOCs of Zygopetalinae orchids to understand the relationship between floral scents and pollinators. We performed focal observations, phenological censuses and breeding system experiments in eight species in southeast Brazil. Floral scents were collected and analysed using SPME/GC-MS. We performed multivariate analyses to group species according to affinities of their VOCs and define compounds associated to each plant. Dichaea cogniauxiana was pollinated by weevils which use their developing ovules, while D. pendula was pollinated by the same weevils and perfume-collecting male euglossine bees. The other species were deceit-pollinated by bees. Zygopetalum crinitum was pollinated by carpenter bees, while W. warreana, Z. mackayi and Z. maxillare were bumblebee-pollinated. The latter was also pollinated by Centris confusa. Breeding system varied widely with no association to any pollinator group. Most VOCs are common to other floral scents. Zygopetalum crinitum presented an exclusive blend of VOCs, mainly composed of benzenoids. The scents of Pabstia jugosa, Promenaea xanthina and the Zygopetalum spp. were similar. The bumblebee-pollinated species have flowering periods partially overlapped, thus neither phenology nor pollinators constitute hybridization barriers among these species. Euglossines are not the only pollinators of Zygopetalinae. Different VOCs, size and lifespan of flowers are associated with distinct pollinators. A distinctive VOC bouquet may determine specialisation in carpenter bees or male euglossines within bee-pollinated flowers. Finally, visitation of deceit-pollinated flowers by perfume-collecting euglossines allows us to hypothesise how pollination by this group of bees had evolved.

  3. Historical nectar assessment reveals the fall and rise of floral resources in Britain

    Science.gov (United States)

    Baude, Mathilde; Kunin, William E.; Boatman, Nigel D.; Conyers, Simon; Davies, Nancy; Gillespie, Mark A. K.; Morton, R. Daniel; Smart, Simon M.; Memmott, Jane

    2016-02-01

    There is considerable concern over declines in insect pollinator communities and potential impacts on the pollination of crops and wildflowers. Among the multiple pressures facing pollinators, decreasing floral resources due to habitat loss and degradation has been suggested as a key contributing factor. However, a lack of quantitative data has hampered testing for historical changes in floral resources. Here we show that overall floral rewards can be estimated at a national scale by combining vegetation surveys and direct nectar measurements. We find evidence for substantial losses in nectar resources in England and Wales between the 1930s and 1970s; however, total nectar provision in Great Britain as a whole had stabilized by 1978, and increased from 1998 to 2007. These findings concur with trends in pollinator diversity, which declined in the mid-twentieth century but stabilized more recently. The diversity of nectar sources declined from 1978 to 1990 and thereafter in some habitats, with four plant species accounting for over 50% of national nectar provision in 2007. Calcareous grassland, broadleaved woodland and neutral grassland are the habitats that produce the greatest amount of nectar per unit area from the most diverse sources, whereas arable land is the poorest with respect to amount of nectar per unit area and diversity of nectar sources. Although agri-environment schemes add resources to arable landscapes, their national contribution is low. Owing to their large area, improved grasslands could add substantially to national nectar provision if they were managed to increase floral resource provision. This national-scale assessment of floral resource provision affords new insights into the links between plant and pollinator declines, and offers considerable opportunities for conservation.

  4. Transitions from distyly to homostyly are associated with floral evolution in the buckwheat genus (Fagopyrum).

    Science.gov (United States)

    Wu, Ling-Yun; Wang, Bo; Schoen, Daniel J; Huang, Shuang-Quan

    2017-08-08

    Documenting trait transitions among species with dimorphic flowers can help to test whether similar patterns of selection are responsible for divergence in floral traits among different species. Heterostyly is thought to promote outcrossing. Theory suggests that the evolutionary transition from heterostylous to homostylous flowers should be accompanied by a reduction in floral size in which pollen size and style length are expected to covary. Patterns of such correlated floral trait evolution have not, however, been widely examined. The evolutionary history of heterostyly and homostyly was reconstructed from a molecular phylogeny of 13 species of Fagopyrum and two outgroups, based on one nuclear gene (nrITS) and three chloroplast regions ( matK , atpB-rbcL , and psbA-trnH spacer). Floral traits of nine Fagopyrum species including pollen number and size, as well as stigma depth (length of the capitate stigma), were measured and ancestral characters of the herkogamic condition were reconstructed. Three transitions from distyly to homostyly were observed. In two transitions, flower size (corolla diameter, pedicel length), herkogamy (stigma-anther distance) and pollen production decreased, but stigma depth and pollen size did not. Changes of anther height and style length were inconsistent. The predicted positive relationship between style length and pollen size in the two transitions to homostyly was not observed. Floral evolution accompanying transitions to homostyly in Fagopyrum were found to be consistent with predictions of mating system evolution theory, and the correlation of traits in distylous vs. homostylous species revealed that pollen size generally correlates with stigma depth rather than style length. © 2017 Botanical Society of America.

  5. Pollinator Competition as a Driver of Floral Divergence: An Experimental Test.

    Directory of Open Access Journals (Sweden)

    Ethan J Temeles

    Full Text Available Optimal foraging models of floral divergence predict that competition between two different types of pollinators will result in partitioning, increased assortative mating, and divergence of two floral phenotypes. We tested these predictions in a tropical plant-pollinator system using sexes of purple-throated carib hummingbirds (Anthracothorax jugularis as the pollinators, red and yellow inflorescence morphs of Heliconia caribaea as the plants, and fluorescent dyes as pollen analogs in an enclosed outdoor garden. When foraging alone, males exhibited a significant preference for the yellow morph of H. caribaea, whereas females exhibited no preference. In competition, males maintained their preference for the yellow morph and through aggression caused females to over-visit the red morph, resulting in resource partitioning. Competition significantly increased within-morph dye transfer (assortative mating relative to non-competitive environments. Competition and partitioning of color morphs by sexes of purple-throated caribs also resulted in selection for floral divergence as measured by dye deposition on stigmas. Red and yellow morphs did not differ significantly in dye deposition in the competition trials, but differences in dye deposition and preferences for morphs when sexes of purple-throated caribs foraged alone implied fixation of one or the other color morph in the absence of competition. Competition also resulted in selection for divergence in corolla length, with the red morph experiencing directional selection for longer corollas and the yellow morph experiencing stabilizing selection on corolla length. Our results thus support predictions of foraging models of floral divergence and indicate that pollinator competition is a viable mechanism for divergence in floral traits of plants.

  6. Cloning and characterization of a benzoic acid/salicylic acid carboxyl methyltransferase gene involved in floral scent production from lily (Lilium 'Yelloween').

    Science.gov (United States)

    Wang, H; Sun, M; Li, L L; Xie, X H; Zhang, Q X

    2015-11-19

    In lily flowers, the volatile ester methyl benzoate is one of the major and abundant floral scent compounds; however, knowledge regarding the biosynthesis of methyl benzoate remains unknown for Lilium. In this study, we isolated a benzoic acid/salicylic acid carboxyl methyltransferase (BSMT) gene, LiBSMT, from petals of Lilium 'Yelloween'. The gene has an open reading frame of 1083 base pairs (bp) and encodes a protein of 41.05 kDa. Sequence alignment and phylogenetic analyses of LiBSMT revealed 40-50% similarity with other known benzenoid carboxyl methyltransferases in other plant species, and revealed homology to BSMT of Oryza sativa. Heterologous expression of this gene in Escherichia coli yielded an enzyme responsible for catalyzing benzoic acid and salicylic acid to methyl benzoate and methyl salicylate, respectively. Quantitative real-time polymerase chain reaction analysis showed that LiBSMT was preferentially expressed in petals. Moreover, the expression of LiBSMT in petals was developmentally regulated. These expression patterns correlate well with the emission of methyl benzoate. Our results indicate that LiBSMT plays an important role in floral scent methyl benzoate production and emission in lily flowers.

  7. Pollen Morphology and Boron Concentration in Floral Tissues as Factors Triggering Natural and GA-Induced Parthenocarpic Fruit Development in Grapevine

    Science.gov (United States)

    Pérez-Díaz, Ricardo; Yáñez, Mónica; Tapia, Jaime; Moreno, Yerko

    2015-01-01

    Parthenocarpic fruit development (PFD) reduces fruit yield and quality in grapevine. Parthenocarpic seedless berries arise from fruit set without effective fertilization due to defective pollen germination. PFD has been associated to micronutrient deficiency but the relation of this phenomenon with pollen polymorphism has not been reported before. In this work, six grapevine cultivars with different tendency for PFD and grown under micronutrient-sufficient conditions were analyzed to determine pollen structure and germination capability as well as PFD rates. Wide variation in non-germinative abnormal pollen was detected either among cultivars as well as for the same cultivar in different growing seasons. A straight correlation with PFD rates was found (R2 = 0.9896), suggesting that natural parthenocarpy is related to defective pollen development. Such relation was not observed when PFD was analyzed in grapevine plants exposed to exogenous gibberellin (GA) or abscissic acid (ABA) applications at pre-anthesis. Increase (GA treatment) or reduction (ABA treatment) in PFD rates without significative changes in abnormal pollen was determined. Although these plants were maintained at sufficient boron (B) condition, a down-regulation of the floral genes VvBOR3 and VvBOR4 together with a reduction of floral B content in GA-treated plants was established. These results suggest that impairment in B mobility to reproductive tissues and restriction of pollen tube growth could be involved in the GA-induced parthenocarpy. PMID:26440413

  8. Pollen Morphology and Boron Concentration in Floral Tissues as Factors Triggering Natural and GA-Induced Parthenocarpic Fruit Development in Grapevine.

    Science.gov (United States)

    Alva, Orlando; Roa-Roco, Rosa Nair; Pérez-Díaz, Ricardo; Yáñez, Mónica; Tapia, Jaime; Moreno, Yerko; Ruiz-Lara, Simón; González, Enrique

    2015-01-01

    Parthenocarpic fruit development (PFD) reduces fruit yield and quality in grapevine. Parthenocarpic seedless berries arise from fruit set without effective fertilization due to defective pollen germination. PFD has been associated to micronutrient deficiency but the relation of this phenomenon with pollen polymorphism has not been reported before. In this work, six grapevine cultivars with different tendency for PFD and grown under micronutrient-sufficient conditions were analyzed to determine pollen structure and germination capability as well as PFD rates. Wide variation in non-germinative abnormal pollen was detected either among cultivars as well as for the same cultivar in different growing seasons. A straight correlation with PFD rates was found (R2 = 0.9896), suggesting that natural parthenocarpy is related to defective pollen development. Such relation was not observed when PFD was analyzed in grapevine plants exposed to exogenous gibberellin (GA) or abscissic acid (ABA) applications at pre-anthesis. Increase (GA treatment) or reduction (ABA treatment) in PFD rates without significative changes in abnormal pollen was determined. Although these plants were maintained at sufficient boron (B) condition, a down-regulation of the floral genes VvBOR3 and VvBOR4 together with a reduction of floral B content in GA-treated plants was established. These results suggest that impairment in B mobility to reproductive tissues and restriction of pollen tube growth could be involved in the GA-induced parthenocarpy.

  9. Receptor tyrosine phosphatase R-PTP-alpha is tyrosine-phosphorylated and associated with the adaptor protein Grb2

    DEFF Research Database (Denmark)

    Su, J; Batzer, A; Sap, J

    1994-01-01

    Receptor tyrosine phosphatases (R-PTPases) have generated interest because of their suspected involvement in cellular signal transduction. The adaptor protein Grb2 has been implicated in coupling receptor tyrosine kinases to Ras. We report that a ubiquitous R-PTPase, R-PTP-alpha, is tyrosine......-phosphorylated and associated in vivo with the Grb2 protein. This association can be reproduced in stably and transiently transfected cells, as well as in vitro using recombinant Grb2 protein. Association requires the presence of an intact SH2 domain in Grb2, as well as tyrosine phosphorylation of R-PTP-alpha. This observation...... links a receptor tyrosine phosphatase with a key component of a central cellular signalling pathway and provides a basis for addressing R-PTP-alpha function....

  10. Shc adaptor proteins are key transducers of mitogenic signaling mediated by the G protein-coupled thrombin receptor

    DEFF Research Database (Denmark)

    Chen, Y; Grall, D; Salcini, A E

    1996-01-01

    The serine protease thrombin activates G protein signaling systems that lead to Ras activation and, in certain cells, proliferation. Whereas the steps leading to Ras activation by G protein-coupled receptors are not well defined, the mechanisms of Ras activation by receptor tyrosine kinases have...... kinase activation, gene induction and cell growth. From these data, we conclude that Shc represents a crucial point of convergence between signaling pathways activated by receptor tyrosine kinases and G protein-coupled receptors....... recently been elucidated biochemically and genetically. The present study was undertaken to determine whether common signaling components are used by these two distinct classes of receptors. Here we report that the adaptor protein Shc, is phosphorylated on tyrosine residues following stimulation...

  11. The structure and polymerase-recognition mechanism of the crucial adaptor protein AND-1 in the human replisome.

    Science.gov (United States)

    Guan, Chengcheng; Li, Jun; Sun, Dapeng; Liu, Yingfang; Liang, Huanhuan

    2017-06-09

    DNA replication in eukaryotic cells is performed by a multiprotein complex called the replisome, which consists of helicases, polymerases, and adaptor molecules. Human a cidic n ucleoplasmic D NA-binding protein 1 (AND-1), also known as WD repeat and high mobility group (HMG)-box DNA-binding protein 1 (WDHD1), is an adaptor molecule crucial for DNA replication. Although structural information for the AND-1 yeast ortholog is available, the mechanistic details for how human AND-1 protein anchors the lagging-strand DNA polymerase α (pol α) to the DNA helicase complex ( C dc45- M CM2-7- G INS, CMG) await elucidation. Here, we report the structures of the N-terminal WD40 and SepB domains of human AND-1, as well as a biochemical analysis of the C-terminal HMG domain. We show that AND-1 exists as a homotrimer mediated by the SepB domain. Mutant study results suggested that a positively charged groove within the SepB domain provides binding sites for pol α. Different from its ortholog protein in budding yeast, human AND-1 is recruited to the CMG complex, mediated by unknown participants other than Go Ichi Ni San. In addition, we show that AND-1 binds to DNA in vitro , using its C-terminal HMG domain. In conclusion, our findings provide important insights into the mechanistic details of human AND-1 function, advancing our understanding of replisome formation during eukaryotic replication. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. Probing the Energetics of Dynactin Filament Assembly and the Binding of Cargo Adaptor Proteins Using Molecular Dynamics Simulation and Electrostatics-Based Structural Modeling.

    Science.gov (United States)

    Zheng, Wenjun

    2017-01-10

    Dynactin, a large multiprotein complex, binds with the cytoplasmic dynein-1 motor and various adaptor proteins to allow recruitment and transportation of cellular cargoes toward the minus end of microtubules. The structure of the dynactin complex is built around an actin-like minifilament with a defined length, which has been visualized in a high-resolution structure of the dynactin filament determined by cryo-electron microscopy (cryo-EM). To understand the energetic basis of dynactin filament assembly, we used molecular dynamics simulation to probe the intersubunit interactions among the actin-like proteins, various capping proteins, and four extended regions of the dynactin shoulder. Our simulations revealed stronger intersubunit interactions at the barbed and pointed ends of the filament and involving the extended regions (compared with the interactions within the filament), which may energetically drive filament termination by the capping proteins and recruitment of the actin-like proteins by the extended regions, two key features of the dynactin filament assembly process. Next, we modeled the unknown binding configuration among dynactin, dynein tails, and a number of coiled-coil adaptor proteins (including several Bicaudal-D and related proteins and three HOOK proteins), and predicted a key set of charged residues involved in their electrostatic interactions. Our modeling is consistent with previous findings of conserved regions, functional sites, and disease mutations in the adaptor proteins and will provide a structural framework for future functional and mutational studies of these adaptor proteins. In sum, this study yielded rich structural and energetic information about dynactin and associated adaptor proteins that cannot be directly obtained from the cryo-EM structures with limited resolutions.

  13. EL ÁCIDO ABSCÍSICO ACELERA EL DESARROLLO FLORAL DE SOLIDAGO EN DÍAS CORTOS ABSCISIC ACID SPEED UP FLORAL DEVELOPMENT OF SOLIDAGO UNDER SHORT DAYS

    Directory of Open Access Journals (Sweden)

    Víctor Julio Flórez Roncancio

    2009-06-01

    Full Text Available Solidago x luteus (M. L. Greene Broulliet y Semple (= x Solidaster hybridus, x S. luteus es una planta que responde a días cortos (DC para el desarrollo floral. En este proceso se ha establecido la participación de varias fitohormonas, entre éstas, la presencia del ácido abscísico (ABA en zonas y periodos específicos durante el desarrollo de la flor lo cual sugiere su acción promotora en la velocidad de antesis floral de esta especie en DC. En este trabajo se buscaron nuevos indicios de la participación de fitohormonas presentes en la fracción ácida con el proceso de floración. En una primera etapa, extractos foliares provenientes de hojas de plantas en días largos (caracterizadas por menor velocidad de antesis floral se aplicaron en botones florales de plantas en días cortos (caracterizadas por una mayor velocidad de antesis floral. Se realizaron ocho aplicaciones con diferentes frecuencias totalizando un periodo de tratamiento de 25 días. Los resultados mostraron que las sustancias presentes en los extractos de la fracción ácida, no alteran la velocidad promedio de antesis floral en los botones florales de plantas en DC. En la segunda etapa del experimento, la cuantificación de los extractos por ELISA, permitió establecer una mayor concentración de ABA en los extractos de hojas y de botones florales de plantas en DC y de botones florales en el inicio del tratamiento. Estos resultados confirman la relación del ABA con la mayor velocidad de antesis floral en plantas de Solidago x luteus en condiciones de DC.Solidago x luteus (M.L. Greene Broulliet & Semple (= x Solidaster hybridus, x S. luteus is a plant that respond to short days (SD for flower development. In this process, there has been established the involvement of many phytohormones, between these, the presence of the abscisic acid (ABA in zones and specific periods during flower development, suggests its promoter roll on the floral anthesis period of this species under

  14. Regulation of floral scent production in petunia revealed by targeted metabolomics

    NARCIS (Netherlands)

    Verdonk, J.C.; Vos, de C.H.; Verhoeven, H.A.; Haring, M.A.; Tunen, van A.J.; Schuurink, R.C.

    2003-01-01

    Petunia hybrida line W115 (Mitchell) has large white flowers that produce a pleasant fragrance. By applying solid phase micro extraction (SPME) techniques coupled to GC-MS analysis, volatile emission was monitored in vivo using a targeted metabolomics approach. Mature flowers released predominantly

  15. Aspectos de biologia floral de cajueiros anão precoce e comum Floral biology aspects of the early dwarf and common cashew

    Directory of Open Access Journals (Sweden)

    Larissa Barbosa de Sousa

    2007-06-01

    Full Text Available O conhecimento da biologia floral é de suma importância para o desenvolvimento da cultura do cajueiro (Anacardium occidentale L.. Com relação aos aspectos botânicos, as características morfológicas das flores contribuíram efetivamente para a determinação das espécies do gênero Anacarduim conhecidas. No presente trabalho, objetivou-se estudar a biologia floral dos cajueiros anão precoce e comum. A pesquisa foi desenvolvida na área experimental do Departamento de Fitotecnia, Centro de Ciências Agrárias, Universidade Federal do Piauí, em Teresina, PI, avaliando-se nove clones de cajueiro anão ("CAP 14", "Embrapa 09", "Embrapa 50", "Embrapa 51", "Embrapa 76", "Embrapa 183", "Embrapa 189", "FAGA 01", "FAGA 11" e um clone de cajueiro comum ("CCA", utilizando-se quatro panículas por planta, cada uma com orientação norte, sul, leste e oeste. Os tipos varietais, cajueiro comum e anão precoce, apresentam pouca variação para a maioria dos caracteres avaliados. A proporção entre flores hermafroditas e o total de flores, em cajueiro comum, pode levá-lo a uma maior produção de frutos por panícula do que nos clones de cajueiro anão precoce analisados. O número de frutos desenvolvidos é bastante reduzido nos dois tipos varietais. As panículas situadas em diferentes orientações cardeais são semelhantes em todos os clones estudados quanto aos aspectos relacionados à biologia floral do cajueiro.The knowledge of the floral biology is very important for the development of the cashew's culture (Anacardium occidentale L.. In relation to botanical aspects, the morphological characteristics of flowers contributed effective to determination of the well-known species of Anacardium. It was aimed at studing the floral biology of the early dwarf and common cashew. The research was developed in the experimental area of the Department of Fitotecnia, Centro de Ciências Agrárias, Universidade Federal do Piauí, in Teresina, PI, and nine

  16. Floral development of Berberidopsis beckleri - can an additional species of the Berberidopsidaceae add evidence to floral evolution in the core eudicots?

    Science.gov (United States)

    Ronse De Craene, Louis P

    2017-03-01

    Berberidopsis beckleri is one of three species of the family Berberidopsidaceae. The flower of Berberidopsis is unusual for core eudicots in being spiral with an undifferentiated perianth. In a previous study of the sister species B. corallina , it was suggested that Berberidopsidaceae represent a prototype for the origin of the bipartite perianth and pentamery in core eudicots. The floral development of B. beckleri was investigated with a scanning electron microscope and compared with previous studies on B. corallina and Aextoxicon punctatum of Berberidopsidales. Flowers are inserted at the end of short shoots, which are not distinguishable from a pedicel. The initiation of perianth parts is highly predictable and spiral with a divergence angle of 137·5°, in a progression of a variable number of bracts to weakly differentiated sepaloid and petaloid tepals. The androecium most often consists 11 stamens arising in a rapid sequence. Compared with B. corallina , the number of perianth parts and stamens is more variable and there is no evidence of an alternation of shorter and longer plastochrons leading to a whorled arrangement. However, the gynoecium is generally pentamerous and arises from five primordia. The carpels are laterally connected into massive intercarpellary ridges on which ovules are initiated. The position of Streptothamnus within Berberidopsidaceae is questioned. It is demonstrated that the floral development of Berberidopsis beckleri lies within a gradient from spiral flowers without perianth differentiation leading to flowers with differentiated sepals and petals. The arrangement of flowers in compact inflorescences in B. corallina and Aextoxicon leads to a more stabilized arrangement of organs in whorls. The inherent variability of the flower of Berberidopsis is well correlated with the limited canalization of flowers in taxa at the base of the core eudicots and could act as a prototype for the current eudicot floral Bauplan. © The Author 2017

  17. Influence of genotype, floral stage, and water stress on floral nectar yield and composition of mānuka (Leptospermum scoparium).

    Science.gov (United States)

    Clearwater, Michael J; Revell, Maria; Noe, Stevie; Manley-Harris, Merilyn

    2018-03-05

    Floral nectar can be variable in composition, influencing pollinator behaviour and the composition of honey derived from it. The non-peroxide antibacterial activity of mānuka (Leptospermum scoparium, Myrtaceae) honey results from the chemical conversion of the triose sugar dihydroxyacetone (DHA), after DHA accumulates for an unknown reason in the nectar. This study examined variation in nectar DHA, glucose, fructose and sucrose content with floral stage of development, between mānuka genotypes with differing flower morphology, and in response to water stress. Six mānuka genotypes were grown without nectar-feeding insects. Stages of flower development were defined, nectar was harvested and its composition was compared between stages and genotypes, and with floral morphology. Water stress was imposed and its effect on nectar composition was examined. Nectar was present from soon after flower opening until the end of petal abscission, with the quantity of accumulated nectar sugars rising, then stabilizing or falling, indicating nectar secretion followed by reabsorption in some genotypes. The quantity of DHA, the ratio of DHA to other nectar sugars and the fructose to glucose ratio also varied with stage of development, indicating differences in rates of production and reabsorption between nectar components. Nectar composition and yield per flower also differed between genotypes, although neither was positively related to nectary area or stomatal density. Drying soil had no effect on nectar composition or yield, but variation in nectar yield was correlated with temperature prior to nectar sampling. Mānuka nectar yield and composition are strongly influenced by plant genotype, flower age and the environment. There were clear stoichiometric relationships between glucose, fructose and sucrose per flower, but DHA per flower was only weakly correlated with the amount of other sugars, suggesting that accumulation of the triose sugar is indirectly coupled to secretion of

  18. Floral Initiation in Response to Planting Date Reveals the Key Role of Floral Meristem Differentiation Prior to Budding in Canola (Brassica napus L.)

    Science.gov (United States)

    Zhang, Yaofeng; Zhang, Dongqing; Yu, Huasheng; Lin, Baogang; Fu, Ying; Hua, Shuijin

    2016-01-01

    In Brassica napus, floral development is a decisive factor in silique formation, and it is influenced by many cultivation practices including planting date. However, the effect of planting date on floral initiation in canola is poorly understood at present. A field experiment was conducted using a split plot design, in which three planting dates (early, 15 September, middle, 1 October, and late, 15 October) served as main plot and five varieties differing in maturity (1358, J22, Zhongshuang 11, Zheshuang 8, and Zheyou 50) employed as subplot. The purpose of this study was to shed light on the process of floral meristem (FM) differentiation, the influence of planting date on growth period (GP) and floral initiation, and silique formation. The main stages of FM developments can be divided into four stages: first, the transition from shoot apical meristem to FM; second, flower initiation; third, gynoecium and androecium differentiation; and fourth, bud formation. Our results showed that all genotypes had increased GPs from sowing to FM differentiation as planting date was delayed while the GPs from FM differentiation to budding varied year by year except the very early variety, 1358. Based on the number of flowers present at the different reproductive stages, the flowers produced from FM differentiation to budding closely approximated the final silique even though the FM differentiated continuously after budding and peaked generally at the middle flowering stage. The ratio of siliques to maximum flower number ranged from 48 to 80%. These results suggest that (1) the period from FM differentiation to budding is vital for effective flower and silique formation although there was no significant correlation between the length of the period and effective flowers and siliques, and (2) the increased number of flowers from budding were generally ineffective. Therefore, maximizing flower numbers prior to budding will improve silique numbers, and reducing FM degeneration should

  19. Effects of floral scents and their dietary experiences on the feeding preference in the blowfly, Phormia regina

    Directory of Open Access Journals (Sweden)

    Toru eMaeda

    2015-12-01

    Full Text Available AbstractThe flowers of different plant species have diverse scents with varied chemical compositions. Hence, every floral scent does not uniformly affect insect feeding preferences. The blowfly, Phormia regina, is a nectar feeder, and when a fly feeds on flower nectar, its olfactory organs, antennae, and maxillary palps are exposed to the scent. Generally, feeding preference is influenced by food flavor, which relies on both taste and odor. Therefore, the flies perceive the sweet taste of nectar and the particular scent of the flower simultaneously, and this olfactory information affects their feeding preference. Here, we show that the floral scents of 50 plant species have various effects on their sucrose feeding motivation, which was evaluated using the proboscis extension reflex (PER. Those floral scents were first categorized into three groups, based on their effects on the PER threshold sucrose concentration, which indicates whether a fly innately dislikes, ignores, or likes the target scent. Moreover, memory of olfactory experience with those floral scents during sugar feeding influenced the PER threshold. After feeding on sucrose solutions flavored with floral scents for 5 days, the scents did not consistently show the previously observed effects. Considering such empirical effects of scents on the PER threshold, we categorized the effects of the 50 tested floral scents on feeding preference into 16 of all possible 27 theoretical types. We then conducted the same experiments with flies whose antennae or maxillary palps were ablated prior to PER test in a fly group naïve to floral scents and prior to the olfactory experience during sugar feeding in the other fly group in order to test how these organs were involved in the effect of the floral scent. The results suggested that olfactory inputs through these organs play different roles in forming or modifying feeding preferences. Thus, our study contributes to an understanding of underlying

  20. Floral development of Berberidopsis corallina: a crucial link in the evolution of flowers in the core Eudicots.

    Science.gov (United States)

    Ronse DE Craene, Louis P

    2004-11-01

    On the basis of molecular evidence Berberidopsidaceae have been linked with Aextoxicaceae in an order Berberidopsidales at the base of the core Eudicots. The floral development of Berberidopsis is central to the understanding of the evolution of floral configurations at the transition of the basal Eudicots to the core Eudicots. It lies at the transition of trimerous or dimerous, simplified apetalous forms into pentamerous, petaliferous flowers. The floral ontogeny of Berberidopsis was studied with a scanning electron microscope. Flowers are grouped in terminal racemes with variable development. The relationship between the number of tepals, stamens and carpels is more or less fixed and floral initiation follows a strict 2/5 phyllotaxis. Two bracteoles, 12 tepals, eight stamens and three carpels are initiated in a regular sequence. The number of stamens can be increased by a doubling of stamen positions. The floral ontogeny of Berberidopsis provides support for the shift in floral bauplan from the basal Eudicots to the core Eudicots as a transition of a spiral flower with a 2/5 phyllotaxis to pentamerous flowers with two perianth whorls, two stamen whorls and a single carpel whorl. The differentiation of sepals and petals from bracteotepals is discussed and a comparison is made with other Eudicots with a similar configuration and development. Depending on the resolution of the relationships among the basalmost core Eudicots it is suggested that Berberidopsis either represents a critical stage in the evolution of pentamerous flowers of major clades of Eudicots, or has a floral prototype that may be at the base of evolution of flowers of other core Eudicots. The distribution of a floral Bauplan in other clades of Eudicots similar to Berberidopsidales is discussed.

  1. Effects of Floral Scents and Their Dietary Experiences on the Feeding Preference in the Blowfly, Phormia regina.

    Science.gov (United States)

    Maeda, Toru; Tamotsu, Miwako; Yamaoka, Ryohei; Ozaki, Mamiko

    2015-01-01

    The flowers of different plant species have diverse scents with varied chemical compositions. Hence, every floral scent does not uniformly affect insect feeding preferences. The blowfly, Phormia regina, is a nectar feeder, and when a fly feeds on flower nectar, its olfactory organs, antennae, and maxillary palps are exposed to the scent. Generally, feeding preference is influenced by food flavor, which relies on both taste and odor. Therefore, the flies perceive the sweet taste of nectar and the particular scent of the flower simultaneously, and this olfactory information affects their feeding preference. Here, we show that the floral scents of 50 plant species have various effects on their sucrose feeding motivation, which was evaluated using the proboscis extension reflex (PER). Those floral scents were first categorized into three groups, based on their effects on the PER threshold sucrose concentration, which indicates whether a fly innately dislikes, ignores, or likes the target scent. Moreover, memory of olfactory experience with those floral scents during sugar feeding influenced the PER threshold. After feeding on sucrose solutions flavored with floral scents for 5 days, the scents did not consistently show the previously observed effects. Considering such empirical effects of scents on the PER threshold, we categorized the effects of the 50 tested floral scents on feeding preference into 16 of all possible 27 theoretical types. We then conducted the same experiments with flies whose antennae or maxillary palps were ablated prior to PER test in a fly group naïve to floral scents and prior to the olfactory experience during sugar feeding in the other fly group in order to test how these organs were involved in the effect of the floral scent. The results suggested that olfactory inputs through these organs play different roles in forming or modifying feeding preferences. Thus, our study contributes to an understanding of underlying mechanisms associated with

  2. Cytological behaviour of floral organs and in silico characterization ...

    Indian Academy of Sciences (India)

    Annotation of characterized sequences showed presence of genes, namely auxin response factor 9. (ARF9) and forkhead-associated ... During successful plant development, there are numerous molecular events regulated by ... dehydration, the flowers were subjected to critical point dry- ing (CPD) using liquid carbon ...

  3. The ASK1 gene regulates B function gene expression in cooperation with UFO and LEAFY in Arabidopsis.

    Science.gov (United States)

    Zhao, D; Yu, Q; Chen, M; Ma, H

    2001-07-01

    The Arabidopsis floral regulatory genes APETALA3 (AP3) and PISTILLATA (PI) are required for the B function according to the ABC model for floral organ identity. AP3 and PI expression are positively regulated by the LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) genes. UFO encodes an F-box protein, and we have shown previously that UFO genetically interacts with the ASK1 gene encoding a SKP1 homologue; both the F-box containing protein and SKP1 are subunits of ubiquitin ligases. We show here that the ask1-1 mutation can enhance the floral phenotypes of weak lfy and ap3 mutants; therefore, like UFO, ASK1 also interacts with LFY and AP3 genetically. Furthermore, our results from RNA in situ hybridizations indicate that ASK1 regulates early AP3 and PI expression. These results support the idea that UFO and ASK1 together positively regulate AP3 and PI expression. We propose that the UFO and ASK1 proteins are components of a ubiquitin ligase that mediates the proteolysis of a repressor of AP3 and PI expression. Our genetic studies also indicate that ASK1 and UFO play a role in regulating the number of floral organ primordia, and we discuss possible mechanisms for such a regulation.

  4. The Arabidopsis floral repressor BFT delays flowering by competing with FT for FD binding under high salinity.

    Science.gov (United States)

    Ryu, Jae Yong; Lee, Hyo-Jun; Seo, Pil Joon; Jung, Jae-Hoon; Ahn, Ji Hoon; Park, Chung-Mo

    2014-02-01

    Soil salinity is one of the most serious agricultural problems that significantly reduce crop yields in the arid and semi-arid regions. It influences various phases of plant growth and developmental processes, such as seed germination, leaf and stem growth, and reproductive propagation. Salt stress delays the onset of flowering in many plant species. We have previously reported that the Arabidopsis BROTHER OF FT AND TFL1 (BFT) acts as a floral repressor under salt stress. However, the molecular mechanisms underlying the BFT function in the salt regulation of flowering induction is unknown. In this work, we found that BFT delays flowering under high salinity by competing with FLOWERING LOCUS T (FT) for binding to the FD transcription factor. The flowering time of FD-deficient fd-2 mutant was insensitive to high salinity. BFT interacts with FD in the nucleus via the C-terminal domain of FD, which is also required for the interaction of FD with FT, and interferes with the FT-FD interaction. These observations indicate that BFT constitutes a distinct salt stress signaling pathway that modulates the function of the FT-FD module and possibly provides an adaptation strategy that fine-tunes photoperiodic flowering under high salinity.

  5. Floral development at multiple spatial scales in Polygonum jucundum (Polygonaceae), a distylous species with broadly open flowers.

    Science.gov (United States)

    Huang, Lan-Jie; Fu, Wen-Long; Wang, Xiao-Fan

    2014-01-01

    Distyly, a special polymorph, has evolved in many groups of angiosperms and has attracted attention since Darwin's time. Development studies on distylous taxa have helped us to understand the evolutionary process of this polymorph, but most of these studies focus on species with narrowly tubular corolla. Here, we studied the floral development of Polygonum jucundum, a distylous species with broadly open flowers, at multiple spatial scales. Results showed that the difference in stigma height between flowers of the two morphs was caused by differences in style growth throughout the entire floral development process. The observed difference in anther heights between the two morphs was because the filaments grew faster in short-styled (SS) than in long-styled (LS) flowers in the later stages of floral development. In addition, the longer styles in LS flowers than in SS flowers was because of faster cell division in the early stages of floral development. However, SS flowers had longer filaments than LS flowers primarily because of greater cell elongation. These results indicate that floral development in P. jucundum differs from that of distylous taxa with floral tubes shown in previous studies. Further, we conclude that the presence of distyly in species with open flowers is a result of convergent evolution.

  6. Diversification in Monkeyflowers: An Investigation of the Effects of Elevation and Floral Color in the Genus Mimulus

    Directory of Open Access Journals (Sweden)

    Ezgi Ogutcen

    2014-01-01

    Full Text Available The vast diversity of floral colours in many flowering plant families, paired with the observation of preferences among pollinators, suggests that floral colour may be involved in the process of speciation in flowering plants. While transitions in floral colour have been examined in numerous genera, we have very little information on the consequences of floral colour transitions to the evolutionary success of a clade. Overlaid upon these patterns is the possibility that certain floral colours are more prevalent in certain environments, with the causes of differential diversification being more directly determined by geographical distribution. Here we examine transition rates to anthocyanin + carotenoid rich (red/orange/fuschia flowers and examine whether red/orange flowers are associated with differences in speciation and/or extinction rates in Mimulus. Because it has been suggested that reddish flowers are more prevalent at high elevation, we also examine the macroevolutionary evidence for this association and determine if there is evidence for differential diversification at high elevations. We find that, while red/orange clades have equivalent speciation rates, the trait state of reddish flowers reverts more rapidly to the nonreddish trait state. Moreover, there is evidence for high speciation rates at high elevation and no evidence for transition rates in floral colour to differ depending on elevation.

  7. Floral Volatiles in Parasitic Plants of the Orobanchaceae. Ecological and Taxonomic Implications

    Directory of Open Access Journals (Sweden)

    Peter eTóth

    2016-03-01

    Full Text Available The holoparasitic broomrapes, Orobanche spp. and Phelipanche spp. (Orobanchaceae, are root parasites that completely depend on a host plant for survival and reproduction. There is considerable controversy on the taxonomy of this biologically and agronomically important family. Flowers of over 25 parasitic Orobanchaceae and a number of close, parasitic and non-parasitic, relatives emitted a complex blend of volatile organic compounds (VOCs, consisting of over 130 VOCs per species. Floral VOC blend-based phylogeny supported the known taxonomy in internal taxonomic grouping of genus and eliminated the uncertainty in some taxonomical groups. Moreover, phylogenetic analysis suggested separation of the broomrapes into two main groups parasitizing annual and perennial hosts, and for the annual hosts, into weedy and non-weedy broomrapes. We conclude that floral VOCs are a significant tool in species identification and possibly even in defining new species and can help to improve controversial taxonomy in the Orobanchaceae.

  8. Floral Volatiles in Parasitic Plants of the Orobanchaceae. Ecological and Taxonomic Implications

    Science.gov (United States)

    Tóth, Peter; Undas, Anna K.; Verstappen, Francel; Bouwmeester, Harro

    2016-01-01

    The holoparasitic broomrapes, Orobanche spp. and Phelipanche spp. (Orobanchaceae), are root parasites that completely depend on a host plant for survival and reproduction. There is considerable controversy on the taxonomy of this biologically and agronomically important family. Flowers of over 25 parasitic Orobanchaceae and a number of close, parasitic and non-parasitic, relatives emitted a complex blend of volatile organic compounds (VOCs), consisting of over 130 VOCs per species. Floral VOC blend-based phylogeny supported the known taxonomy in internal taxonomic grouping of genus and eliminated the uncertainty in some taxonomical groups. Moreover, phylogenetic analysis suggested separation of the broomrapes into two main groups parasitizing annual and perennial hosts, and for the annual hosts, into weedy and non-weedy broomrapes. We conclude that floral VOCs are a significant tool in species identification and possibly even in defining new species and can help to improve controversial taxonomy in the Orobanchaceae. PMID:27014329

  9. Local bumble bee decline linked to recovery of honey bees, drought effects on floral resources.

    Science.gov (United States)

    Thomson, Diane M

    2016-10-01

    Time series of abundances are critical for understanding how abiotic factors and species interactions affect population dynamics, but are rarely linked with experiments and also scarce for bee pollinators. This gap is important given concerns about declines in some bee species. I monitored honey bee (Apis mellifera) and bumble bee (Bombus spp.) foragers in coastal California from 1999, when feral A. mellifera populations were low due to Varroa destructor, until 2014. Apis mellifera increased substantially, except between 2006 and 2011, coinciding with declines in managed populations. Increases in A. mellifera strongly correlated with declines in Bombus and reduced diet overlap between them, suggesting resource competition consistent with past experimental results. Lower Bombus numbers also correlated with diminished floral resources. Declines in floral abundances were associated with drought and reduced spring rainfall. These results illustrate how competition with an introduced species may interact with climate to drive local decline of native pollinators. © 2016 John Wiley & Sons Ltd/CNRS.

  10. Caffeine in floral nectar enhances a pollinator’s memory of reward

    Science.gov (United States)

    Wright, G. A.; Baker, D. D.; Palmer, M. J.; Stabler, D.; Mustard, J. A.; Power, E. F.; Borland, A. M.; Stevenson, P. C.

    2015-01-01

    Plant defence compounds occur in floral nectar, but their ecological role is not well-understood. We provide the first evidence that plant compounds pharmacologically alter pollinator behaviour by enhancing their memory of reward. Honeybees rewarded with caffeine, which occurs naturally in nectar of Coffea and Citrus species, were three times more likely to remember a learned floral scent than those rewarded with sucrose alone. Caffeine potentiated responses of mushroom body neurons involved in olfactory learning and memory by acting as an adenosine receptor antagonist. Caffeine concentrations in nectar never exceeded the bees’ bitter taste threshold, implying that pollinators impose selection for nectar that is pharmacologically active but not repellent. By using a drug to enhance memories of reward, plants secure pollinator fidelity and improve reproductive success. PMID:23471406

  11. Identification of Atg2 and ArfGAP1 as Candidate Genetic Modifiers of the Eye Pigmentation Phenotype of Adaptor Protein-3 (AP-3 Mutants in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Imilce A Rodriguez-Fernandez

    Full Text Available The Adaptor Protein (AP-3 complex is an evolutionary conserved, molecular sorting device that mediates the intracellular trafficking of proteins to lysosomes and related organelles. Genetic defects in AP-3 subunits lead to impaired biogenesis of lysosome-related organelles (LROs such as mammalian melanosomes and insect eye pigment granules. In this work, we have performed a forward screening for genetic modifiers of AP-3 function in the fruit fly, Drosophila melanogaster. Specifically, we have tested collections of large multi-gene deletions--which together covered most of the autosomal chromosomes-to identify chromosomal regions that, when deleted in single copy, enhanced or ameliorated the eye pigmentation phenotype of two independent AP-3 subunit mutants. Fine-mapping led us to define two non-overlapping, relatively small critical regions within fly chromosome 3. The first critical region included the Atg2 gene, which encodes a conserved protein involved in autophagy. Loss of one functional copy of Atg2 ameliorated the pigmentation defects of mutants in AP-3 subunits as well as in two other genes previously implicated in LRO biogenesis, namely Blos1 and lightoid, and even increased the eye pigment content of wild-type flies. The second critical region included the ArfGAP1 gene, which encodes a conserved GTPase-activating protein with specificity towards GTPases of the Arf family. Loss of a single functional copy of the ArfGAP1 gene ameliorated the pigmentation phenotype of AP-3 mutants but did not to modify the eye pigmentation of wild-type flies or mutants in Blos1 or lightoid. Strikingly, loss of the second functional copy of the gene did not modify the phenotype of AP-3 mutants any further but elicited early lethality in males and abnormal eye morphology when combined with mutations in Blos1 and lightoid, respectively. These results provide genetic evidence for new functional links connecting the machinery for biogenesis of LROs with

  12. Floral trait associations in hawkmoth-specialized and mixed pollination systems

    Science.gov (United States)

    Alarcón, Ruben; Abrell, Leif

    2008-01-01

    Variation in floral traits including odor, color and morphology, demonstrate the selective pressures imposed by specific pollinator taxa, such as insects and birds. In southern Arizona, Manduca sexta (Sphingidae) hawkmoths are associated with Datura wrightii (Solanaceae) at both the larval (herbivore) and adult (nectar feeding) stages. However during most of the summer Manduca feeds on “bat-adapted” Agave spp. (Agaveacea) flowers, and only use Datura when it is at peak bloom. Manduca's nectar-host use appears to be mediated through innate odor preferences and olfactory learning; they prefer Datura's “hawkmoth-adapted” traits, which facilitate the maintenance of their coevolutionary relationship, yet they are flexible enough to explore and learn to utilize novel resources, such as agave. This behavioral flexibility is likely responsible for the frequent observation of generalized, or mixed, pollination systems. Given that Manduca visit agave species in southern Arizona, we hypothesize that the differences in flower phenotype between two closely related agave species may be associated with the importance of hawkmoths relative to bats. The southernmost agave, Agave palmeri (Agavacea), exhibits floral traits typical of bat pollination, whereas the northernmost species, Agave chrysantha (Agavacea), exhibits mixed floral traits which appear to be adapted to insects, and to a lesser extent, bats. The differences between these agaves are likely correlated with the geographic overlap in migratory bats from Mexico and resident hawkmoth populations. Thus D. wrightii, A. palmeri and A. chrysantha populations represent a unique system in which to examine the evolution of floral traits in both specialized and mixed pollination systems associated with spatially variable pollinator assemblages. PMID:19704447

  13. Kontrolle der Expression des UNUSUAL FLORAL ORGANS (UFO) Gens in Arabidopsis thaliana

    OpenAIRE

    Hobe, Martin

    2004-01-01

    Die vorliegende Arbeit befaßt sich mit der Kontrolle des Expressionsmusters des UNUSUAL FLORAL ORGANS (UFO) Gens von Arabidopsis thaliana. UFO wird im Sproß- und Blütenmeristemen aller Entwicklungsstadien der Pflanze exprimiert. In Blütenmeristemen agiert UFO als Kofaktor von LEAFY (LFY) bei der Aktivierung der Organidentitätsgene des zweiten und dritten Wirtels. UFO stellt also einen generellen Faktor der Musterbildung in Meristemen dar. Um regulatorische Gene, die die Expression von UFO bee...

  14. Effects of floral display and plant abundance on fruit production of Ryncholaelia glauca (Orchidaceae)

    OpenAIRE

    Alejandro Flores-Palacios; José G. García-Franco

    2003-01-01

    Flowering plant density can increase number of visits and fruit set in multi-flowering plants, however this aspect has not been studied on few flower species. We studied the effects of individual floral display and plant density on the fruit production of the epiphytic, moth-pollinated orchid, Ryncholaelia glauca, in an oak forest of Chavarrillo, Veracruz, Mexico. Species is nonautogamous, and produced one flower per flowering shoot each flowering season. We hypothesized that orchids with mor...

  15. A sexually dimorphic corolla appendage affects pollen removal and floral longevity in gynodioecious Cyananthus delavayi (Campanulaceae).

    Science.gov (United States)

    Niu, Yang; Zhang, Zhi-Qiang; Liu, Chang-Qiu; Li, Zhi-Min; Sun, Hang

    2015-01-01

    The floral traits of bisexual flowers may evolve in response to selection on both male and female functions, but the relative importance of selection associated with each of these two aspects is poorly resolved. Sexually dimorphic traits in plants with unisexual flowers may reflect gender-specific selection, providing opportunities for gaining an increased understanding of the evolution of specific floral traits. We examined sexually dimorphic patterns of floral traits in perfect and female flowers of the gynodioecious species Cyananthus delavayi. A special corolla appendage, the throat hair, was investigated experimentally to examine its influences on male and female function. We found that perfect flowers have larger corollas and much longer throat hairs than female flowers, while female ones have much exerted stigmas. The presence of throat hairs prolonged the duration of pollen presentation by restricting the amount of pollen removed by pollen-collecting bees during each visit. Floral longevity was negatively related to the rate of pollen removal. When pollen removal rate was limited in perfect flowers, the duration of the female phases diminished with the increased male phase duration. There was a weak negative correlation between throat hair length and seed number per fruit in female flowers, but this correlation was not significant in perfect flowers. These results suggest that throat hairs may enhance male function in terms of prolonged pollen presentation. However, throat hairs have no obvious effect on female function in terms of seed number per fruit. The marked sexual dimorphism of this corolla appendage in C. delavayi is likely to have evolved and been maintained by gender-specific selection.

  16. A sexually dimorphic corolla appendage affects pollen removal and floral longevity in gynodioecious Cyananthus delavayi (Campanulaceae.

    Directory of Open Access Journals (Sweden)

    Yang Niu

    Full Text Available The floral traits of bisexual flowers may evolve in response to selection on both male and female functions, but the relative importance of selection associated with each of these two aspects is poorly resolved. Sexually dimorphic traits in plants with unisexual flowers may reflect gender-specific selection, providing opportunities for gaining an increased understanding of the evolution of specific floral traits. We examined sexually dimorphic patterns of floral traits in perfect and female flowers of the gynodioecious species Cyananthus delavayi. A special corolla appendage, the throat hair, was investigated experimentally to examine its influences on male and female function. We found that perfect flowers have larger corollas and much longer throat hairs than female flowers, while female ones have much exerted stigmas. The presence of throat hairs prolonged the duration of pollen presentation by restricting the amount of pollen removed by pollen-collecting bees during each visit. Floral longevity was negatively related to the rate of pollen removal. When pollen removal rate was limited in perfect flowers, the duration of the female phases diminished with the increased male phase duration. There was a weak negative correlation between throat hair length and seed number per fruit in female flowers, but this correlation was not significant in perfect flowers. These results suggest that throat hairs may enhance male function in terms of prolonged pollen presentation. However, throat hairs have no obvious effect on female function in terms of seed number per fruit. The marked sexual dimorphism of this corolla appendage in C. delavayi is likely to have evolved and been maintained by gender-specific selection.

  17. Pollination syndromes in a specialised plant-pollinator interaction: does floral morphology predict pollinators in Calceolaria?

    Science.gov (United States)

    Murúa, M; Espíndola, A

    2015-03-01

    Pollination syndromes are defined as suites of floral traits evolved in response to selection imposed by a particular group of pollinators (e.g., butterflies, hummingbirds, bats). Although numerous studies demonstrated their occurrence in plants pollinated by radically different pollinators, it is less known whether it is possible to identify them within species pollinated by one functional pollinator group. In such a framework, we expect floral traits to evolve also in response to pollinator subgroups (e.g., species, genera) within that unique functional group. On this, specialised pollination systems represent appropriate case studies to test such expectations. Calceolaria is a highly diversified plant genus pollinated by oil-collecting bees in genera Centris and Chalepogenus. Variation in floral traits in Calceolaria has recently been suggested to reflect adaptations to pollinator types. However, to date no study has explicitly tested that observation. In this paper, we quantitatively test that hypothesis by evaluating the presence of pollination syndromes within the specialised pollination system formed by several Calceolaria and their insect pollinators. To do so, we use multivariate approaches and explore the structural matching between the morphology of 10 Calceolaria taxa and that of their principal pollinators. Our results identify morphological matching between floral traits related to access to the reward and insect traits involved in oil collection, confirming the presence of pollinator syndromes in Calceolaria. From a general perspective, our findings indicate that the pollination syndrome concept can be also extended to the intra-pollinator group level. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  18. Floral reward, advertisement and attractiveness to honey bees in dioecious Salix caprea.

    Directory of Open Access Journals (Sweden)

    Stefan Dötterl

    Full Text Available In dioecious, zoophilous plants potential pollinators have to be attracted to both sexes and switch between individuals of both sexes for pollination to occur. It often has been suggested that males and females require different numbers of visits for maximum reproductive success because male fertility is more likely limited by access to mates, whereas female fertility is rather limited by resource availability. According to sexual selection theory, males therefore should invest more in pollinator attraction (advertisement, reward than females. However, our knowledge on the sex specific investment in floral rewards and advertisement, and its effects on pollinator behaviour is limited. Here, we use an approach that includes chemical, spectrophotometric, and behavioural studies i to elucidate differences in floral nectar reward and advertisement (visual, olfactory cues in dioecious sallow, Salix caprea, ii to determine the relative importance of visual and olfactory floral cues in attracting honey bee pollinators, and iii to test for differential attractiveness of female and male inflorescence cues to honey bees. Nectar amount and sugar concentration are comparable, but sugar composition varies between the sexes. Olfactory sallow cues are more attractive to honey bees than visual cues; however, a combination of both cues elicits the strongest behavioural responses in bees. Male flowers are due to the yellow pollen more colourful and emit a higher amount of scent than females. Honey bees prefer the visual but not the olfactory display of males over those of females. In all, the data of our multifaceted study are consistent with the sexual selection theory and provide novel insights on how the model organism honey bee uses visual and olfactory floral cues for locating host plants.

  19. Floral resource availability from groundcover promotes bee abundance in coffee agroecosystems.

    Science.gov (United States)

    Fisher, Kaleigh; Gonthier, David J; Ennis, Katherine K; Perfecto, Ivette

    2017-09-01

    Patterns of bee abundance and diversity across different spatial scales have received thorough research consideration. However, the impact of short- and long-term temporal resource availability on biodiversity has been less explored. This is highly relevant in tropical agricultural systems for pollinators, as many foraging periods of pollinators extend beyond flowering of any single crop species. In this study, we sought to understand how bee communities in tropical agroecosystems changed between seasons, and if short- and long-term floral resource availability influenced their diversity and abundance. We used a threshold analysis approach in order to explore this relationship at two time scales. This study took place in a region dominated by coffee agroecosystems in Southern Mexico. This was an ideal system because the landscape offers a range of coffee management regimes that maintain heterogeneity in floral resource availability spatially and temporally. We found that the bee community varies significantly between seasons. There were higher abundances of native social, solitary and managed honey bees during the dry season when coffee flowers. Additionally, we found that floral resources from groundcover, but not trees, were associated with bee abundance. Further, the temporal scale of the availability of these resources is important, whereby short-term floral resource availability appears particularly important in maintaining high bee abundance at sites with lower seasonal complementarity. We argue that in addition to spatial resource heterogeneity, temporal resource heterogeneity is critical in explaining bee community patterns, and should thus be considered to promote pollinator conservation. © 2017 by the Ecological Society of America.

  20. Floral transmission of Erwinia tracheiphila by cucumber beetles in a wild Cucurbita pepo.

    Science.gov (United States)

    Sasu, M A; Seidl-Adams, I; Wall, K; Winsor, J A; Stephenson, A G

    2010-02-01

    Cucumber beetles, Acalymma vittatum (F.) and Diabrotica undecipunctata howardi (Barber), are specialist herbivores of cucurbits and the vector of Erwinia tracheiphila (E.F. Smith) Holland, the causative agent of wilt disease. Cucumber beetles transmit E. tracheiphila when infected frass falls onto leaf wounds at the site of beetle feeding. We show that E. tracheiphila also can be transmitted via the floral nectaries of Cucurbita pepo ssp. texana L. Andres (Texas gourd). Under field conditions, we found that beetles aggregate in flowers in the late morning, that these beetles chew the anther filaments that cover the nectaries in male flowers thereby exposing the nectary, and that beetle frass accumulates on the nectary. We use real-time polymerase chain reaction to show that most of the flowers produced during the late summer possess beetle frass containing E. tracheiphila. Greenhouse experiments, in which cultures of E. tracheiphila are deposited onto floral nectaries, show that Texas gourds can contract wilt disease through the floral nectaries. Finally, we use green fluorescent protein-transformed E. tracheiphila to document the movement of E. tracheiphila through the nectary into the xylem of the pedicel before the abscission of the flower. Together, these data show that E. tracheiphila can be transmitted through infected frass that falls on or near the floral nectaries. We hypothesize that the concentration of frass from many beetles in the flowers increases both exposure to and the concentration of E. tracheiphila and plays a major role in the dynamics of wilt disease in both wild populations and cultivated squash fields.

  1. Development of TGMS lines with improved floral traits through mutation breeding in rice

    International Nuclear Information System (INIS)

    Thiyagarajan, K.; Abirami, S.; Robin, S.; Manonmani, S.; Jambhulkar, S.J.

    2006-01-01

    Mutation breeding is now accepted as an useful means of adding valuable attributes to a variety. Plant breeders have used this tool for the improvement of some cultivated crop varieties. The current investigation is aimed to develop mutants with respect to temperature sensitivity and good floral traits for use in two line breeding. The putative Thermosensitive Genic Male Sterile lines viz,, TS 6 and CBTS 0282 were subjected to induce mutagenesis with gamma rays (300 and 350 Gy) and EMS (0.5 and 0.6%) for developing new TGMS lines with desirable floral traits. The seeds treated with gamma ray and EMS were raised in M1 generation and seeds collected from this population were raised in M2 generation as plant to progeny rows for screening the best TGMS lines with desirable floral traits. In the M2 generation a total of 469 progeny rows of CBTS 0282 and 854 progeny rows of TS 6 were raised. A population of 128, 975 plants in CBTS 0282 and 1,28,100 plants in TS 6 were raised. In M2 generation 361 sterile, uniform stable individual plants with good stigma exertion percentage and wide angle of glume opening were selected and stubble planted at HREC, Gudalur, a low temperature region. At HREC, again the same screening process was carried out and 13 stubbles with excellent stigma exertion percentage were selected and their progenies were raised in M3 generation along with control and check IR 58025 A. A total of 63 sterile and stable M3 plants with good stigma exertion percentage wider angle of glume opening excelling over the check and control were identified and raised in M4 generation along with control and check IR 58025 A. In the M4 generation a total of 16 progeny rows were found to be uniform and homozygous with good floral traits. These lines can be utilized for developing new two line hybrids

  2. Floral micromorphology of the Australian carnivorous bladderwort Utricularia dunlopii, a putative pseudocopulatory species.

    Science.gov (United States)

    Płachno, Bartosz J; Stpiczyńska, Małgorzata; Świątek, Piotr; Davies, Kevin L

    2016-11-01

    Flowers of sexually deceptive taxa generally possess a set of morphological and physiological characters that mimic their insect pollinators. These characters often include a specific insect-like floral configuration, together with scent glands (osmophores) that produce fragrances which chemically resemble insect sex pheromones. Furthermore, these flowers tend not to produce pollinator food rewards. According to some authors, flowers of the Australian bladderwort Utricularia dunlopii (and species of the Utricularia capilliflora complex) resemble insects, and pollination perhaps occurs by pseudocopulation. The aims of this paper are to compare the structure and distribution of floral glandular trichomes in the Australian carnivorous plant U. dunlopii with those of closely related species assigned to the same section and to discuss their putative function. Floral tissues of U. dunlopii P. Taylor, Utricularia paulinae Lowrie, Utricularia dichotoma Labill. and Utricularia uniflora R.Br. (section Pleiochasia) were investigated using light microscopy, scanning electron microscopy, transmission electron microscopy and histochemistry. In U. dunlopii, two long, erect, filiform appendages arising from the upper lip of the corolla, together with three arising from the lower lip, bear numerous glandular trichomes that may function as osmophores. In other species, such as U. uniflora and U. paulinae, glandular papillae on the corolla palate may also function as osmophores. The floral anatomical and morphological organisation of U. dunlopii differs from that of the other investigated species, indicating that its insect pollinators are also likely to differ. Morphological and ultrastructural observations, while generally contributing to our understanding of the flower of U. dunlopii, do not refute the possibility that pollination here may occur by pseudocopulation. Further field-based investigations, however, are now necessary to test this hypothesis.

  3. Pollination effectiveness of different strawberry floral visitors in Ribatejo, Portugal : selection of potential pollinators : Part 2

    OpenAIRE

    Albano, Sílvia; Salvado, Eva; Duarte, Sónia; Mexia, António; Borges, Paulo A. V.

    2009-01-01

    Copyright © 2009 Universita degli Studi di Firenze. This study was carried out in a strawberry (Fragaria × ananassa Duch.) field located in Ribatejo, Portugal, and aims to describe the qualitative component of the visits for three strawberry floral visitors, attaining the best results in a previous work. The main objectives were: (1) to assess the pollination rate (PR) resulting from a single visit of Apis mellifera L., Syrphidae and native bees, and (2) to characterize the foraging behavi...

  4. The floral morphospace--a modern comparative approach to study angiosperm evolution.

    Science.gov (United States)

    Chartier, Marion; Jabbour, Florian; Gerber, Sylvain; Mitteroecker, Philipp; Sauquet, Hervé; von Balthazar, Maria; Staedler, Yannick; Crane, Peter R; Schönenberger, Jürg

    2014-12-01

    Morphospaces are mathematical representations used for studying the evolution of morphological diversity and for the evaluation of evolved shapes among theoretically possible ones. Although widely used in zoology, they--with few exceptions--have been disregarded in plant science and in particular in the study of broad-scale patterns of floral structure and evolution. Here we provide basic information on the morphospace approach; we review earlier morphospace applications in plant science; and as a practical example, we construct and analyze a floral morphospace. Morphospaces are usually visualized with the help of ordination methods such as principal component analysis (PCA) or nonmetric multidimensional scaling (NMDS). The results of these analyses are then coupled with disparity indices that describe the spread of taxa in the space. We discuss these methods and apply modern statistical tools to the first and only angiosperm-wide floral morphospace published by Stebbins in 1951. Despite the incompleteness of Stebbins’ original dataset, our analyses highlight major, angiosperm-wide trends in the diversity of flower morphology and thereby demonstrate the power of this previously neglected approach in plant science.

  5. Sex expression and floral diversity in Jatropha curcas: a population study in its center of origin

    Science.gov (United States)

    Adriano-Anaya, María de Lourdes; Pérez-Castillo, Edilma; Salvador-Figueroa, Miguel; Ruiz-González, Sonia; Vázquez-Ovando, Alfredo; Grajales-Conesa, Julieta

    2016-01-01

    Sex expression and floral morphology studies are central to understand breeding behavior and to define the productive potential of plant genotypes. In particular, the new bioenergy crop Jatropha curcas L. has been classified as a monoecious species. Nonetheless, there is no information about its reproductive diversity in the Mesoamerican region, which is considered its center of origin and diversification. Thus, we determined sex expression and floral morphology in J. curcas populations from southern Mexico and Guatemala. Our results showed that most of J. curcas specimens had typical inflorescences with separate sexes (monoecious); meanwhile, the rest were atypical (gynoecious, androecious, andromonoecious, androgynomonoecious). The most important variables to group these populations, based on a discriminant analysis, were: male flower diameter, female petal length and male nectary length. From southern Mexico “Guerrero” was the most diverse population, and “Centro” had the highest variability among the populations from Chiapas. A cluster analysis showed that the accessions from southern Mexico were grouped without showing any correlation with the geographical origin, while those accessions with atypical sexuality were grouped together. To answer the question of how informative are floral morphological traits compared to molecular markers, we perform a Mantel correlation test between the distance matrix generated in this study and the genetic distance matrix (AFLP) previously reported for the same accessions. We found significant correlation between data at the level of accessions. Our results contribute to design genetic improvement programs by using sexually and morphologically contrasting plants from the center of origin. PMID:27257548

  6. Effect of Organic Fertilization and AMF Inoculation on Yield and Floral Quality Parameters of Common Marigold

    Directory of Open Access Journals (Sweden)

    Panayiota PAPASTYLIANOU

    2017-05-01

    Full Text Available In Greece common marigold is one of the major medicinal plants widely used in cosmetics, perfumes and the pharmaceutical industry. A field experiment was conducted at Komotini, Greece, to compare the effect of organic and conventional fertilization combined with arbuscular mycorrhizal fungi inoculation on yield and floral qualitative characteristics of the common marigold during the 2015 growing season. The experiment was set up as a split plot design with three replicates, three main plots (fertilization treatments, inorganic, organic and untreated and two sub-plots (addition/non-addition of commercial mycorrhiza of the genus Glomus spp.. Floral fresh and dry weight as well as total phenolic and flavonoid content of the dried flowers were recorded. Data analysis confirmed no significant correlation between fresh/dry floral yield, total phenolic and flavonoid content of the dried flowers and type of fertilization. The results also demonstrate a tendency of increase of the fresh or dry weight of the flowers when the commercial mycorrhiza is applied but it is not statistically significant.

  7. Floral development and morphology of Vochysiaceae. I. The structure of the gynoecium.

    Science.gov (United States)

    Litt, Amy; Stevenson, Dennis W

    2003-11-01

    Vochysiaceae are divided into two tribes on the basis of ovary structure (superior trilocular or inferior unilocular). The superior trilocular ovary has been considered basal in the family, and the term "pseudomonomerous" was used to indicate the presumed evolutionary derivation of the unilocular condition from the trilocular. However, recent evidence that Vochysiaceae are Myrtalean suggests that the superior ovary may be secondarily derived. In addition, published figures cast doubt on the interpretation of the putatively unilocular ovaries. To understand these features, floral ontogeny and anatomy were examined using scanning electron microscopy and serial sectioning. In all taxa examined, the ovary develops in an epigynous fashion, on a concave floral apex, supporting the hypothesis that the superior ovary is secondarily derived. Subsequent to initiation of the ovary, differential growth results in ovaries that are superior, inferior, or partly inferior in different genera. Sections of floral buds of the two unilocular genera, Erisma and Erismadelphus, show aborted locules in the latter but not in the former. The application of the term "pseudomonomerous" to both genera obscures this significant difference. The position of the placenta in the truly unilocular genus varies among species, suggesting a character transformation series from multilocular through intermediates to truly unilocular.

  8. Floral ontogeny of two Jatropha species (Euphorbiaceae s.s) and its systematic implications

    International Nuclear Information System (INIS)

    Liu, H.; Liao, J.

    2015-01-01

    Floral ontogeny of Jatropha multifida L. and Jatropha integerrima Jacq. (Euphorbiaceae) was studied using scanning electron microscopy (SEM). These two species possess unisexual male flowers and bisexual (with unfunctional staminodes) female flowers. In both male and female flowers, five sepal primordia arise in a 2/5 sequence on the periphery of the floral apex and initiate anticlockwise or clockwise in different floral buds. Five petal primordia initiate simultaneously alternate to sepals. Dicyclic stamens (obdiplostemony) arise in both male and female flowers. In J. multifida, five outer stamen primordia arise first simultaneously and then three inner stamens initiate simultaneously. However, in J. integerrima, ten stamen primordia arranged in two whorls initiate simultaneously. While the ovary is absent in the male flowers, in the female flowers, three carpel primordia appear simultaneously. With further development of the ovary the stamens degenerate in the female flowers, whereas in the male flowers, the stamens grow normally. Ancestral state reconstruction using MacClade indicates that stamen simultaneous vs. non-simultaneous initiation supports the phylogenetic analysis based on nuclear ribosomal DNA ITS sequence. (author)

  9. Floral and reproductive biology of Alcantarea nahoumii (Bromeliaceae, a vulnerable endemic species of the Atlantic Forest

    Directory of Open Access Journals (Sweden)

    Maria Josirene Souza Moreira Bastos

    Full Text Available ABSTRACT Alcantarea nahoumii occurs exclusively in the state of Bahia, Brazil, and is classified as vulnerable due to deforestation and frequent fires in the region. Knowledge of floral and reproductive biology is fundamental to understanding ecological interactions, as well as the reproductive success of plant species. The objective of this study was to evaluate the floral and reproductive biology of A. nahoumii in an Atlantic Forest fragment with regard to phenology, pollen viability, stigma receptivity, pollination ecology and reproductive systems, all of which are important parameters for of the development of conservation strategies for the species. Anthesis is diurnal and heterogeneous, starting at 6:30 a.m. and lasting until 8:00 a.m. Highest germination percentages and greatest pollen tube lengths were obtained in BK culture medium. Histochemical tests revealed high pollen viability (89.71 %. Stigma receptivity occurred during anthesis and lasted for up to 24 hours after floral opening. Alcantarea nahoumii exhibited preferential allogamy and self-compatibility, and required a pollinator to production of viable seeds. Sixteen species of pollinators were observed visiting A. nahoumii, among which were five hummingbird species. Even though its reproductive system is efficient, this bromeliad remains threatened mainly due to habitat fragmentation caused by deforestation, burning and predatory extractivism.

  10. Preferência Floral de Vespas (Hymenoptera, Vespidae no Rio Grande do Sul, Brasil

    Directory of Open Access Journals (Sweden)

    Alexandre Somavilla

    2012-03-01

    Abstract Wasps integrate the floral visitors’ community and they can constitute a representative portion of the pollinators. For this reason, it was aimed to know and to analyze the floral preference of the Vespidae species and to investigate the use of floral resources for these wasps. The collects were performed between 2001 and 2008 in different localities of Rio Grande do Sul state (Estrela Velha, Santa Cruz do Sul, São Francisco de Paula e Sinimbu between 08:00 at 17:00 hours, utilizing entomological nets to catch the flower-visiting wasps. The collected specimens were deposited at the Coleção Entomológica de Santa Cruz do Sul (CESC. 1.483 specimens were captured belonging to 73 wasp species, whose 78.9% were Polistinae (30 species and 21.1% Eumeninae (43 species, visiting the flowers of 33 plant species classified in 16 botanical families; the families with the larger number of plant species were Asteraceae (12, Fabaceae (4 and Apiaceae (3. The plant species with the largest number of wasps collected was Schinus terebinthifolius Raddi (616, followed by Eryngium pandanifolium L. (137 and Eryngium horridum Spreng (122. The analysis of the trophic niche overlap of 26 species with four or more visited plant species, showed an overlap equal or higher than 50% in six cases.

  11. Floral specialization and angiosperm diversity: phenotypic divergence, fitness trade-offs and realized pollination accuracy

    Science.gov (United States)

    Armbruster, W. Scott

    2014-01-01

    Plant reproduction by means of flowers has long been thought to promote the success and diversification of angiosperms. It remains unclear, however, how this success has come about. Do flowers, and their capacity to have specialized functions, increase speciation rates or decrease extinction rates? Is floral specialization fundamental or incidental to the diversification? Some studies suggest that the conclusions we draw about the role of flowers in the diversification and increased phenotypic disparity (phenotypic diversity) of angiosperms depends on the system. For orchids, for example, specialized pollination may have increased speciation rates, in part because in most orchids pollen is packed in discrete units so that pollination is precise enough to contribute to reproductive isolation. In most plants, however, granular pollen results in low realized pollination precision, and thus key innovations involving flowers more likely reflect reduced extinction rates combined with opportunities for evolution of greater phenotypic disparity (phenotypic diversity) and occupation of new niches. Understanding the causes and consequences of the evolution of specialized flowers requires knowledge of both the selective regimes and the potential fitness trade-offs in using more than one pollinator functional group. The study of floral function and flowering-plant diversification remains a vibrant evolutionary field. Application of new methods, from measuring natural selection to estimating speciation rates, holds much promise for improving our understanding of the relationship between floral specialization and evolutionary success. PMID:24790124

  12. Multiple Plantago species (Plantaginaceae) modify floral reflectance and color in response to thermal change.

    Science.gov (United States)

    Anderson, Erin R; Lovin, Mary E; Richter, Scott J; Lacey, Elizabeth P

    2013-12-01

    Understanding how plant reproduction responds to temperature has become increasingly important because of global climate change. Temperature-sensitive plasticity in floral reflectance is likely involved in some of these responses. Such plasticity, which underlies thermoregulatory ability, affects reproductive success in Plantago lanceolata. To see whether other Plantago species also show thermal plasticity in reflectance, we measured plasticity in P. lagopus, P. coronopus, P. major, P. subulata, P. albicans, P. tomentosa, P. maritima, and P. weldenii. We induced plants to flower at two temperatures in growth chambers and recorded floral reflectance (362-800 nm). All species were thermally plastic in visible and near-IR regions. Species and populations differed in response. Some showed greater variation in reflectance at warm temperature, while the reverse was true for others. Plasticity was greatest in the P. lanceolata clade. Cosmopolitan species were not more plastic than were geographically restricted species. The data suggest that (1) thermal plasticity is an ancestral trait for Plantago, (2) plasticities in visible and near-IR regions have evolved along different pathways within the genus, and (3) phylogenetic history partially explains this evolutionary divergence. Our data combined with those of previous studies suggest that global climate change will modify floral reflectance and color in many plant species. These modifications are likely to affect plant reproductive success.

  13. SEP-class genes in Prunus mume and their likely role in floral organ development.

    Science.gov (United States)

    Zhou, Yuzhen; Xu, Zongda; Yong, Xue; Ahmad, Sagheer; Yang, Weiru; Cheng, Tangren; Wang, Jia; Zhang, Qixiang

    2017-01-13

    Flower phylogenetics and genetically controlled development have been revolutionised during the last two decades. However, some of these evolutionary aspects are still debatable. MADS-box genes are known to play essential role in specifying the floral organogenesis and differentiation in numerous model plants like Petunia hybrida, Arabidopsis thaliana and Antirrhinum majus. SEPALLATA (SEP) genes, belonging to the MADS-box gene family, are members of the ABCDE and quartet models of floral organ development and play a vital role in flower development. However, few studies of the genes in Prunus mume have yet been conducted. In this study, we cloned four PmSEPs and investigated their phylogenetic relationship with other species. Expression pattern analyses and yeast two-hybrid assays of these four genes indicated their involvement in the floral organogenesis with PmSEP4 specifically related to specification of the prolificated flowers in P. mume. It was observed that the flower meristem was specified by PmSEP1 and PmSEP4, the sepal by PmSEP1 and PmSEP4, petals by PmSEP2 and PmSEP3, stamens by PmSEP2 and PmSEP3 and pistils by PmSEP2 and PmSEP3. With the above in mind, flower development in P. mume might be due to an expression of SEP genes. Our findings can provide a foundation for further investigations of the transcriptional factors governing flower development, their molecular mechanisms and genetic basis.

  14. Antagonistic effects of floral scent in an insect–plant interaction

    Science.gov (United States)

    Reisenman, Carolina E.; Riffell, Jeffrey A.; Bernays, Elizabeth A.; Hildebrand, John G.

    2010-01-01

    In southwestern USA, the jimsonweed Datura wrightii and the nocturnal moth Manduca sexta form a pollinator–plant and herbivore–plant association. Because the floral scent is probably important in mediating this interaction, we investigated the floral volatiles that might attract M. sexta for feeding and oviposition. We found that flower volatiles increase oviposition and include small amounts of both enantiomers of linalool, a common component of the scent of hawkmoth-pollinated flowers. Because (+)-linalool is processed in a female-specific glomerulus in the primary olfactory centre of M. sexta, we hypothesized that the enantiomers of linalool differentially modulate feeding and oviposition. Using a synthetic mixture that mimics the D. wrightii floral scent, we found that the presence of linalool was not necessary to evoke feeding and that mixtures containing (+)- and/or (−)-linalool were equally effective in mediating this behaviour. By contrast, females oviposited more on plants emitting (+)-linalool (alone or in mixtures) over control plants, while plants emitting (−)-linalool (alone or in mixtures) were less preferred than control plants. Together with our previous investigations, these results show that linalool has differential effects in feeding and oviposition through two neural pathways: one that is sexually isomorphic and non-enantioselective, and another that is female-specific and enantioselective. PMID:20335210

  15. Floral specialization and angiosperm diversity: phenotypic divergence, fitness trade-offs and realized pollination accuracy.

    Science.gov (United States)

    Armbruster, W Scott

    2014-01-01

    Plant reproduction by means of flowers has long been thought to promote the success and diversification of angiosperms. It remains unclear, however, how this success has come about. Do flowers, and their capacity to have specialized functions, increase speciation rates or decrease extinction rates? Is floral specialization fundamental or incidental to the diversification? Some studies suggest that the conclusions we draw about the role of flowers in the diversification and increased phenotypic disparity (phenotypic diversity) of angiosperms depends on the system. For orchids, for example, specialized pollination may have increased speciation rates, in part because in most orchids pollen is packed in discrete units so that pollination is precise enough to contribute to reproductive isolation. In most plants, however, granular pollen results in low realized pollination precision, and thus key innovations involving flowers more likely reflect reduced extinction rates combined with opportunities for evolution of greater phenotypic disparity (phenotypic diversity) and occupation of new niches. Understanding the causes and consequences of the evolution of specialized flowers requires knowledge of both the selective regimes and the potential fitness trade-offs in using more than one pollinator functional group. The study of floral function and flowering-plant diversification remains a vibrant evolutionary field. Application of new methods, from measuring natural selection to estimating speciation rates, holds much promise for improving our understanding of the relationship between floral specialization and evolutionary success.

  16. The floral morphospace – a modern comparative approach to study angiosperm evolution

    Science.gov (United States)

    Chartier, Marion; Jabbour, Florian; Gerber, Sylvain; Mitteroecker, Philipp; Sauquet, Hervé; von Balthazar, Maria; Staedler, Yannick; Crane, Peter R.; Schönenberger, Jürg

    2017-01-01

    Summary Morphospaces are mathematical representations used for studying the evolution of morphological diversity and for the evaluation of evolved shapes among theoretically possible ones. Although widely used in zoology, they – with few exceptions – have been disregarded in plant science and in particular in the study of broad-scale patterns of floral structure and evolution. Here we provide basic information on the morphospace approach; we review earlier morphospace applications in plant science; and as a practical example, we construct and analyze a floral morphospace. Morphospaces are usually visualized with the help of ordination methods such as principal component analysis (PCA) or nonmetric multidimensional scaling (NMDS). The results of these analyses are then coupled with disparity indices that describe the spread of taxa in the space. We discuss these methods and apply modern statistical tools to the first and only angiosperm-wide floral morphospace published by Stebbins in 1951. Despite the incompleteness of Stebbins’ original dataset, our analyses highlight major, angiosperm-wide trends in the diversity of flower morphology and thereby demonstrate the power of this previously neglected approach in plant science. PMID:25539005

  17. The evolution of floral scent and olfactory preferences in pollinators: coevolution or pre-existing bias?

    Science.gov (United States)

    Schiestl, Florian P; Dötterl, Stefan

    2012-07-01

    Coevolution is thought to be a major factor in shaping plant-pollinator interactions. Alternatively, plants may have evolved traits that fitted pre-existing preferences or morphologies in the pollinators. Here, we test these two scenarios in the plant family of Araceae and scarab beetles (Coleoptera, Scarabaeidae) as pollinators. We focused on floral volatile organic compounds (VOCs) and production/detection of VOCs by scarab beetles. We found phylogenetic structure in the production/detection of methoxylated aromatics in scarabs, but not plants. Within the plants, most of the compounds showed a well-supported pattern of correlated evolution with scarab-beetle pollination. In contrast, the scarabs showed no correlation between VOC production/detection and visitation to Araceae flowers, with the exception of the VOC skatole. Moreover, many VOCs were found in nonpollinating beetle groups (e.g., Melolonthinae) that are ancestors of pollinating scarabs. Importantly, none of the tested VOCs were found to have originated in pollinating taxa. Our analysis indicates a Jurassic origin of VOC production/detection in scarabs, but a Cretaceous/Paleocene origin of floral VOCs in plants. Therefore, we argue against coevolution, instead supporting the scenario of sequential evolution of floral VOCs in Araceae driven by pre-existing bias of pollinators. © 2012 The Author(s).

  18. Biologia floral e polinização de Arrabidaea conjugata (Vell. Mart. (Bignoniaceae Floral and pollination biology of Arrabidaea conjugata (Vell. Mart. (Bignoniaceae

    Directory of Open Access Journals (Sweden)

    Maria Célia Rodrigues Correia

    2005-09-01

    Full Text Available O trabalho aborda a biologia floral, a atividade forrageira dos visitantes florais (polinizadores e pilhadores, os eventos fenológicos e o sistema de reprodução de Arrabidaea conjugata (Vell. Mart. (Bignoniaceae, em área de vegetação de restinga, município de Maricá, Rio de Janeiro, no período 1997 a 2000. A espécie estudada tem flores com antese diurna, lilases, tubulosas, hermafroditas, odoríferas e oferecem néctar como recurso floral. O néctar é secretado por um disco localizado na base do gineceu e é acumulado em câmara nectarífera. Os grãos de pólen são liberados gradativamente, prolongando-se a fase de doação de pólen. As abelhas Euglossa cordata Linnaeus, Centris analis Fabricius e C. tarsata Smith são os polinizadores da espécie. Destaca-se pilhagem primária de néctar, por abelhas, e secundária, por borboletas e beija-flor. A espécie é auto-incompatível, apresentando baixos índices de formação de frutos em condições naturais (Frutos/Flores = 12,2%. Foi registrado padrão de floração "cornucópia", entre os meses de dezembro a março (estação quente/chuvosa, com pico em janeiro. As sementes são anemocóricas e liberadas gradativamente na estação fria e seca.This work deals with the floral biology, the foraging activities of floral visitors (pollinators and robbers, phenology and reproductive system of Arrabidaea conjugata (Vell. Mart. (Bignoniaceae in the "restinga" of Maricá, Rio de Janeiro, Brazil, from 1997 to 2000. The flowers display daytime anthesis and last only one day. These attractive pink flowers are tubular, hermaphroditic, odoriferous and produce nectar as the floral reward. The nectar is secreted by a nectariferous disk concealed within a chamber. The pollen grains are gradually released throughout anthesis, extending the pollen presentation phase. The bees Euglossa cordata Linnaeus, Centris analis Fabricius and C. tarsata Smith are the pollinator species. Primary and secondary

  19. Isolation and Role ofPmRGL2in GA-mediated Floral Bud Dormancy Release in Japanese Apricot (Prunus mumeSiebold et Zucc.).

    Science.gov (United States)

    Lv, Lin; Huo, Ximei; Wen, Luhua; Gao, Zhihong; Khalil-Ur-Rehman, Muhammad

    2018-01-01

    Bud dormancy release is regulated by gibberellins (GAs). DELLA proteins are highly conserved and act as negative regulators in GA signaling pathway. The present study established a relationship between PmRGL2 in Japanese apricot and GA 4 levels during dormancy release of floral buds. Overexpression of PmRGL2 in poplar delayed the onset of bud dormancy and resulted in dwarf plants, relative to wild-type trees. PmRGL2 exhibited higher expression during ecodormancy and relatively lower expression during endodormancy. The relative level of GA 4 exhibited an increasing trend at the transition from endodormancy to ecodormancy and displayed a similar expression pattern of genes related to GA metabolism, PmGA20ox2 , PmGA3ox1, PmGID1b , in both Japanese apricot and transgenic poplar. These results suggests that PmRGL2 acts as an integrator and negative regulator of dormancy via a GA-signaling pathway. Moreover, an interaction between RGL2 and SLY1 in a yeast two hybrid (Y2H) system further suggests that SCF E3 ubiquitin ligases, such as SLY1 , may be a critical factor in the regulation of RGL2 through an SCF SLY1 -proteasome pathway. Our study demonstrated that PmRGL2 plays a negative role in bud dormancy release by regulating the GA biosynthetic enzymes, GA20ox and GA3ox1 and the GA receptor, GID1b .

  20. LST1/A is a myeloid leukocyte-specific transmembrane adaptor protein recruiting protein tyrosine phosphatases SHP-1 and SHP-2 to the plasma membrane

    Czech Academy of Sciences Publication Activity Database

    Dráber, Peter; Štěpánek, Ondřej; Hrdinka, Matouš; Drobek, Aleš; Chmátal, Lukáš; Malá, Linda; Ormsby, Tereza; Angelisová, Pavla; Hořejší, Václav; Brdička, Tomáš

    2012-01-01

    Roč. 287, č. 27 (2012), s. 22812-228221 ISSN 0021-9258 R&D Projects: GA ČR GEMEM/09/E011; GA ČR(CZ) GBP302/12/G101; GA MŠk 1M0506 Institutional research plan: CEZ:AV0Z50520514 Institutional support: RVO:68378050 Keywords : adaptor proteins * myeloid cell * signal transduction * tetraspanins * LST1/A Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.651, year: 2012

  1. Downregulation of the NHE3-binding PDZ-adaptor protein PDZK1 expression during cytokine-induced inflammation in interleukin-10-deficient mice.

    Directory of Open Access Journals (Sweden)

    Henrike Lenzen

    Full Text Available BACKGROUND: Impaired salt and water absorption is an important feature in the pathogenesis of diarrhea in inflammatory bowel disease (IBD. We analyzed the expression of proinflammatory cytokines in the infiltrating immune cells and the function and expression of the Na(+/H(+ exchanger isoform 3 (NHE3 and its regulatory PDZ-adaptor proteins NHERF1, NHERF2, and PDZK1 in the colon of interleukin-10-deficient (IL-10(-/- mice. METHODOLOGY/PRINCIPAL FINDINGS: Gene and protein expression were analyzed by real-time reverse transcription polymerase chain reaction (qRT-PCR, in situ RT-PCR, and immunohistochemistry. NHE3 activity was measured fluorometrically in apical enterocytes within isolated colonic crypts. Mice developed chronic colitis characterized by a typical immune cell infiltration composed of T-lymphocytes and macrophages, with high levels of gene and protein expression of the proinflammatory cytokines interleukin-1β and tumor necrosis factor-α. In parallel, inducible nitric oxide synthase expression was increased while procaspase 3 expression was unaffected. Interferon-γ expression remained low. Although acid-activated NHE3 activity was significantly decreased, the inflammatory process did not affect its gene and protein expression or its abundance and localization in the apical membrane. However, expression of the PDZ-adaptor proteins NHERF2 and PDZK1 was downregulated. NHERF1 expression was unchanged. In a comparative analysis we observed the PDZK1 downregulation also in the DSS (dextran sulphate sodium model of colitis. CONCLUSIONS/SIGNIFICANCE: The impairment of the absorptive function of the inflamed colon in the IL-10(-/- mouse, in spite of unaltered NHE3 expression and localization, is accompanied by the downregulation of the NHE3-regulatory PDZ adaptors NHERF2 and PDZK1. We propose that the downregulation of PDZ-adaptor proteins may be an important factor leading to NHE3 dysfunction and diarrhea in the course of the cytokine

  2. Functional aspects of floral nectar secretion of Ananas ananassoides, an ornithophilous bromeliad from the Brazilian savanna

    Science.gov (United States)

    Stahl, Juliana Marin; Nepi, Massimo; Galetto, Leonardo; Guimarães, Elza; Machado, Silvia Rodrigues

    2012-01-01

    Background and Aims Several members of Bromeliaceae show adaptations for hummingbird pollination in the Neotropics; however, the relationships between floral structure, nectar production, pollination and pollinators are poorly understood. The main goal of this study was to analyse the functional aspects of nectar secretion related to interaction with pollinators by evaluating floral biology, cellular and sub-cellular anatomy of the septal nectary and nectar composition of Ananas ananassoides, including an experimental approach to nectar dynamics. Methods Observations on floral anthesis and visitors were conducted in a population of A. ananassoides in the Brazilian savanna. Nectary samples were processed using standard methods for light and transmission electron microscopy. The main metabolites in nectary tissue were detected via histochemistry. Sugar composition was analysed by high-performance liquid chromatography (HPLC). The accumulated nectar was determined from bagged flowers (‘unvisited’), and floral response to repeated nectar removal was evaluated in an experimental design simulating multiple visits by pollinators to the same flowers (‘visited’) over the course of anthesis. Key Results The hummingbirds Hylocharis chrysura and Thalurania glaucopis were the most frequent pollinators. The interlocular septal nectary, composed of three lenticular canals, extends from the ovary base to the style base. It consists of a secretory epithelium and nectary parenchyma rich in starch grains, which are hydrolysed during nectar secretion. The median volume of nectar in recently opened ‘unvisited’ flowers was 27·0 µL, with a mean (sucrose-dominated) sugar concentration of 30·5 %. Anthesis lasts approx. 11 h, and nectar secretion begins before sunrise. In ‘visited’ flowers (experimentally emptied every hour) the nectar total production per flower was significantly higher than in the ‘unvisited’ flowers (control) in terms of volume (t = 4·94, P = 0

  3. Brucella TIR-like protein TcpB/Btp1 specifically targets the host adaptor protein MAL/TIRAP to promote infection.

    Science.gov (United States)

    Li, Wenna; Ke, Yuehua; Wang, Yufei; Yang, Mingjuan; Gao, Junguang; Zhan, Shaoxia; Xinying, Du; Huang, Liuyu; Li, Wenfeng; Chen, Zeliang; Li, Juan

    2016-08-26

    Brucella spp. are known to avoid host immune recognition and weaken the immune response to infection. Brucella like accomplish this by employing two clever strategies, called the stealth strategy and hijacking strategy. The TIR domain-containing protein (TcpB/Btp1) of Brucella melitensis is thought to be involved in inhibiting host NF-κB activation by binding to adaptors downstream of Toll-like receptors. However, of the five TIR domain-containing adaptors conserved in mammals, whether MyD88 or MAL, even other three adaptors, are specifically targeted by TcpB has not been identified. Here, we confirmed the effect of TcpB on B.melitensis virulence in mice and found that TcpB selectively targets MAL. By using siRNA against MAL, we found that TcpB from B.melitensis is involved in intracellular survival and that MAL affects intracellular replication of B.melitensis. Our results confirm that TcpB specifically targets MAL/TIRAP to disrupt downstream signaling pathways and promote intra-host survival of Brucella spp. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Adaptor Protein Complexes AP-1 and AP-3 Are Required by the HHV-7 Immunoevasin U21 for Rerouting of Class I MHC Molecules to the Lysosomal Compartment

    Science.gov (United States)

    Kimpler, Lisa A.; Glosson, Nicole L.; Downs, Deanna; Gonyo, Patrick; May, Nathan A.; Hudson, Amy W.

    2014-01-01

    The human herpesvirus-7 (HHV-7) U21 gene product binds to class I major histocompatibility complex (MHC) molecules and reroutes them to a lysosomal compartment. Trafficking of integral membrane proteins to lysosomes is mediated through cytoplasmic sorting signals that recruit heterotetrameric clathrin adaptor protein (AP) complexes, which in turn mediate protein sorting in post-Golgi vesicular transport. Since U21 can mediate rerouting of class I molecules to lysosomes even when lacking its cytoplasmic tail, we hypothesize the existence of a cellular protein that contains the lysosomal sorting information required to escort class I molecules to the lysosomal compartment. If such a protein exists, we expect that it might recruit clathrin adaptor protein complexes as a means of lysosomal sorting. Here we describe experiments demonstrating that the μ adaptins from AP-1 and AP-3 are involved in U21-mediated trafficking of class I molecules to lysosomes. These experiments support the idea that a cellular protein(s) is necessary for U21-mediated lysosomal sorting of class I molecules. We also examine the impact of transient versus chronic knockdown of these adaptor protein complexes, and show that the few remaining μ subunits in the cells are eventually able to reroute class I molecules to lysosomes. PMID:24901711

  5. Basolateral sorting of the coxsackie and adenovirus receptor through interaction of a canonical YXXPhi motif with the clathrin adaptors AP-1A and AP-1B.

    Science.gov (United States)

    Carvajal-Gonzalez, Jose Maria; Gravotta, Diego; Mattera, Rafael; Diaz, Fernando; Perez Bay, Andres; Roman, Angel C; Schreiner, Ryan P; Thuenauer, Roland; Bonifacino, Juan S; Rodriguez-Boulan, Enrique

    2012-03-06

    The coxsackie and adenovirus receptor (CAR) plays key roles in epithelial barrier function at the tight junction, a localization guided in part by a tyrosine-based basolateral sorting signal, (318)YNQV(321). Sorting motifs of this type are known to route surface receptors into clathrin-mediated endocytosis through interaction with the medium subunit (μ2) of the clathrin adaptor AP-2, but how they guide new and recycling membrane proteins basolaterally is unknown. Here, we show that YNQV functions as a canonical YxxΦ motif, with both Y318 and V321 required for the correct basolateral localization and biosynthetic sorting of CAR, and for interaction with a highly conserved pocket in the medium subunits (μ1A and μ1B) of the clathrin adaptors AP-1A and AP-1B. Knock-down experiments demonstrate that AP-1A plays a role in the biosynthetic sorting of CAR, complementary to the role of AP-1B in basolateral recycling of this receptor. Our study illustrates how two clathrin adaptors direct basolateral trafficking of a plasma membrane protein through interaction with a canonical YxxΦ motif.

  6. Evidence against roles for phorbol binding protein Munc13-1, ADAM adaptor Eve-1, or vesicle trafficking phosphoproteins Munc18 or NSF as phospho-state-sensitive modulators of phorbol/PKC-activated Alzheimer APP ectodomain shedding

    Directory of Open Access Journals (Sweden)

    Lovestone Simon

    2007-12-01

    Full Text Available Abstract Background Shedding of the Alzheimer amyloid precursor protein (APP ectodomain can be accelerated by phorbol esters, compounds that act via protein kinase C (PKC or through unconventional phorbol-binding proteins such as Munc13-1. We have previously demonstrated that application of phorbol esters or purified PKC potentiates budding of APP-bearing secretory vesicles at the trans-Golgi network (TGN and toward the plasma membrane where APP becomes a substrate for enzymes responsible for shedding, known collectively as α-secretase(s. However, molecular identification of the presumptive "phospho-state-sensitive modulators of ectodomain shedding" (PMES responsible for regulated shedding has been challenging. Here, we examined the effects on APP ectodomain shedding of four phorbol-sensitive proteins involved in regulation of vesicular membrane trafficking of APP: Munc13-1, Munc18, NSF, and Eve-1. Results Overexpression of either phorbol-sensitive wildtype Munc13-1 or phorbol-insensitive Munc13-1 H567K resulted in increased basal APP ectodomain shedding. However, in contrast to the report of Roßner et al (2004, phorbol ester-dependent APP ectodomain shedding from cells overexpressing APP and Munc13-1 wildtype was indistinguishable from that observed following application of phorbol to cells overexpressing APP and Munc13-1 H567K mutant. This pattern of similar effects on basal and stimulated APP shedding was also observed for Munc18 and NSF. Eve-1, an ADAM adaptor protein reported to be essential for PKC-regulated shedding of pro-EGF, was found to play no obvious role in regulated shedding of sAPPα. Conclusion Our results indicate that, in the HEK293 system, Munc13-1, Munc18, NSF, and EVE-1 fail to meet essential criteria for identity as PMES for APP.

  7. Evidence against roles for phorbol binding protein Munc13-1, ADAM adaptor Eve-1, or vesicle trafficking phosphoproteins Munc18 or NSF as phospho-state-sensitive modulators of phorbol/PKC-activated Alzheimer APP ectodomain shedding.

    Science.gov (United States)

    Ikin, Annat F; Causevic, Mirsada; Pedrini, Steve; Benson, Lyndsey S; Buxbaum, Joseph D; Suzuki, Toshiharu; Lovestone, Simon; Higashiyama, Shigeki; Mustelin, Tomas; Burgoyne, Robert D; Gandy, Sam

    2007-12-09

    Shedding of the Alzheimer amyloid precursor protein (APP) ectodomain can be accelerated by phorbol esters, compounds that act via protein kinase C (PKC) or through unconventional phorbol-binding proteins such as Munc13-1. We have previously demonstrated that application of phorbol esters or purified PKC potentiates budding of APP-bearing secretory vesicles at the trans-Golgi network (TGN) and toward the plasma membrane where APP becomes a substrate for enzymes responsible for shedding, known collectively as alpha-secretase(s). However, molecular identification of the presumptive "phospho-state-sensitive modulators of ectodomain shedding" (PMES) responsible for regulated shedding has been challenging. Here, we examined the effects on APP ectodomain shedding of four phorbol-sensitive proteins involved in regulation of vesicular membrane trafficking of APP: Munc13-1, Munc18, NSF, and Eve-1. Overexpression of either phorbol-sensitive wildtype Munc13-1 or phorbol-insensitive Munc13-1 H567K resulted in increased basal APP ectodomain shedding. However, in contrast to the report of Rossner et al (2004), phorbol ester-dependent APP ectodomain shedding from cells overexpressing APP and Munc13-1 wildtype was indistinguishable from that observed following application of phorbol to cells overexpressing APP and Munc13-1 H567K mutant. This pattern of similar effects on basal and stimulated APP shedding was also observed for Munc18 and NSF. Eve-1, an ADAM adaptor protein reported to be essential for PKC-regulated shedding of pro-EGF, was found to play no obvious role in regulated shedding of sAPPalpha. Our results indicate that, in the HEK293 system, Munc13-1, Munc18, NSF, and EVE-1 fail to meet essential criteria for identity as PMES for APP.

  8. The adaptor protein alpha-syntrophin is reduced in human non-alcoholic steatohepatitis but is unchanged in hepatocellular carcinoma.

    Science.gov (United States)

    Rein-Fischboeck, Lisa; Pohl, Rebekka; Haberl, Elisabeth M; Weiss, Thomas S; Buechler, Christa

    2017-10-01

    The adaptor protein alpha-syntrophin (SNTA) is differentially expressed in varying types of cancer and affects triglyceride levels, inflammatory response and cell proliferation. However, little is known about the expression of SNTA in liver diseases. Non-alcoholic steatohepatitis (NASH) is characterized by hepatic steatosis, inflammation and eventually fibrosis, and may progress to hepatocellular carcinoma (HCC). Here, SNTA mRNA was analyzed in liver tissues from 71 non-alcoholic fatty liver disease patients and 32 controls to assess associations with disease characteristics. SNTA mRNA expression was reduced in NASH liver and negatively correlated with steatosis, inflammation, fibrosis and NASH scores. In the NASH patients, those with type 2 diabetes had a higher fibrosis score, reduced inflammation and increased hepatic SNTA mRNA levels demonstrating a strong association of SNTA mRNA levels with inflammation. Recently, we have shown diminished expression of the high-density lipoprotein scavenger receptor BI (SR-BI) in the liver of syntrophin-deficient mice. Indeed, hepatic SNTA and SR-BI mRNA were positively correlated. SNTA protein was further determined in tumor and non-tumorous tissues of 21 HCC patients. Protein expression was unchanged in the tumor and not related to staging and grading. Present study identified associations of hepatic SNTA mRNA levels with SR-BI and features of NASH assuming a function of this protein in chronic liver disease and cholesterol metabolism. Copyright © 2017 Elsevier Inc. All rights reserved.