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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. Negative regulation of lymphocyte activation by the adaptor protein LAX.

    Science.gov (United States)

    Zhu, Minghua; Granillo, Olivia; Wen, Renren; Yang, Kaiyong; Dai, Xuezhi; Wang, Demin; Zhang, Weiguo

    2005-05-01

    The membrane-associated adaptor protein LAX is a linker for activation of T cells (LAT)-like molecule that is expressed in lymphoid tissues. Upon stimulation of T or B cells, it is phosphorylated and interacts with Grb2 and the p85 subunit of PI3K. LAX, however, is not capable of replacing LAT in the TCR signaling pathway. In this study we report that upon T or B cell activation, the LAX protein was up-regulated dramatically. Although disruption of the LAX gene by homologous recombination had no major impact on lymphocyte development, it caused a significant reduction in CD23 expression on mature B cells. Interestingly, naive LAX(-/-) mice had spontaneous germinal center formation. Compared with normal T and B cells, LAX(-/-) T and B cells were hyperresponsive and had enhanced calcium flux, protein tyrosine phosphorylation, MAPK and Akt activation, and cell survival upon engagement of the T or B AgRs. Our data demonstrate that LAX functions as a negative regulator in lymphocyte signaling.

  3. 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 prote... (.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 recep

  4. 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.

  5. Autoinhibition of Mint1 adaptor protein regulates amyloid precursor protein binding and processing

    OpenAIRE

    Matos, Maria F.; Xu, Yibin; Dulubova, Irina; Otwinowski, Zbyszek; Richardson, John M.; Tomchick, Diana R.; Rizo, Josep; Ho, Angela

    2012-01-01

    Mint adaptor proteins bind to the amyloid precursor protein (APP) and regulate APP processing associated with Alzheimer’s disease; however, the molecular mechanisms underlying Mint regulation in APP binding and processing remain unclear. Biochemical, biophysical, and cellular experiments now show that the Mint1 phosphotyrosine binding (PTB) domain that binds to APP is intramolecularly inhibited by the adjacent C-terminal linker region. The crystal structure of a C-terminally extended Mint1 PT...

  6. Synapse formation is regulated by the signaling adaptor GIT1

    OpenAIRE

    Zhang, Huaye; Webb, Donna J.; Asmussen, Hannelore; Horwitz, Alan F.

    2003-01-01

    Dendritic spines in the central nervous system undergo rapid actin-based shape changes, making actin regulators potential modulators of spine morphology and synapse formation. Although several potential regulators and effectors for actin organization have been identified, the mechanisms by which these molecules assemble and localize are not understood. Here we show that the G protein–coupled receptor kinase–interacting protein (GIT)1 serves such a function by targeting actin regulators and lo...

  7. 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.

  8. Src-like-adaptor protein (SLAP) differentially regulates normal and oncogenic c-Kit signaling.

    Science.gov (United States)

    Kazi, Julhash U; Agarwal, Shruti; Sun, Jianmin; Bracco, Enrico; Rönnstrand, Lars

    2014-02-01

    The Src-like-adaptor protein (SLAP) is an adaptor protein sharing considerable structural homology with Src. SLAP is expressed in a variety of cells and regulates receptor tyrosine kinase signaling by direct association. In this report, we show that SLAP associates with both wild-type and oncogenic c-Kit (c-Kit-D816V). The association involves the SLAP SH2 domain and receptor phosphotyrosine residues different from those mediating Src interaction. Association of SLAP triggers c-Kit ubiquitylation which, in turn, is followed by receptor degradation. Although SLAP depletion potentiates c-Kit downstream signaling by stabilizing the receptor, it remains non-functional in c-Kit-D816V signaling. Ligand-stimulated c-Kit or c-Kit-D816V did not alter membrane localization of SLAP. Interestingly oncogenic c-Kit-D816V, but not wild-type c-Kit, phosphorylates SLAP on residues Y120, Y258 and Y273. Physical interaction between c-Kit-D816V and SLAP is mandatory for the phosphorylation to take place. Although tyrosine-phosphorylated SLAP does not affect c-Kit-D816V signaling, mutation of these tyrosine sites to phenylalanine can restore SLAP activity. Taken together the data demonstrate that SLAP negatively regulates wild-type c-Kit signaling, but not its oncogenic counterpart, indicating a possible mechanism by which the oncogenic c-Kit bypasses the normal cellular negative feedback control.

  9. The Hypoxic Regulator of Sterol Synthesis Nro1 Is a Nuclear Import Adaptor

    Energy Technology Data Exchange (ETDEWEB)

    T Yeh; C Lee; L Amzel; P Espenshade; M Bianchet

    2011-12-31

    Fission yeast protein Sre1, the homolog of the mammalian sterol regulatory element-binding protein (SREBP), is a hypoxic transcription factor required for sterol homeostasis and low-oxygen growth. Nro1 regulates the stability of the N-terminal transcription factor domain of Sre1 (Sre1N) by inhibiting the action of the prolyl 4-hydroxylase-like Ofd1 in an oxygen-dependent manner. The crystal structure of Nro1 determined at 2.2 {angstrom} resolution shows an all-{alpha}-helical fold that can be divided into two domains: a small N-terminal domain, and a larger C-terminal HEAT-repeat domain. Follow-up studies showed that Nro1 defines a new class of nuclear import adaptor that functions both in Ofd1 nuclear localization and in the oxygen-dependent inhibition of Ofd1 to control the hypoxic response.

  10. Adaptor protein LNK is a negative regulator of brain neural stem cell proliferation after stroke.

    Science.gov (United States)

    Ahlenius, Henrik; Devaraju, Karthikeyan; Monni, Emanuela; Oki, Koichi; Wattananit, Somsak; Darsalia, Vladimer; Iosif, Robert E; Torper, Olof; Wood, James C; Braun, Sebastian; Jagemann, Lucas; Nuber, Ulrike A; Englund, Elisabet; Jacobsen, Sten-Eirik W; Lindvall, Olle; Kokaia, Zaal

    2012-04-11

    Ischemic stroke causes transient increase of neural stem and progenitor cell (NSPC) proliferation in the subventricular zone (SVZ), and migration of newly formed neuroblasts toward the damaged area where they mature to striatal neurons. The molecular mechanisms regulating this plastic response, probably involved in structural reorganization and functional recovery, are poorly understood. The adaptor protein LNK suppresses hematopoietic stem cell self-renewal, but its presence and role in the brain are poorly understood. Here we demonstrate that LNK is expressed in NSPCs in the adult mouse and human SVZ. Lnk(-/-) mice exhibited increased NSPC proliferation after stroke, but not in intact brain or following status epilepticus. Deletion of Lnk caused increased NSPC proliferation while overexpression decreased mitotic activity of these cells in vitro. We found that Lnk expression after stroke increased in SVZ through the transcription factors STAT1/3. LNK attenuated insulin-like growth factor 1 signaling by inhibition of AKT phosphorylation, resulting in reduced NSPC proliferation. Our findings identify LNK as a stroke-specific, endogenous negative regulator of NSPC proliferation, and suggest that LNK signaling is a novel mechanism influencing plastic responses in postischemic brain. PMID:22496561

  11. 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.

  12. 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.

  13. Four tomato FLOWERING LOCUS T-like proteins act antagonistically to regulate floral initiation

    OpenAIRE

    Kai eCao; Lirong eCui; Xiaoting eZhou; Lin eYe; Zhirong eZou; Shulin eDeng

    2016-01-01

    The transition from vegetative growth to floral meristems in higher plants is regulated through the integration of internal cues and environmental signals. We were interested to examine the molecular mechanism of flowering in the day-neutral plant tomato (Solanum lycopersicum L.) and the effect of environmental conditions on tomato flowering. Analysis of the tomato genome uncovered 13 PEBP (phosphatidylethanolamine-binding protein) genes, and found six of them were FT-like genes which named a...

  14. Four Tomato FLOWERING LOCUS T-Like Proteins Act Antagonistically to Regulate Floral Initiation

    OpenAIRE

    Cao, Kai; Cui, Lirong; Zhou, Xiaoting; Lin YE; Zou, Zhirong; Deng, Shulin

    2016-01-01

    The transition from vegetative growth to floral meristems in higher plants is regulated through the integration of internal cues and environmental signals. We were interested to examine the molecular mechanism of flowering in the day-neutral plant tomato (Solanum lycopersicum L.) and the effect of environmental conditions on tomato flowering. Analysis of the tomato genome uncovered 13 PEBP (phosphatidylethanolamine-binding protein) genes, and found six of them were FT-like genes which named a...

  15. Nck adaptors are positive regulators of the size and sensitivity of the T-cell repertoire.

    Science.gov (United States)

    Roy, Edwige; Togbe, Dieudonnée; Holdorf, Amy D; Trubetskoy, Dmitry; Nabti, Sabrina; Küblbeck, Günter; Klevenz, Alexandra; Kopp-Schneider, Annette; Leithäuser, Frank; Möller, Peter; Bladt, Friedhelm; Hämmerling, Günter; Arnold, Bernd; Pawson, Tony; Tafuri, Anna

    2010-08-31

    The size and sensitivity of the T-cell repertoire governs the effectiveness of immune responses against invading pathogens. Both are modulated by T-cell receptor (TCR) activity through molecular mechanisms, which remain unclear. Here, we provide genetic evidence that the SH2/SH3 domain containing proteins Nck lower the threshold of T-cell responsiveness. The hallmarks of Nck deletion were T-cell lymphopenia and hyporeactivity to TCR-mediated stimulation. In the absence of the Nck adaptors, peripheral T cells expressing a TCR with low avidity for self-antigens were strongly reduced, whereas an overall impairment of T-cell activation by weak antigenic stimulation was observed. Mechanistically, Nck deletion resulted in a significant decrease in calcium mobilization and ERK phosphorylation upon TCR engagement. Taken together, our findings unveil a crucial role for the Nck adaptors in shaping the T-cell repertoire to ensure maximal antigenic coverage and optimal T cell excitability. PMID:20709959

  16. Nck adaptors are positive regulators of the size and sensitivity of the T-cell repertoire.

    Science.gov (United States)

    Roy, Edwige; Togbe, Dieudonnée; Holdorf, Amy D; Trubetskoy, Dmitry; Nabti, Sabrina; Küblbeck, Günter; Klevenz, Alexandra; Kopp-Schneider, Annette; Leithäuser, Frank; Möller, Peter; Bladt, Friedhelm; Hämmerling, Günter; Arnold, Bernd; Pawson, Tony; Tafuri, Anna

    2010-08-31

    The size and sensitivity of the T-cell repertoire governs the effectiveness of immune responses against invading pathogens. Both are modulated by T-cell receptor (TCR) activity through molecular mechanisms, which remain unclear. Here, we provide genetic evidence that the SH2/SH3 domain containing proteins Nck lower the threshold of T-cell responsiveness. The hallmarks of Nck deletion were T-cell lymphopenia and hyporeactivity to TCR-mediated stimulation. In the absence of the Nck adaptors, peripheral T cells expressing a TCR with low avidity for self-antigens were strongly reduced, whereas an overall impairment of T-cell activation by weak antigenic stimulation was observed. Mechanistically, Nck deletion resulted in a significant decrease in calcium mobilization and ERK phosphorylation upon TCR engagement. Taken together, our findings unveil a crucial role for the Nck adaptors in shaping the T-cell repertoire to ensure maximal antigenic coverage and optimal T cell excitability.

  17. Nck adaptors are positive regulators of the size and sensitivity of the T-cell repertoire

    OpenAIRE

    Roy, Edwige; Togbe, Dieudonnée; Holdorf, Amy D.; Trubetskoy, Dmitry; Nabti, Sabrina; Küblbeck, Günter; Klevenz, Alexandra; Kopp-Schneider, Annette; Leithäuser, Frank; Möller, Peter; Bladt, Friedhelm; Hämmerling, Günter; Arnold, Bernd; Pawson, Tony; Tafuri, Anna

    2010-01-01

    The size and sensitivity of the T-cell repertoire governs the effectiveness of immune responses against invading pathogens. Both are modulated by T-cell receptor (TCR) activity through molecular mechanisms, which remain unclear. Here, we provide genetic evidence that the SH2/SH3 domain containing proteins Nck lower the threshold of T-cell responsiveness. The hallmarks of Nck deletion were T-cell lymphopenia and hyporeactivity to TCR-mediated stimulation. In the absence of the Nck adaptors, pe...

  18. 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

    2016-08-01

    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. PMID:27493185

  19. 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

    2016-08-01

    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.

  20. Lymphocytes and the Dap12 adaptor are key regulators of osteoclast activation associated with gonadal failure.

    Directory of Open Access Journals (Sweden)

    Adrienne Anginot

    Full Text Available Bone resorption by osteoclasts is necessary to maintain bone homeostasis. Osteoclast differentiation from hematopoietic progenitors and their activation depend on M-CSF and RANKL, but also requires co-stimulatory signals acting through receptors associated with DAP12 and FcRgamma adaptors. Dap12 mutant mice (KDelta75 are osteopetrotic due to inactive osteoclasts but, surprisingly, these mice are more sensitive than WT mice to bone loss following an ovariectomy. Because estrogen withdrawal is known to disturb bone mass, at least in part, through lymphocyte interaction, we looked at the role of mature lymphocytes on osteoclastogenesis and bone mass in the absence of functional DAP12. Lymphocytes were found to stimulate an early osteoclast differentiation response from Dap12-deficient progenitors in vitro. In vivo, Rag1-/- mice lacking mature lymphocytes did not exhibit any bone phenotype, but lost their bone mass after ovariectomy like KDelta75 mice. KDelta75;Rag1-/- double mutant female mice exhibited a more severe osteopetrosis than Dap12-deficient animals but lost their bone mass after ovariectomy, like single mutants. These results suggest that both DAP12 and mature lymphocytes act synergistically to maintain bone mass under physiological conditions, while playing similar but not synergistic co-stimulatory roles in protecting bone loss after gonadal failure. Thus, our data support a role for lymphocytes during osteoclast differentiation and suggest that they may function as accessory cells when regular osteoclast function is compromised.

  1. Regulation and function of the CD3¿ DxxxLL motif: a binding site for adaptor protein-1 and adaptor protein-2 in vitro

    DEFF Research Database (Denmark)

    Dietrich, J; Kastrup, J; Nielsen, B L;

    1997-01-01

    /CD3gamma chimeras; and in vitro by binding CD3gamma peptides to clathrin-coated vesicle adaptor proteins (APs). We find that the CD3gamma D127xxxLL131/132 sequence represents one united motif for binding of both AP-1 and AP-2, and that this motif functions as an active sorting motif in monomeric CD4....../ CD3gamma molecules independently of S126. An acidic amino acid is required at position 127 and a leucine (L) is required at position 131, whereas the requirements for position 132 are more relaxed. The spacing between aspartic acid 127 (D127) and L131 is crucial for the function of the motif in vivo...... subunit clusters of differentiation (CD)3gamma. Thus, phosphorylation of CD3gamma serine 126 (S126) causes a downregulation of the TCR. In this study, we have analyzed the CD3gamma internalization motif in three different systems in parallel: in the context of the complete multimeric TCR; in monomeric CD4...

  2. Regulation of ITAM adaptor molecules and their receptors by inhibition of calcineurin-NFAT signalling during late stage osteoclast differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Zawawi, M.S.F. [Universiti Sains Malaysia (USM) (Malaysia); Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, SA 5005 (Australia); Dharmapatni, A.A.S.S.K.; Cantley, M.D. [Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, SA 5005 (Australia); McHugh, K.P. [University of Florida, College of Dentistry, Fl (United States); Haynes, D.R. [Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, SA 5005 (Australia); Crotti, T.N., E-mail: tania.crotti@adelaide.edu.au [Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, SA 5005 (Australia)

    2012-10-19

    Highlights: Black-Right-Pointing-Pointer Calcineurin/NFAT inhibitors FK506 and VIVIT treated human PBMC derived osteoclasts in vitro. Black-Right-Pointing-Pointer Differential regulation of ITAM receptors and adaptor molecules by calcineurin/NFAT inhibitors. Black-Right-Pointing-Pointer FK506 and VIVIT suppress ITAM factors during late phase osteoclast differentiation. -- Abstract: Osteoclasts are specialised bone resorptive cells responsible for both physiological and pathological bone loss. Osteoclast differentiation and activity is dependent upon receptor activator NF-kappa-B ligand (RANKL) interacting with its receptor RANK to induce the transcription factor, nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1). The immunoreceptor tyrosine-based activation motif (ITAM)-dependent pathway has been identified as a co-stimulatory pathway in osteoclasts. Osteoclast-associated receptor (OSCAR) and triggering receptor expressed in myeloid cells (TREM2) are essential receptors that pair with adaptor molecules Fc receptor common gamma chain (FcR{gamma}) and DNAX-activating protein 12 kDa (DAP12) respectively to induce calcium signalling. Treatment with calcineurin-NFAT inhibitors, Tacrolimus (FK506) and the 11R-VIVIT (VIVIT) peptide, reduces NFATc1 expression consistent with a reduction in osteoclast differentiation and activity. This study aimed to investigate the effects of inhibiting calcineurin-NFAT signalling on the expression of ITAM factors and late stage osteoclast genes including cathepsin K (CathK), Beta 3 integrin ({beta}3) and Annexin VIII (AnnVIII). Human peripheral blood mononuclear cells (PBMCs) were differentiated with RANKL and macrophage-colony stimulating factor (M-CSF) over 10 days in the presence or absence of FK506 or VIVIT. Osteoclast formation (as assessed by tartrate resistant acid phosphatase (TRAP)) and activity (assessed by dentine pit resorption) were significantly reduced with treatment. Quantitative real

  3. Regulation of ITAM adaptor molecules and their receptors by inhibition of calcineurin-NFAT signalling during late stage osteoclast differentiation

    International Nuclear Information System (INIS)

    Highlights: ► Calcineurin/NFAT inhibitors FK506 and VIVIT treated human PBMC derived osteoclasts in vitro. ► Differential regulation of ITAM receptors and adaptor molecules by calcineurin/NFAT inhibitors. ► FK506 and VIVIT suppress ITAM factors during late phase osteoclast differentiation. -- Abstract: Osteoclasts are specialised bone resorptive cells responsible for both physiological and pathological bone loss. Osteoclast differentiation and activity is dependent upon receptor activator NF-kappa-B ligand (RANKL) interacting with its receptor RANK to induce the transcription factor, nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1). The immunoreceptor tyrosine-based activation motif (ITAM)-dependent pathway has been identified as a co-stimulatory pathway in osteoclasts. Osteoclast-associated receptor (OSCAR) and triggering receptor expressed in myeloid cells (TREM2) are essential receptors that pair with adaptor molecules Fc receptor common gamma chain (FcRγ) and DNAX-activating protein 12 kDa (DAP12) respectively to induce calcium signalling. Treatment with calcineurin-NFAT inhibitors, Tacrolimus (FK506) and the 11R-VIVIT (VIVIT) peptide, reduces NFATc1 expression consistent with a reduction in osteoclast differentiation and activity. This study aimed to investigate the effects of inhibiting calcineurin-NFAT signalling on the expression of ITAM factors and late stage osteoclast genes including cathepsin K (CathK), Beta 3 integrin (β3) and Annexin VIII (AnnVIII). Human peripheral blood mononuclear cells (PBMCs) were differentiated with RANKL and macrophage-colony stimulating factor (M-CSF) over 10 days in the presence or absence of FK506 or VIVIT. Osteoclast formation (as assessed by tartrate resistant acid phosphatase (TRAP)) and activity (assessed by dentine pit resorption) were significantly reduced with treatment. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis demonstrated that FK506 treatment

  4. A Cyclic di-GMP-binding Adaptor Protein Interacts with Histidine Kinase to Regulate Two-component Signaling.

    Science.gov (United States)

    Xu, Linghui; Venkataramani, Prabhadevi; Ding, Yichen; Liu, Yang; Deng, Yinyue; Yong, Grace Lisi; Xin, Lingyi; Ye, Ruijuan; Zhang, Lianhui; Yang, Liang; Liang, Zhao-Xun

    2016-07-29

    The bacterial messenger cyclic di-GMP (c-di-GMP) binds to a diverse range of effectors to exert its biological effect. Despite the fact that free-standing PilZ proteins are by far the most prevalent c-di-GMP effectors known to date, their physiological function and mechanism of action remain largely unknown. Here we report that the free-standing PilZ protein PA2799 from the opportunistic pathogen Pseudomonas aeruginosa interacts directly with the hybrid histidine kinase SagS. We show that PA2799 (named as HapZ: histidine kinase associated PilZ) binds directly to the phosphoreceiver (REC) domain of SagS, and that the SagS-HapZ interaction is further enhanced at elevated c-di-GMP concentration. We demonstrate that binding of HapZ to SagS inhibits the phosphotransfer between SagS and the downstream protein HptB in a c-di-GMP-dependent manner. In accordance with the role of SagS as a motile-sessile switch and biofilm growth factor, we show that HapZ impacts surface attachment and biofilm formation most likely by regulating the expression of a large number of genes. The observations suggest a previously unknown mechanism whereby c-di-GMP mediates two-component signaling through a PilZ adaptor protein.

  5. Lipid raft-dependent FcepsilonRI ubiquitination regulates receptor endocytosis through the action of ubiquitin binding adaptors.

    Directory of Open Access Journals (Sweden)

    Rosa Molfetta

    Full Text Available The best characterized role for ubiquitination of membrane receptors is to negatively regulate signaling by targeting receptors for lysosomal degradation. The high affinity receptor for IgE (FcepsilonRI expressed on mast cells and basophils is rapidly ubiquitinated upon antigen stimulation. However, the nature and the role of this covalent modification are still largelly unknown. Here, we show that FcepsilonRI subunits are preferentially ubiquitinated at multiple sites upon stimulation, and provide evidence for a role of ubiquitin as an internalization signal: under conditions of impaired receptor ubiquitination a decrease of receptor entry is observed by FACS analysis and fluorescence microscopy. We also used biochemical approaches combined with fluorescence microscopy, to demonstrate that receptor endocytosis requires the integrity of specific membrane domains, namely lipid rafts. Additionally, by RNA interference we demonstrate the involvement of ubiquitin-binding endocytic adaptors in FcepsilonRI internalization and sorting. Notably, the triple depletion of Eps15, Eps15R and Epsin1 negatively affects the early steps of Ag-induced receptor endocytosis, whereas Hrs depletion retains ubiquitinated receptors into early endosomes and partially prevents their sorting into lysosomes for degradation. Our results are compatible with a scenario in which the accumulation of engaged receptor subunits into lipid rafts is required for receptor ubiquitination, a prerequisite for efficient receptor internalization, sorting and delivery to a lysosomal compartment.

  6. Positive and negative regulation of FcepsilonRI-mediated signaling by the adaptor protein LAB/NTAL.

    Science.gov (United States)

    Zhu, Minghua; Liu, Yan; Koonpaew, Surapong; Granillo, Olivia; Zhang, Weiguo

    2004-10-18

    Linker for activation of B cells (LAB, also called NTAL; a product of wbscr5 gene) is a newly identified transmembrane adaptor protein that is expressed in B cells, NK cells, and mast cells. Upon BCR activation, LAB is phosphorylated and interacts with Grb2. LAB is capable of rescuing thymocyte development in LAT-deficient mice. To study the in vivo function of LAB, LAB-deficient mice were generated. Although disruption of the Lab gene did not affect lymphocyte development, it caused mast cells to be hyperresponsive to stimulation via the FcepsilonRI, evidenced by enhanced Erk activation, calcium mobilization, degranulation, and cytokine production. These data suggested that LAB negatively regulates mast cell function. However, mast cells that lacked both linker for activation of T cells (LAT) and LAB proteins had a more severe block in FcepsilonRI-mediated signaling than LAT(-/-) mast cells, demonstrating that LAB also shares a redundant function with LAT to play a positive role in FcepsilonRI-mediated signaling.

  7. A Cyclic di-GMP-binding Adaptor Protein Interacts with Histidine Kinase to Regulate Two-component Signaling.

    Science.gov (United States)

    Xu, Linghui; Venkataramani, Prabhadevi; Ding, Yichen; Liu, Yang; Deng, Yinyue; Yong, Grace Lisi; Xin, Lingyi; Ye, Ruijuan; Zhang, Lianhui; Yang, Liang; Liang, Zhao-Xun

    2016-07-29

    The bacterial messenger cyclic di-GMP (c-di-GMP) binds to a diverse range of effectors to exert its biological effect. Despite the fact that free-standing PilZ proteins are by far the most prevalent c-di-GMP effectors known to date, their physiological function and mechanism of action remain largely unknown. Here we report that the free-standing PilZ protein PA2799 from the opportunistic pathogen Pseudomonas aeruginosa interacts directly with the hybrid histidine kinase SagS. We show that PA2799 (named as HapZ: histidine kinase associated PilZ) binds directly to the phosphoreceiver (REC) domain of SagS, and that the SagS-HapZ interaction is further enhanced at elevated c-di-GMP concentration. We demonstrate that binding of HapZ to SagS inhibits the phosphotransfer between SagS and the downstream protein HptB in a c-di-GMP-dependent manner. In accordance with the role of SagS as a motile-sessile switch and biofilm growth factor, we show that HapZ impacts surface attachment and biofilm formation most likely by regulating the expression of a large number of genes. The observations suggest a previously unknown mechanism whereby c-di-GMP mediates two-component signaling through a PilZ adaptor protein. PMID:27231351

  8. Global identification of target genes regulated by APETALA3 and PISTILLATA floral homeotic gene action.

    Science.gov (United States)

    Zik, Moriyah; Irish, Vivian F

    2003-01-01

    Identifying the genes regulated by the floral homeotic genes APETALA3 (AP3) and PISTILLATA (PI) is crucial for understanding the molecular mechanisms that lead to petal and stamen formation. We have used microarray analysis to conduct a broad survey of genes whose expression is affected by AP3 and PI activity. DNA microarrays consisting of 9216 Arabidopsis ESTs were screened with probes corresponding to mRNAs from different mutant and transgenic lines that misexpress AP3 and/or PI. The microarray results were further confirmed by RNA gel blot analyses. Our results suggest that AP3 and PI regulate a relatively small number of genes, implying that many genes used in petal and stamen development are not tissue specific and likely have roles in other processes as well. We recovered genes similar to previously identified petal- and stamen-expressed genes as well as genes that were not implicated previously in petal and stamen development. A very low percentage of the genes recovered encoded transcription factors. This finding suggests that AP3 and PI act relatively directly to regulate the genes required for the basic cellular processes responsible for petal and stamen morphogenesis.

  9. 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

  10. 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.

  11. The ERECTA, CLAVATA and class III HD-ZIP Pathways Display Synergistic Interactions in Regulating Floral Meristem Activities.

    Directory of Open Access Journals (Sweden)

    Udi Landau

    Full Text Available In angiosperms, the production of flowers marks the beginning of the reproductive phase. At the emergence of flower primordia on the flanks of the inflorescence meristem, the WUSCHEL (WUS gene, which encodes a homeodomain transcription factor starts to be expressed and establishes de novo stem cell population, founder of the floral meristem (FM. Similarly to the shoot apical meristem a precise spatial and temporal expression pattern of WUS is required and maintained through strict regulation by multiple regulatory inputs to maintain stem cell homeostasis. However, following the formation of a genetically determined fixed number of floral organs, this homeostasis is shifted towards organogenesis and the FM is terminated. In here we performed a genetic study to test how a reduction in ERECTA, CLAVATA and class III HD-ZIP pathways affects floral meristem activity and flower development. We revealed strong synergistic phenotypes of extra flower number, supernumerary whorls, total loss of determinacy and extreme enlargement of the meristem as compared to any double mutant combination indicating that the three pathways, CLV3, ER and HD-ZIPIII distinctively regulate meristem activity and that they act in parallel. Our findings yield several new insights into stem cell-driven development. We demonstrate the crucial requirement for coupling floral meristem termination with carpel formation to ensure successful reproduction in plants. We also show how regulation of meristem size and alternation in spatial structure of the meristem serve as a mechanism to determine flower organogenesis. We propose that the loss of FM determinacy due to the reduction in CLV3, ER and HD-ZIPIII activity is genetically separable from the AGAMOUS core mechanism of meristem termination.

  12. ARGONAUTE10 and ARGONAUTE1 regulate the termination of floral stem cells through two microRNAs in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Lijuan Ji

    2011-03-01

    Full Text Available Stem cells are crucial in morphogenesis in plants and animals. Much is known about the mechanisms that maintain stem cell fates or trigger their terminal differentiation. However, little is known about how developmental time impacts stem cell fates. Using Arabidopsis floral stem cells as a model, we show that stem cells can undergo precise temporal regulation governed by mechanisms that are distinct from, but integrated with, those that specify cell fates. We show that two microRNAs, miR172 and miR165/166, through targeting APETALA2 and type III homeodomain-leucine zipper (HD-Zip genes, respectively, regulate the temporal program of floral stem cells. In particular, we reveal a role of the type III HD-Zip genes, previously known to specify lateral organ polarity, in stem cell termination. Both reduction in HD-Zip expression by over-expression of miR165/166 and mis-expression of HD-Zip genes by rendering them resistant to miR165/166 lead to prolonged floral stem cell activity, indicating that the expression of HD-Zip genes needs to be precisely controlled to achieve floral stem cell termination. We also show that both the ubiquitously expressed ARGONAUTE1 (AGO1 gene and its homolog AGO10, which exhibits highly restricted spatial expression patterns, are required to maintain the correct temporal program of floral stem cells. We provide evidence that AGO10, like AGO1, associates with miR172 and miR165/166 in vivo and exhibits "slicer" activity in vitro. Despite the common biological functions and similar biochemical activities, AGO1 and AGO10 exert different effects on miR165/166 in vivo. This work establishes a network of microRNAs and transcription factors governing the temporal program of floral stem cells and sheds light on the relationships among different AGO genes, which tend to exist in gene families in multicellular organisms.

  13. An Arabidopsis F-box protein acts as a transcriptional co-factor to regulate floral development.

    Science.gov (United States)

    Chae, Eunyoung; Tan, Queenie K-G; Hill, Theresa A; Irish, Vivian F

    2008-04-01

    Plants flower in response to both environmental and endogenous signals. The Arabidopsis LEAFY (LFY) transcription factor is crucial in integrating these signals, and acts in part by activating the expression of multiple floral homeotic genes. LFY-dependent activation of the homeotic APETALA3 (AP3) gene requires the activity of UNUSUAL FLORAL ORGANS (UFO), an F-box component of an SCF ubiquitin ligase, yet how this regulation is effected has remained unclear. Here, we show that UFO physically interacts with LFY both in vitro and in vivo, and this interaction is necessary to recruit UFO to the AP3 promoter. Furthermore, a transcriptional repressor domain fused to UFO reduces endogenous LFY activity in plants, supporting the idea that UFO acts as part of a transcriptional complex at the AP3 promoter. Moreover, chemical or genetic disruption of proteasome activity compromises LFY-dependent AP3 activation, indicating that protein degradation is required to promote LFY activity. These results define an unexpected role for an F-box protein in functioning as a DNA-associated transcriptional co-factor in regulating floral homeotic gene expression. These results suggest a novel mechanism for promoting flower development via protein degradation and concomitant activation of the LFY transcription factor. This mechanism may be widely conserved, as homologs of UFO and LFY have been identified in a wide array of plant species. PMID:18287201

  14. An Arabidopsis F-box protein acts as a transcriptional co-factor to regulate floral development.

    Science.gov (United States)

    Chae, Eunyoung; Tan, Queenie K-G; Hill, Theresa A; Irish, Vivian F

    2008-04-01

    Plants flower in response to both environmental and endogenous signals. The Arabidopsis LEAFY (LFY) transcription factor is crucial in integrating these signals, and acts in part by activating the expression of multiple floral homeotic genes. LFY-dependent activation of the homeotic APETALA3 (AP3) gene requires the activity of UNUSUAL FLORAL ORGANS (UFO), an F-box component of an SCF ubiquitin ligase, yet how this regulation is effected has remained unclear. Here, we show that UFO physically interacts with LFY both in vitro and in vivo, and this interaction is necessary to recruit UFO to the AP3 promoter. Furthermore, a transcriptional repressor domain fused to UFO reduces endogenous LFY activity in plants, supporting the idea that UFO acts as part of a transcriptional complex at the AP3 promoter. Moreover, chemical or genetic disruption of proteasome activity compromises LFY-dependent AP3 activation, indicating that protein degradation is required to promote LFY activity. These results define an unexpected role for an F-box protein in functioning as a DNA-associated transcriptional co-factor in regulating floral homeotic gene expression. These results suggest a novel mechanism for promoting flower development via protein degradation and concomitant activation of the LFY transcription factor. This mechanism may be widely conserved, as homologs of UFO and LFY have been identified in a wide array of plant species.

  15. Palmitoylation of protease-activated receptor-1 regulates adaptor protein complex-2 and -3 interaction with tyrosine-based motifs and endocytic sorting.

    Science.gov (United States)

    Canto, Isabel; Trejo, JoAnn

    2013-05-31

    Protease-activated receptor-1 (PAR1) is a G protein-coupled receptor for the coagulant protease thrombin. Thrombin binds to and cleaves the N terminus of PAR1, generating a new N terminus that functions as a tethered ligand that cannot diffuse away. In addition to rapid desensitization, PAR1 trafficking is critical for the regulation of cellular responses. PAR1 displays constitutive and agonist-induced internalization. Constitutive internalization of unactivated PAR1 is mediated by the clathrin adaptor protein complex-2 (AP-2), which binds to a distal tyrosine-based motif localized within the C-terminal tail (C-tail) domain. Once internalized, PAR1 is sorted from endosomes to lysosomes via AP-3 interaction with a second C-tail tyrosine motif proximal to the transmembrane domain. However, the regulatory processes that control adaptor protein recognition of PAR1 C-tail tyrosine-based motifs are not known. Here, we report that palmitoylation of PAR1 is critical for regulating proper utilization of tyrosine-based motifs and endocytic sorting. We show that PAR1 is basally palmitoylated at highly conserved C-tail cysteines. A palmitoylation-deficient PAR1 mutant is competent to signal and exhibits a marked increase in constitutive internalization and lysosomal degradation compared with wild type receptor. Intriguingly, enhanced constitutive internalization of PAR1 is mediated by AP-2 and requires the proximal tyrosine-based motif rather than the distal tyrosine motif used by wild type receptor. Moreover, palmitoylation-deficient PAR1 displays increased degradation that is mediated by AP-3. These findings suggest that palmitoylation of PAR1 regulates appropriate utilization of tyrosine-based motifs by adaptor proteins and endocytic trafficking, processes that are critical for maintaining appropriate expression of PAR1 at the cell surface. PMID:23580642

  16. 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. PMID:24297163

  17. Functional analyses of Src-like adaptor (SLA), a glucocorticoid-regulated gene in acute lymphoblastic leukemia.

    Science.gov (United States)

    Mansha, Muhammad; Carlet, Michela; Ploner, Christian; Gruber, Georg; Wasim, Muhammad; Wiegers, Gerrit Jan; Rainer, Johannes; Geley, Stephan; Kofler, Reinhard

    2010-04-01

    Glucocorticoids (GCs) cause apoptosis and cell cycle arrest in lymphoid cells and are used in the therapy of lymphoid malignancies. SLA (Src-like-adaptor), an inhibitor of T- and B-cell receptor signaling, is a promising candidate derived from expression profiling analyses in children with acute lymphoblastic leukemia (ALL). Over-expression and knock-down experiments in ALL in vitro model revealed that transgenic SLA alone had no effect on survival or cell cycle progression, nor did it affect sensitivity to, or kinetics of, GC-induced apoptosis. Although SLA is a prominent GC response gene, it does not seem to contribute to the anti-leukemic effects of GC.

  18. Two tobacco AP1-like gene promoters drive highly specific, tightly regulated and unique expression patterns during floral transition, initiation and development.

    Science.gov (United States)

    Zhang, Jinjin; Yan, Guohua; Wen, Zhifeng; An, Young-Qiang; Singer, Stacy D; Liu, Zongrang

    2014-02-01

    The genetic engineering of agronomic traits requires an array of highly specific and tightly regulated promoters that drive expression in floral tissues. In this study, we isolated and characterized two tobacco APETALA1-like (AP1-like) promoters (termed NtAP1La and NtAP1Lb1) in transgenic plants using the GUS reporter system, along with tissue-specific ablation analyses. Our results demonstrated that the two promoters are active in floral inflorescences but not in vegetative apical meristems or other vegetative tissues, as reflected by strong GUS staining and DT-A-mediated ablation of apical shoot tips during reproductive but not vegetative growth. We also showed that the NtAP1Lb1 promoter was more active than NtAP1La in inflorescences, as the former yielded higher frequencies and greater phenotypic evidence of tissue ablation compared to the latter. We further revealed that both promoters were uniformly expressed in the meristems of stage 1 and 2 floral buds, but were differentially expressed in floral organs later during development. While NtAP1La was found to be active in stage 4-5 carpels, later becoming confined to ovary tissue from stage 9 onwards, NtAP1Lb1 activity was apparent in all floral organs from stages 3 to 7, becoming completely absent in all floral organs from stage 11 onward. Therefore, it seems that the two tobacco promoters have acquired similar but distinct inflorescence-, floral meristem- and floral organ-specific and development-dependent regulatory features without any leaky activity in vegetative tissues. These features are novel and have rarely been observed in other flower-specific promoters characterized to date. The potential application of these promoters for engineering sterility, increasing biomass production and modifying flower architecture, as well as their putative use in flower-specific transgene excision, will be discussed.

  19. 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.

  20. Fission yeast arrestin-related trafficking adaptor, Arn1/Any1, is ubiquitinated by Pub1 E3 ligase and regulates endocytosis of Cat1 amino acid transporter

    Directory of Open Access Journals (Sweden)

    Akio Nakashima

    2014-05-01

    Full Text Available The Tsc1–Tsc2 complex homologous to human tuberous sclerosis complex proteins governs amino acid uptake by regulating the expression and intracellular distribution of amino acid transporters in Schizosaccharomyces pombe. Here, we performed a genetic screening for molecules that are involved in amino acid uptake and found Arn1 (also known as Any1. Arn1 is homologous to ART1, an arrestin-related trafficking adaptor (ART in Saccharomyces cerevisiae, and contains a conserved arrestin motif, a ubiquitination site, and two PY motifs. Overexpression of arn1+ confers canavanine resistance on cells, whereas its disruption causes hypersensitivity to canavanine. We also show that Arn1 regulates endocytosis of the Cat1 amino acid transporter. Furthermore, deletion of arn1+ suppresses a defect of amino acid uptake and the aberrant Cat1 localization in tsc2Δ. Arn1 interacts with and is ubiquitinated by the Pub1 ubiquitin ligase, which is necessary to regulate Cat1 endocytosis. Cat1 undergoes ubiquitinations on lysine residues within the N-terminus, which are mediated, in part, by Arn1 to determine Cat1 localization. Correctively, Arn1 is an ART in S. pombe and contributes to amino acid uptake through regulating Cat1 endocytosis in which Tsc2 is involved.

  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. PMID:27451356

  2. 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.

  3. Duplication and Divergence of Floral MADS-Box Genes in Grasses: Evidence for the Generation and Modification of Novel Regulators

    Institute of Scientific and Technical Information of China (English)

    Guixia Xu; Hongzhi Kong

    2007-01-01

    The process of flowering is controlled by a hierarchy of floral genes that act as flowering time genes, inflorescence/floral meristem identity genes, and/or floral organ-identity genes. The most important and well-characterized floral genes are those that belong to the MADS-box family of transcription factors. Compelling evidence suggests that floral MADS-box genes have experienced a few large-scale duplication events. In particular, the pre-core eudicot duplication events have been considered to correlate with the emergence and diversification of core eudicots. Duplication of floral MADS-box genes has also been documented in monocots, particularly in grasses, although a systematic study is lacking. In the present study, by conducting extensive phylogenetic analyses, we identified pre-Poaceae gene duplication events in each of the AP1, PI, AG, AGL11, AGL2/3/4, and AGL9gene lineages. Comparative genomic studies further indicated that some of these duplications actually resulted from the genome doubling event that occurred 66-70 million years ago (MYA). In addition, we found that after gene duplication, exonization (of intron sequences) and pseudoexonization (of exon sequences) have contributed to the divergence of duplicate genes in sequence structure and, possibly, gene function.

  4. Floral volatiles: from biosynthesis to function.

    Science.gov (United States)

    Muhlemann, Joëlle K; Klempien, Antje; Dudareva, Natalia

    2014-08-01

    Floral volatiles have attracted humans' attention since antiquity and have since then permeated many aspects of our lives. Indeed, they are heavily used in perfumes, cosmetics, flavourings and medicinal applications. However, their primary function is to mediate ecological interactions between flowers and a diverse array of visitors, including pollinators, florivores and pathogens. As such, they ultimately ensure the plants' reproductive and evolutionary success. To date, over 1700 floral volatile organic compounds (VOCs) have been identified. Interestingly, they are derived from only a few biochemical networks, which include the terpenoid, phenylpropanoid/benzenoid and fatty acid biosynthetic pathways. These pathways are intricately regulated by endogenous and external factors to enable spatially and temporally controlled emission of floral volatiles, thereby fine-tuning the ecological interactions facilitated by floral volatiles. In this review, we will focus on describing the biosynthetic pathways leading to floral VOCs, the regulation of floral volatile emission, as well as biological functions of emitted volatiles. PMID:24588567

  5. 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.

  6. Cul3 and the BTB adaptor insomniac are key regulators of sleep homeostasis and a dopamine arousal pathway in Drosophila.

    Directory of Open Access Journals (Sweden)

    Cory Pfeiffenberger

    Full Text Available Sleep is homeostatically regulated, such that sleep drive reflects the duration of prior wakefulness. However, despite the discovery of genes important for sleep, a coherent molecular model for sleep homeostasis has yet to emerge. To better understand the function and regulation of sleep, we employed a reverse-genetics approach in Drosophila. An insertion in the BTB domain protein CG32810/insomniac (inc exhibited one of the strongest baseline sleep phenotypes thus far observed, a ~10 h sleep reduction. Importantly, this is coupled to a reduced homeostatic response to sleep deprivation, consistent with a disrupted sleep homeostat. Knockdown of the INC-interacting protein, the E3 ubiquitin ligase Cul3, results in reduced sleep duration, consolidation, and homeostasis, suggesting an important role for protein turnover in mediating INC effects. Interestingly, inc and Cul3 expression in post-mitotic neurons during development contributes to their adult sleep functions. Similar to flies with increased dopaminergic signaling, loss of inc and Cul3 result in hyper-arousability to a mechanical stimulus in adult flies. Furthermore, the inc sleep duration phenotype can be rescued by pharmacological inhibition of tyrosine hydroxylase, the rate-limiting enzyme for dopamine biosynthesis. Taken together, these results establish inc and Cul3 as important new players in setting the sleep homeostat and a dopaminergic arousal pathway in Drosophila.

  7. Protease-activated Receptor-4 Signaling and Trafficking Is Regulated by the Clathrin Adaptor Protein Complex-2 Independent of β-Arrestins.

    Science.gov (United States)

    Smith, Thomas H; Coronel, Luisa J; Li, Julia G; Dores, Michael R; Nieman, Marvin T; Trejo, JoAnn

    2016-08-26

    Protease-activated receptor-4 (PAR4) is a G protein-coupled receptor (GPCR) for thrombin and is proteolytically activated, similar to the prototypical PAR1. Due to the irreversible activation of PAR1, receptor trafficking is intimately linked to signal regulation. However, unlike PAR1, the mechanisms that control PAR4 trafficking are not known. Here, we sought to define the mechanisms that control PAR4 trafficking and signaling. In HeLa cells depleted of clathrin by siRNA, activated PAR4 failed to internalize. Consistent with clathrin-mediated endocytosis, expression of a dynamin dominant-negative K44A mutant also blocked activated PAR4 internalization. However, unlike most GPCRs, PAR4 internalization occurred independently of β-arrestins and the receptor's C-tail domain. Rather, we discovered a highly conserved tyrosine-based motif in the third intracellular loop of PAR4 and found that the clathrin adaptor protein complex-2 (AP-2) is important for internalization. Depletion of AP-2 inhibited PAR4 internalization induced by agonist. In addition, mutation of the critical residues of the tyrosine-based motif disrupted agonist-induced PAR4 internalization. Using Dami megakaryocytic cells, we confirmed that AP-2 is required for agonist-induced internalization of endogenous PAR4. Moreover, inhibition of activated PAR4 internalization enhanced ERK1/2 signaling, whereas Akt signaling was markedly diminished. These findings indicate that activated PAR4 internalization requires AP-2 and a tyrosine-based motif and occurs independent of β-arrestins, unlike most classical GPCRs. Moreover, these findings are the first to show that internalization of activated PAR4 is linked to proper ERK1/2 and Akt activation. PMID:27402844

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

    NARCIS (Netherlands)

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

    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 ch

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

    OpenAIRE

    Kusters, E.; Pina, Della, 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 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 cons...

  10. Floral induction, floral hormones and flowering

    NARCIS (Netherlands)

    Pol, van der P.A.

    1972-01-01

    The factors, influencing the synthesis and action of floral hormones, and possible differences between floral hormones in different plants were studied. The experimental results are summarized in the conclusions 1-20, on pages 35-36 (Crassulaceae'); 21-39 on pages 58-59 ('Xanthium strumarium') and 4

  11. 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. PMID:26220938

  12. 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.

  13. Sequential action of FRUITFULL as a modulator of the activity of the floral regulators SVP and SOC1.

    Science.gov (United States)

    Balanzà, Vicente; Martínez-Fernández, Irene; Ferrándiz, Cristina

    2014-03-01

    The role in flowering time of the MADS-box transcription factor fruitfulL (FUL) has been proposed in many works. FUL has been connected to several flowering pathways as a target of the photoperiod, ambient temperature, and age pathways and it is has been shown to promote flowering in a partially redundant manner with suppressor of overexpression of constans 1 (SOC1). However, the position of FUL in these genetic networks, as well as the functional output of FUL activity during floral transition, remains unclear. In this work, a genetic approach has been undertaken to understand better the functional hierarchies involving FUL and other MADS-box factors with well established roles as floral integrators such as SOC1, short vegetative phase (svp) or flowering locus C (FLC). Our results suggest a prominent role of FUL in promoting reproductive transition when photoinductive signalling is suppressed by short-day conditions or by high levels of FLC expression, as in non-vernalized winter ecotypes. A model is proposed where the sequential formation of FUL-SVP and FUL-SOC1 heterodimers may mediate the vegetative and meristem identity transitions, counteracting the repressive effect of FLC and SVP on flowering.

  14. Trace concentrations of imazethapyr (IM) affect floral organs development and reproduction in Arabidopsis thaliana: IM-induced inhibition of key genes regulating anther and pollen biosynthesis.

    Science.gov (United States)

    Qian, Haifeng; Li, Yali; Sun, Chongchong; Lavoie, Michel; Xie, Jun; Bai, Xiaocui; Fu, Zhengwei

    2015-01-01

    Understanding how herbicides affect plant reproduction and growth is critical to develop herbicide toxicity model and refine herbicide risk assessment. Although our knowledge of herbicides toxicity mechanisms at the physiological and molecular level in plant vegetative phase has increased substantially in the last decades, few studies have addressed the herbicide toxicity problematic on plant reproduction. Here, we determined the long-term (4-8 weeks) effect of a chiral herbicide, imazethapyr (IM), which has been increasingly used in plant crops, on floral organ development and reproduction in the model plant Arabidopsis thaliana. More specifically, we followed the effect of two IM enantiomers (R- and S-IM) on floral organ structure, seed production, pollen viability and the transcription of key genes involved in anther and pollen development. The results showed that IM strongly inhibited the transcripts of genes regulating A. thaliana tapetum development (DYT1: DYSFUNCTIONAL TAPETUM 1), tapetal differentiation and function (TDF1: TAPETAL DEVELOPMENT AND FUNCTION1), and pollen wall formation and developments (AMS: ABORTED MICROSPORES, MYB103: MYB DOMAIN PROTEIN 103, MS1: MALE STERILITY 1, MS2: MALE STERILITY 2). Since DYT1 positively regulates 33 genes involved in cell-wall modification (such as, TDF1, AMS, MYB103, MS1, MS2) that can catalyze the breakdown of polysaccharides to facilitate anther dehiscence, the consistent decrease in the transcription of these genes after IM exposure should hamper anther opening as observed under scanning electron microscopy. The toxicity of IM on anther opening further lead to a decrease in pollen production and pollen viability. Furthermore, long-term IM exposure increased the number of apurinic/apyrimidinic sites (AP sites) in the DNA of A. thaliana and also altered the DNA of A. thaliana offspring grown in IM-free soils. Toxicity of IM on floral organs development and reproduction was generally higher in the presence of the R

  15. 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

  16. 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.

  17. The fifth adaptor protein complex.

    OpenAIRE

    Jennifer Hirst; Barlow, Lael D.; Gabriel Casey Francisco; Sahlender, Daniela A.; Seaman, Matthew N.J.; Dacks, Joel B.; Robinson, Margaret S.

    2011-01-01

    Adaptor protein (AP) complexes sort cargo into vesicles for transport from one membrane compartment of the cell to another. Four distinct AP complexes have been identified, which are present in most eukaryotes. We report the existence of a fifth AP complex, AP-5. Tagged AP-5 localises to a late endosomal compartment in HeLa cells. AP-5 does not associate with clathrin and is insensitive to brefeldin A. Knocking down AP-5 subunits interferes with the trafficking of the cation-independent manno...

  18. The Fifth Adaptor Protein Complex

    OpenAIRE

    Hirst, Jennifer; D. Barlow, Lael; Francisco, Gabriel Casey; Sahlender, Daniela A.; Seaman, Matthew N.J.; Dacks, Joel B.; Robinson, Margaret S.

    2011-01-01

    Adaptor protein (AP) complexes sort cargo into vesicles for transport from one membrane compartment of the cell to another. Four distinct AP complexes have been identified, which are present in most eukaryotes. We report the existence of a fifth AP complex, AP-5. Tagged AP-5 localises to a late endosomal compartment in HeLa cells. AP-5 does not associate with clathrin and is insensitive to brefeldin A. Knocking down AP-5 subunits interferes with the trafficking of the cation-independent manno...

  19. The fifth adaptor protein complex.

    Directory of Open Access Journals (Sweden)

    Jennifer Hirst

    2011-10-01

    Full Text Available Adaptor protein (AP complexes sort cargo into vesicles for transport from one membrane compartment of the cell to another. Four distinct AP complexes have been identified, which are present in most eukaryotes. We report the existence of a fifth AP complex, AP-5. Tagged AP-5 localises to a late endosomal compartment in HeLa cells. AP-5 does not associate with clathrin and is insensitive to brefeldin A. Knocking down AP-5 subunits interferes with the trafficking of the cation-independent mannose 6-phosphate receptor and causes the cell to form swollen endosomal structures with emanating tubules. AP-5 subunits can be found in all five eukaryotic supergroups, but they have been co-ordinately lost in many organisms. Concatenated phylogenetic analysis provides robust resolution, for the first time, into the evolutionary order of emergence of the adaptor subunit families, showing AP-3 as the basal complex, followed by AP-5, AP-4, and AP-1 and AP-2. Thus, AP-5 is an evolutionarily ancient complex, which is involved in endosomal sorting, and which has links with hereditary spastic paraplegia.

  20. Suppressor of Cytokine Signaling (SOCS 5 utilises distinct domains for regulation of JAK1 and interaction with the adaptor protein Shc-1.

    Directory of Open Access Journals (Sweden)

    Edmond M Linossi

    Full Text Available Suppressor of Cytokine Signaling (SOCS5 is thought to act as a tumour suppressor through negative regulation of JAK/STAT and epidermal growth factor (EGF signaling. However, the mechanism/s by which SOCS5 acts on these two distinct pathways is unclear. We show for the first time that SOCS5 can interact directly with JAK via a unique, conserved region in its N-terminus, which we have termed the JAK interaction region (JIR. Co-expression of SOCS5 was able to specifically reduce JAK1 and JAK2 (but not JAK3 or TYK2 autophosphorylation and this function required both the conserved JIR and additional sequences within the long SOCS5 N-terminal region. We further demonstrate that SOCS5 can directly inhibit JAK1 kinase activity, although its mechanism of action appears distinct from that of SOCS1 and SOCS3. In addition, we identify phosphoTyr317 in Shc-1 as a high-affinity substrate for the SOCS5-SH2 domain and suggest that SOCS5 may negatively regulate EGF and growth factor-driven Shc-1 signaling by binding to this site. These findings suggest that different domains in SOCS5 contribute to two distinct mechanisms for regulation of cytokine and growth factor signaling.

  1. Gama-Tocopherol Accumulation and Floral Differentiation of Medicinal Pumpkin (Cucurbita pepo L. in Response to Plant Growth Regulators

    Directory of Open Access Journals (Sweden)

    Mohammad SEDGHI

    2008-08-01

    Full Text Available Changes in biochemical and agronomical characteristics were studied in medicinal pumpkin (Cucurbita pepo L. plants under different treatments with plant growth regulators (PGRs. The seeds were subjected to priming with PGRs before planting and plants unerwent foliar sprays with different solutions of PGRs at 10 day-intervals after flowering. y-tocopherol (y-toc content of grains was found to be increased under gibberellic acid (GA3 treatment. The accumulation of y-tocopherol in the grains of GA3 treated plants was approximately 19.5 % higher than the control and reached 220.2 mg kg-1 dry pumpkin grains. The number of female flowers per plant was positively affected by PGRs and was 10.1 and 1.89 respectively, in the naphthalene acetic acid (NAA and GA3 treated plants. A significant efficiency of treatments was observed upon fresh fruit yield. The yield increased from 4831 t ha-1 in the control to 6820 t ha-1 with NAA treatment. Priming treatments increased seedling emergence rate and percent. The highest seedling emergence rate was found in GA3 treated seeds.

  2. The E3 Ubiquitin Ligase Adaptor Protein Skp1 Is Glycosylated by an Evolutionarily Conserved Pathway That Regulates Protist Growth and Development.

    Science.gov (United States)

    Rahman, Kazi; Zhao, Peng; Mandalasi, Msano; van der Wel, Hanke; Wells, Lance; Blader, Ira J; West, Christopher M

    2016-02-26

    Toxoplasma gondii is a protist parasite of warm-blooded animals that causes disease by proliferating intracellularly in muscle and the central nervous system. Previous studies showed that a prolyl 4-hydroxylase related to animal HIFα prolyl hydroxylases is required for optimal parasite proliferation, especially at low O2. We also observed that Pro-154 of Skp1, a subunit of the Skp1/Cullin-1/F-box protein (SCF)-class of E3-ubiquitin ligases, is a natural substrate of this enzyme. In an unrelated protist, Dictyostelium discoideum, Skp1 hydroxyproline is modified by five sugars via the action of three glycosyltransferases, Gnt1, PgtA, and AgtA, which are required for optimal O2-dependent development. We show here that TgSkp1 hydroxyproline is modified by a similar pentasaccharide, based on mass spectrometry, and that assembly of the first three sugars is dependent on Toxoplasma homologs of Gnt1 and PgtA. Reconstitution of the glycosyltransferase reactions in extracts with radioactive sugar nucleotide substrates and appropriate Skp1 glycoforms, followed by chromatographic analysis of acid hydrolysates of the reaction products, confirmed the predicted sugar identities as GlcNAc, Gal, and Fuc. Disruptions of gnt1 or pgtA resulted in decreased parasite growth. Off target effects were excluded based on restoration of the normal glycan chain and growth upon genetic complementation. By analogy to Dictyostelium Skp1, the mechanism may involve regulation of assembly of the SCF complex. Understanding the mechanism of Toxoplasma Skp1 glycosylation is expected to help develop it as a drug target for control of the pathogen, as the glycosyltransferases are absent from mammalian hosts. PMID:26719340

  3. The E3 Ubiquitin Ligase Adaptor Protein Skp1 Is Glycosylated by an Evolutionarily Conserved Pathway That Regulates Protist Growth and Development.

    Science.gov (United States)

    Rahman, Kazi; Zhao, Peng; Mandalasi, Msano; van der Wel, Hanke; Wells, Lance; Blader, Ira J; West, Christopher M

    2016-02-26

    Toxoplasma gondii is a protist parasite of warm-blooded animals that causes disease by proliferating intracellularly in muscle and the central nervous system. Previous studies showed that a prolyl 4-hydroxylase related to animal HIFα prolyl hydroxylases is required for optimal parasite proliferation, especially at low O2. We also observed that Pro-154 of Skp1, a subunit of the Skp1/Cullin-1/F-box protein (SCF)-class of E3-ubiquitin ligases, is a natural substrate of this enzyme. In an unrelated protist, Dictyostelium discoideum, Skp1 hydroxyproline is modified by five sugars via the action of three glycosyltransferases, Gnt1, PgtA, and AgtA, which are required for optimal O2-dependent development. We show here that TgSkp1 hydroxyproline is modified by a similar pentasaccharide, based on mass spectrometry, and that assembly of the first three sugars is dependent on Toxoplasma homologs of Gnt1 and PgtA. Reconstitution of the glycosyltransferase reactions in extracts with radioactive sugar nucleotide substrates and appropriate Skp1 glycoforms, followed by chromatographic analysis of acid hydrolysates of the reaction products, confirmed the predicted sugar identities as GlcNAc, Gal, and Fuc. Disruptions of gnt1 or pgtA resulted in decreased parasite growth. Off target effects were excluded based on restoration of the normal glycan chain and growth upon genetic complementation. By analogy to Dictyostelium Skp1, the mechanism may involve regulation of assembly of the SCF complex. Understanding the mechanism of Toxoplasma Skp1 glycosylation is expected to help develop it as a drug target for control of the pathogen, as the glycosyltransferases are absent from mammalian hosts.

  4. 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.

  5. Floral evolution: Beyond traditional viewpoint of pollinator mediated floral design

    Institute of Scientific and Technical Information of China (English)

    YANG Chunfeng; GUO Youhao

    2005-01-01

    Pollination biology provides new insight for understanding the evolutionary mechanism and process of the existing diversity in floral design of angiosperms. Evolutionary biologists have established some rules and models to try to explain the ubiquitous relationship between pollination system and floral evolution. However, as new techniques have been applied and more and more new pollination events found in recent years, the relationship between pollination system and floral evolution has become less clear. Researchers realized that floral evolution is more complicated and idiosyncratic than simple adaptive models. The traditional viewpoints of pollinator mediated floral design urgently need new reevaluation. This paper attempts to make a brief review of such main opinions and introduce their new insights according to recent studies. Finally, we also give some suggestions for future study by reviewing several new viewpoints about floral evolution.

  6. Transcriptional control of floral anthocyanin pigmentation in monkeyflowers (Mimulus)

    OpenAIRE

    Yuan, Yao-Wu; Sagawa, Janelle M.; Frost, Laura; Vela, James P.; Bradshaw, Harvey D.

    2014-01-01

    A molecular description of the control of floral pigmentation in a multi-species group displaying various flower color patterns is of great interest for understanding the molecular bases of phenotypic diversification and pollinator-mediated speciation.Through transcriptome profiling, mutant analyses, and transgenic experiments, we aim to establish a ‘baseline’ floral anthocyanin regulation model in Mimulus lewisii and to examine the different ways of tinkering with this model in generating th...

  7. Circadian rhythms in floral scent emission

    Directory of Open Access Journals (Sweden)

    Myles eFenske

    2016-04-01

    Full Text Available To successfully recruit pollinators, plants often release attractive floral scents at specific times of day to coincide with pollinator foraging. This timing of scent emission is thought to be evolutionarily beneficial to maximize resource efficiency while attracting only useful pollinators. Temporal regulation of scent emission is tied to the activity of the specific metabolic pathways responsible for scent production. Although floral volatile profiling in various plants indicated a contribution by the circadian clock, the mechanisms by which the circadian clock regulates timing of floral scent emission remained elusive. Recent studies using two species in the Solanaceae family provided initial insight into molecular clock regulation of scent emission timing. In Petunia hybrida, the benzenoid/phenylpropanoid (FVBP pathway is the major metabolic pathway that produces floral volatiles. Three MYB-type transcription factors, ODORANT1 (ODO1, EMISSION OF BENZENOIDS I (EOBI, and EOBII, all of which show diurnal rhythms in mRNA expression, act as positive regulators for several enzyme genes in the FVBP pathway. Recently, in P. hybrida and Nicotiana attenuata, homologs of the Arabidopsis clock gene LATE ELONGATED HYPOCOTYL (LHY have been shown to have a similar role in the circadian clock in these plants, and to also determine the timing of scent emission. In addition, in P. hybrida, PhLHY directly represses ODO1 and several enzyme genes in the FVBP pathway during the morning as an important negative regulator of scent emission. These findings facilitate our understanding of the relationship between a molecular timekeeper and the timing of scent emission, which may influence reproductive success.

  8. ABC model and floral evolution

    Institute of Scientific and Technical Information of China (English)

    LI Guisheng; MENG Zheng; KONG Hongzhi; CHEN Zhiduan; LU Anming

    2003-01-01

    The paper introduces the classical ABC model of floral development and thereafter ABCD, ABCDE and quartet models, and presents achievements in the studies on floral evolution such as the improved understanding on the relationship of reproductive organs between gnetophytes and angiosperms, new results in perianth evolution and identified homology of floral organs between dicots and monocots. The evo-devo studies on plant taxa at different evolutionary levels are useful to better understanding the homology of floral organs, and to clarifying the mysteries of the origin and subsequent diversification of flowers.

  9. Research Progress on Network Regulation of LEAFY(LFY) in Floral Development%LEAFY(LFY)基因在花发育网络调控中的研究进展

    Institute of Scientific and Technical Information of China (English)

    张亚萍; 习珺珺; 于丽霞; 李斌; 高则睿; 鄢波

    2012-01-01

    成花是高等植物生命过程中最重要的阶段,在相当的程度上决定着繁育的成功和失败。综述了花分生组织特性基因LEAFY(LFY)基因,及其花发育(成花诱导途径)网络调控的相关研究进展。LFY基因在植物的营养性生长和生殖生长组织中均表达,从花序分生组织到花器官形成的过程中,LFY都起到重要的作用。%Flowering is a critical event in the life cycle of higher plants which decides the success of breeding to some extent. This article reviewed some correlational researches on floral meristem identity gene LEA FY (LFY), and flower-development-network-regulation. LFY gene expresses widely in both vegetative and reproductive tissues in different higher plants. LFY gene plays an important role from the inflorescence meristem to the forming of floral organs.

  10. The AP-3 adaptor complex is required for vacuolar function in Arabidopsis

    NARCIS (Netherlands)

    Zwiewka, M.; Feraru, E.; Moller, B.K.; Hwang, I.; Feraru, M.I.; Kleine-Vehn, J.; Weijers, D.; Friml, J.

    2011-01-01

    Subcellular trafficking is required for a multitude of functions in eukaryotic cells. It involves regulation of cargo sorting, vesicle formation, trafficking and fusion processes at multiple levels. Adaptor protein (AP) complexes are key regulators of cargo sorting into vesicles in yeast and mammals

  11. An Activated Form of UFO Alters Leaf Development and Produces Ectopic Floral and Inflorescence Meristems

    OpenAIRE

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

    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 ...

  12. Dermatoses among floral shop workers.

    Science.gov (United States)

    Thiboutot, D M; Hamory, B H; Marks, J G

    1990-01-01

    Concern about the increasing incidence of hand dermatitis in floral shop workers in the United States and its possible association to the plant Alstroemeria, a flower that has become popular since its introduction in 1981, prompted investigation of the prevalence and cause of hand dermatitis in a sample of floral workers. Fifty-seven floral workers were surveyed, and 15 (26%) reported hand dermatitis within the previous 12 months. Sixteen floral workers (eight with dermatitis) volunteered to be patch tested to the North American Contact Dermatitis Group Standard and Perfume Trays, a series of eight pesticides and 20 plant allergens. Of four of seven floral designers and arrangers who reported hand dermatitis, three reacted positively to patch tests to tuliposide A, the allergen in Alstroemeria. Patch test readings for all other plant extracts were negative. A positive reading for a test to one pesticide, difolatan (Captafol), was noted, the relevance of which is unknown. PMID:2137139

  13. The UNUSUAL FLORAL ORGANS gene of Arabidopsis thaliana is an F-box protein required for normal patterning and growth in the floral meristem.

    Science.gov (United States)

    Samach, A; Klenz, J E; Kohalmi, S E; Risseeuw, E; Haughn, G W; Crosby, W L

    1999-11-01

    Genetic and molecular studies have suggested that the UNUSUAL FLORAL ORGANS (UFO) gene, from Arabidopsis thaliana, is expressed in all shoot apical meristems, and is involved in the regulation of a complex set of developmental events during floral development, including floral meristem and floral organ identity. Results from in situ hybridization using genes expressed early in floral development as probes indicate that UFO controls growth of young floral primordia. Transgenic constructs were used to provide evidence that UFO regulates floral organ identity by activating or maintaining transcription of the class B organ-identity gene APETALA 3, but not PISTILLATA. In an attempt to understand the biochemical mode of action of the UFO gene product, we show here that UFO is an F-box protein that interacts with Arabidopsis SKP1-like proteins, both in the yeast two-hybrid system and in vitro. In yeast and other organisms both F-box proteins and SKP1 homologues are subunits of specific ubiquitin E3 enzyme complexes that target specific proteins for degradation. The protein selected for degradation by the complex is specified by the F-box proteins. It is therefore possible that the role of UFO is to target for degradation specific proteins controlling normal growth patterns in the floral primordia, as well as proteins that negatively regulate APETALA 3 transcription.

  14. Control of floral transition in the bioenergy crop switchgrass.

    Science.gov (United States)

    Niu, Lifang; Fu, Chunxiang; Lin, Hao; Wolabu, Tezera W; Wu, Yanqi; Wang, Zeng-Yu; Tadege, Million

    2016-10-01

    Switchgrass (Panicum virgatum L.), a perennial warm season bunchgrass native to North America, has been a target in the U.S. as a renewable bioenergy crop because of its ability to produce moderate to high biomass yield on marginal soils. Delaying flowering can increase vegetative biomass production by allowing prolonged growth before switching to the reproductive phase. Despite the identification of flowering time as a biomass trait in switchgrass, the molecular regulatory factors involved in controlling floral transition are poorly understood. Here we identified PvFT1, PvAPL1-3 and PvSL1, 2 as key flowering regulators required from floral transition initiation to development of floral organs. PvFT1 expression in leaves is developmentally regulated peaking at the time of floral transition, and diurnally regulated with peak at approximately 2 h into the dark period. Ectopic expression of PvFT1 in Arabidopsis, Brachypodium and switchgrass led to extremely early flowering, and activation of FT downstream target genes, confirming that it is a strong activator of flowering in switchgrass. Ectopic expression of PvAPL1-3 and PvSL1, 2 in Arabidopsis also activated early flowering with distinct floral organ phenotypes. Our results suggest that switchgrass has conserved flowering pathway regulators similar to Arabidopsis and rice.

  15. UNUSUAL FLORAL ORGANS Controls Meristem Identity and Organ Primordia Fate in Arabidopsis.

    Science.gov (United States)

    Wilkinson, M. D.; Haughn, G. W.

    1995-09-01

    A novel gene that is involved in regulating flower initiation and development has been identified in Arabidopsis. This gene has been designated UNUSUAL FLORAL ORGANS (UFO), with five corresponding nuclear recessive alleles designated ufo[middot]1 to ufo[middot]5. Under short day-length conditions, ufo homozygotes generate more coflorescences than do the wild type, and coflorescences often appear apical to the first floral shoot, resulting in a period of inflorescence development in which regions of floral and coflorescence shoots are produced alternately. ufo enhances the phenotype of weak leafy alleles, and the double mutant Ufo-1 Apetala1-1 produces only coflorescence-like shoots, suggesting that these two genes control different aspects of floral initiation. Floral development was also altered in Ufo plants. Ufo flowers have an altered organ number in all whorls, and organs in the first, second, and third whorls exhibit variable homeotic transformations. Ufo single and double mutant phenotypes suggest that the floral changes result from reduction in class B floral homeotic gene expression and fluctuations in the expression boundaries of class C function and FLO10. Surprisingly, in situ hybridization analysis revealed no obvious differences in expression pattern or level in developing Ufo flowers compared with that of the wild type for any class B or C gene studied. We propose that UFO acts in concert with known floral initiation genes and regulates the domains of floral homeotic gene function.

  16. The Emerging and Diverse Roles of Src-Like Adaptor Proteins in Health and Disease

    Directory of Open Access Journals (Sweden)

    Nikolett Marton

    2015-01-01

    Full Text Available Although Src-like adaptor proteins (SLAP-1 and SLAP-2 were mainly studied in lymphocytes, where they act as negative regulators and provide fine control of receptor signaling, recently, several other functions of these proteins were discovered. In addition to the well-characterized immunoregulatory functions, SLAP proteins appear to have an essential role in the pathogenesis of type I hypersensitivity, osteoporosis, and numerous malignant diseases. Both adaptor proteins are expressed in a wide variety of tissues, where they have mostly inhibitory effects on multiple intracellular signaling pathways. In this review, we summarize the diverse effects of SLAP proteins.

  17. Preliminary Proteomic Analysis of Tobacco Leaves Influenced by Floral Scent from Rose

    Institute of Scientific and Technical Information of China (English)

    Ping Yu; Yuan Su; Xiaogan Zhou

    2012-01-01

    The volatile organic compounds (VOCs) play an important role in plant communication.There are many VOCs such as:aroma alcohols,esters and terpenes in rose floral scent.The tobacco would be influenced by floral scent from rose is unclear.To understand tobacco response induced by rose floral scent,we carried out proteomic analysis of tobacco leaves influenced by floral scent from rose using 2-DE.Protein profiles showed that 470 ±37 protein spots could be detected in sole tobacco and 319 ±18 in tobacco/rose respectively.Among them,26 protein spots showed 2-fold change in protein expression level,6 protein spots were up-regulated and 20 were down-regulated.We hope to acquire more information to interpret proteomic change of tobacco leaves influenced by floral scent from rose after MS identification above differential expression proteins.

  18. XB130: A novel adaptor protein in cancer signal transduction

    Science.gov (United States)

    ZHANG, RUIYAO; ZHANG, JINGYAO; WU, QIFEI; MENG, FANDI; LIU, CHANG

    2016-01-01

    Adaptor proteins are functional proteins that contain two or more protein-binding modules to link signaling proteins together, which affect cell growth and shape and have no enzymatic activity. The actin filament-associated protein (AFAP) family is an important member of the adaptor proteins, including AFAP1, AFAP1L1 and AFAP1L2/XB130. AFAP1 and AFAP1L1 share certain common characteristics and function as an actin-binding protein and a cSrc-activating protein. XB130 exhibits certain unique features in structure and function. The mRNA of XB130 is expressed in human spleen, thyroid, kidney, brain, lung, pancreas, liver, colon and stomach, and the most prominent disease associated with XB130 is cancer. XB130 has a controversial effect on cancer. Studies have shown that XB130 can promote cancer progression and downregulation of XB130-reduced growth of tumors derived from certain cell lines. A higher mRNA level of XB130 was shown to be associated with a better survival in non-small cell lung cancer. Previous studies have shown that XB130 can regulate cell growth, migration and invasion and possibly has the effect through the cAMP-cSrc-phosphoinositide 3-kinase/Akt pathway. Except for cancer, XB130 is also associated with other pathological or physiological procedures, such as airway repair and regeneration. PMID:26998266

  19. 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.

  20. Adaptor protein complexes and intracellular transport

    OpenAIRE

    2014-01-01

    The AP (adaptor protein) complexes are heterotetrameric protein complexes that mediate intracellular membrane trafficking along endocytic and secretory transport pathways. There are five different AP complexes: AP-1, AP-2 and AP-3 are clathrin-associated complexes; whereas AP-4 and AP-5 are not. These five AP complexes localize to different intracellular compartments and mediate membrane trafficking in distinct pathways. They recognize and concentrate cargo proteins into vesicular carriers th...

  1. Floral thermogenesis: An adaptive strategy of pollination biology in Magnoliaceae.

    Science.gov (United States)

    Wang, Ruohan; Zhang, Zhixiang

    2015-01-01

    Floral thermogenesis plays a crucial role in pollination biology, especially in plant-pollinator interactions. We have recently explored how thermogenesis is related to pollinator activity and odour release in Magnolia sprengeri. By analyzing flower temperatures, emission of volatiles, and insect visitation, we found that floral blends released during pistillate and staminate stages were similar and coincided with sap beetle visitation. Thus, odour mimicry of staminate-stage flowers may occur during the pistillate stage and may be an adaptive strategy of Magnolia species to attract pollinators during both stages, ensuring successful pollination. In addition to the biological significance of floral thermogenesis in Magnolia species, we explored the underlying regulatory mechanisms via profiling miRNA expression in M. denudata flowers during thermogenic and non-thermogenic stages. We identified 17 miRNAs that may play regulatory roles in floral thermogenesis. Functional annotation of their target genes indicated that these miRNAs regulate floral thermogenesis by influencing cellular respiration and light reactions. These findings increase our understanding of plant-pollinator interactions and the regulatory mechanisms in thermogenic plants.

  2. Floral development and floral phyllotaxis in Anaxagorea (Annonaceae).

    Science.gov (United States)

    Endress, Peter K; Armstrong, Joseph E

    2011-10-01

    Background and Aims Anaxagorea is the phylogenetically basalmost genus in the large tropical Annonaceae (custard apple family) of Magnoliales, but its floral structure is unknown in many respects. The aim of this study is to analyse evolutionarily interesting floral features in comparison with other genera of the Annonaceae and the sister family Eupomatiaceae. Methods Live flowers of Anaxagorea crassipetala were examined in the field with vital staining, liquid-fixed material was studied with scanning electron microscopy, and microtome section series were studied with light microscopy. In addition, herbarium material of two other Anaxagorea species was cursorily studied with the dissecting microscope. Key Results Floral phyllotaxis in Anaxagorea is regularly whorled (with complex whorls) as in all other Annonaceae with a low or medium number of floral organs studied so far (in those with numerous stamens and carpels, phyllotaxis becoming irregular in the androecium and gynoecium). The carpels are completely plicate as in almost all other Annonaceae. In these features Anaxagorea differs sharply from the sister family Eupomatiaceae, which has spiral floral phyllotaxis and ascidiate carpels. Flat stamens and the presence of inner staminodes differ from most other Annonaceae and may be plesiomorphic in Anaxagorea. However, the inner staminodes appear to be non-secretory in most Anaxagorea species, which differs from inner staminodes in other families of Magnoliales (Eupomatiaceae, Degeneriacae, Himantandraceae), which are secretory. Conclusions Floral phyllotaxis in Anaxagorea shows that there is no signature of a basal spiral pattern in Annonaceae and that complex whorls are an apomorphy not just for a part of the family but for the family in its entirety, and irregular phyllotaxis is derived. This and the presence of completely plicate carpels in Anaxagorea makes the family homogeneous and distinguishes it from the closest relatives in Magnoliales.

  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. PMID:22367063

  4. Role of SRC-like adaptor protein (SLAP) in immune and malignant cell signaling.

    Science.gov (United States)

    Kazi, Julhash U; Kabir, Nuzhat N; Rönnstrand, Lars

    2015-07-01

    SRC-like adaptor protein (SLAP) is an adaptor protein structurally similar to the SRC family protein kinases. Like SRC, SLAP contains an SH3 domain followed by an SH2 domain but the kinase domain has been replaced by a unique C-terminal region. SLAP is expressed in a variety of cell types. Current studies suggest that it regulates signaling of various cell surface receptors including the B cell receptor, the T cell receptor, cytokine receptors and receptor tyrosine kinases which are important regulator of immune and cancer cell signaling. SLAP targets receptors, or its associated components, by recruiting the ubiquitin machinery and thereby destabilizing signaling. SLAP directs receptors to ubiquitination-mediated degradation and controls receptors turnover as well as signaling. Thus, SLAP appears to be an important component in regulating signal transduction required for immune and malignant cells.

  5. 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. PMID:26944680

  6. [Floral essences, a fascinating world].

    Science.gov (United States)

    Llonch, María

    2005-05-01

    Floral essences were discovered in the decade of the thirties by the English doctor, bacteriologist and homeopath Dr. Edward Bach. He described 38 remedies elaborated with flowers and shoots; each one correspondeds to an emotional pattern or a typical personality. Furthermore, he describes a remedy developed for emergency situations. PMID:15981972

  7. [Floral essences, a fascinating world].

    Science.gov (United States)

    Llonch, María

    2005-05-01

    Floral essences were discovered in the decade of the thirties by the English doctor, bacteriologist and homeopath Dr. Edward Bach. He described 38 remedies elaborated with flowers and shoots; each one correspondeds to an emotional pattern or a typical personality. Furthermore, he describes a remedy developed for emergency situations.

  8. PIP2: choreographer of actin-adaptor proteins in the HIV-1 dance

    Science.gov (United States)

    Rocha-Perugini, Vera; Gordon-Alonso, Mónica; Sánchez-Madrid, Francisco

    2014-01-01

    The actin cytoskeleton plays a key role during the replication cycle of human immunodeficiency virus-1 (HIV-1). HIV-1 infection is affected by cellular proteins that influence the clustering of viral receptors or the subcortical actin cytoskeleton. Several of these actin-adaptor proteins are controlled by the second messenger phosphatidylinositol 4,5-biphosphate (PIP2), an important regulator of actin organization. PIP2 production is induced by HIV-1 attachment and facilitates viral infection. However, the importance of PIP2 in regulating cytoskeletal proteins and thus HIV-1 infection has been overlooked. This review examines recent reports describing the roles played by actin-adaptor proteins during HIV-1 infection of CD4+ T cells, highlighting the influence of the signaling lipid PIP2 in this process. PMID:24768560

  9. Two tobacco AP1-like gene promoters with highly specific, tightly regulated and uniquely expressed activity during floral transition, initiation and development

    Science.gov (United States)

    Biotech engineering of agronomic traits requires an array of highly specific and tightly regulated promoters in flower or other tissues. In this study, we isolated and characterized two tobacco AP1-like promoters (termed NtAP1La and NtAP1Lb1) in transgenic plants using GUS reporter and tissue-speci...

  10. Chromatin Adaptor Brd4 Modulates E2 Transcription Activity and Protein Stability*

    OpenAIRE

    Lee, A-Young; Chiang, Cheng-Ming

    2009-01-01

    Brd4 is a chromatin adaptor containing tandem bromodomains binding to acetylated histone H3 and H4. Although Brd4 has been implicated in the transcriptional control of papillomavirus-encoded E2 protein, it is unclear how Brd4 regulates E2 function and whether the involvement of Brd4 in transactivation and transrepression is common to different types of E2 proteins. Using DNase I footprinting performed with in vitro reconstituted human papillomavirus (HPV) chromatin and...

  11. 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

  12. Optimization of multiplexed RADseq libraries using low-cost adaptors.

    Science.gov (United States)

    Henri, Hélène; Cariou, Marie; Terraz, Gabriel; Martinez, Sonia; El Filali, Adil; Veyssiere, Marine; Duret, Laurent; Charlat, Sylvain

    2015-04-01

    Reduced representation genomics approaches, of which RADseq is currently the most popular form, offer the possibility to produce genome wide data from potentially any species, without previous genomic information. The application of RADseq to highly multiplexed libraries (including numerous specimens, and potentially numerous different species) is however limited by technical constraints. First, the cost of synthesis of Illumina adaptors including molecular identifiers (MIDs) becomes excessive when numerous specimens are to be multiplexed. Second, the necessity to empirically adjust the ratio of adaptors to genomic DNA concentration impedes the high throughput application of RADseq to heterogeneous samples, of variable DNA concentration and quality. In an attempt to solve these problems, we propose here some adjustments regarding the adaptor synthesis. First, we show that the common and unique (MID) parts of adaptors can be synthesized separately and subsequently ligated, which drastically reduces the synthesis cost, and thus allows multiplexing hundreds of specimens. Second, we show that self-ligation of adaptors, which makes the adaptor concentration so critical, can be simply prevented by using unphosphorylated adaptors, which significantly improves the ligation and sequencing yield.

  13. Science Signaling Podcast for 12 July 2016: Adaptor proteins limit signaling.

    Science.gov (United States)

    Wiley, H Steven; VanHook, Annalisa M

    2016-01-01

    This Podcast features an interview with Steven Wiley, senior author of a Research Article that appears in the 12 July 2016 issue of Science Signaling, about how the abundance of adaptor proteins and feedback regulators affect the flow of information downstream of the epidermal growth factor receptor (EGFR). Information flows through a signaling pathway by sequential interactions between core components of the pathway, many of which have enzymatic activity. Adaptor proteins do not directly participate in relaying the signal and do not have enzymatic activity, but are important for signaling because they facilitate interactions between the core components. Using quantitative methods, Shi et al demonstrated that core components of the EGFR pathway were highly abundant in both normal cells and cancer cells. However, adaptor proteins were present in much lower abundance in both cell types, indicating that it is the abundance of these proteins that limit signaling downstream of EGFR. The authors also found that differences in EGFR signaling between different cell types likely resulted from the variable abundance of feedback regulators.Listen to Podcast. PMID:27405978

  14. The adaptor molecule CARD9 is essential for tuberculosis control

    OpenAIRE

    Dorhoi, Anca; Desel, Christiane; Yeremeev, Vladimir; Pradl, Lydia; Brinkmann, Volker; Mollenkopf, Hans J; Hanke, Karin; Gross, Olaf; Ruland, Jürgen; Stefan H. E. Kaufmann

    2010-01-01

    The cross talk between host and pathogen starts with recognition of bacterial signatures through pattern recognition receptors (PRRs), which mobilize downstream signaling cascades. We investigated the role of the cytosolic adaptor caspase recruitment domain family, member 9 (CARD9) in tuberculosis. This adaptor was critical for full activation of innate immunity by converging signals downstream of multiple PRRs. Card9(-/-) mice succumbed early after aerosol infection, with higher mycobacteria...

  15. 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.

  16. Floral ontogeny of Cneorum tricoccon L. (Rutaceae)

    NARCIS (Netherlands)

    Caris, P.; Smets, E.; De Coster, K.; Ronse De Craene, L.

    2006-01-01

    The floral ontogeny of the Spurge olive (Cneorum tricoccon L.) is studied by means of scanning electron microscopic observations. Special attention is paid to the sequence of initiation of the floral parts, the occurrence of septal cavities, and the development of the nectariferous tissue. The necta

  17. Versatile modes of peptide recognition by the AAA+ adaptor protein SspB

    Energy Technology Data Exchange (ETDEWEB)

    Levchenko, Igor; Grant, Robert A.; Flynn, Julia M.; Sauer, Robert T.; Baker, Tania A. (MIT)

    2010-07-19

    Energy-dependent proteases often rely on adaptor proteins to modulate substrate recognition. The SspB adaptor binds peptide sequences in the stress-response regulator RseA and in ssrA-tagged proteins and delivers these molecules to the AAA+ ClpXP protease for degradation. The structure of SspB bound to an ssrA peptide is known. Here, we report the crystal structure of a complex between SspB and its recognition peptide in RseA. Notably, the RseA sequence is positioned in the peptide-binding groove of SspB in a direction opposite to the ssrA peptide, the two peptides share only one common interaction with the adaptor, and the RseA interaction site is substantially larger than the overlapping ssrA site. This marked diversity in SspB recognition of different target proteins indicates that it is capable of highly flexible and dynamic substrate delivery.

  18. Selective autophagy of non-ubiquitylated targets in plants: looking for cognate receptor/adaptor proteins

    Directory of Open Access Journals (Sweden)

    Vasko eVeljanovski

    2014-06-01

    Full Text Available Cellular homeostasis is essential for the physiology of eukaryotic cells. Eukaryotic cells, including plant cells, utilize two main pathways to adjust the level of cytoplasmic components, namely the proteasomal and the lysosomal/vacuolar pathways. Macroautophagy is a lysosomal/vacuolar pathway which, until recently, was thought to be non-specific and a bulk degradation process. However, selective autophagy which can be activated in the cell under various physiological conditions, involves the specific degradation of defined macromolecules or organelles by a conserved molecular mechanism. For this process to be efficient, the mechanisms underlying the recognition and selection of the cargo to be engulfed by the double-membrane autophagosome are critical, and not yet well understood. Ubiquitin (poly-ubiquitin conjugation to the target appears to be a conserved ligand mechanism in many types of selective autophagy, and defined receptors/adaptors recognizing and regulating the autophagosomal capture of the ubiquitylated target have been characterized. However, non-proteinaceous and non-ubiquitylated cargoes are also selectively degraded by this pathway. This ubiquitin-independent selective autophagic pathway also involves receptor and/or adaptor proteins linking the cargo to the autophagic machinery. Some of these receptor/adaptor proteins including accessory autophagy-related (Atg and non-Atg proteins have been described in yeast and animal cells but not yet in plants. In this review we discuss the ubiquitin-independent cargo selection mechanisms in selective autophagy degradation of organelles and macromolecules and speculate on potential plant receptor/adaptor proteins.

  19. Patterning and evolution of floral structures - marking time.

    Science.gov (United States)

    McKim, Sarah; Hay, Angela

    2010-08-01

    The diversity of flowering structures dazzles the eye, dominates the landscape, and invites evolutionary questions regarding the development of such variety. Comparative work in a number of genetically tractable plant species has addressed how diverse floral architectures develop, and started to reveal the balance between conservation and divergence of the patterning mechanisms responsible for when and where flowers form on a plant. We highlight findings from Petunia where conserved LFY/UFO function is under species-specific regulation, and a novel mechanism involving WOX homeodomain proteins for modulating cyme development in diverse nightshades. We also draw attention to recent findings in Arabidopsis of miRNA and chromatin-based timing mechanisms controlling floral development, and illustrate how genetic studies in Arabidopsis relatives can reveal how evolutionary changes in such mechanisms generate diversity in form. PMID:20452201

  20. Mint3/X11γ Is an ADP-Ribosylation Factor-dependent Adaptor that Regulates the Traffic of the Alzheimer's Precursor Protein from the Trans-Golgi Network

    OpenAIRE

    Shrivastava-Ranjan, Punya; Faundez, Victor; Fang, Guofu; Rees, Howard; Lah, James J.; Allan I Levey; Kahn, Richard A.

    2008-01-01

    β-Amyloid peptides (Aβ) are the major component of plaques in brains of Alzheimer's patients, and are they derived from the proteolytic processing of the β-amyloid precursor protein (APP). The movement of APP between organelles is highly regulated, and it is tightly connected to its processing by secretases. We proposed previously that transport of APP within the cell is mediated in part through its sorting into Mint/X11-containing carriers. To test our hypothesis, we purified APP-containing ...

  1. 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.

  2. Spatiotemporal Floral Scent Variation of Penstemon digitalis.

    Science.gov (United States)

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

    2015-07-01

    Variability in floral volatile emissions can occur temporally through floral development, during diel cycles, as well as spatially within a flower. These spatiotemporal patterns are hypothesized to provide additional information to floral visitors, but they are rarely measured, and their attendant hypotheses are even more rarely tested. In Penstemon digitalis, a plant whose floral scent has been shown to be under strong phenotypic selection for seed fitness, we investigated spatiotemporal variation in floral scent by using dynamic headspace collection, respectively solid-phase microextraction, and analyzed the volatile samples by combined gas chromatography-mass spectrometry. Total volatile emission was greatest during flowering and peak pollinator activity hours, suggesting its importance in mediating ecological interactions. We also detected tissue and reward-specific compounds, consistent with the hypothesis that complexity in floral scent composition reflects several ecological functions. In particular, we found tissue-specific scents for the stigma, stamens, and staminode (a modified sterile stamen common to all Penstemons). Our findings emphasize the dynamic nature of floral scents and highlight a need for greater understanding of ecological and physiological mechanisms driving spatiotemporal patterns in scent production. PMID:26133675

  3. 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.

  4. Fenología floral y visitantes florales en drimys granadensis (winteraceae)

    OpenAIRE

    Lara Katherine; Sarmiento Rodrigo; Marquínez-Casas Xavier

    2009-01-01

    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 de...

  5. Negative Group Velocity and Spin-Flip in Microwave Adaptors

    CERN Document Server

    Carot, Alexander; Nimtz, Guenter

    2012-01-01

    A Fabry-Perot like interferometer with two microwaveguide adaptors as reflectors creates a passive dielectric medium with a negative group delay time due to polarization shift. A rotational strain of the polarization vector by one of the adaptors is coupled with a drastic negative group velocity. The adapted rectangular and circular waveguides have the same dispersion. The input rectangular waveguide mode is linearly polarized, whereas the basic mode of the adapted circular waveguide is circularly polarized. A 667 wavelengths long circular waveguide connects the input with the output adaptor. Experiments are performed in the frequency and in the time domain. We describe, how the helical polarization change and the spin-flip of the two different circular wave modes produce the observed negative group velocity.

  6. Optimized Adaptor Polymerase Chain Reaction Method for Efficient Genomic Walking

    Institute of Scientific and Technical Information of China (English)

    Peng XU; Rui-Ying HU; Xiao-Yan DING

    2006-01-01

    Genomic walking is one of the most useful approaches in genome-related research. Three kinds of PCR-based methods are available for this purpose. However, none of them has been generally applied because they are either insensitive or inefficient. Here we present an efficient PCR protocol, an optimized adaptor PCR method for genomic walking. Using a combination of a touchdown PCR program and a special adaptor, the optimized adaptor PCR protocol achieves high sensitivity with low background noise. By applying this protocol, the insertion sites of a gene trap mouse line and two gene promoters from the incompletely sequenced Xenopus laevis genome were successfully identified with high efficiency. The general application of this protocol in genomic walking was promising.

  7. Multimodal floral signals and moth foraging decisions.

    Directory of Open Access Journals (Sweden)

    Jeffrey A Riffell

    Full Text Available 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

  8. Anti-adaptors use distinct modes of binding to inhibit the RssB-dependent turnover of RpoS (σS by ClpXP.

    Directory of Open Access Journals (Sweden)

    Dimce eMicevski

    2015-04-01

    Full Text Available In Escherichia coli, σS is the master regulator of the general stress response. The level of σS changes in response to multiple stress conditions and it is regulated at many levels including protein turnover. In the absence of stress, σS is rapidly degraded by the AAA+ protease, ClpXP in a regulated manner that depends on the adaptor protein RssB. This two-component response regulator mediates the recognition of σS and its delivery to ClpXP. The turnover of σS however, can be inhibited in a stress specific manner, by one of three anti-adaptor proteins. Each anti-adaptor binds to RssB and inhibits its activity, but how this is achieved is not fully understood at a molecular level. Here we describe details of the interaction between each anti-adaptor and RssB that leads to the stabilization of σS. By defining the domains of RssB using partial proteolysis we demonstrate that each anti-adaptor uses a distinct mode of binding to inhibit RssB activity. IraD docks specifically to the N-terminal domain of RssB, IraP interacts primarily with the C-terminal domain, while IraM interacts with both domains. Despite these differences in binding, we propose that docking of each anti-adaptor induces a conformational change in RssB, which resembles the inactive dimer of RssB. This dimer-like state of RssB not only prevents substrate binding but also triggers substrate release from a pre-bound complex.

  9. The Clathrin Adaptor AP-1A Mediates Basolateral Polarity

    OpenAIRE

    Gravotta, Diego; Carvajal-Gonzalez, Jose Maria; Mattera, Rafael; Deborde, Sylvie; Banfelder, Jason R.; Bonifacino, Juan S.; Rodriguez-Boulan, Enrique

    2012-01-01

    Clathrin and the epithelial-specific clathrin adaptor AP-1B mediate basolateral trafficking in epithelia. However, several epithelia lack AP-1B and mice knocked-out for AP-1B are viable, suggesting the existence of additional mechanisms that control basolateral polarity. Here, we demonstrate a distinct role of the ubiquitous clathrin adaptor AP-1A in basolateral protein sorting. Knock-down of AP-1A causes missorting of basolateral proteins in MDCK cells but only after knock-down of AP-1B, sug...

  10. 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. PMID:19082619

  11. 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.

  12. DMPD: Adaptor usage and Toll-like receptor signaling specificity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15876435 Adaptor usage and Toll-like receptor signaling specificity. Dunne A, O'Nei...sage and Toll-like receptor signaling specificity. PubmedID 15876435 Title Adaptor usage and Toll-like receptor signaling specific

  13. Cytosol- and clathrin-dependent stimulation of endocytosis in vitro by purified adaptors

    OpenAIRE

    1992-01-01

    Using stage-specific assays for receptor-mediated endocytosis of transferrin (Tfn) into perforated A431 cells we show that purified adaptors stimulate coated pit assembly and ligand sequestration into deeply invaginated coated pits. Late events in endocytosis involving membrane fission and coated vesicle budding which lead to the internalization of Tfn are unaffected. AP2, plasma membrane adaptors, are active at physiological concentrations, whereas AP1, Golgi adaptors, are inactive. Adaptor-...

  14. Cell cycle-dependent adaptor complex for ClpXP-mediated proteolysis directly integrates phosphorylation and second messenger signals.

    Science.gov (United States)

    Smith, Stephen C; Joshi, Kamal K; Zik, Justin J; Trinh, Katherine; Kamajaya, Aron; Chien, Peter; Ryan, Kathleen R

    2014-09-30

    The cell-division cycle of Caulobacter crescentus depends on periodic activation and deactivation of the essential response regulator CtrA. Although CtrA is critical for transcription during some parts of the cell cycle, its activity must be eliminated before chromosome replication because CtrA also blocks the initiation of DNA replication. CtrA activity is down-regulated both by dephosphorylation and by proteolysis, mediated by the ubiquitous ATP-dependent protease ClpXP. Here we demonstrate that proteins needed for rapid CtrA proteolysis in vivo form a phosphorylation-dependent and cyclic diguanylate (cdG)-dependent adaptor complex that accelerates CtrA degradation in vitro by ClpXP. The adaptor complex includes CpdR, a single-domain response regulator; PopA, a cdG-binding protein; and RcdA, a protein whose activity cannot be predicted. When CpdR is unphosphorylated and when PopA is bound to cdG, they work together with RcdA in an all-or-none manner to reduce the Km of CtrA proteolysis 10-fold. We further identified a set of amino acids in the receiver domain of CtrA that modulate its adaptor-mediated degradation in vitro and in vivo. Complex formation between PopA and CtrA depends on these amino acids, which reside on alpha-helix 1 of the CtrA receiver domain, and on cdG binding by PopA. These results reveal that each accessory factor plays an essential biochemical role in the regulated proteolysis of CtrA and demonstrate, to our knowledge, the first example of a multiprotein, cdG-dependent proteolytic adaptor.

  15. 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 remain. Fo

  16. The endocytic adaptor Eps15 controls marginal zone B cell numbers.

    Directory of Open Access Journals (Sweden)

    Benedetta Pozzi

    Full Text Available Eps15 is an endocytic adaptor protein involved in clathrin and non-clathrin mediated endocytosis. In Caenorhabditis elegans and Drosophila melanogaster lack of Eps15 leads to defects in synaptic vesicle recycling and synapse formation. We generated Eps15-KO mice to investigate its function in mammals. Eps15-KO mice are born at the expected Mendelian ratio and are fertile. Using a large-scale phenotype screen covering more than 300 parameters correlated to human disease, we found that Eps15-KO mice did not show any sign of disease or neural deficits. Instead, altered blood parameters pointed to an immunological defect. By competitive bone marrow transplantation we demonstrated that Eps15-KO hematopoietic precursor cells were more efficient than the WT counterparts in repopulating B220⁺ bone marrow cells, CD19⁻ thymocytes and splenic marginal zone (MZ B cells. Eps15-KO mice showed a 2-fold increase in MZ B cell numbers when compared with controls. Using reverse bone marrow transplantation, we found that Eps15 regulates MZ B cell numbers in a cell autonomous manner. FACS analysis showed that although MZ B cells were increased in Eps15-KO mice, transitional and pre-MZ B cell numbers were unaffected. The increase in MZ B cell numbers in Eps15 KO mice was not dependent on altered BCR signaling or Notch activity. In conclusion, in mammals, the endocytic adaptor protein Eps15 is a regulator of B-cell lymphopoiesis.

  17. Exploring potential new floral organ morphogenesis genes of Arabidopsis thaliana using systems biology approach.

    Science.gov (United States)

    Xie, Wenchuan; Huang, Junfeng; Liu, Yang; Rao, Jianan; Luo, Da; He, Miao

    2015-01-01

    Flowering is one of the important defining features of angiosperms. The initiation of flower development and the formation of different floral organs are the results of the interplays among numerous genes. But until now, just fewer genes have been found linked with flower development. And the functions of lots of genes of Arabidopsis thaliana are still unknown. Although, the quartet model successfully simplified the ABCDE model to elaborate the molecular mechanism by introducing protein-protein interactions (PPIs). We still don't know much about several important aspects of flower development. So we need to discriminate even more genes involving in the flower development. In this study, we identified seven differentially modules through integrating the weighted gene co-expression network analysis (WGCNA) and Support Vector Machine (SVM) method to analyze co-expression network and PPIs using the public floral and non-floral expression profiles data of Arabidopsis thaliana. Gene set enrichment analysis was used for the functional annotation of the related genes, and some of the hub genes were identified in each module. The potential floral organ morphogenesis genes of two significant modules were integrated with PPI information in order to detail the inherent regulation mechanisms. Finally, the functions of the floral patterning genes were elucidated by combining the PPI and evolutionary information. It was indicated that the sub-networks or complexes, rather than the genes, were the regulation unit of flower development. We found that the most possible potential new genes underlining the floral pattern formation in A. thaliana were FY, CBL2, ZFN3, and AT1G77370; among them, FY, CBL2 acted as an upstream regulator of AP2; ZFN3 activated the flower primordial determining gene AP1 and AP2 by HY5/HYH gene via photo induction possibly. And AT1G77370 exhibited similar function in floral morphogenesis, same as ELF3. It possibly formed a complex between RFC3 and RPS15 in

  18. Exploring potential new floral organ morphogenesis genes of Arabidopsis thaliana using systems biology approach

    Directory of Open Access Journals (Sweden)

    Wenchuan eXie

    2015-10-01

    Full Text Available Flowering is one of the important defining features of angiosperms. The initiation of flower development and the formation of different floral organs are the results of the interplays among numerous genes. But until now, just fewer genes have been found linked with flower development. And the functions of lots of genes of Arabidopsis thaliana are still unknown. Although, the quartet model successfully simplified the ABCDE model to elaborate the molecular mechanism by introducing protein-protein interactions (PPIs. We still don't know much about several important aspects of flower development. So we need to discriminate even more genes involving in the flower development. In this study, we identified seven differentially modules through integrating the weighted gene co-expression network analysis (WGCNA and Support Vector Machine (SVM method to analyze co-expression network and PPIs using the public floral and non-floral expression profiles data of Arabidopsis thaliana. Gene set enrichment analysis was used for the functional annotation of the related genes, and some of the hub genes were identified in each module. The potential floral organ morphogenesis genes of two significant modules were integrated with PPI information in order to detail the inherent regulation mechanisms. Finally, the functions of the floral patterning genes were elucidated by combining the PPI and evolutionary information. It was indicated that the sub-networks or complexes, rather than the genes, were the regulation unit of flower development. We found that the most possible potential new genes underlining the floral pattern formation in A. thaliana were FY, CBL2, ZFN3 and AT1G77370; among them, FY, CBL2 acted as an upstream regulator of AP2; ZFN3 activated the flower primordial determining gene AP1 and AP2 by HY5/HYH gene via photo induction possibly. And AT1G77370 exhibited similar function in floral morphogenesis, same as ELF3. It possibly formed a complex between RFC3

  19. Structural basis for the interaction of the adaptor protein grb14 with activated ras.

    Directory of Open Access Journals (Sweden)

    Rohini Qamra

    Full Text Available Grb14, a member of the Grb7-10-14 family of cytoplasmic adaptor proteins, is a tissue-specific negative regulator of insulin signaling. Grb7-10-14 contain several signaling modules, including a Ras-associating (RA domain, a pleckstrin-homology (PH domain, a family-specific BPS (between PH and SH2 region, and a C-terminal Src-homology-2 (SH2 domain. We showed previously that the RA and PH domains, along with the BPS region and SH2 domain, are necessary for downregulation of insulin signaling. Here, we report the crystal structure at 2.4-Å resolution of the Grb14 RA and PH domains in complex with GTP-loaded H-Ras (G12V. The structure reveals that the Grb14 RA and PH domains form an integrated structural unit capable of binding simultaneously to small GTPases and phosphoinositide lipids. The overall mode of binding of the Grb14 RA domain to activated H-Ras is similar to that of the RA domains of RalGDS and Raf1 but with important distinctions. The integrated RA-PH structural unit in Grb7-10-14 is also found in a second adaptor family that includes Rap1-interacting adaptor molecule (RIAM and lamellipodin, proteins involved in actin-cytoskeleton rearrangement. The structure of Grb14 RA-PH in complex with H-Ras represents the first detailed molecular characterization of tandem RA-PH domains bound to a small GTPase and provides insights into the molecular basis for specificity.

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

    Energy Technology Data Exchange (ETDEWEB)

    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. 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.

  2. Floral organogenesis of Delavaya toxocarpa (Sapindaceae; Sapindales)

    Institute of Scientific and Technical Information of China (English)

    Li-Min CAO; Nian-He XIA

    2009-01-01

    The floral organogenesis and development of Delavaya toxocarpa Franch. (Sapindaceae) were studied under scanning electron microscope and light microscope to determine its systematic position within Sapindaceae. Flowers arise in terminal thyrses. The sepal primordia initiate in a spiral (2/5) sequence, which are not synchronous. The five petal primordia initiate almost synchronously and alternate with sepal primordia. Eight stamens initiate almost simultaneously and their differentiation precedes that of the petals. The last formed petal and one stamen initiate from a common primordium. Mature stamens curve inwards and cover the ovary in bud. The gynoecium begins as a hemispheric primordium on which two carpellary lobes arise simultaneously. Later in development a single gynocium is formed with two locules and two ovules per locule. Floral morphology suggests a closer affinity with Sapindaceae, although certain features of floral ontogenesis are similar to those observed in certain members of the former Hippocastanaceae, such as Handeliodendron.

  3. 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.

  4. 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.

  5. 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. PMID:27288534

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

    Directory of Open Access Journals (Sweden)

    Hua Liu

    Full Text Available 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

  7. 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.

  8. Functional analyses of a flavonol synthase - like gene from Camellia nitidissima reveal its roles in flavonoid metabolism during floral pigmentation

    Indian Academy of Sciences (India)

    Xing-Wen Zhou; Zheng-Qi Fan; Yue Chen; Yu-Lin Zhu; Ji-Yuan Li; Heng-Fu Yin

    2013-09-01

    The flavonoids metabolic pathway plays central roles in floral coloration, in which anthocyanins and flavonols are derived from common precursors, dihydroflavonols. Flavonol synthase (FLS) catalyses dihydroflavonols into flavonols, which presents a key branch of anthocyanins biosynthesis. The yellow flower of Camellia nitidissima Chi. is a unique feature within the genus Camellia, which makes it a precious resource for breeding yellow camellia varieties. In this work, we characterized the secondary metabolites of pigments during floral development of C. nitidissima and revealed that accumulation of flavonols correlates with floral coloration. We first isolated CnFLS1 and showed that it is a FLS of C. nitidissima by gene family analysis. Second, expression analysis during floral development and different floral organs indicated that the expression level of CnFLS1 was regulated by developmental cues, which was in agreement with the accumulating pattern of flavonols. Furthermore, over-expression of CnFLS1 in Nicotiana tabacum altered floral colour into white or light yellow, and metabolic analysis showed significant increasing of flavonols and reducing of anthocyanins in transgenic plants. Our work suggested CnFLS1 plays critical roles in yellow colour pigmentation and is potentially a key point of genetic engineering toward colour modification in Camellia.

  9. 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. PMID:26654856

  10. Diversity of floral visitors to sympatric Lithophragma species differing in floral morphology

    OpenAIRE

    Cuautle, Mariana; Thompson, John N

    2010-01-01

    Most coevolving relationships between pairs of species are embedded in a broader multispecific interaction network. The mutualistic interaction between Lithophragma parviflorum (Saxifragaceae) and its pollinating floral parasite Greya politella (Lepidoptera, Prodoxidae) occurs in some communities as a pairwise set apart from most other interactions in those communities. In other communities, however, this pair of species occurs with congeners and with other floral visitors to Lithophragma. We...

  11. Induced floral heteromorphism in Petunia hybrida

    Directory of Open Access Journals (Sweden)

    S. G. Kashikar

    2014-02-01

    Full Text Available Floral heteromorphism induced in Petunia hybrida with several chemical mutagens and gamma-radiation is discussed. Potentials of these mutagens in inducing various forms are described. The effect of heteromorphism on flower production, pollen sterility and seed set besides cross and self compatibilities between different heteromorphic forms have also been reported.

  12. Differential association of the Na+/H+ exchanger regulatory factor (NHERF) family of adaptor proteins with the raft- and the non-raft brush border membrane fractions of NHE3

    NARCIS (Netherlands)

    A. Sultan (Ayesha); M. Luo (Ma); Q. Yu (Qingbao); B. Riederer (Beat Michel); W. Xia (Weiliang); M. Chen (Mingmin); S. Lissner (Simone); J.E. Gessner (Johannes); M. Donowitz (Mark); C. Chris Yun (C.); H. deJonge (Hugo); G. Lamprecht (Georg); U. Seidler (Ursula)

    2013-01-01

    textabstractBackground/Aims: Trafficking, brush border membrane (BBM) retention, and signal-specific regulation of the Na+/H+ exchanger NHE3 is regulated by the Na+/H+ Exchanger Regulatory Factor (NHERF) family of PDZ-adaptor proteins, which enable the formation of multiprotein complexes. It is uncl

  13. 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

  14. 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. PMID:24376756

  15. 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.

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    Lara Katherine

    2009-12-01

    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.

  18. Contributions of iridescence to floral patterning.

    Science.gov (United States)

    Whitney, Heather M; Kolle, Mathias; Alvarez-Fernandez, Ruben; Steiner, Ullrich; Glover, Beverley J

    2009-05-01

    The Hibiscus trionum flower is distinctly patterned, with white petals each with a patch of red pigment at the base, producing a 'bulls-eye' pattern on the whole flower. The red pigmented patches are also iridescent, due to the presence of a series of overlying cuticular striations that act as a diffraction grating. We have previously reported that scanning electron microscopy revealed a sharply defined difference between the surface structure overlying the pigmented patch and that over the rest of the petal, with the diffraction grating only present over the pigmented region. Here we show that differences in petal surface structure overlie differences in pigment color in three other species, in a range of different patterns. Floral patterns have previously been shown to be advantageous in pollinator attraction, and we discuss whether emphasis of pigment patterns by structural color may increase floral recognition by pollinators. PMID:19641739

  19. Unique and conserved features of floral evocation in legumes

    Institute of Scientific and Technical Information of China (English)

    Lim Chee Liew; Mohan B.Singh; Prem L.Bhalla

    2014-01-01

    Legumes, with their unique ability to fix atmo-spheric nitrogen, play a vital role in ensuring future food security and mitigating the effects of climate change because they use less fossil energy and produce less greenhouse gases compared with N-fertilized systems. Grain legumes are second only to cereal crops as a source of human and animal food, and they contribute approximately one third of the protein consumed by the human population. The productivity of seed crops, such as grain legumes, is dependent on flowering. Despite the genetic variation and importance of flowering in legume production, studies of the molecular pathways that control flowering in legumes are limited. Recent advances in genomics have revealed that legume flowering pathways are divergent from those of such model species as Arabidopsis thaliana. Here, we discuss the current understanding of flowering time regulation in legumes and highlight the unique and conserved features of floral evocation in legumes.

  20. Floral volatiles play a key role in specialized ant pollination

    OpenAIRE

    Vega, Clara de; Carlos M Herrera; Dötterl, Stefan

    2014-01-01

    Chemical signals emitted by plants are crucial to understand the ecology and evolution of plant–animal interactions. Scent is an important component of floral phenotype and represents a decisive communication channel between plants and floral visitors. Floral volatiles promote attraction of mutualistic pollinators and, in some cases, serve to prevent flower visitation by antagonists such as ants. Despite ant visits to flowers have been suggested to be detrimental to plant fitness, in recent y...

  1. Diesel exhaust rapidly degrades floral odours used by honeybees

    OpenAIRE

    Girling, Robbie D.; Inka Lusebrink; Emily Farthing; Newman, Tracey A.; Poppy, Guy M.

    2013-01-01

    Honeybees utilise floral odours when foraging for flowers; we investigated whether diesel exhaust pollution could interrupt these floral odour stimuli. A synthetic blend of eight floral chemicals, identified from oilseed rape, was exposed to diesel exhaust pollution. Within one minute of exposure the abundances of four of the chemicals were significantly lowered, with two components rendered undetectable. Honeybees were trained to recognise the full synthetic odour mix; altering the blend, by...

  2. Behavioural ecology: bees associate warmth with floral colour.

    Science.gov (United States)

    Dyer, Adrian G; Whitney, Heather M; Arnold, Sarah E J; Glover, Beverley J; Chittka, Lars

    2006-08-01

    Floral colour signals are used by pollinators as predictors of nutritional rewards, such as nectar. But as insect pollinators often need to invest energy to maintain their body temperature above the ambient temperature, floral heat might also be perceived as a reward. Here we show that bumblebees (Bombus terrestris) prefer to visit warmer flowers and that they can learn to use colour to predict floral temperature before landing. In what could be a widespread floral adaptation, plants may modulate their temperature to encourage pollinators to visit.

  3. Histone acetylation accompanied with promoter sequences displaying differential expression profiles of B-class MADS-box genes for phalaenopsis floral morphogenesis.

    Directory of Open Access Journals (Sweden)

    Chia-Chi Hsu

    Full Text Available Five B-class MADS-box genes, including four APETALA3 (AP3-like PeMADS2∼5 and one PISTILLATA (PI-like PeMADS6, specify the spectacular flower morphology in orchids. The PI-like PeMADS6 ubiquitously expresses in all floral organs. The four AP3-like genes, resulted from two duplication events, express ubiquitously at floral primordia and early floral organ stages, but show distinct expression profiles at late floral organ primordia and floral bud stages. Here, we isolated the upstream sequences of PeMADS2∼6 and studied the regulatory mechanism for their distinct gene expression. Phylogenetic footprinting analysis of the 1.3-kb upstream sequences of AP3-like PeMADS2∼5 showed that their promoter regions have sufficiently diverged and contributed to their subfunctionalization. The amplified promoter sequences of PeMADS2∼6 could drive beta-glucuronidase (GUS gene expression in all floral organs, similar to their expression at the floral primordia stage. The promoter sequence of PeMADS4, exclusively expressed in lip and column, showed a 1.6∼3-fold higher expression in lip/column than in sepal/petal. Furthermore, we noted a 4.9-fold increase in histone acetylation (H3K9K14ac in the translation start region of PeMADS4 in lip as compared in petal. All these results suggest that the regulation via the upstream sequences and increased H3K9K14ac level may act synergistically to display distinct expression profiles of the AP3-like genes at late floral organ primordia stage for Phalaenopsis floral morphogenesis.

  4. DMPD: Signalling adaptors used by Toll-like receptors: an update. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18706831 Signalling adaptors used by Toll-like receptors: an update. Kenny EF, O'Ne...tors used by Toll-like receptors: an update. PubmedID 18706831 Title Signalling adaptors used by Toll-like receptors: an update

  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. Floral biology of candeia (Eremanthus erythropappus, Asteraceae)

    Biologia floral da candeia (Eremanthus erythropappus, Asteraceae)

    OpenAIRE

    Fábio de Almeida Vieira; Cristiane Gouvêa Fajardo; Dulcinéia de Carvalho

    2012-01-01

    Floral biology and pollinators of candeia (Eremanthus erythropappus) were analyzed in a natural population. We studied anthesis, flower morphology, stigmatic receptivity, pollen viability and floral visitors. The small flowers (10.17 mm in length) are pink, hermaphrodites and organized in dense capitula (mean = 29 flowers). We observed a large percentage of viable pollen (77.25%) and relatively scarce nectar availability for floral visitors (0.63 μL). The bees Apis mellifera and Trigona sp. w...

  7. The adaptedness of the floral phenotype in a relict endemic, hawkmoth-pollinated violet. 1. Reproductive correlates of floral variation

    OpenAIRE

    Herrera, Carlos M.

    1990-01-01

    This paper examines the relationship between quantitative variation in floral morphology (sizes of petals, spur and peduncle) and maternal reproductive success (seed production) in Viola cazorlensic (Violaceae), a narrowly endemic violet of south-eastern Spain pollinated by day-flying hawkmoths (Sphingidae). This plant is characterized by broad intraspecific variation in size and proportions of floral parts. Floral morphology does not influence significantly the probability of fruit set. Amon...

  8. Structure of the periplasmic adaptor protein from a major facilitator superfamily (MFS) multidrug efflux pump.

    Science.gov (United States)

    Hinchliffe, Philip; Greene, Nicholas P; Paterson, Neil G; Crow, Allister; Hughes, Colin; Koronakis, Vassilis

    2014-08-25

    Periplasmic adaptor proteins are key components of bacterial tripartite efflux pumps. The 2.85 Å resolution structure of an MFS (major facilitator superfamily) pump adaptor, Aquifex aeolicus EmrA, shows linearly arranged α-helical coiled-coil, lipoyl, and β-barrel domains, but lacks the fourth membrane-proximal domain shown in other pumps to interact with the inner membrane transporter. The adaptor α-hairpin, which binds outer membrane TolC, is exceptionally long at 127 Å, and the β-barrel contains a conserved disordered loop. The structure extends the view of adaptors as flexible, modular components that mediate diverse pump assembly, and suggests that in MFS tripartite pumps a hexamer of adaptors could provide a periplasmic seal. PMID:24996185

  9. 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.

  10. DMPD: TIR domain-containing adaptors define the specificity of TLR signaling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14698224 TIR domain-containing adaptors define the specificity of TLR signaling. Ya...in-containing adaptors define the specificity of TLR signaling. PubmedID 14698224 Title TIR domain-containing adaptors define the spe...cificity of TLR signaling. Authors Yamamoto M, Takeda K,

  11. Novel and conserved microRNAs in soybean floral whorls.

    Science.gov (United States)

    Kulcheski, F R; Molina, L G; da Fonseca, G C; de Morais, G L; de Oliveira, L F V; Margis, R

    2016-01-10

    MicroRNAs (miRNAs) correspond to a class of endogenous small non-coding RNAs (19-24 nt) that regulates the gene expression, through mRNA target cleavage or translation inhibition. In plants, miRNAs have been shown to play pivotal roles in a wide variety of metabolic and biological processes like plant growth, development, and response to biotic and abiotic stress. Soybean is one of the most important crops worldwide, due to the production of oil and its high protein content. The reproductive phase is considered the most important for soybean yield, which is mainly intended to produce the grains. The identification of miRNAs is not yet saturated in soybean, and there are no studies linking them to the different floral organs. In this study, three different mature soybean floral whorls were used in the construction of sRNA libraries. The sequencing of petal, carpel and stamen libraries generated a total of 10,165,661 sequences. Subsequent analyses identified 200 miRNAs sequences, among which, 41 were novel miRNAs, 80 were conserved soybean miRNAs, 31 were new antisense conserved soybean miRNAs and 46 were soybean miRNAs isoforms. We also found a new miRNA conserved in other plant species, and finally one miRNA-sibling of a soybean conserved miRNA. Conserved and novel miRNAs were evaluated by RT-qPCR. We observed a differential expression across the three whorls for six miRNAs. Computational predicted targets for miRNAs analyzed by RT-qPCR were identified and present functions related to reproductive process in plants. In summary, the increased accumulation of specific and novel miRNAs in different whorls indicates that miRNAs are an important part of the regulatory network in soybean flower.

  12. Air pollutants degrade floral scents and increase insect foraging times

    Science.gov (United States)

    Fuentes, Jose D.; Chamecki, Marcelo; Roulston, T.'ai; Chen, Bicheng; Pratt, Kenneth R.

    2016-09-01

    Flowers emit mixtures of scents that mediate plant-insect interactions such as attracting insect pollinators. Because of their volatile nature, however, floral scents readily react with ozone, nitrate radical, and hydroxyl radical. The result of such reactions is the degradation and the chemical modification of scent plumes downwind of floral sources. Large Eddy Simulations (LES) are developed to investigate dispersion and chemical degradation and modification of floral scents due to reactions with ozone, hydroxyl radical, and nitrate radical within the atmospheric surface layer. Impacts on foraging insects are investigated by utilizing a random walk model to simulate insect search behavior. Results indicate that even moderate air pollutant levels (e.g., ozone mixing ratios greater than 60 parts per billion on a per volume basis, ppbv) substantially degrade floral volatiles and alter the chemical composition of released floral scents. As a result, insect success rates of locating plumes of floral scents were reduced and foraging times increased in polluted air masses due to considerable degradation and changes in the composition of floral scents. Results also indicate that plant-pollinator interactions could be sensitive to changes in floral scent composition, especially if insects are unable to adapt to the modified scentscape. The increase in foraging time could have severe cascading and pernicious impacts on the fitness of foraging insects by reducing the time devoted to other necessary tasks.

  13. Ozone degrades floral scent and reduces pollinator attraction to flowers.

    Science.gov (United States)

    Farré-Armengol, Gerard; Peñuelas, Josep; Li, Tao; Yli-Pirilä, Pasi; Filella, Iolanda; Llusia, Joan; Blande, James D

    2016-01-01

    In this work we analyzed the degradation of floral scent volatiles from Brassica nigra by reaction with ozone along a distance gradient and the consequences for pollinator attraction. For this purpose we used a reaction system comprising three reaction tubes in which we conducted measurements of floral volatiles using a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) and GC-MS. We also tested the effects of floral scent degradation on the responses of the generalist pollinator Bombus terrestris. The chemical analyses revealed that supplementing air with ozone led to an increasing reduction in the concentrations of floral volatiles in air with distance from the volatile source. The results revealed different reactivities with ozone for different floral scent constituents, which emphasized that ozone exposure not only degrades floral scents, but also changes the ratios of compounds in a scent blend. Behavioural tests revealed that floral scent was reduced in its attractiveness to pollinators after it had been exposed to 120 ppb O3 over a 4.5 m distance. The combined results of chemical analyses and behavioural responses of pollinators strongly suggest that high ozone concentrations have significant negative impacts on pollination by reducing the distance over which floral olfactory signals can be detected by pollinators. PMID:26346807

  14. Nickel accumulation by Streptanthus polygaloides (Brassicaceae) reduces floral visitation rate.

    Science.gov (United States)

    Meindl, George A; Ashman, Tia-Lynn

    2014-02-01

    Hyperaccumulation is the phenomenon whereby plants take up and sequester in high concentrations elements that generally are excluded from above-ground tissues. It largely is unknown whether the metals taken up by these plants are transferred to floral rewards (i.e., nectar and pollen) and, if so, whether floral visitation is affected. We grew Streptanthus polygaloides, a nickel (Ni) hyperaccumulator, in short-term Ni supplemented soils and control soils to determine whether Ni is accumulated in floral rewards and whether floral visitation is affected by growth in Ni-rich soils. We found that while supplementation of soils with Ni did not alter floral morphology or reward quantity (i.e., anther size or nectar volume), Ni did accumulate in the nectar and pollen-filled anthers-providing the first demonstration that Ni is accumulated in pollinator rewards. Further, S. polygaloides grown in Ni-supplemented soils received fewer visits per flower per hour from both bees and flies (both naïve to Ni-rich floral resources in the study area) relative to plants grown in control soils, although the probability a plant was visited initially was unaffected by Ni treatment. Our findings show that while Ni-rich floral rewards decrease floral visitation, floral visitors are not completely deterred, so some floral visitors may collect and ingest potentially toxic resources from metal-hyperaccumulating plants. In addition to broadening our understanding of the effects of metal accumulation on ecological interactions in natural populations, these results have implications for the use of insect-pollinated plants in phytoremediation. PMID:24477333

  15. Does the relative importance of resource competition and architectural effect in floral variation vary with stages of floral ontogeny?

    Institute of Scientific and Technical Information of China (English)

    Chang-Qiu LIU; Shuang-Quan HUANG

    2012-01-01

    Variation in floral allocation within inflorescences has been attributed to resource competition and/or architectural effect.The two hypotheses were extensively studied and both hypotheses were partly supported by previous studies.However,the relative importance of resource competition and architectural effect may vary with stages of floral ontogeny in a species.To detect the effects ofontogenetic stages on floral variation,we manipulated the 6-flowered inflorescences ofAdenophorajasionifolia (Campanulaceae) by early,late,and non-thinning flowers.Our results indicated that pollen and ovule production of the remaining flowers were not significantly different between early and late thinning manipulations,suggesting that floral sex allocation was determined far before flowering,in support of the architectural effect hypothesis.Under hand-pollination treatments,early thinning but not late thinning resulted in a significant increase in seed number and seed set of the remaining flowers.Therefore,the increase in seed production of the remaining flowers related to the floral ontogeny.The resource competition for floral allocation was significant under early thinning rather than late thinning manipulation.Our results suggest that studies on floral variation within inflorescences should take into account the stages of floral ontogeny.

  16. Structure of the periplasmic adaptor protein from a major facilitator superfamily (MFS) multidrug efflux pump

    OpenAIRE

    Hinchliffe, Philip; Greene, Nicholas P.; Paterson, Neil G.; Crow, Allister; Hughes, Colin; Koronakis, Vassilis

    2014-01-01

    Periplasmic adaptor proteins are key components of bacterial tripartite efflux pumps. The 2.85 Å resolution structure of an MFS (major facilitator superfamily) pump adaptor, Aquifex aeolicus EmrA, shows linearly arranged α-helical coiled-coil, lipoyl, and β-barrel domains, but lacks the fourth membrane-proximal domain shown in other pumps to interact with the inner membrane transporter. The adaptor α-hairpin, which binds outer membrane TolC, is exceptionally long at 127 Å, and the β-barrel co...

  17. 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.

  18. 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.

  19. 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.

  20. Biologia floral de Virola surinamensis (Rol.) Warb. (Myristicaceae) Virola surinamensis (Rol.) Warb. (Myristicaceae) floral biology

    OpenAIRE

    Mario Augusto Gonçalves Jardim; Cléo Gomes da Mota

    2007-01-01

    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 aparecim...

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

    Science.gov (United States)

    Cane, James H

    2011-09-01

    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 floral traits can yield mixed reproductive outcomes among pollinator-dependent species. In these cases, floral constancy by polyleges sometimes serves as an ethological mating barrier. More often, their foraging infidelities instead facilitate host introgression and hybridization. Many other bee species are oligolectic (taxonomic specialists for pollen). Oligoleges could be more discriminating connoisseurs than polyleges when foraging among their limited set of related floral hosts. If true, greater foraging constancy might ensue, contributing to positive assortative mating and disruptive selection, thereby facilitating speciation among their interfertile floral hosts. To test this Connoisseur Hypothesis, nesting females of two species of oligolectic Osmia bees were presented with randomized mixed arrays of flowers of two sympatric species of their pollen host, Balsamorhiza, a genus known for hybridization. In a closely spaced grid, the females of both species preferred the larger flowered B. macrophylla, evidence for discrimination. However, both species' females showed no floral constancy whatsoever during their individual foraging bouts, switching randomly between species proportional to their floral preference. In a wider spaced array in which the bouquets reflected natural plant spacing, foraging oligolectic bees often transferred pollen surrogates (fluorescent powders) both between conspecific flowers (geitonogamy and xenogamy) and between the two Balsamorhiza species. The Connoisseur Hypothesis was therefore rejected. Foraging infidelity by these oligolectic Osmia bees will contribute to

  2. 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...

  3. Non-Additive Effects of Genotypic Diversity Increase Floral Abundance and Abundance of Floral Visitors

    OpenAIRE

    Mark A Genung; Jean-Philippe Lessard; Claire B Brown; Bunn, Windy A.; Cregger, Melissa A.; W M Nicholas Reynolds; Emmi Felker-Quinn; Stevenson, Mary L.; Hartley, Amanda S.; Gregory M. Crutsinger; Schweitzer, Jennifer A.; Bailey, Joseph K.

    2010-01-01

    BACKGROUND: In the emerging field of community and ecosystem genetics, genetic variation and diversity in dominant plant species have been shown to play fundamental roles in maintaining biodiversity and ecosystem function. However, the importance of intraspecific genetic variation and diversity to floral abundance and pollinator visitation has received little attention. METHODOLOGY/PRINCIPAL FINDINGS: Using an experimental common garden that manipulated genotypic diversity (the number of dist...

  4. The role of SEUSS in auxin response and floral organ patterning.

    Science.gov (United States)

    Pfluger, Jennifer; Zambryski, Patricia

    2004-10-01

    Genetic and physiological analyses implicate auxin flux in patterning, initiation and growth of floral organs. Within the Arabidopsis flower, the ETTIN/ARF3 transcription factor responds to auxin to effect perianth organ number and reproductive organ differentiation. This work describes a modifier of ettin that causes filamentous, mispositioned outer whorl organs and reduced numbers of malformed stamens in the double mutant. The modifier was discovered to be a new allele of the seuss (seu) mutant. SEU encodes a novel protein that is predicted to transcriptionally co-repress the AGAMOUS floral organ identity gene. The effects of seu on ett are shown to be independent of the SEU-AG pathway. Furthermore, morphological, physiological and genetic evidence implicate SEU in auxin-regulated growth and development. seu has a pleiotropic phenotype that includes reductions in several classic auxin responses such as apical dominance, lateral root initiation, sensitivity to exogenous auxin and activation of the DR5 auxin response reporter. seu displays a synergistic interaction with the auxin response mutant pinoid, producing flowers with few outer whorl organs. Collectively, these data suggest that SEU is a novel factor affecting auxin response. A model is proposed in which SEU functions jointly with ETT in auxin response to promote floral organ patterning and growth.

  5. Increasing the efficiency of SAGE adaptor ligation by directed ligation chemistry

    Science.gov (United States)

    So, Austin P.; Turner, Robin F. B.; Haynes, Charles A.

    2004-01-01

    The ability of Serial Analysis of Gene Expression (SAGE) to provide a quantitative picture of global gene expression relies not only on the depth and accuracy of sequencing into the SAGE library, but also on the efficiency of each step required to generate the SAGE library from the starting mRNA material. The first critical step is the ligation of adaptors containing a Type IIS recognition sequence to the anchored 3′ end cDNA population that permits the release of short sequence tags (SSTs) from defined sites within the 3′ end of each transcript. Using an in vitro transcript as a template, we observed that only a small fraction of anchored 3′ end cDNA are successfully ligated with added SAGE adaptors under typical reaction conditions currently used in the SAGE protocol. Although the introduction of ∼500-fold molar excess of adaptor or the inclusion of 15% (w/v) PEG-8000 increased the yield of the adaptor-modified product, complete conversion to the desired adaptor:cDNA hetero-ligation product is not achieved. An alternative method of ligation, termed as directed ligation, is described which exploits a favourable mass-action condition created by the presence of NlaIII during ligation in combination with a novel SAGE adaptor containing a methylated base within the ligation site. Using this strategy, we were able to achieve near complete conversion of the anchored 3′ end cDNA into the desired adaptor-modified product. This new protocol therefore greatly increases the probability that a SST will be generated from every transcript, greatly enhancing the fidelity of SAGE. Directed ligation also provides a powerful means to achieve near-complete ligation of any appropriately designed adaptor to its respective target. PMID:15247329

  6. Autumn floral inventory : Walnut Creek National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is an autumn floral inventory conducted on Neal Smith National Wildlife Refuge formerly Walnut Creek National Wildlife Refuge in 1991.

  7. New functions for secondary compounds in floral nectar

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Floral nectar, which is mainly composed of sugar, plays a major role in attracting pollinators. However, many studies show that most of the nectar also contains antiherbivore secondary compounds, such as phenolics, which could keep away some flower visitors.

  8. 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.

  9. Floral sesquiterpenes and their synthesis in dioecious kiwifruit

    OpenAIRE

    Nieuwenhuizen, Niels J.; Green, Sol; Atkinson, Ross G.

    2010-01-01

    Kiwifruit species are vigorously growing dioecious vines that rely on bees and other insects for pollen transfer between spatially separated male and female individuals. Floral volatile terpene cues for insect pollinator attraction were characterized from flowers of the most widely grown and economically important kiwifruit cultivar Actinidia deliciosa ‘Hayward’ and its male pollinator ‘Chieftain’. The sesquiterpenes α-farnesene and germacrene D dominated in all floral tissues and the emissio...

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

    OpenAIRE

    Campbell, DR; Powers, JM

    2015-01-01

    © 2015 Royal Society of London. All rights reserved. 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 hawkmo...

  11. Three-dimensional geometric morphometrics for studying floral shape variation

    OpenAIRE

    Van der Niet, T; Zollikofer, C P E; Ponce de León, M S; Johnson, S D; H. P. Linder

    2010-01-01

    Variation in floral shape is of major interest to evolutionary and pollination biologists, plant systematists and developmental geneticists. Quantifying this variation has been difficult due to the three-dimensional (3D) complexity of angiosperm flowers. By combining 3D geometric representations of flowers obtained by micro-computed tomography scanning with geometric morphometric methods, well established in zoology and anthropology, floral shape variation can be analyzed quantitatively, allo...

  12. Floral isolation between Aquilegia formosa and Aquilegia pubescens

    OpenAIRE

    Fulton, M; Hodges, S. A.

    1999-01-01

    The acquisition of floral nectar spurs is correlated with increased species diversity across multiple clades. We tested whether variation in nectar spurs influences reproductive isolation and, thus, can potentially promote species diversity using two species of Aquilegia, Aquilegia formosa and Aquilegia pubescens, which form narrow hybrid zones. Floral visitors strongly discriminated between the two species both in natural populations and at mixed-species arrays of individual flowers. Bees an...

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

    OpenAIRE

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

    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...

  14. Surfactant Protein A Enhances Constitutive Immune Functions of Clathrin Heavy Chain and Clathrin Adaptor Protein 2.

    Science.gov (United States)

    Moulakakis, Christina; Steinhäuser, Christine; Biedziak, Dominika; Freundt, Katja; Reiling, Norbert; Stamme, Cordula

    2016-07-01

    NF-κB transcription factors are key regulators of pulmonary inflammatory disorders and repair. Constitutive lung cell type- and microenvironment-specific NF-κB/inhibitor κBα (IκB-α) regulation, however, is poorly understood. Surfactant protein (SP)-A provides both a critical homeostatic and lung defense control, in part by immune instruction of alveolar macrophages (AMs) via clathrin-mediated endocytosis. The central endocytic proteins, clathrin heavy chain (CHC) and the clathrin adaptor protein (AP) complex AP2, have pivotal alternative roles in cellular homeostasis that are endocytosis independent. Here, we dissect endocytic from alternative functions of CHC, the α-subunit of AP2, and dynamin in basal and SP-A-modified LPS signaling of macrophages. As revealed by pharmacological inhibition and RNA interference in primary AMs and RAW264.7 macrophages, respectively, CHC and α-adaptin, but not dynamin, prevent IκB-α degradation and TNF-α release, independent of their canonical role in membrane trafficking. Kinetics studies employing confocal microscopy, Western analysis, and immunomagnetic sorting revealed that SP-A transiently enhances the basal protein expression of CHC and α-adaptin, depending on early activation of protein kinase CK2 (former casein kinase II) and Akt1 in primary AMs from rats, SP-A(+/+), and SP-A(-/-) mice, as well as in vivo when intratracheally administered to SP-A(+/+) mice. Constitutive immunomodulation by SP-A, but not SP-A-mediated inhibition of LPS-induced NF-κB activity and TNF-α release, requires CHC, α-adaptin, and dynamin. Our data demonstrate that endocytic proteins constitutively restrict NF-κB activity in macrophages and provide evidence that SP-A enhances the immune regulatory capacity of these proteins, revealing a previously unknown pathway of microenvironment-specific NF-κB regulation in the lung. PMID:26771574

  15. The AP-3 adaptor complex is required for vacuolar function in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Maria Zwiewka; Elena Feraru; Barbara M(o)ller; Inhwan Hwang; Mugurel I Feraru; Jürgen Kleine-Vehn; Dolf Weijers; Ji(n) Friml

    2011-01-01

    Subcellular trafficking is required for a multitude of functions in eukaryotic cells.It involves regulation of cargo sorting,vesicle formation,trafficking and fusion processes at multiple levels.Adaptor protein (AP) complexes are key regulators of cargo sorting into vesicles in yeast and mammals but their existence and function in plants have not been demonstrated.Here we report the identification of the protein-affected trafficking 4 (pat4) mutant defective in the putative δ subunit of the AP-3 complex.pat4 and pat2,a mutant isolated from the same GFP imaging-based forward genetic screen that lacks a functional putative AP-3 β,as well as dominant negative AP-3 μ transgenic lines display undistinguishable phenotypes characterized by largely normal morphology and development,but strong intracellular accumulation of membrane proteins in aberrant vacuolar structures.All mutants are defective in morphology and function of lytic and protein storage vacuoles (PSVs) but show normal sorting of reserve proteins to PSVs.Immunoprecipitation experiments and genetic studies revealed tight functional and physical associations of putative AP-3 β and AP-3 δ subunits.Furthermore,both proteins are closely linked with putative AP-3 μ and σ subunits and several components of the clathrin and dynamin machineries.Taken together,these results demonstrate that AP complexes,similar to those in other eukaryotes,exist in plants,and that AP-3 plays a specific role in the regulation of biogenesis and function of vacuoles in plant cells.

  16. Pollination ecology and breeding system of Xylopia championii (Annonaceae): curculionid beetle pollination, promoted by floral scents and elevated floral temperatures

    OpenAIRE

    Saunders, RMK; Ratnayake, RMCS; Gunatilleke, IAUN; Wijesundara, DSA

    2007-01-01

    Data on the reproductive biology of the Annonaceae are rather fragmentary, particularly for paleotropical species. The pollination ecology and breeding system of the Sri Lankan endemic Xylopia championii (Annonaceae) are described in detail. The pollination ecology was investigated using a diverse range of approaches, including (1) observations of flower-level and population-level phenology, (2) assessments of floral visitors and effective pollinators, (3) monitoring of floral temperature in ...

  17. 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

  18. Ascent Heating Thermal Analysis on Spacecraft Adaptor Fairings

    Science.gov (United States)

    Wang, Xiao Yen; Yuko, James; Motil, Brian

    2011-01-01

    When the Crew Exploration Vehicle (CEV) is launched, the spacecraft adaptor (SA) fairings that cover the CEV service module (SM) are exposed to aero heating. Thermal analysis is performed to compute the fairing temperatures and to investigate whether the temperatures are within the material limits for nominal ascent aeroheating case. The ascent heating is analyzed by using computational fluid dynamics (CFD) and engineering codes at Marshall Space Flight Center. The aeroheating environment data used for this work is known as Thermal Environment 3 (TE3) heating data. One of the major concerns is with the SA fairings covering the CEV SM and the SM/crew launch vehicle (CLV) flange interface. The TE3 heating rate is a function of time, wall temperature, and the spatial locations. The implementation of the TE3 heating rate as boundary conditions in the thermal analysis becomes challenging. The ascent heating thermal analysis on SA fairings and SM/CLV flange interface are performed using two commercial software packages: Cullimore & Ring (C&R) Thermal Desktop (TD) 5.1 and MSC Patran 2007r1 b. TD is the pre-and post-processor for SINDA, which is a finite-difference-based solver. In TD, the geometry is built and meshed, the boundary conditions are defined, and then SINDA is used to compute temperatures. MSC Pthermal is a finite-element- based thermal solver. MSC Patran is the pre- and post-processor for Pthermal. Regarding the boundary conditions, the convection, contact resistance, and heat load can be imposed in different ways in both programs. These two software packages are used to build the thermal model for the same analysis to validate each other and show the differences in the modeling details.

  19. Floral adaptation and diversification under pollen limitation.

    Science.gov (United States)

    Harder, Lawrence D; Aizen, Marcelo A

    2010-02-12

    Pollen limitation (PL) of seed production creates unique conditions for reproductive adaptation by angiosperms, in part because, unlike under ovule or resource limitation, floral interactions with pollen vectors can contribute to variation in female success. Although the ecological and conservation consequences of PL have received considerable attention in recent times, its evolutionary implications are poorly appreciated. To identify general influences of PL on reproductive adaptation compared with those under other seed-production limits and their implications for evolution in altered environments, we derive a model that incorporates pollination and post-pollination aspects of PL. Because PL always favours increased ovule fertilization, even when population dynamics are not seed limited, it should pervasively influence selection on reproductive traits. Significantly, under PL the intensity of inbreeding does not determine whether outcrossing or autonomous selfing can evolve, although it can affect which response is most likely. Because the causes of PL are multifaceted in both natural and anthropogenically altered environments, the possible outcrossing solutions are diverse and context dependent, which may contribute to the extensive variety of angiosperm reproductive characteristics. Finally, the increased adaptive options available under PL may be responsible for positive global associations between it and angiosperm diversity. PMID:20047878

  20. A novel allele of FILAMENTOUS FLOWER reveals new insights on the link between inflorescence and floral meristem organization and flower morphogenesis

    Directory of Open Access Journals (Sweden)

    Bochnik Rachel

    2010-06-01

    Full Text Available Abstract Background The Arabidopsis FILAMENTOUS FLOWER (FIL gene encodes a YABBY (YAB family putative transcription factor that has been implicated in specifying abaxial cell identities and thus regulating organ polarity of lateral organs. In contrast to double mutants of fil and other YAB genes, fil single mutants display mainly floral and inflorescence morphological defects that do not reflect merely a loss of abaxial identity. Recently, FIL and other YABs have been shown to regulate meristem organization in a non-cell-autonomous manner. In a screen for new mutations affecting floral organ morphology and development, we have identified a novel allele of FIL, fil-9 and characterized its floral and meristem phenotypes. Results The fil-9 mutation results in highly variable disruptions in floral organ numbers and size, partial homeotic transformations, and in defective inflorescence organization. Examination of meristems indicates that both fil-9 inflorescence and floral meristems are enlarged as a result of an increase in cell number, and deformed. Furthermore, primordia emergence from these meristems is disrupted such that several primordia arise simultaneously instead of sequentially. Many of the organs produced by the inflorescence meristems are filamentous, yet they are not considered by the plant as flowers. The severity of both floral organs and meristem phenotypes is increased acropetally and in higher growth temperature. Conclusions Detailed analysis following the development of fil-9 inflorescence and flowers throughout flower development enabled the drawing of a causal link between multiple traits of fil-9 phenotypes. The study reinforces the suggested role of FIL in meristem organization. The loss of spatial and temporal organization of fil-9 inflorescence and floral meristems presumably leads to disrupted cell allocation to developing floral organs and to a blurring of organ whorl boundaries. This disruption is reflected in

  1. Non-additive effects of genotypic diversity increase floral abundance and abundance of floral visitors.

    Directory of Open Access Journals (Sweden)

    Mark A Genung

    Full Text Available BACKGROUND: In the emerging field of community and ecosystem genetics, genetic variation and diversity in dominant plant species have been shown to play fundamental roles in maintaining biodiversity and ecosystem function. However, the importance of intraspecific genetic variation and diversity to floral abundance and pollinator visitation has received little attention. METHODOLOGY/PRINCIPAL FINDINGS: Using an experimental common garden that manipulated genotypic diversity (the number of distinct genotypes per plot of Solidago altissima, we document that genotypic diversity of a dominant plant can indirectly influence flower visitor abundance. Across two years, we found that 1 plant genotype explained 45% and 92% of the variation in flower visitor abundance in 2007 and 2008, respectively; and 2 plant genotypic diversity had a positive and non-additive effect on floral abundance and the abundance of flower visitors, as plots established with multiple genotypes produced 25% more flowers and received 45% more flower visits than would be expected under an additive model. CONCLUSIONS/SIGNIFICANCE: These results provide evidence that declines in genotypic diversity may be an important but little considered factor for understanding plant-pollinator dynamics, with implications for the global decline in pollinators due to reduced plant diversity in both agricultural and natural ecosystems.

  2. Integrative effect of drought and low temperature on litchi (Litchi chinensis Sonn.) floral initiation revealed by dynamic genome-wide transcriptome analysis.

    Science.gov (United States)

    Shen, Jiyuan; Xiao, Qiusheng; Qiu, Haiji; Chen, Chengjie; Chen, Houbin

    2016-01-01

    Floral induction in litchi is influenced by multiple environment cues including temperature and soil water condition. In the present study, we determined that a combined treatment consisting of 14-day drought imposed prior to exposure to 35-day low temperature (T3) significantly promoted litchi flowering relative to the low temperature alone (T2), suggesting an integrative effect of drought and low temperature on litchi floral initiation. Analysis of transcriptomic changes in leaves from different treatments showed that 2,198 and 4,407 unigenes were differentially expressed in response to drought and low temperature, respectively. 1,227 of these unigenes were expressed in response to both treatments, implying an interaction of drought and low temperature on expression of genes involved in litchi floral initiation. Additionally, 932 unigenes were consistently differentially expressed during floral induction between T2 and T3 plants, which potentially accounts for the difference of flowering time. Thirty-eight transcription factors out of these 932 unigenes were identified as hub genes with central roles in regulation of litchi floral induction. The expression of litchi homologs of well-known flowering genes was also investigated, and one Flowering Locus T (FT) homolog may play a crucial role in litchi flowering in responses to drought and low temperature. PMID:27557749

  3. 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.

  4. Floral nectar guide patterns discourage nectar robbing by bumble bees.

    Directory of Open Access Journals (Sweden)

    Anne S Leonard

    Full Text Available Floral displays are under selection to both attract pollinators and deter antagonists. Here we show that a common floral trait, a nectar guide pattern, alters the behavior of bees that can act opportunistically as both pollinators and as antagonists. Generally, bees access nectar via the floral limb, transporting pollen through contact with the plant's reproductive structures; however bees sometimes extract nectar from a hole in the side of the flower that they or other floral visitors create. This behavior is called "nectar robbing" because bees may acquire the nectar without transporting pollen. We asked whether the presence of a symmetric floral nectar guide pattern on artificial flowers affected bumble bees' (Bombus impatiens propensity to rob or access nectar "legitimately." We discovered that nectar guides made legitimate visits more efficient for bees than robbing, and increased the relative frequency of legitimate visits, compared to flowers lacking nectar guides. This study is the first to show that beyond speeding nectar discovery, a nectar guide pattern can influence bees' flower handling in a way that could benefit the plant.

  5. Fuel combustion test in constant volume combustion chamber with built-in adaptor

    Institute of Scientific and Technical Information of China (English)

    JEONG; DongSoo; CHO; GyuBack; CHOI; SuJin; LEE; JinSoo

    2010-01-01

    Combustion tests of pre-mixture of methane and air in constant volume combustion chamber(CVCC) have been carried out by means of flame propagation photo and gas pressure measurement,the effects of CVCC body temperature,intake pressure of pre-mixture of methane and air,equivalence ratio and location of the built-in adaptor have been investigated.The whole combustion chamber can be divided into two parts,i.e.the upper combustion chamber and the lower combustion chamber,by the built-in adaptor with through hole.Owing to the built-in adaptor with through hole,jet ignition or compression ignition(auto-ignition) phenomena may occur in the lower combustion chamber,which is helpful to getting higher flame propagation velocity,higher combustion peak pressure,low cycle-to-cycle variation and more stable combustion process.

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

    Directory of Open Access Journals (Sweden)

    AMAYA MARISOL

    2009-08-01

    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

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

    International Nuclear Information System (INIS)

    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

  8. Understanding the Effects of Floral Density on Flower Visitation Rates and Species Composition of Flower Visitors

    OpenAIRE

    Essenberg, Carla Jean

    2012-01-01

    Pollinator responses to varying floral density have important implications for plant population dynamics, conservation, and the evolution of floral traits. Floral density can influence both flower visitation rates and the species composition of flower visitors, but neither of these effects is well understood. In my dissertation, I generate and test hypotheses explaining the relations of flower visitation rate and flower visitor species composition to floral density.In the first chapter, I p...

  9. Flowering phenology, floral traits and pollinator composition in a herbaceous Mediterranean plant community

    OpenAIRE

    Bosch, Jordi; Retana, Javier; CERDÁ, XIM

    1997-01-01

    The relationships between flowering plants and their insect visitors were studied in a Mediterranean grassland in north-east Spain. Floral traits (size, shape, symmetry, and colour), floral rewards (pollen and nectar), flowering period, and floral visitors were recorded for the 17 most abundant plants in the community. Flowering was year-round, but most species flowered in spring. The three species that flowered after spring had small flowers, but the distribution of floral features (includin...

  10. Plant regeneration and floral bud formation from intact floral parts of African violet (Saintpaulia ionantha H. Wendl.) cultured in vitro.

    Science.gov (United States)

    Daud, N; Taha, R M

    2008-04-01

    Intact immature flower buds of African violet (Saintpaulia ionantha H. Wendl.) were used as explant sources for in vitro studies. The effect of exogenous hormones, NAA and BAP on the indirect organogenesis of this species was observed. Callus was formed on the cut end (base) of pedicels of floral buds where they were in contact with the medium. When maintained on the same medium, callus was differentiated into adventitious shoots after 10 weeks in culture. MS media supplemented with 2.0 mg L(-1) NAA and 1.0 mg L(-1) BAP gave the highest number of sterile or vegetative floral buds from the surface of callus of the explants, but these buds failed to develop further. The floral buds were expanded as abnormal flowers. The floral structures were smaller in size compared to intact flowers. Petals (corolla) were white to purple in colour but did not form any reproductive organs, i.e., stamens or pistils. All sterile or vegetative floral buds and abnormal flowers survived for 3 months in culture but failed to reach anthesis. PMID:18810979

  11. Floral Ontogeny of Two Species in Magnolia L.

    Institute of Scientific and Technical Information of China (English)

    Feng-Xia Xu

    2006-01-01

    Floral ontogeny is described in two species of genus Magnolia (Magnoliaceae), Magnolia albosericea Chun et C. Tsoong, and M. amoena Cheng, representing subgenus Magnolia and subgenus Yulania in Magnolia, by using scanning electron microscope (SEM). The sequence of initiation of floral organs is from proximal to distal. The three distinct outermost and middle organs are initiated in sequence, but ultimately form a single whorl, thus their ontogeny is consistent with a sepal interpretation. The last three tepals (petals) alternate with the preceding tepal whorl. The members of androecium and gynoecium arise spirally,although the androecium shows some intermedlacy between a spiral and whorled arrangement. The carpel primordia initiate in group of four to five. The order of stamen initiation within each tier is not determined.The floral ontogeny is remarkably homogeneous between the subgenus Magnolia and subgenus Yulania that does not support the resuming of genus Yulania.

  12. The Toll-Like receptor adaptor TRIF contributes to otitis media pathogenesis and recovery

    Directory of Open Access Journals (Sweden)

    Pak Kwang

    2009-08-01

    Full Text Available Abstract Background Toll-like receptor (TLR signalling is crucial for innate immune responses to infection. The involvement of TLRs in otitis media (OM, the most prevalent childhood disease in developed countries, has been implicated by studies in middle ear cell lines, by association studies of TLR-related gene polymorphisms, and by altered OM in mice bearing mutations in TLR genes. Activated TLRs signal via two alternative intracellular signaling molecules with differing effects; MyD88 (Myeloid differentiation primary response gene 88 inducing primarily interleukin expression and TRIF (Tir-domain-containing adaptor inducing interferon β mediating type I interferon (IFN expression. We tested the hypothesis that TRIF and type I IFN signaling play a role in OM, using a murine model of OM induced by non-typeable Haemophilus influenzae (NTHi. The ME inflammatory response to NTHi was examined in wild-type (WT and TRIF-/- mice by qPCR, gene microarray, histopathology and bacterial culture. Results Expression of TRIF mRNA was only modesty enhanced during OM, but both type I IFN signalling genes and type I IFN-inducible genes were significantly up-regulated in WT mice. TRIF-deficient mice showed reduced but more persistent mucosal hyperplasia and less leukocyte infiltration into the ME in response to NTHi infection than did WT animals. Viable bacteria could be cultured from MEs of TRIF-/- mice for much longer in the course of disease than was the case for middle ears of WT mice. Conclusion Our results demonstrate that activation of TRIF/type I IFN responses is important in both the pathogenesis and resolution of NTHi-induced OM.

  13. 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.

  14. Floral colour change as a potential signal to pollinators.

    Science.gov (United States)

    Ruxton, Graeme D; Schaefer, H Martin

    2016-08-01

    Colour change in flowers (with age and/or after pollination) is taxonomically widespread, has evolved repeatedly, and has a range of putative selective benefits linked to modifying pollinator behaviour; however, this phenomenon seems paradoxically uncommon. We explore this paradox by reviewing the empirical evidence and argue that the evolution and maintenance of floral colour change as a signal to modify pollinator behaviour require special ecological circumstances that will often not be met across a plant population for a sustained number of generations, which potentially explains the scarcity of this phenomenon. We discuss alternative explanations for floral colour change and potentially fruitful lines of future research. PMID:27428780

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

    Institute of Scientific and Technical Information of China (English)

    Yulan; KUANG; Qifang; LI; Wangyun; NING

    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 faster development of Yunnan floral e-commerce.

  16. The pleiotropic ABNORMAL FLOWER AND DWARF1 affects plant height, floral development and grain yield in rice

    Institute of Scientific and Technical Information of China (English)

    Deyong Ren; Li Zhu; Zhenyu Gao; Guojun Dong; Guangheng Zhang; Longbiao Guo; Dali Zeng; and Qian Qian; Yuchun Rao; Liwen Wu; Qiankun Xu; Zizhuang Li; Haiping Yu; Yu Zhang; Yujia Leng; Jiang Hu

    2016-01-01

    Moderate plant height and successful establish-ment of reproductive organs play pivotal roles in rice grain production. The molecular mechanism that controls the two aspects remains unclear in rice. In the present study, we characterized a rice gene, ABNORMAL FLOWER AND DWARF1 (AFD1) that determined plant height, floral development and grain yield. The afd1 mutant showed variable defects including the dwarfism, long panicle, low seed setting and reduced grain yield. In addition, abnormal floral organs were also observed in the afd1 mutant including slender and thick hulls, and hull-like lodicules. AFD1 encoded a DUF640 domain protein and was ex-pressed in all tested tissues and organs. Subcellular localization showed AFD1-green fluorescent fusion protein (GFP) was localized in the nucleus. Meantime, our results suggested that AFD1 regulated the expression of cell division and expansion related genes.

  17. The pleiotropic ABNORMAL FLOWER AND DWARF1 affects plant height, floral development and grain yield in rice

    Science.gov (United States)

    Ren, Deyong; Rao, Yuchun; Wu, Liwen; Xu, Qiankun; Li, Zizhuang; Yu, Haiping; Zhang, Yu; Leng, Yujia; Hu, Jiang; Zhu, Li; Gao, Zhenyu; Dong, Guojun; Zhang, Guangheng; Guo, Longbiao

    2016-01-01

    Abstract Moderate plant height and successful establishment of reproductive organs play pivotal roles in rice grain production. The molecular mechanism that controls the two aspects remains unclear in rice. In the present study, we characterized a rice gene, ABNORMAL FLOWER AND DWARF1 (AFD1) that determined plant height, floral development and grain yield. The afd1 mutant showed variable defects including the dwarfism, long panicle, low seed setting and reduced grain yield. In addition, abnormal floral organs were also observed in the afd1 mutant including slender and thick hulls, and hull‐like lodicules. AFD1 encoded a DUF640 domain protein and was expressed in all tested tissues and organs. Subcellular localization showed AFD1‐green fluorescent fusion protein (GFP) was localized in the nucleus. Meantime, our results suggested that AFD1 regulated the expression of cell division and expansion related genes. PMID:26486996

  18. Floral Benzenoid Carboxyl Methyltransferases: From in Vitro to in Planta Function

    Energy Technology Data Exchange (ETDEWEB)

    Effmert,U.; Saschenbrecker, S.; Ross, J.; Negre, F.; Fraser, C.; Noel, J.; Dudareva, N.; Piechulla, B.

    2005-01-01

    Benzenoid carboxyl methyltransferases synthesize methyl esters (e.g., methyl benzoate and methyl salicylate), which are constituents of aromas and scents of many plant species and play important roles in plant communication with the surrounding environment. Within the past five years, eleven such carboxyl methyltransferases were isolated and most of them were comprehensively investigated at the biochemical, molecular and structural level. Two types of enzymes can be distinguished according to their substrate preferences: the SAMT-type enzymes isolated from Clarkia breweri, Stephanotis floribunda, Antirrhinum majus, Hoya carnosa, and Petunia hybrida, which have a higher catalytic efficiency and preference for salicylic acid, while BAMT-type enzymes from A. majus, Arabidopsis thaliana, Arabidopsis lyrata, and Nicotiana suaveolens prefer benzoic acid. The elucidation of C. breweri SAMT's three-dimensional structure allowed a detailed modelling of the active sites of the carboxyl methyltransferases and revealed that the SAM binding pocket is highly conserved among these enzymes while the methyl acceptor binding site exhibits some variability, allowing a classification into SAMT-type and BAMT-type enzymes. The analysis of expression patterns coupled with biochemical characterization showed that these carboxyl methyltransferases are involved either in floral scent biosynthesis or in plant defense responses. While the latter can be induced by biotic or abiotic stress, the genes responsible for floral scent synthesis exhibit developmental and rhythmic expression pattern. The nature of the product and efficiency of its formation in plants depend on the availability of substrates, the catalytic efficiency of the enzyme toward benzoic acid and/or salicylic acid, and the transcriptional, translational, and post-translational regulation at the enzyme level. The biochemical properties of benzenoid carboxyl methyltransferases suggest that the genes involved in plant defenses

  19. Genetic architecture, biochemical underpinnings and ecological impact of floral UV patterning.

    Science.gov (United States)

    Brock, Marcus T; Lucas, Lauren K; Anderson, Nickolas A; Rubin, Matthew J; Markelz, R J Cody; Covington, Michael F; Devisetty, Upendra K; Chapple, Clint; Maloof, Julin N; Weinig, Cynthia

    2016-03-01

    Floral attraction traits can significantly affect pollinator visitation patterns, but adaptive evolution of these traits may be constrained by correlations with other traits. In some cases, molecular pathways contributing to floral attraction are well characterized, offering the opportunity to explore loci potentially underlying variation among individuals. Here, we quantify the range of variation in floral UV patterning (i.e. UV 'bulls-eye nectar guides) among crop and wild accessions of Brassica rapa. We then use experimental crosses to examine the genetic architecture, candidate loci and biochemical underpinnings of this patterning as well as phenotypic manipulations to test the ecological impact. We find qualitative variation in UV patterning between wild (commonly lacking UV patterns) and crop (commonly exhibiting UV patterns) accessions. Similar to the majority of crops, recombinant inbred lines (RILs) derived from an oilseed crop × WI fast-plant® cross exhibit UV patterns, the size of which varies extensively among genotypes. In RILs, we further observe strong statistical-genetic and QTL correlations within petal morphological traits and within measurements of petal UV patterning; however, correlations between morphology and UV patterning are weak or nonsignificant, suggesting that UV patterning is regulated and may evolve independently of overall petal size. HPLC analyses reveal a high concentration of sinapoyl glucose in UV-absorbing petal regions, which, in concert with physical locations of UV-trait QTLs, suggest a regulatory and structural gene as candidates underlying observed quantitative variation. Finally, insects prefer flowers with UV bulls-eye patterns over those that lack patterns, validating the importance of UV patterning in pollen-limited populations of B. rapa. PMID:26800256

  20. FENOLOGÍA FLORAL Y VISITANTES FLORALES EN Drimys granadensis L.f. (WINTERACEAE Floral Phenology And Flower Visitors In Drimys granadensis L.f. (Winteraceae

    Directory of Open Access Journals (Sweden)

    XAVIER MARQUINEZ

    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 (nombre común: canelo; Winteraceae ubicada en Altos de Yerbabuena ( 2.850 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 seis 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.The purpose of this research was to characterize the flowering phenological phases and to determine the flower visitors in a natural population of Drimys granadensis (common name: canelo; Winteraceae in Altos de Yerbabuena, eastern mountains of Sabana de Bogotá ( Colombia . Floral phenology development lasted 9.5 days when flowering occurred under sunny conditions, 12.5 days under rainy conditions and 16 days when flower visitors were excluded using cloth bags. It was done observations related with the resources used, the phenological phases of visited flowers and the pollen load on the flower visitors. Visitors corresponded with 29 morphospecies, 6 orders y 21 families of insects. Four species of coleoptera and two species of diptera were considered as possible pollinators taking in account abundance and pollen load. The results are analyzed in relation with those reported for other species in the genus Drimys and in the family Winteraceae.

  1. MEMORIA Y APRENDIZAJE EN LA ESCOGENCIA FLORAL DE LAS ABEJAS Memory And Learning In Bees' Floral Choices

    Directory of Open Access Journals (Sweden)

    MARISOL AMAYA MÁRQUEZ

    Full Text Available 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 ser m

  2. Floral biology and breeding system of three Ipomoea weeds Biologia floral e sistema reprodutivo de três espécies daninhas de Ipomoea

    OpenAIRE

    R.C.S Maimoni-Rodella; Y.A.N.P. Yanagizawa

    2007-01-01

    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 pro...

  3. Scaffold functions of 14-3-3 adaptors in B cell immunoglobulin class switch DNA recombination.

    Directory of Open Access Journals (Sweden)

    Tonika Lam

    Full Text Available Class switch DNA recombination (CSR of the immunoglobulin heavy chain (IgH locus crucially diversifies antibody biological effector functions. CSR involves the induction of activation-induced cytidine deaminase (AID expression and AID targeting to switch (S regions by 14-3-3 adaptors. 14-3-3 adaptors specifically bind to 5'-AGCT-3' repeats, which make up for the core of all IgH locus S regions. They selectively target the upstream and downstream S regions that are set to undergo S-S DNA recombination. We hypothesized that 14-3-3 adaptors function as scaffolds to stabilize CSR enzymatic elements on S regions. Here we demonstrate that all seven 14-3-3β, 14-3-3ε, 14-3-3γ, 14-3-3η, 14-3-3σ, 14-3-3τ and 14-3-3ζ adaptors directly interacted with AID, PKA-Cα (catalytic subunit and PKA-RIα (regulatory inhibitory subunit and uracil DNA glycosylase (Ung. 14-3-3 adaptors, however, did not interact with AID C-terminal truncation mutant AIDΔ(180-198 or AIDF193A and AIDL196A point-mutants (which have been shown not to bind to S region DNA and fail to mediate CSR. 14-3-3 adaptors colocalized with AID and replication protein A (RPA in B cells undergoing CSR. 14-3-3 and AID binding to S region DNA was disrupted by viral protein R (Vpr, an accessory protein of human immunodeficiency virus type-1 (HIV-1, which inhibited CSR without altering AID expression or germline IH-CH transcription. Accordingly, we demonstrated that 14-3-3 directly interact with Vpr, which in turn, also interact with AID, PKA-Cα and Ung. Altogether, our findings suggest that 14-3-3 adaptors play important scaffold functions and nucleate the assembly of multiple CSR factors on S regions. They also show that such assembly can be disrupted by a viral protein, thereby allowing us to hypothesize that small molecule compounds that specifically block 14-3-3 interactions with AID, PKA and/or Ung can be used to inhibit unwanted CSR.

  4. Scaffold functions of 14-3-3 adaptors in B cell immunoglobulin class switch DNA recombination.

    Science.gov (United States)

    Lam, Tonika; Thomas, Lisa M; White, Clayton A; Li, Guideng; Pone, Egest J; Xu, Zhenming; Casali, Paolo

    2013-01-01

    Class switch DNA recombination (CSR) of the immunoglobulin heavy chain (IgH) locus crucially diversifies antibody biological effector functions. CSR involves the induction of activation-induced cytidine deaminase (AID) expression and AID targeting to switch (S) regions by 14-3-3 adaptors. 14-3-3 adaptors specifically bind to 5'-AGCT-3' repeats, which make up for the core of all IgH locus S regions. They selectively target the upstream and downstream S regions that are set to undergo S-S DNA recombination. We hypothesized that 14-3-3 adaptors function as scaffolds to stabilize CSR enzymatic elements on S regions. Here we demonstrate that all seven 14-3-3β, 14-3-3ε, 14-3-3γ, 14-3-3η, 14-3-3σ, 14-3-3τ and 14-3-3ζ adaptors directly interacted with AID, PKA-Cα (catalytic subunit) and PKA-RIα (regulatory inhibitory subunit) and uracil DNA glycosylase (Ung). 14-3-3 adaptors, however, did not interact with AID C-terminal truncation mutant AIDΔ(180-198) or AIDF193A and AIDL196A point-mutants (which have been shown not to bind to S region DNA and fail to mediate CSR). 14-3-3 adaptors colocalized with AID and replication protein A (RPA) in B cells undergoing CSR. 14-3-3 and AID binding to S region DNA was disrupted by viral protein R (Vpr), an accessory protein of human immunodeficiency virus type-1 (HIV-1), which inhibited CSR without altering AID expression or germline IH-CH transcription. Accordingly, we demonstrated that 14-3-3 directly interact with Vpr, which in turn, also interact with AID, PKA-Cα and Ung. Altogether, our findings suggest that 14-3-3 adaptors play important scaffold functions and nucleate the assembly of multiple CSR factors on S regions. They also show that such assembly can be disrupted by a viral protein, thereby allowing us to hypothesize that small molecule compounds that specifically block 14-3-3 interactions with AID, PKA and/or Ung can be used to inhibit unwanted CSR.

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

    OpenAIRE

    Ivana de Freitas Barbola; Sebastião Laroca; Maria Christina de Almeida; Elynton Alves do Nascimento

    2006-01-01

    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 pol...

  6. Eugenol synthase genes in floral scent variation in Gymnadenia species.

    Science.gov (United States)

    Gupta, Alok K; Schauvinhold, Ines; Pichersky, Eran; Schiestl, Florian P

    2014-12-01

    Floral signaling, especially through floral scent, is often highly complex, and little is known about the molecular mechanisms and evolutionary causes of this complexity. In this study, we focused on the evolution of "floral scent genes" and the associated changes in their functions in three closely related orchid species of the genus Gymnadenia. We developed a benchmark repertoire of 2,571 expressed sequence tags (ESTs) in Gymnadenia odoratissima. For the functional characterization and evolutionary analysis, we focused on eugenol synthase, as eugenol is a widespread and important scent compound. We obtained complete coding complementary DNAs (cDNAs) of two copies of putative eugenol synthase genes in each of the three species. The proteins encoded by these cDNAs were characterized by expression and testing for activity in Escherichia coli. While G. odoratissima and Gymnadenia conopsea enzymes were found to catalyze the formation of eugenol only, the Gymnadenia densiflora proteins synthesize eugenol, as well as a smaller amount of isoeugenol. Finally, we showed that the eugenol and isoeugenol producing gene copies of G. densiflora are evolutionarily derived from the ancestral genes of the other species producing only eugenol. The evolutionary switch from production of one to two compounds evolved under relaxed purifying selection. In conclusion, our study shows the molecular bases of eugenol and isoeugenol production and suggests that an evolutionary transition in a single gene can lead to an increased complexity in floral scent emitted by plants.

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

    Indian Academy of Sciences (India)

    Prajakta V Belsare; Balasubramanian Sriram; Milind G Watve

    2009-12-01

    In most insect-pollinated flowers, pollinators cannot detect the presence of nectar without entering the flower. Therefore, flowers may cheat by not producing nectar and may still get pollinated. Earlier studies supported this ‘cheater flower’ hypothesis and suggested that the cost saving by cheater flowers could be the most predominant 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. One of the key questions that arises is whether the floral display will evolve to be an honest indicator of nectar reward. We use a mathematical model to cooptimize the investments in nectar and floral display in order to achieve maximum reproductive success. The model assumes that pollinators rely on a relative rather than an absolute judgement of reward. A conspicuous floral display attracts naïve pollinators on the one hand and enhances pollinator learning on the other. We show that under these assumptions, plant–pollinator co-evolution leads to honest signalling, i.e. a positive correlation between display and reward.

  8. Flies and Flowers II: Floral Attractants and Rewards

    Directory of Open Access Journals (Sweden)

    Thomas S. Woodcock

    2014-02-01

    Full Text Available This paper comprises Part II of a review of flower visitation and pollination by Diptera (myiophily or myophily. While Part I examined taxonomic diversity of anthophilous flies, here we consider the rewards and attractants used by flowers to procure visits by flies, and their importance in the lives of flies. Food rewards such as pollen and nectar are the primary reasons for flower visits, but there is also a diversity of non-nutritive rewards such as brood sites, shelter, and places of congregation. Floral attractants are the visual and chemical cues used by Diptera to locate flowers and the rewards that they offer, and we show how they act to increase the probability of floral visitation. Lastly, we discuss the various ways in which flowers manipulate the behaviour of flies, deceiving them to visit flowers that do not provide the advertised reward, and how some flies illegitimately remove floral rewards without causing pollination. Our review demonstrates that myiophily is a syndrome corresponding to elements of anatomical, behavioural and physiological adaptations of flower-visiting Diptera. The bewildering diversity of anthophilous Diptera and of the floral attractants and rewards to which they respond allows for only broad generalizations on myiophily and points to the need for more investigation. Ecological relationships between flies and flowers are critical to the survival of each group in many habitats. We require greater understanding of the significance of flies in pollination, especially in the face of recent pollinator declines.

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

    Science.gov (United States)

    Burkle, Laura A; Runyon, Justin B

    2016-04-01

    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 compounds (VOCs) and, in turn, plant-pollinator interactions. In this study, we experimentally manipulated drought and herbivory for four forb species to determine effects of these treatments and their interactions on (1) visual plant traits traditionally associated with pollinator attraction, (2) floral VOCs, and (3) the visitation rates and community composition of pollinators. For all forbs tested, experimental drought universally reduced flower size and floral display, but there were species-specific effects of drought on volatile emissions per flower, the composition of compounds produced, and subsequent pollinator visitation rates. Moreover, the community of pollinating visitors was influenced by drought across forb species (i.e. some pollinator species were deterred by drought while others were attracted). Together, these results indicate that VOCs may provide more nuanced information to potential floral visitors and may be relatively more important than visual traits for pollinator attraction, particularly under shifting environmental conditions. PMID:26546275

  10. Diallel analysis of floral longevity in Impatiens walleriana

    Science.gov (United States)

    Impatiens walleriana is currently among the most valuable and widely cultivated floriculture crops in the world. Highly floriferous cultivars are a primary goal for breeders of I. walleriana. Although breeders have selected for floriferousness, little consideration has been given to floral longevity...

  11. 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, pinocembr

  12. Trapping noctuid moths with synthetic floral volatile lures

    Science.gov (United States)

    Male and female noctuid moths were collected from plastic bucket traps that were baited with different synthetic floral chemicals and placed in peanut fields. Traps baited with phenylacetaldehyde, benzyl acetate, and a blend of phenylacetaldehyde, benzyl acetate, and benzaldehyde collected more soyb...

  13. RTK SLAP down: the emerging role of Src-like adaptor protein as a key player in receptor tyrosine kinase signaling.

    Science.gov (United States)

    Wybenga-Groot, Leanne E; McGlade, C Jane

    2015-02-01

    SLAP (Src like adaptor protein) contains adjacent Src homology 3 (SH3) and Src homology 2 (SH2) domains closely related in sequence to that of cytoplasmic Src family tyrosine kinases. Expressed most abundantly in the immune system, SLAP function has been predominantly studied in the context of lymphocyte signaling, where it functions in the Cbl dependent downregulation of antigen receptor signaling. However, accumulating evidence suggests that SLAP plays a role in the regulation of a broad range of membrane receptors including members of the receptor tyrosine kinase (RTK) family. In this review we highlight the role of SLAP in the ubiquitin dependent regulation of type III RTKs PDGFR, CSF-1R, KIT and Flt3, as well as Eph family RTKs. SLAP appears to bind activated type III and Eph RTKs via a conserved autophosphorylated juxtamembrane tyrosine motif in an SH2-dependent manner, suggesting that SLAP is important in regulating RTK signaling.

  14. 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. PMID:27148960

  15. Correlation Between Endogenous Hormones of Stem Apices and Fruit Locule Numbers in Tomatoes During Floral Bud Differentiation Stages

    Institute of Scientific and Technical Information of China (English)

    LI Yue; LI Tian-lai; WANG Dan

    2008-01-01

    The study was designed to elucidate the changes in the endogenous hormones of stem apices in tomatoes and the function of correlative endogenous hormones in tomatoes during floral bud differentiation stages. The tomato parents were crossed and reverse crossed by using two inbred lines of multi-locule (MLK1) and few-locule (FL1) with significant difference, and the relationship between endogenous hormones GA3, IAA, and ABA levels and ovary locule numbers of parents and progeny during floral bud differentiation initial stage, floral bud differentiation stage, sepal petal formation stage, carpel formation initial stage, and ovary locule complete formation stage was studied. GA3 levels in P1, P2, F3, and RF1 were consistent with locule numbers, and IAA and ABA levels were reverse to ovary locule numbers during the key stage. The correlation showed that, during sepal petal formation stage, the ovary locule numbers were positively correlated with GA3, GA3/IAA, and GA/ABA, and were negatively correlated with IAA and ABA. It was speculated that increasing GA3 levels or decreasing IAA and ABA levels of stem apices in tomato might be able to enhance ovary locule numbers. The sepal petal formation stage was an important stage which regulated endogenous hormones in the ovary locule formation.

  16. Patterns of pollen removal and deposition in Polemonium brandegeei (Polemoniaceae): the role of floral visitors, floral design and sexual interference.

    Science.gov (United States)

    Kulbaba, M W; Worley, A C

    2014-11-01

    The arrangement, colour, shape and size of floral parts (collectively floral design) have evolved primarily to promote mating success via animal-mediated pollen transfer. Although numerous studies have examined variation in pollinator assemblages, relatively few have examined patterns of pollen removal and deposition in the presence of fluctuating pollinators and ineffective floral visitors; therefore, net pollen removal and deposition by entire visitor assemblages are unclear. We studied the timing (diurnal or nocturnal) and effects of floral traits on pollen removal and deposition under a dynamic visitor assemblage of Polemonium brandegeei. We quantified pollen grains remaining in anthers (pollen removal) and deposited on stigmas (pollen deposition) of plants visited during either the day (07:30-20:00 h) or night (20:30-07:30 h) in natural populations over two flowering seasons. Pollen removal and deposition occurred both diurnally and nocturnally during our study. Increased diurnal removal and deposition coincided with peak floral visitations in 2006. This increase in pollen removal and deposition may reflect increased visits by pollen consumers, effective hawkmoth pollinators and increased self-pollen deposition due to hot, dry weather. Nonlinear effects of style length significantly affected pollen removal, with less pollen remaining in flowers with intermediate style lengths. Pollen deposition was more complex, with herkogamy and anther height affecting deposition. Further, close proximity of stigmas and anthers increased the potential for sexual interference between pollen removal and deposition. Overall, flower visitations and pollen removal and deposition varied between years and populations, but sex organ placement consistently influenced the removal and deposition of pollen. PMID:24850527

  17. Arranging the bouquet of disease: floral traits and the transmission of plant and animal pathogens.

    Science.gov (United States)

    McArt, Scott H; Koch, Hauke; Irwin, Rebecca E; Adler, Lynn S

    2014-05-01

    Several floral microbes are known to be pathogenic to plants or floral visitors such as pollinators. Despite the ecological and economic importance of pathogens deposited in flowers, we often lack a basic understanding of how floral traits influence disease transmission. Here, we provide the first systematic review regarding how floral traits attract vectors (for plant pathogens) or hosts (for animal pathogens), mediate disease establishment and evolve under complex interactions with plant mutualists that can be vectors for microbial antagonists. Attraction of floral visitors is influenced by numerous phenological, morphological and chemical traits, and several plant pathogens manipulate floral traits to attract vectors. There is rapidly growing interest in how floral secondary compounds and antimicrobial enzymes influence disease establishment in plant hosts. Similarly, new research suggests that consumption of floral secondary compounds can reduce pathogen loads in animal pollinators. Given recent concerns about pollinator declines caused in part by pathogens, the role of floral traits in mediating pathogen transmission is a key area for further research. We conclude by discussing important implications of floral transmission of pathogens for agriculture, conservation and human health, suggesting promising avenues for future research in both basic and applied biology. PMID:24528408

  18. Wild bees preferentially visit Rudbeckia flower heads with exaggerated ultraviolet absorbing floral guides

    Science.gov (United States)

    Horth, Lisa; Campbell, Laura; Bray, Rebecca

    2014-01-01

    ABSTRACT Here, we report on the results of an experimental study that assessed the visitation frequency of wild bees to conspecific flowers with different sized floral guides. UV absorbent floral guides are ubiquitous in Angiosperms, yet surprisingly little is known about conspecific variation in these guides and very few studies have evaluated pollinator response to UV guide manipulation. This is true despite our rich understanding about learning and color preferences in bees. Historical dogma indicates that flower color serves as an important long-range visual signal allowing pollinators to detect the flowers, while floral guides function as close-range signals that direct pollinators to a reward. We initiated the work presented here by first assessing the population level variation in UV absorbent floral guides for conspecific flowers. We assessed two species, Rudbeckia hirta and R. fulgida. We then used several petal cut-and-paste experiments to test whether UV floral guides can also function to attract visitors. We manipulated floral guide size and evaluated visitation frequency. In all experiments, pollinator visitation rates were clearly associated with floral guide size. Diminished floral guides recruited relatively few insect visitors. Exaggerated floral guides recruited more visitors than smaller or average sized guides. Thus, UV floral guides play an important role in pollinator recruitment and in determining the relative attractiveness of conspecific flower heads. Consideration of floral guides is therefore important when evaluating the overall conspicuousness of flower heads relative to background coloration. This work raises the issue of whether floral guides serve as honest indicators of reward, since guide size varies in nature for conspecific flowers at the same developmental stage and since preferences for larger guides were found. To our knowledge, these are the first cut-and-paste experiments conducted to examine whether UV absorbent floral

  19. Wild bees preferentially visit Rudbeckia flower heads with exaggerated ultraviolet absorbing floral guides.

    Science.gov (United States)

    Horth, Lisa; Campbell, Laura; Bray, Rebecca

    2014-01-01

    Here, we report on the results of an experimental study that assessed the visitation frequency of wild bees to conspecific flowers with different sized floral guides. UV absorbent floral guides are ubiquitous in Angiosperms, yet surprisingly little is known about conspecific variation in these guides and very few studies have evaluated pollinator response to UV guide manipulation. This is true despite our rich understanding about learning and color preferences in bees. Historical dogma indicates that flower color serves as an important long-range visual signal allowing pollinators to detect the flowers, while floral guides function as close-range signals that direct pollinators to a reward. We initiated the work presented here by first assessing the population level variation in UV absorbent floral guides for conspecific flowers. We assessed two species, Rudbeckia hirta and R. fulgida. We then used several petal cut-and-paste experiments to test whether UV floral guides can also function to attract visitors. We manipulated floral guide size and evaluated visitation frequency. In all experiments, pollinator visitation rates were clearly associated with floral guide size. Diminished floral guides recruited relatively few insect visitors. Exaggerated floral guides recruited more visitors than smaller or average sized guides. Thus, UV floral guides play an important role in pollinator recruitment and in determining the relative attractiveness of conspecific flower heads. Consideration of floral guides is therefore important when evaluating the overall conspicuousness of flower heads relative to background coloration. This work raises the issue of whether floral guides serve as honest indicators of reward, since guide size varies in nature for conspecific flowers at the same developmental stage and since preferences for larger guides were found. To our knowledge, these are the first cut-and-paste experiments conducted to examine whether UV absorbent floral guides affect

  20. Phosphorylation of APP-CTF-AICD domains and interaction with adaptor proteins: signal transduction and/or transcriptional role--relevance for Alzheimer pathology.

    Science.gov (United States)

    Schettini, Gennaro; Govoni, Stefano; Racchi, Marco; Rodriguez, Guido

    2010-12-01

    In recent decades, the study of the amyloid precursor protein (APP) and of its proteolytic products carboxy terminal fragment (CTF), APP intracellular C-terminal domain (AICD) and amyloid beta has been mostly focussed on the role of APP as a producer of the toxic amyloid beta peptide. Here, we reconsider the role of APP suggesting, in a provocative way, the protein as a central player in a putative signalling pathway. We highlight the presence in the cytosolic tail of APP of the YENPTY motif which is typical of tyrosine kinase receptors, the phosphorylation of the tyrosine, serine and threonine residues, the kinases involved and the interaction with intracellular adaptor proteins. In particular, we examine the interaction with Shc and Grb2 regulators, which through the activation of Ras proteins elicit downstream signalling events such as the MAPK pathway. The review also addresses the interaction of APP, CTFs and AICD with other adaptor proteins and in particular with Fe65 for nuclear transcriptional activity and the importance of phosphorylation for sorting the secretases involved in the amyloidogenic or non-amyloidogenic pathways. We provide a novel perspective on Alzheimer's disease pathogenesis, focussing on the perturbation of the physiological activities of APP-CTFs and AICD as an alternative perspective from that which normally focuses on the accumulation of neurotoxic proteolytic fragments. PMID:21039524

  1. Distribution of XTH, Expansin, and Secondary-wall-related CesA in Floral and Fruit Abscission Zones during Fruit Development in Tomato (Solanum lycopersicum

    Directory of Open Access Journals (Sweden)

    Mutsumi eTsuchiya

    2015-05-01

    Full Text Available After fruit development is triggered by pollination, the abscission zone (AZ in the fruit pedicel strengthens its adhesion to keep the fruit attached. We previously reported that xyloglucan and arabinan accumulation in the AZ accompanies the shedding of unpollinated flowers. After the fruit has developed and is fully ripened, shedding occurs easily in the AZ due to lignin accumulation. Regulation of cell wall metabolism may play an important role in these processes, but it is not well understood. In the present report, we used immunohistochemistry to visualize changes in the distributions of xyloglucan and arabinan metabolism-related enzymes in the AZs of pollinated and unpollinated flowers, and in ripened fruits. During floral abscission, we observed a gradual increase in polyclonal antibody labeling of expansin in the AZ. The intensities of LM6 and LM15 labeling of arabinan and xyloglucan, respectively, also increased. However, during floral abscission, we observed a large 1 day post anthesis (DPA peak in the polyclonal antibody labeling of XTH in the AZ, which then decreased. These results suggest that expansin and XTH play important, but different roles in the floral abscission process. During fruit abscission, unlike during floral abscission, no AZ-specific expansin and XTH were observed. Although lignification was seen in the AZ of over-ripe fruit pedicels, secondary cell wall-specific cellulose synthase signals were not observed. This suggests that cellulose metabolism-related enzymes do not play important roles in the AZ prior to fruit abscission.

  2. Rice ABERRANT PANICLE ORGANIZATION 1, encoding an F-box protein, regulates meristem fate.

    Science.gov (United States)

    Ikeda, Kyoko; Ito, Momoyo; Nagasawa, Nobuhiro; Kyozuka, Junko; Nagato, Yasuo

    2007-09-01

    Inflorescence architecture is one of the most important agronomical traits. Characterization of rice aberrant panicle organization 1 (apo1) mutants revealed that APO1 positively controls spikelet number by suppressing the precocious conversion of inflorescence meristems to spikelet meristems. In addition, APO1 is associated with the regulation of the plastchron, floral organ identity, and floral determinacy. Phenotypic analyses of apo1 and floral homeotic double mutants demonstrate that APO1 positively regulates class-C floral homeotic genes, but not class-B genes. Molecular studies revealed that APO1 encodes an F-box protein, an ortholog of Arabidopsis UNUSUAL FLORAL ORGAN (UFO), which is a positive regulator of class-B genes. Overexpression of APO1 caused an increase in inflorescence branches and spikelets. As the mutant inflorescences and flowers differed considerably between apo1 and ufo, the functions of APO1 and UFO appear to have diverged during evolution. PMID:17666027

  3. Rice ABERRANT PANICLE ORGANIZATION 1, encoding an F-box protein, regulates meristem fate.

    Science.gov (United States)

    Ikeda, Kyoko; Ito, Momoyo; Nagasawa, Nobuhiro; Kyozuka, Junko; Nagato, Yasuo

    2007-09-01

    Inflorescence architecture is one of the most important agronomical traits. Characterization of rice aberrant panicle organization 1 (apo1) mutants revealed that APO1 positively controls spikelet number by suppressing the precocious conversion of inflorescence meristems to spikelet meristems. In addition, APO1 is associated with the regulation of the plastchron, floral organ identity, and floral determinacy. Phenotypic analyses of apo1 and floral homeotic double mutants demonstrate that APO1 positively regulates class-C floral homeotic genes, but not class-B genes. Molecular studies revealed that APO1 encodes an F-box protein, an ortholog of Arabidopsis UNUSUAL FLORAL ORGAN (UFO), which is a positive regulator of class-B genes. Overexpression of APO1 caused an increase in inflorescence branches and spikelets. As the mutant inflorescences and flowers differed considerably between apo1 and ufo, the functions of APO1 and UFO appear to have diverged during evolution.

  4. ER Adaptor SCAP Translocates and Recruits IRF3 to Perinuclear Microsome Induced by Cytosolic Microbial DNAs

    Science.gov (United States)

    Yu, Huansha; Liu, Xing; Huang, Lulu; Wang, Qiang; Liu, Heng; Cui, Ye; Tang, Yijun; Zhang, Peng; Wang, Chen

    2016-01-01

    Stimulator of interferon genes (STING, also known as MITA, ERIS or MPYS) induces the activation of TBK1 kinase and IRF3 transcription factor, upon sensing of microbial DNAs. How IRF3 is recruited onto the STING signalosome remains unknown. We report here that silencing of the ER adaptor SCAP markedly impairs the IRF3-responsive gene expression induced by STING. Scap knockdown mice are more susceptible to HSV-1 infection. Interestingly, SCAP translocates from ER, via Golgi, to perinuclear microsome in a STING-dependent manner. Mechanistically, the N-terminal transmembrane domain of SCAP interacts with STING, and the C-terminal cytosolic domain of SCAP binds to IRF3, thus recruiting IRF3 onto STING signalosome. Mis-localization of SCAP abolishes its antiviral function. Collectively, this study characterizes SCAP as an essential adaptor in the STING signaling pathway, uncovering a critical missing link in DNAs-triggered host antiviral responses. PMID:26900919

  5. ER Adaptor SCAP Translocates and Recruits IRF3 to Perinuclear Microsome Induced by Cytosolic Microbial DNAs.

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2016-02-01

    Full Text Available Stimulator of interferon genes (STING, also known as MITA, ERIS or MPYS induces the activation of TBK1 kinase and IRF3 transcription factor, upon sensing of microbial DNAs. How IRF3 is recruited onto the STING signalosome remains unknown. We report here that silencing of the ER adaptor SCAP markedly impairs the IRF3-responsive gene expression induced by STING. Scap knockdown mice are more susceptible to HSV-1 infection. Interestingly, SCAP translocates from ER, via Golgi, to perinuclear microsome in a STING-dependent manner. Mechanistically, the N-terminal transmembrane domain of SCAP interacts with STING, and the C-terminal cytosolic domain of SCAP binds to IRF3, thus recruiting IRF3 onto STING signalosome. Mis-localization of SCAP abolishes its antiviral function. Collectively, this study characterizes SCAP as an essential adaptor in the STING signaling pathway, uncovering a critical missing link in DNAs-triggered host antiviral responses.

  6. Clathrin and HA2 adaptors: effects of potassium depletion, hypertonic medium, and cytosol acidification

    OpenAIRE

    1993-01-01

    The effects of methods known to perturb endocytosis from clathrin- coated pits on the localization of clathrin and HA2 adaptors in HEp-2 carcinoma cells have been studied by immunofluorescence and ultrastructural immunogold microscopy, using internalization of transferrin as a functional assay. Potassium depletion, as well as incubation in hypertonic medium, remove membrane-associated clathrin lattices: flat clathrin lattices and coated pits from the plasma membrane, and clathrin-coated vesic...

  7. Floral and ecological isolation between Aquilegia formosa and Aquilegia pubescens.

    OpenAIRE

    Hodges, S. A.; Arnold, M L

    1994-01-01

    Habitat preference and pollination syndrome have been suggested as major factors in reproductive isolation among plant species. The columbine genus Aquilegia contains species that have been used as classic examples of reproductive isolation due to ecological and floral factors. In this analysis Aquilegia formosa, Aquilegia pubescens, and natural hybrid populations between these two species were assayed for genetic and morphological variation. Clinal variation was evident for three "random amp...

  8. Active pollination favours sexual dimorphism in floral scent

    OpenAIRE

    Okamoto, Tomoko; Kawakita, Atsushi; Goto, Ryutaro; Svensson, Glenn P.; Kato, Makoto

    2013-01-01

    Zoophilous flowers often transmit olfactory signals to attract pollinators. In plants with unisexual flowers, such signals are usually similar between the sexes because attraction of the same animal to both male and female flowers is essential for conspecific pollen transfer. Here, we present a remarkable example of sexual dimorphism in floral signal observed in reproductively highly specialized clades of the tribe Phyllantheae (Phyllanthaceae). These plants are pollinated by species-specific...

  9. 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...

  10. 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...

  11. attracting antagonists: does floral nectar increase leaf herbivory?

    OpenAIRE

    Adler, L.S.; Bronstein, J. L.

    2004-01-01

    Traits that are attractive to mutualists may also attract antagonists, resulting in conflicting selection pressures. Here we develop the idea that increased floral nectar production can, in some cases, increase herbivory. In these situations, selection for increased nectar production to attract pollinators may be constrained by a linked cost of herbivore attraction. In support of this hypothesis, we report that experimentally supplementing nectar rewards in Datura stramonium led to increased ...

  12. 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.

  13. The adaptor molecule Trif contributes to murine host defense during Leptospiral infection.

    Science.gov (United States)

    Jayaraman, Priya A; Devlin, Amy A; Miller, Jennifer C; Scholle, Frank

    2016-09-01

    Leptospirosis is a zoonotic disease and is caused by pathogenic species of the Leptospira genus, including Leptospira interrogans (L. interrogans). Humans, domestic and wild animals are susceptible to acute or chronic infection. The innate immune response is a critical defense mechanism against Leptospira interrogans, and has been investigated in mouse models. Murine Toll-like receptors (TLRs) have been shown to be key factors in sensing and responding to L. interrogans infection. Specifically, TLR2, TLR4 and the TLR adaptor molecule MyD88 are essential for host defense against L. interrogans; however, the role of the TLR adaptor molecule TIR-domain-containing adaptor-inducing interferon β (TRIF) in the response to L. interrogans has not been previously determined. In the present study, TRIF was found to play an important role during leptospiral infection. Following challenge with L. interrogans, Trif(-/-) mice exhibited delayed weight gain compared to wild-type mice. Moreover, Trif(-/-) mice exhibited an increase in L. interrogans burden in the kidneys, lungs, and blood at early time points (less than 7days post infection). Multiple components of the innate immune responses were dampened in response to leptospiral infection including transcription and production of cytokines, and the humoral response, which suggested that TRIF contributes to expression and production of cytokines important for the host defense against L. interrogans. PMID:27259371

  14. 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.

  15. 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. PMID:16244866

  16. 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.

  17. Scents as Floral Defence : Impact on Species and Communities, Mechanisms and Ecological Consequences

    OpenAIRE

    Junker, Robert R

    2010-01-01

    Floral scents are compositions of diverse volatile substances. Despite the chemical complexity, the interpretation of their ecological relevance was mostly confined to the attractive function facilitating interactions with pollinators. However, the negative impact on plants’ reproduction by non-pollinating flower visitors is pronounced and demands floral adaptations that exclude antagonists. The aim of this dissertation was to explore the defensive properties of floral odours and to imbed the...

  18. Relative floral density of an invasive plant affects pollinator foraging behaviour on a native plant

    OpenAIRE

    Amy Marie Iler; Karen Goodell

    2014-01-01

    Interactions between invasive and native plants for pollinators vary from competition to facilitation of pollination of native plants. Theory predicts that relative floral densities should account for some of this variation in outcomes, with facilitation at low floral densities and competition at high floral densities of the invader. We tested this prediction by quantifying pollination and female reproductive success of a native herb, Geranium maculatum, in three experimental arrays that vari...

  19. The dual role of floral traits: Pollinator attraction and plant defense

    OpenAIRE

    Irwin, R. E.; Adler, L.S.; Brody, A. K.

    2004-01-01

    Plants are under siege from a diversity of enemies that consume both leaf and floral parts. Plants resist damage to leaves in a variety of ways, and we now have a rich literature documenting how plants defend themselves against herbivore attack. In contrast, the mechanisms by which plants resist enemies that consume floral parts or resources are much less known, even though damage to floral tissue usually has tighter links to plant fitness than damage to leaf tissue. Many plants experience ne...

  20. Relationship between floral colour and pollinator composition in four plant communities

    OpenAIRE

    Reverté Saiz, Sara; Bosch Gras, Jordi; Retana Alumbreros, Javier

    2014-01-01

    Pollinators use a variety of floral cues to locate resources, but the relative importance of these different cues on pollinator foraging decisions is unclear. However, floral colour is undoubtedly one of the most important, as evidenced in previous works revealing the importance of floral colour on pollinator choices and determining flower visitor composition. Our purpose is to establish whether there is a relationship between flower colour and pollinator composition in natural communities. W...

  1. 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

  2. The Pch2 AAA+ ATPase promotes phosphorylation of the Hop1 meiotic checkpoint adaptor in response to synaptonemal complex defects

    Science.gov (United States)

    Herruzo, Esther; Ontoso, David; González-Arranz, Sara; Cavero, Santiago; Lechuga, Ana; San-Segundo, Pedro A.

    2016-01-01

    Meiotic cells possess surveillance mechanisms that monitor critical events such as recombination and chromosome synapsis. Meiotic defects resulting from the absence of the synaptonemal complex component Zip1 activate a meiosis-specific checkpoint network resulting in delayed or arrested meiotic progression. Pch2 is an evolutionarily conserved AAA+ ATPase required for the checkpoint-induced meiotic block in the zip1 mutant, where Pch2 is only detectable at the ribosomal DNA array (nucleolus). We describe here that high levels of the Hop1 protein, a checkpoint adaptor that localizes to chromosome axes, suppress the checkpoint defect of a zip1 pch2 mutant restoring Mek1 activity and meiotic cell cycle delay. We demonstrate that the critical role of Pch2 in this synapsis checkpoint is to sustain Mec1-dependent phosphorylation of Hop1 at threonine 318. We also show that the ATPase activity of Pch2 is essential for its checkpoint function and that ATP binding to Pch2 is required for its localization. Previous work has shown that Pch2 negatively regulates Hop1 chromosome abundance during unchallenged meiosis. Based on our results, we propose that, under checkpoint-inducing conditions, Pch2 also possesses a positive action on Hop1 promoting its phosphorylation and its proper distribution on unsynapsed chromosome axes. PMID:27257060

  3. Molecular cloning and functional analysis of the duck TIR domain-containing adaptor inducing IFN-β (TRIF) gene.

    Science.gov (United States)

    Wei, Xiaoqin; Qian, Wei; Sizhu, Suolang; Shi, Lijuan; Jin, Meilin; Zhou, Hongbo

    2016-12-01

    Toll-like receptors (TLRs) trigger the innate immune response by responding to specific components of microorganisms. The TIR domain-containing adaptor inducing IFN-β (TRIF) plays an essential role in mammalian TLR-mediated signaling. The role of TRIF in ducks (duTRIF) remains poorly understood. In this study, we cloned and characterized the full-length coding sequence of duTRIF from duck embryo fibroblasts (DEFs). In healthy ducks, duTRIF transcripts were broadly expressed in different tissues, with higher expression levels in the spleen and liver. Using quantitative real-time PCR (qRT-PCR), we demonstrated the upregulation of duTRIF in DEFs infected with AIV or DTMUV, and DEFs treated with Poly I:C or LPS. Overexpression of duTRIF was able to induce the NF-κB and IFN-β expression. Furthermore, the IFN induction function of duTRIF was impaired when Ala517 was mutated to Pro or His. Taken together, these results suggested that duTRIF regulated duck innate immune responses. PMID:27539203

  4. Floral phenology, floral rewards and insect visitation in an ornamental species Geranium platypetalum Fisch. and C. A. Mey., Geraniaceae

    OpenAIRE

    Marzena Masierowska

    2012-01-01

    This 4-year study examined the flowering pattern, floral display, nectar and pollen production as well as insect visitation to a perennial Geranium platypetalum Fisch. and C. A. Mey. G. platypetalum bloomed from the end of May until the end of June. The pattern of flowering shows the skewed distribution with a tendency towards a more symmetrical curve. The flower display size fluctuated during the flowering season. The most intense blooming fell in the 2nd and 3rd flowering week. The flowers ...

  5. 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

  6. Study on Floral and Pollen Characters of Tetraploid Rice

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-xin; CHEN Jian-guo; CHEN Dong-ling; SONG Zhao-jian; DAI Bing-cheng; CAI De-tian

    2009-01-01

    Polyploidization is the evolution trend of many crops, and the yield increased obviously after polyploidization. The polyploidization of rice often brings "gigas" of both vegetative organs and seeds. Howevere, in rice breeding, it is required for restoring lines to have not only big anthers but also abundant pollens. People often doubt that the enlargement of the floral organ may just be enlargement of cell size in polyploid rice. So, it is of significance to study characteristics of floral organs and pollens of several tetraploid rice varieties or lines. Floral organ and pollen characteristics of Sg99012 and HN2026 were studied comparatively by stages and different ploidy levels, with the materials 9311, HD9802S, and PA64S as the control. The results showed that chromosome doubling had much more influence on floral characteristics of every lines than seeding by stages, and the tetraploids of every lines displayed "gigas". In correlation analysis, spikelet length, spikelet width, and anther length had significant correlation; spikelet width and anther width had significant correlation, too. Both seeding by stages and chromosome doubling made the correlations of characters between every floral organ changed to some extent. Seeding by stages had little effect on pollen diameter and fertility of HN2026-4X and Sg99012-4X. But chromosome doubling increased pollen size of every lines remarkably, and also increased the pollen quantity of PMeS (polyploid meiosis stability) restoring line HN2026-4X and gene map restoring line 9311-4X remarkably, whereas only had little effect on that of sterile lines. Moreover, chromosome doubling changed pollen fertility and made the number of fertility pollen of 9311 reduced significantly, but the pollen fertility of HN2026 (PMeS restoring line) and PA64S (sterile line) almost had no change after chromosome doubling. The results showed that tetraploid restoring lines had advantage of abundant and big size pollens, and tetraploid sterile

  7. Heritability of floral volatiles and pleiotropic responses to artificial selection in Brassica rapa.

    Science.gov (United States)

    Zu, Pengjuan; Blanckenhorn, Wolf U; Schiestl, Florian P

    2016-02-01

    The evolution of the vast diversity of floral volatiles is little understood, although they serve fundamental functions, such as pollinator attraction and herbivore deterrence. Floral volatiles are often species specific, yet highly variable and sensitive to environmental factors. To date, nothing is known about the heritability of floral volatiles, and whether individual compounds can evolve independently or solely in concert with the whole volatile bouquet. We conducted bi-directional artificial selection on four target floral volatiles to estimate heritability and correlated pleiotropic responses in the wild turnip (Brassica rapa). The realized heritability of the four target volatiles ranged from 20% to 45%. The average narrow-sense heritability of all 13 analyzed floral volatiles was 18% based on parent-offspring regressions. There were pleiotropic effects of the selected floral volatile compounds on other constituents of the floral scent bouquet, on flowering time and on some morphological traits. We found that the whole floral scent bouquet changed, even when there was selection only on single compounds, with the overall phenotypic covariance being unaffected. Our study demonstrates that floral scent can evolve rapidly under phenotypic selection, but with additional correlated responses in traits that are not direct targets of selection. PMID:26391626

  8. Floral gradient in flowering tobacco in relation to free amino acids

    Institute of Scientific and Technical Information of China (English)

    CHENYONGNING; WENANLI

    1993-01-01

    By employing TCLs (thin cell layers) culture, the floral gradient in flowering tobacco of different developmental stages was confirmed. The TCLs from early flowering tobacco regenerated more floral buds than those from the tobacco plants in full blooming or fruiting stages. Analysis of free amino acid levels revealed the acropetal gradient of Pro in flowering tobacco stem. L-Pro. L-Trp. D,L-Met and L-Arg were respectively added into the culture medium for testing their influence on floral bud formation from tobacco pedicel segments. Only L-Trp evidently enhanced the floral bud neoformation.

  9. Macroevolutionary patterns of ultraviolet floral pigmentation explained by geography and associated bioclimatic factors.

    Science.gov (United States)

    Koski, Matthew H; Ashman, Tia-Lynn

    2016-07-01

    Selection driven by biotic interactions can generate variation in floral traits. Abiotic selection, however, also contributes to floral diversity, especially with respect to patterns of pigmentation. Combining comparative studies of floral pigmentation and geography can reveal the bioclimatic factors that may drive macroevolutionary patterns of floral color. We create a molecular phylogeny and measure ultraviolet (UV) floral pattern for 177 species in the Potentilleae tribe (Rosaceae). Species are similar in flower shape and visible color but vary in UV floral pattern. We use comparative approaches to determine whether UV pigmentation variation is associated with geography and/or bioclimatic features (UV-B, precipitation, temperature). Floral UV pattern was present in half of the species, while others were uniformly UV-absorbing. Phylogenetic signal was detected for presence/absence of pattern, but among patterned species, quantitative variation in UV-absorbing area was evolutionarily labile. Uniformly UV-absorbing species tended to experience higher UV-B irradiance. Patterned species occurring at higher altitudes had larger UV-absorbing petal areas, corresponding with low temperature and high UV exposure. This analysis expands our understanding of the covariation of UV-B irradiance and UV floral pigmentation from within species to that among species, and supports the view that abiotic selection is associated with floral diversification among species.

  10. The olfactory component of floral display in Asimina and Deeringothamnus (Annonaceae).

    Science.gov (United States)

    Goodrich, Katherine R; Raguso, Robert A

    2009-01-01

    Floral scent is a key component of floral display, and probably one of the first floral attractants linking insect pollinators to the radiation of Angiosperms. In this article, we investigate floral scent in two extra-tropical genera of Annonaceae. We discuss floral scent in the context of differing pollination strategies in these genera, and compare their scent to that of a close tropical relative. Floral volatiles were collected for Annona glabra, Asimina and Deeringothamnus whole flowers and dissected floral organs, using a standardized static-headspace solid phase microextraction method. Scents were analyzed using gas chromatography-mass spectrometry, and identified using known standards. The floral scents of these species are highly dynamic, varying between floral organs, sexual stages and species. Maroon-flowered species of Asimina produce 'yeasty' odors, dominated by fermentation volatiles and occasionally containing sulfurous or nitrogenous compounds. White-flowered species of Asimina and Deeringothamnus produce pleasant odors characterized by lilac compounds, benzenoids and hydrocarbons. Annona glabra produces a strong, fruity-acetonic scent dominated by 3-pentanyl acetate and 1,8-cineole. The fermented/decaying scents of maroon-flowered species of Asimina suggest mimicry-based pollination strategies similar to aroids and stapeliads, whereas the pleasant scents of white-flowered species of Asimina suggest honest, reward-based pollination strategies. The scent of Annona glabra is typical of specialized beetle pollination systems common to tropical Annonaceae.

  11. 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

  12. The euAP1 protein MPF3 represses MPF2 to specify floral calyx identity and displays crucial roles in Chinese lantern development in Physalis.

    Science.gov (United States)

    Zhao, Jing; Tian, Ying; Zhang, Ji-Si; Zhao, Man; Gong, Pichang; Riss, Simone; Saedler, Rainer; He, Chaoying

    2013-06-01

    The Chinese lantern phenotype or inflated calyx syndrome (ICS) is a postfloral morphological novelty in Physalis. Its origin is associated with the heterotopic expression of the MADS box gene 2 from Physalis floridana (MPF2) in floral organs, yet the process underlying its identity remains elusive. Here, we show that MPF3, which is expressed specifically in floral tissues, encodes a core eudicot APETALA1-like (euAP1) MADS-domain protein. MPF3 was primarily localized to the nucleus, and it interacted with MPF2 and some floral MADS-domain proteins to selectively bind the CC-A-rich-GG (CArG) boxes in the MPF2 promoter. Downregulating MPF3 resulted in a dramatic elevation in MPF2 in the calyces and androecium, leading to enlarged and leaf-like floral calyces; however, the postfloral lantern was smaller and deformed. Starch accumulation in pollen was blocked. MPF3 MPF2 double knockdowns showed normal floral calyces and more mature pollen than those found in plants in which either MPF3 or MPF2 was downregulated. Therefore, MPF3 specifies calyx identity and regulates ICS formation and male fertility through interactions with MPF2/MPF2. Furthermore, both genes were found to activate Physalis floridana invertase gene 4 homolog, which encodes an invertase cleaving Suc, a putative key gene in sugar partitioning. The novel role of the MPF3-MPF2 regulatory circuit in male fertility is integral to the origin of ICS. Our results shed light on the evolution and development of ICS in Physalis and on the functional evolution of euAP1s in angiosperms.

  13. A combinatorial F box protein directed pathway controls TRAF adaptor stability to regulate inflammation

    OpenAIRE

    Chen, Bill B; Coon, Tiffany A.; Glasser, Jennifer R; McVerry, Bryan J.; Zhao, Jing; Zhao, Yutong; Zou, Chunbin; Ellis, Bryon; Sciurba, Frank C.; Zhang, Yingze; Mallampalli, Rama K.

    2013-01-01

    Uncontrolled activation of tumor necrosis factor receptor-associated factor (TRAF) proteins may result in profound tissue injury by linking surface signals to cytokine release. Here we show that a ubiquitin E3 ligase component, Fbxo3, potently stimulates cytokine secretion from human inflammatory cells by destabilizing a sentinel TRAF inhibitor, Fbxl2. Fbxo3 and TRAF protein in circulation positively correlated with cytokine responses in septic subjects and we furthermore identified a hypofun...

  14. A combinatorial F box protein directed pathway controls TRAF adaptor stability to regulate inflammation.

    Science.gov (United States)

    Chen, Bill B; Coon, Tiffany A; Glasser, Jennifer R; McVerry, Bryan J; Zhao, Jing; Zhao, Yutong; Zou, Chunbin; Ellis, Bryon; Sciurba, Frank C; Zhang, Yingze; Mallampalli, Rama K

    2013-05-01

    Uncontrolled activation of tumor necrosis factor receptor-associated factor (TRAF) proteins may result in profound tissue injury by linking surface signals to cytokine release. Here we show that a ubiquitin E3 ligase component, Fbxo3, potently stimulates cytokine secretion from human inflammatory cells by destabilizing a sentinel TRAF inhibitor, Fbxl2. Fbxo3 and TRAF protein in circulation positively correlated with cytokine responses in subjects with sepsis, and we identified a polymorphism in human Fbxo3, with one variant being hypofunctional. A small-molecule inhibitor targeting Fbxo3 was sufficient to lessen severity of cytokine-driven inflammation in several mouse disease models. These studies identified a pathway of innate immunity that may be useful to detect subjects with altered immune responses during critical illness or provide a basis for therapeutic intervention targeting TRAF protein abundance. PMID:23542741

  15. 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 loca

  16. 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.

  17. Pollinator and herbivore attraction to cucurbita floral volatiles.

    Science.gov (United States)

    Andrews, Elizabeth S; Theis, Nina; Adler, Lynn S

    2007-09-01

    Mutualists and antagonists may place conflicting selection pressures on plant traits. For example, the evolution of floral traits is typically studied in the context of attracting pollinators, but traits may incur fitness costs if they are also attractive to antagonists. Striped cucumber beetles (Acalymma vittatum) feed on cucurbits and are attracted to several volatiles emitted by Cucurbita blossoms. However, the effect of these volatiles on pollinator attraction is unknown. Our goal was to determine whether pollinators were attracted to the same or different floral volatiles as herbivorous cucumber beetles. We tested three volatiles previously found to attract cucumber beetles in a factorial design to determine attraction of squash bees (Peponapis pruinosa), the specialist pollinators of cucurbita species, as well as the specialist herbivore A. vittatum. We found that 1,2,4-trimethoxybenzene was attractive to both the pollinator and the herbivore, indole was attractive only to the herbivore, and (E)-cinnamaldehyde was attractive only to the pollinator. There were no interactions among volatiles on attraction of squash bees or cucumber beetles. Our results suggest that reduced indole emission could benefit plants by reducing herbivore attraction without loss of pollination, and that 1,2,4-trimethoxybenzene might be under conflicting selection pressure from mutualists and antagonists. By examining the attraction of both mutualists and antagonists to Cucurbita floral volatiles, we have demonstrated the potential for some compounds to influence only one type of interaction, while others may affect both interactions and possibly result in tradeoffs. These results shed light on the potential evolution of fragrance in native Cucurbita, and may have consequences for yield in agricultural settings.

  18. Interacciones causales del necrosamiento de yemas florales en zarzamora 'Tupy'.

    OpenAIRE

    Argote Hernández, Cajeme Nicolás

    2013-01-01

    Actualmente en México la principal frutilla que se exporta en fresco es la zarzamora ‘Tupy’ (Rubus spp.). El Estado de Michoacán produce más de 90% del total a nivel nacional. Uno de los problemas de producción es el necrosamiento de las yemas florales. No existen reportes documentados sobre el necrosamiento de las yemas en zarzamora. Se diseñó un experimento con zarzamora ´Tupy´ en Los Reyes, Michoacán para diagnosticar las posibles interacciones causales del necrosamiento de yemas. Se pro...

  19. Floral CO2 reveals flower profitability to moths.

    Science.gov (United States)

    Thom, Corinna; Guerenstein, Pablo G; Mechaber, Wendy L; Hildebrand, John G

    2004-06-01

    The hawkmoth Manduca sexta (Lepidoptera: Sphingidae), an experimentally favorable Lepidopteran that is highly sensitive to carbon dioxide (CO2), feeds on the nectar of a range of flowering plants, such as Datura wrightii (Solanaceae). Newly opened Datura flowers give off dramatically elevated levels of CO2 and offer ample nectar. Thus, floral CO2 emission could indicate food-source profitability. This study documents that foraging Manduca moths prefer surrogate flowers that emit high levels of CO2, characteristic of newly opened Datura flowers. We show for the first time that CO2 may play an important role in the foraging behavior of nectar-feeding insects. PMID:15303329

  20. The Floral Symbol in the Poetry of Heinrich Heine

    Directory of Open Access Journals (Sweden)

    Aleksandra Chepelyk

    2013-08-01

    Full Text Available The article is devoted the plant symbolics which became the inalienable constituent of the original creation of Heinrich Heine. The distinctive traits of the artist’s lyric poetry are floral images, which are able to reflect the psychology of the human soul in the correlation with the spiritual substance – the divine nature. The immersion of Heinrich Heine in the world of the plants was conducived to the activation of the special emotional and psychological loading with the purpose of the comprehension of the internal experience of the lyric subject, represented in the sensory perceptible figurative, sound and visual landscapes.

  1. Variation in floral longevity in the genus Leptosiphon: mating system consequences.

    Science.gov (United States)

    Weber, J J; Goodwillie, C

    2013-01-01

    Pollination or fertilisation trigger floral senescence in a wide range of flowering plants, and yet little attention has been given to the implications of this phenomenon to mating system evolution. We examined the effects of pollination on floral senescence in the genus Leptosiphon. Species in the genus exhibit a wide range of breeding systems. In all cases, compatible pollination induced senescence; emasculated flowers lived longer than hand-outcrossed flowers. In the self-compatible species, Leptosiphon acicularis and L. bicolor, and in one highly selfing population of L. jepsonii, unmanipulated flowers had reduced longevity compared to emasculated flowers, suggesting that autonomous self-pollination limits floral longevity in these species. Limited floral longevity in these highly selfing taxa may reduce opportunities for male outcross success, representing a possible source of selection on the mating system. In turn, the mating system might influence how selection acts on floral longevity; obligately outcrossing taxa are expected to benefit from longer floral longevities to maximise opportunities for pollination, while selfing taxa might benefit from earlier floral senescence to reduce resource expenditure. Overall, the longevity of unpollinated flowers increased with the level of outcrossing in the genus Leptosiphon. Our results taken together with those of a previous study and similar results in other species suggest that floral longevity may represent a largely unexamined role in mating system evolution. PMID:22607097

  2. 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.

  3. 40 CFR 180.1127 - Biochemical pesticide plant floral volatile attractant compounds: cinnamaldehyde, cinnamyl...

    Science.gov (United States)

    2010-07-01

    ..., chinese cabbage, cowpeas, cucurbitis (cucumbers, squash, pumpkin), egg plant, endive (escarole... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Biochemical pesticide plant floral... From Tolerances § 180.1127 Biochemical pesticide plant floral volatile attractant...

  4. Evidence for an evolutionary relationship between the large adaptor nucleoporin Nup192 and karyopherins.

    Science.gov (United States)

    Stuwe, Tobias; Lin, Daniel H; Collins, Leslie N; Hurt, Ed; Hoelz, André

    2014-02-18

    Nucleocytoplasmic transport is facilitated by nuclear pore complexes (NPCs), which are massive proteinaceous transport channels embedded in the nuclear envelope. Nup192 is a major component of an adaptor nucleoporin subcomplex proposed to link the NPC coat with the central transport channel. Here, we present the structure of the ∼110-kDa N-terminal domain (NTD) of Nup192 at 2.7-Å resolution. The structure reveals an open ring-shaped architecture composed of Huntingtin, EF3, PP2A, and TOR1 (HEAT) and Armadillo (ARM) repeats. A comparison of different conformations indicates that the NTD consists of two rigid halves connected by a flexible hinge. Unexpectedly, the two halves of the ring are structurally related to karyopherin-α (Kap-α) and β-karyopherin family members. Biochemically, we identify a conserved patch that binds an unstructured segment in Nup53 and show that a C-terminal tail region binds to a putative helical fragment in Nic96. The Nup53 segment that binds Nup192 is a classical nuclear localization-like sequence that interacts with Kap-α in a mutually exclusive and mechanistically distinct manner. The disruption of the Nup53 and Nic96 binding sites in vivo yields growth and mRNA export defects, revealing their critical role in proper NPC function. Surprisingly, both interactions are dispensable for NPC localization, suggesting that Nup192 possesses another nucleoporin interaction partner. These data indicate that the structured domains in the adaptor nucleoporin complex are held together by peptide interactions that resemble those found in karyopherin•cargo complexes and support the proposal that the adaptor nucleoporins arose from ancestral karyopherins. PMID:24505056

  5. Distinct adaptor proteins assist exit of Kre2-family proteins from the yeast ER

    Directory of Open Access Journals (Sweden)

    Yoichi Noda

    2014-07-01

    Full Text Available The Svp26 protein of S. cerevisiae is an ER- and Golgi-localized integral membrane protein with 4 potential membrane-spanning domains. It functions as an adaptor protein that facilitates the ER exit of Ktr3, a mannosyltransferase required for biosynthesis of O-linked oligosaccharides, and the ER exit of Mnn2 and Mnn5, mannosyltransferases, which participate in the biosynthesis of N-linked oligosaccharides. Ktr3 belongs to the Kre2 family, which consists of 9 members of type-II membrane proteins sharing sequence similarities. In this report, we examined all Kre2 family members and found that the Golgi localizations of two others, Kre2 and Ktr1, were dependent on Svp26 by immunofluorescence microscopy and cell fractionations in sucrose density gradients. We show that Svp26 functions in facilitating the ER exit of Kre2 and Ktr1 by an in vitro COPII budding assay. Golgi localization of Ktr4 was not dependent on Svp26. Screening null mutants of the genes encoding abundant COPII membrane proteins for those showing mislocalization of Ktr4 in the ER revealed that Erv41 and Erv46 are required for the correct Golgi localization of Ktr4. We provide biochemical evidence that the Erv41-Erv46 complex functions as an adaptor protein for ER exit of Ktr4. This is the first demonstration of the molecular function of this evolutionally conserved protein complex. The domain switching experiments show that the lumenal domain of Ktr4 is responsible for recognition by the Erv41-Erv46 complex. Thus, ER exit of Kre2-family proteins is dependent on distinct adaptor proteins and our results provide new insights into the traffic of Kre2-family mannosyltransferases.

  6. Evolutionary Co-Option of Floral Meristem Identity Genes for Patterning of the Flower-Like Asteraceae Inflorescence.

    Science.gov (United States)

    Zhao, Yafei; Zhang, Teng; Broholm, Suvi K; Tähtiharju, Sari; Mouhu, Katriina; Albert, Victor A; Teeri, Teemu H; Elomaa, Paula

    2016-09-01

    The evolutionary success of Asteraceae, the largest family of flowering plants, has been attributed to the unique inflorescence architecture of the family, which superficially resembles an individual flower. Here, we show that Asteraceae inflorescences (flower heads, or capitula) resemble solitary flowers not only morphologically but also at the molecular level. By conducting functional analyses for orthologs of the flower meristem identity genes LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) in Gerbera hybrida, we show that GhUFO is the master regulator of flower meristem identity, while GhLFY has evolved a novel, homeotic function during the evolution of head-like inflorescences. Resembling LFY expression in a single flower meristem, uniform expression of GhLFY in the inflorescence meristem defines the capitulum as a determinate structure that can assume floral fate upon ectopic GhUFO expression. We also show that GhLFY uniquely regulates the ontogeny of outer, expanded ray flowers but not inner, compact disc flowers, indicating that the distinction of different flower types in Asteraceae is connected with their independent evolutionary origins from separate branching systems. PMID:27382139

  7. Evolutionary Co-Option of Floral Meristem Identity Genes for Patterning of the Flower-Like Asteraceae Inflorescence.

    Science.gov (United States)

    Zhao, Yafei; Zhang, Teng; Broholm, Suvi K; Tähtiharju, Sari; Mouhu, Katriina; Albert, Victor A; Teeri, Teemu H; Elomaa, Paula

    2016-09-01

    The evolutionary success of Asteraceae, the largest family of flowering plants, has been attributed to the unique inflorescence architecture of the family, which superficially resembles an individual flower. Here, we show that Asteraceae inflorescences (flower heads, or capitula) resemble solitary flowers not only morphologically but also at the molecular level. By conducting functional analyses for orthologs of the flower meristem identity genes LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) in Gerbera hybrida, we show that GhUFO is the master regulator of flower meristem identity, while GhLFY has evolved a novel, homeotic function during the evolution of head-like inflorescences. Resembling LFY expression in a single flower meristem, uniform expression of GhLFY in the inflorescence meristem defines the capitulum as a determinate structure that can assume floral fate upon ectopic GhUFO expression. We also show that GhLFY uniquely regulates the ontogeny of outer, expanded ray flowers but not inner, compact disc flowers, indicating that the distinction of different flower types in Asteraceae is connected with their independent evolutionary origins from separate branching systems.

  8. The clathrin adaptor complexes as a paradigm for membrane-associated allostery

    OpenAIRE

    Canagarajah, Bertram J.; Ren, Xuefeng; Bonifacino, Juan S.; Hurley, James H.

    2013-01-01

    The clathrin-associated adaptor protein (AP) complexes AP-1 and AP-2 are two members of a family of heterotetrameric assemblies that connect transmembrane protein cargo to vesicular coats. Cargo binding by AP-1 is activated by the small GTPase Arf1, while AP-2 is activated by the phosphoinositide PI(4,5)P2. The structures of both AP-1 and AP-2 have been determined in their locked and unlocked conformations. The structures show how different activators use different mechanisms to trigger simil...

  9. Intercellular transport of epidermis-expressed MADS domain transcription factors and their effect on plant morphology and floral transition

    NARCIS (Netherlands)

    Urbanus, S.L.; Martinelli, A.P.; Dinh, Q.D.; Aizza, L.C.B.; Dornelas, M.; Angenent, G.C.; Immink, G.H.

    2010-01-01

    During the lifetime of an angiosperm plant various important processes such as floral transition, specification of floral organ identity and floral determinacy, are controlled by members of the MADS domain transcription factor family. To investigate the possible non-cell-autonomous function of MADS

  10. The modular structure of the floral phenotype in Mimulus luteus var. luteus (Phrymaceae) Estructura modular del fenotipo floral en Mimulus luteus var. luteus (Phrymaceae)

    OpenAIRE

    GASTÓN CARVALLO; RODRIGO MEDEL

    2005-01-01

    Most studies of multivariate evolution on the floral phenotype assume that traits evolve independently one from each other, ignoring the modular structure that results from genetic correlations or developmental constraints. In this paper we describe the interdependence of nine floral traits in the herb Mimulus luteus var. luteus (Phrymaceae), as an attempt to characterize functional modules on which natural selection can potentially act upon. Using edge exclusion deviance analysis, we detecte...

  11. 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...

  12. Study on Supercooling Point and Freezing Point in Floral Organs of Apricot

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Under the environment of an artificial climate chamber, supercooling point (SCP) and freezing point (FP) in flower and young fruit at different development stages and freezing injuries of floral organs were studied. The apricot cultivars tested were Kety, Golden Sun and Honghebao. With the development of flower buds, SCP and FP increased, which indicated that their cold resistance decreased. SCP and FP varied with different floral organs. For different apricot cultivars, it was found that, the lower SCP or FP in floral organs was, the more resistant capacity the cultivar had, and the larger the temperature interval from SCP to FP was. SCP was not a constant value, but a range. Frequency distribution of SCP in petals was more dispersing than that in stamens and pistils. Floral organs could maintain a supercooling state to avoid ice formation, but they were sensitive to freezing. Once floral organs froze, they turned brown after thawing.

  13. Natural selection on floral volatile production in Penstemon digitalis: highlighting the role of linalool.

    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.

  14. Ecology and evolution of floral volatile-mediated information transfer in plants.

    Science.gov (United States)

    Schiestl, Florian P

    2015-04-01

    Floral volatiles are complex, multi-functional signals that are often used by pollinators in combination with other signals, such as color. Floral visitors use floral scent to estimate the amount of reward present in flowers, to facilitate the identification of a specific host flower or as signals that chemically resemble those important for pollinator insects in other ecological contexts. There is good evidence that floral scent evolves under selection imposed by both mutualists and antagonists. Antagonists may often limit the amount of scent emitted by flowers, thus contributing to spatial population variation, and select for phenotypic plasticity after enemy attack. Floral scent is also an important component of pollinator-mediated reproductive isolation, as it often co-varies with color and morphology in sister species with different pollination systems. PMID:25605223

  15. Floral Reversion in Arabidopsis suecica Is Correlated with the Onset of Flowering and Meristem Transitioning.

    Directory of Open Access Journals (Sweden)

    Amelia Asbe

    Full Text Available Angiosperm flowers are usually determinate structures that may produce seeds. In some species, flowers can revert from committed flower development back to an earlier developmental phase in a process called floral reversion. The allopolyploid Arabidopsis suecica displays photoperiod-dependent floral reversion in a subset of its flowers, yet little is known about the environmental conditions enhancing this phenotype, or the morphological processes leading to reversion. We have used light and electron microscopy to further describe this phenomenon. Additionally, we have further studied the phenology of flowering and floral reversion in A. suecica. In this study we confirm and expand upon our previous findings that floral reversion in the allopolyploid A. suecica is photoperiod-dependent, and show that its frequency is correlated with the timing for the onset of flowering. Our results also suggest that floral reversion in A. suecica displays natural variation in its penetrance between geographic populations of A. suecica.

  16. Floral visitation by the Argentine ant reduces bee visitation and plant seed set.

    Science.gov (United States)

    Hanna, Cause; Naughton, Ida; Boser, Christina; Alarcón, Ruben; Hung, Keng-Lou James; Holway, David

    2015-01-01

    Ants often visit flowers, but have only seldom been documented to provide effective pollination services. Floral visitation by ants can also compromise plant reproduction in situations where ants interfere with more effective pollinators. Introduced ants may be especially likely to reduce plant reproductive success through floral visitation, but existing experimental studies have found little support for this hypothesis. Here, we combine experimental and observational approaches to examine the importance of floral visitation by the nonnative Argentine ant (Linepithema humile) on plant species native to Santa Cruz Island, California, USA. First, we determine how L. humile affects floral visitor diversity, bee visitation rates, and levels of pollen limitation for the common, focal plant species island morning glory (Calystegia macrostegia ssp. macrostegia). Second, we assess the broader ecological consequences of floral visitation by L. humile by comparing floral visitation networks between invaded and uninvaded sites. The Argentine ant and native ants both visited island morning glory flowers, but L. humile was much more likely to behave aggressively towards other floral visitors and to be the sole floral occupant. The presence of L. humile in morning glory flowers reduced floral visitor diversity, decreased rates of bee visitation, and increased levels of pollen limitation. Network comparisons between invaded and uninvaded. sites revealed differences in both network structure and species-level attributes. In. invaded sites, floral visitors were observed on fewer plant species, ants had a higher per-plant interaction strength relative to that of other visitors, and interaction strengths between bees and plants were weaker. These results illustrate that introduced ants can negatively affect plant reproduction and potentially disrupt pollination services at an ecosystem scale. PMID:26236907

  17. 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

    2014-08-01

    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

  18. 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. PMID:26552380

  19. 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.

  20. Effectiveness of Needleless Vial Adaptors and Blunt Cannulas for Drug Administration in a Microgravity Environment

    Science.gov (United States)

    Hailey, M.; Bayuse, T.

    2010-01-01

    Fluid Isolation in the medication vial: Air/ fluid isolation maneuvers were used to move the medication to the septum end of vial. This isolation may be achieved in multiple ways based on the experience of the astronaut with fluid management in microgravity. If vial adaptors/blunt cannula or syringe assembly is inserted into the to vial before fluid isolation commences, the stability of this assembly should be considered in an effort to limit the risk of "slinging off" of the vial during isolation. Alternatively, fluid isolation can be performed prior to attaching the syringe/vial adaptor assembly. Terrestrial practices for medication withdrawal from a nonvented vial require injection of an equivalent amount of air as the expected medication volume prior to withdrawing liquid. In microgravity, this action is still valid, however the injection of additional air into the vial creates a multitude of micro bubbles and increases the volume of medication mixed with air that then must be withdrawn to achieve the desired drug volume in syringe. This practice is more likely to be required when using vials >30ml in size and injection volumes >10mL. It is felt that based on the microgravity flight, the practice of air injection is more of a hindrance than help.

  1. Chimeric adaptor proteins translocate diverse type VI secretion system effectors in Vibrio cholerae.

    Science.gov (United States)

    Unterweger, Daniel; Kostiuk, Benjamin; Ötjengerdes, Rina; Wilton, Ashley; Diaz-Satizabal, Laura; Pukatzki, Stefan

    2015-08-13

    Vibrio cholerae is a diverse species of Gram-negative bacteria, commonly found in the aquatic environment and the causative agent of the potentially deadly disease cholera. These bacteria employ a type VI secretion system (T6SS) when they encounter prokaryotic and eukaryotic competitors. This contractile puncturing device translocates a set of effector proteins into neighboring cells. Translocated effectors are toxic unless the targeted cell produces immunity proteins that bind and deactivate incoming effectors. Comparison of multiple V. cholerae strains indicates that effectors are encoded in T6SS effector modules on mobile genetic elements. We identified a diverse group of chimeric T6SS adaptor proteins required for the translocation of diverse effectors encoded in modules. An example for a T6SS effector that requires T6SS adaptor protein 1 (Tap-1) is TseL found in pandemic V. cholerae O1 serogroup strains and other clinical isolates. We propose a model in which Tap-1 is required for loading TseL onto the secretion apparatus. After T6SS-mediated TseL export is completed, Tap-1 is retained in the bacterial cell to load other T6SS machines.

  2. Synthetic protein scaffolds based on peptide motifs and cognate adaptor domains for improving metabolic productivity

    Directory of Open Access Journals (Sweden)

    Anselm H.C. Horn

    2015-11-01

    Full Text Available The efficiency of many cellular processes relies on the defined interaction among different proteins within the same metabolic or signaling pathway. Consequently, a spatial colocalization of functionally interacting proteins has frequently emerged during evolution. This concept has been adapted within the synthetic biology community for the purpose of creating artificial scaffolds. A recent advancement of this concept is the use of peptide motifs and their cognate adaptor domains. SH2, SH3, GBD, and PDZ domains have been used most often in research studies to date. The approach has been successfully applied to the synthesis of a variety of target molecules including catechin, D-glucaric acid, H2, hydrochinone, resveratrol, butyrate, gamma-aminobutyric acid, and mevalonate. Increased production levels of up to 77-fold have been observed compared to non-scaffolded systems. A recent extension of this concept is the creation of a covalent linkage between peptide motifs and adaptor domains, which leads to a more stable association of the scaffolded systems and thus bears the potential to further enhance metabolic productivity.

  3. The CRKL gene encoding an adaptor protein is amplified, overexpressed, and a possible therapeutic target in gastric cancer

    Directory of Open Access Journals (Sweden)

    Natsume Hiroko

    2012-07-01

    Full Text Available Abstract Background Genomic DNA amplification is a genetic factor involved in cancer, and some oncogenes, such as ERBB2, are highly amplified in gastric cancer. We searched for the possible amplification of other genes in gastric cancer. Methods and Results A genome-wide single nucleotide polymorphism microarray analysis was performed using three cell lines of differentiated gastric cancers, and 22 genes (including ERBB2 in five highly amplified chromosome regions (with a copy number of more than 6 were identified. Particular attention was paid to the CRKL gene, the product of which is an adaptor protein containing Src homology 2 and 3 (SH2/SH3 domains. An extremely high CRKL copy number was confirmed in the MKN74 gastric cancer cell line using fluorescence in situ hybridization (FISH, and a high level of CRKL expression was also observed in the cells. The RNA-interference-mediated knockdown of CRKL in MKN74 disclosed the ability of CRKL to upregulate gastric cell proliferation. An immunohistochemical analysis revealed that CRKL protein was overexpressed in 24.4% (88/360 of the primary gastric cancers that were analyzed. The CRKL copy number was also examined in 360 primary gastric cancers using a FISH analysis, and CRKL amplification was found to be associated with CRKL overexpression. Finally, we showed that MKN74 cells with CRKL amplification were responsive to the dual Src/BCR-ABL kinase inhibitor BMS354825, likely via the inhibition of CRKL phosphorylation, and that the proliferation of MKN74 cells was suppressed by treatment with a CRKL-targeting peptide. Conclusion These results suggested that CRKL protein is overexpressed in a subset of gastric cancers and is associated with CRKL amplification in gastric cancer. Furthermore, our results suggested that CRKL protein has the ability to regulate gastric cell proliferation and has the potential to serve as a molecular therapy target for gastric cancer.

  4. CRM1 and its ribosome export adaptor NMD3 localize to the nucleolus and affect rRNA synthesis.

    Science.gov (United States)

    Bai, Baoyan; Moore, Henna M; Laiho, Marikki

    2013-01-01

    CRM1 is an export factor that together with its adaptor NMD3 transports numerous cargo molecules from the nucleus to cytoplasm through the nuclear pore. Previous studies have suggested that CRM1 and NMD3 are detected in the nucleolus. However, their localization with subnucleolar domains or participation in the activities of the nucleolus are unclear. We demonstrate here biochemically and using imaging analyses that CRM1 and NMD3 co-localize with nucleolar marker proteins in the nucleolus. In particular, their nucleolar localization is markedly increased by inhibition of RNA polymerase I (Pol I) transcription by actinomycin D or by silencing Pol I catalytic subunit, RPA194. We show that CRM1 nucleolar localization is dependent on its activity and the expression of NMD3, whereas NMD3 nucleolar localization is independent of CRM1. This suggests that NMD3 provides nucleolar tethering of CRM1. While inhibition of CRM1 by leptomycin B inhibited processing of 28S ribosomal (r) RNA, depletion of NMD3 did not, suggesting that their effects on 28S rRNA processing are distinct. Markedly, depletion of NMD3 and inhibition of CRM1 reduced the rate of pre-47S rRNA synthesis. However, their inactivation did not lead to nucleolar disintegration, a hallmark of Pol I transcription stress, suggesting that they do not directly regulate transcription. These results indicate that CRM1 and NMD3 have complex functions in pathways that couple rRNA synthetic and processing engines and that the rRNA synthesis rate may be adjusted according to proficiency in rRNA processing and export.

  5. The membrane-associated adaptor protein DOK5 is upregulated in systemic sclerosis and associated with IGFBP-5-induced fibrosis.

    Directory of Open Access Journals (Sweden)

    Hidekata Yasuoka

    Full Text Available Systemic sclerosis (SSc is characterized by excessive fibrosis of the skin and internal organs due to fibroblast proliferation and excessive production of extracellular matrix (ECM. We have shown that insulin-like growth factor binding protein (IGFBP-5 plays an important role in the development of fibrosis in vitro, ex vivo, and in vivo. We identified a membrane-associated adaptor protein, downstream of tyrosine kinase/docking protein (DOK5, as an IGFBP-5-regulated target gene using gene expression profiling of primary fibroblasts expressing IGFBP-5. DOK5 is a tyrosine kinase substrate associated with intracellular signaling. Our objective was to determine the role of DOK5 in the pathogenesis of SSc and specifically in IGFBP-5-induced fibrosis. DOK5 mRNA and protein levels were increased in vitro by endogenous and exogenous IGFBP-5 in primary human fibroblasts. DOK5 upregulation required activation of the mitogen-activated protein kinase (MAPK signaling cascade. Further, IGFBP-5 triggered nuclear translocation of DOK5. DOK5 protein levels were also increased in vivo in mouse skin and lung by IGFBP-5. To determine the effect of DOK5 on fibrosis, DOK5 was expressed ex vivo in human skin in organ culture. Expression of DOK5 in human skin resulted in a significant increase in dermal thickness. Lastly, levels of DOK5 were compared in primary fibroblasts and lung tissues of patients with SSc and healthy donors. Both DOK5 mRNA and protein levels were significantly increased in fibroblasts and skin tissues of patients with SSc compared with those of healthy controls, as well as in lung tissues of SSc patients. Our findings suggest that IGFBP-5 induces its pro-fibrotic effects, at least in part, via DOK5. Furthermore, IGFBP-5 and DOK5 are both increased in SSc fibroblasts and tissues and may thus be acting in concert to promote fibrosis.

  6. De novo transcriptome assembly of floral buds of pineapple and identification of differentially expressed genes in response to ethephon induction

    Directory of Open Access Journals (Sweden)

    Chuan He Liu

    2016-02-01

    -seq and gene expression profiling results. Ethephon-mediated induction likely mimics the process of vernalization in the floral transition in pineapple by increasing LTI, FT and VRN1 expression and promoting the up-regulation of floral meristem identity genes involved in flower development. The candidate genes screened can be used in investigations of the molecular mechanisms of the flowering pathway and of various other biological mechanisms in pineapple.

  7. De novo Transcriptome Assembly of Floral Buds of Pineapple and Identification of Differentially Expressed Genes in Response to Ethephon Induction.

    Science.gov (United States)

    Liu, Chuan-He; Fan, Chao

    2016-01-01

    expression profiling results. Ethephon-mediated induction likely mimics the process of vernalization in the floral transition in pineapple by increasing LTI, FT, and VRN1 expression and promoting the up-regulation of floral meristem identity genes involved in flower development. The candidate genes screened can be used in investigations of the molecular mechanisms of the flowering pathway and of various other biological mechanisms in pineapple. PMID:26955375

  8. 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.

  9. 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

    2012-06-12

    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

  10. 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. PMID:25326292

  11. Functional analysis of B and C class floral organ genes in spinach demonstrates their role in sexual dimorphism

    Directory of Open Access Journals (Sweden)

    Jovanovic Maja

    2010-03-01

    Full Text Available Abstract Background Evolution of unisexual flowers entails one of the most extreme changes in plant development. Cultivated spinach, Spinacia oleracea L., is uniquely suited for the study of unisexual flower development as it is dioecious and it achieves unisexually by the absence of organ development, rather than by organ abortion or suppression. Male staminate flowers lack fourth whorl primordia and female pistillate flowers lack third whorl primordia. Based on theoretical considerations, early inflorescence or floral organ identity genes would likely be directly involved in sex-determination in those species in which organ initiation rather than organ maturation is regulated. In this study, we tested the hypothesis that sexual dimorphism occurs through the regulation of B class floral organ gene expression by experimentally knocking down gene expression by viral induced gene silencing. Results Suppression of B class genes in spinach resulted in the expected homeotic transformation of stamens into carpels but also affected the number of perianth parts and the presence of fourth whorl. Phenotypically normal female flowers developed on SpPI-silenced male plants. Suppression of the spinach C class floral organ identity gene, SpAG, resulted in loss of reproductive organ identity, and indeterminate flowers, but did not result in additional sex-specific characteristics or structures. Analysis of the genomic sequences of both SpAP3 and SpPI did not reveal any allelic differences between males and females. Conclusion Sexual dimorphism in spinach is not the result of homeotic transformation of established organs, but rather is the result of differential initiation and development of the third and fourth whorl primordia. SpAG is inferred to have organ identity and meristem termination functions similar to other angiosperm C class genes. In contrast, while SpPI and SpAP3 resemble other angiosperms in their essential functions in establishing stamen

  12. Molecular cloning and expression analysis of HAG1 in the floral organs of Hyacinthus orientalis L.

    Institute of Scientific and Technical Information of China (English)

    张宪省; 李全梓; 李兴国; 白书农; 陆文樑

    2000-01-01

    HAG1 gene was isolated from the floral organs of Hyacinthus orientalis L. by using RT-PCR. Sequence analysis showed that this gene was homologous to AGAMOUS. Northern hybridization indicated that HAG1 was specifically expressed in floral organs using 3’ end of HAG1 as a probe. Further, transcript of this gene was not detected in differentiating tepals induced by lower concentration of hormones, however, it was detected in differentiating stemans by higher concentration of hormones in vitro. It is possible that there is a close relationship between the concentration of hormones, homeotic genes and identities of floral organs.

  13. Molecular cloning and expression analysis of HAG1 in the floral organs of Hyacinthus orientalis L.

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    HAG1 gene was isolated from the floral organs of Hyacinthus orientalis L. by using RT-PCR. Sequence analysis showed that this gene was homologous to AGAMOUS. Northern hybridization indicated that HAG1 was specifically expressed in floral organs using 3′ end of HAG1 as a probe. Further, transcript of this gene was not detected in differentiating tepals induced by lower concentration of hormones, however, it was detected in differentiating stemans by higher concentration of hormones in vitro. It is possible that there is a close relationship between the concentration of hormones, homeotic genes and identities of floral organs.

  14. 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).

  15. The effect of floral resources on parasitoid and host longevity

    DEFF Research Database (Denmark)

    Sigsgaard, Lene; Betzer, Cathrine; Naulin, Cyril;

    2013-01-01

    to increase functional biodiversity, the longevity of C. aretas and its host A. comariana was assessed on 5 flowering species: buckwheat, Fagopyrum esculentum Moench (Caryophyllales: Polygonaceae); borage, Borago officinalis L. (Boraginaceae); strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae...... at 1, 6, and 11 m distances from buckwheat flower strips in 3 fields. The proportion of field-collected larvae that were parasitized by C. aretas or fungi was assessed. Among the tested floral diets, buckwheat was superior for C. aretas, increasing its longevity by 1.4 times compared to water. Although...... buckwheat also increased longevity of A. comariana, its longevity and survival on buckwheat, borage, and strawberry was not significantly different, so buckwheat was chosen for field experiments. A. comariana densities in the 3 fields with sown buckwheat flower strips were 0.5, 4.0, and 8.3 larvae per m per...

  16. Respiratory Response of Dormant Nectarine Floral Buds on Chilling Deficiency

    Institute of Scientific and Technical Information of China (English)

    TAN Yue; GAO Dong-sheng; LI Ling; CHEN Xiu-de; XU Ai-hong

    2010-01-01

    Changes in main biochemical respiratory pathways in dormant nectarine floral buds were studied with nectarine trees (Prunus persica.var,nectariana cv.Shuguang) in order to determine the function of respiration in dormancy release.Oxygen-electrode system and respiratory inhibitors were used to measure total respiratory rates and rates of respiratory pathways.Results showed that chilling deficiency blocked the transition of respiratory mode,and made buds stay in a state of high level pentose phosphate pathway (PPP) and low level tricarboxylic acid cycle (TCA).The decline of PPP and activation of TCA occurred synchronously with the release of dormancy.In addition,the inhibition of PPP stimulated a respiration increase related with TCA.It could be concluded that the function of PPP activation in dormancy release might be limited and PPP declination inducing TCA activation might be part of respiration mode transition mechanism during bud sprouting.

  17. Floral advertisement and the competition for pollination services.

    Science.gov (United States)

    Fishman, Michael A; Hadany, Lilach

    2015-06-01

    Flowering plants are a major component of terrestrial ecosystems, and most of them depend on animal pollinators for reproduction. Thus, the mutualism between flowering plants and their pollinators is a keystone ecological relationship in both natural and agricultural ecosystems. Though plant-pollinator interactions have received considerable amount of attention, there are still many unanswered questions. In this paper, we use methods of evolutionary game theory to investigate the co-evolution of floral advertisement and pollinator preferences Our results indicate that competition for pollination services among plant species can in some cases lead to specialization of the pollinator population to a single plant species (oligolecty). However, collecting pollen from multiple plants - at least at the population level - is evolutionarily stable under a wider parameter range. Finally, we show that, in the presence of pollinators, plants that optimize their investment in attracting vs. rewarding visiting pollinators outcompete plants that do not. PMID:25869274

  18. Construction of Suppression Subtractive Hybridization Library from the Floral Buds of Paphiopedilum Micranthum%硬叶兜兰花芽SSH文库的构建

    Institute of Scientific and Technical Information of China (English)

    王燕君; 闻真珍; 张娥; 谭志勇; 王亚平; 刘运权; 刘伟

    2012-01-01

    With high ornamental and research value, Paphiopedilum micranthum is a species of the genus Paphio-pedilum native to China, which is endangered and protected intensively by the country. However, there are few reports on its floral development mechanism because of the supply shortage and backward cultivation technology. In this study, a suppression subtractive hybridization (SSH) library was constructed using the cDNAs from the floral and vegetative buds of P. Micranthum as the tester and the driver, respectively. The insert fragments were tested by PCR, and 288 clones with 500 bp or longer from the library were selected for sequencing. Totally, 18 ESTs were obtained, after vector sequences removed and clustered. The ESTs were functionally annotated by Blast. Those which matched significantly with Nr database were further classified into functional groups including photosynthesis, biosynthetic metabolism, gene regulation, etc. Among them, a few sequences with homology to transposons or retro - transposons were obtained. The genes differentially expressed in floral buds of P. Micranthum isolated in this study could make a base for investigating the molecular mechanism of floral development.%利用SMART策略构建了硬叶兜兰花芽的抑制性消减杂交(SSH)文库.通过PCR对文库中插入的片段进行检测后,筛选了288个插入片段为500 bp以上的克隆进行测序.测序结果去除载体序列后聚类得到18条差异表达片段,用BLAST进行比对分析表明,这些差异表达基因所编码的蛋白涉及光合作用、合成代谢、基因调控等功能,其中,包括多个转座子和反转录转座子的同源基因.

  19. The late endosomal adaptor p14 is a macrophage host-defense factor against Salmonella infection.

    Science.gov (United States)

    Taub, Nicole; Nairz, Manfred; Hilber, Diana; Hess, Michael W; Weiss, Günter; Huber, Lukas A

    2012-06-01

    The outcome of an infection depends on the balance between host resistance and bacterial virulence. Here, we show that the late endosomal adaptor p14 (also known as LAMTOR2) is one of the components for cellular host defense against the intracellular pathogen Salmonella enterica serovar Typhimurium. During Salmonella infection, the complex of p14 and MP1 is required for the accurately timed transport of Salmonella through the endolysosomal system. Loss of p14 opens a time window that allows Salmonella to populate a replication niche, in which early and late antimicrobial effector systems, comprising NADPH phagocytic oxidase and inducible nitric oxide synthase, respectively, are inappropriately activated. Thus, p14 supports the accurate transport of Salmonella through the endolysosomal system, thereby limiting bacterial replication in both, professional phagocytes and in non-phagocytic cells in vitro, and helps mice to successfully battle Salmonella infection in vivo.

  20. A role for adaptor protein-3 complex in the organization of the endocytic pathway in Dictyostelium.

    Science.gov (United States)

    Charette, Steve J; Mercanti, Valentina; Letourneur, François; Bennett, Nelly; Cosson, Pierre

    2006-11-01

    Dictyostelium discoideum cells continuously internalize extracellular material, which accumulates in well-characterized endocytic vacuoles. In this study, we describe a new endocytic compartment identified by the presence of a specific marker, the p25 protein. This compartment presents features reminiscent of mammalian recycling endosomes: it is localized in the pericentrosomal region but distinct from the Golgi apparatus. It specifically contains surface proteins that are continuously endocytosed but rapidly recycled to the cell surface and thus absent from maturing endocytic compartments. We evaluated the importance of each clathrin-associated adaptor complex in establishing a compartmentalized endocytic system by studying the phenotype of the corresponding mutants. In knockout cells for mu3, a subunit of the AP-3 clathrin-associated complex, membrane proteins normally restricted to p25-positive endosomes were mislocalized to late endocytic compartments. Our results suggest that AP-3 plays an essential role in the compartmentalization of the endocytic pathway in Dictyostelium. PMID:17010123

  1. 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.

  2. 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.

  3. The Influences of Connectors and Adaptors to Fiber-To-The-Home Network Performance

    Directory of Open Access Journals (Sweden)

    Mohammad S. Ab-Rahman

    2012-01-01

    Full Text Available Problem statement: The reliability of the entire communications network was dependent on the reliability of each single element. Connector was important devices that can affect the performance of the fiber communication. There were a large number of issues that affect the performance of fiber optic connectors in todays networks. These factors were increasingly as data rates, the number of wavelengths and transmission distances continue to escalate. Approach: Therefore this study was carried out to test on the influence of connectors and adapters to the performance of the optical network. Initially the actual attenuation of connector and adaptor were tested by using multifunction loss tester. The first two 1 m corning optical fibers with a connector at each end are measured. Then, both the 1 m corning optical fibers were joined together by an adaptor and connected to the Multifunction loss tester. Three types of wavelength are used as the source to test the attenuation of the fiber which is 1310, 1490-1550 nm. In order to measure the Bit Error Rate (BER and the power loss in optical fiber communication, a simple simulation was carried out by using software opti sys. Results: The attenuation on the connector was caused mainly by existence of impurities in the connector, less perfect connection, scattering of beam and others. These causes the parameter such as power received, Q-factor, minimum BER and also the eye-height to change. Changes in these parameters also affect the performance at the user end. It was very critical that causes of attenuation to be eliminated. Conclusion/Recommendations: From the result it can be concluded that, the greater the attenuation, the greater the decrease in power received. It also affects the Q-factor of the system where as the attenuation increase, the maximum Q-factor decreases. As for the minimum BER, minimum BER changes as the attenuation increase initially, after a maximum value it decreases as the

  4. Molecular basis of substrate selection by the N-end rule adaptor protein ClpS

    Energy Technology Data Exchange (ETDEWEB)

    Román-Hernández, Giselle; Grant, Robert A.; Sauer, Robert T.; Baker, Tania A.; (HHMI)

    2009-06-19

    The N-end rule is a conserved degradation pathway that relates the stability of a protein to its N-terminal amino acid. Here, we present crystal structures of ClpS, the bacterial N-end rule adaptor, alone and engaged with peptides containing N-terminal phenylalanine, leucine, and tryptophan. These structures, together with a previous structure of ClpS bound to an N-terminal tyrosine, illustrate the molecular basis of recognition of the complete set of primary N-end rule amino acids. In each case, the alpha-amino group and side chain of the N-terminal residue are the major determinants of recognition. The binding pocket for the N-end residue is preformed in the free adaptor, and only small adjustments are needed to accommodate N-end rule residues having substantially different sizes and shapes. M53A ClpS is known to mediate degradation of an expanded repertoire of substrates, including those with N-terminal valine or isoleucine. A structure of Met53A ClpS engaged with an N-end rule tryptophan reveals an essentially wild-type mechanism of recognition, indicating that the Met(53) side chain directly enforces specificity by clashing with and excluding beta-branched side chains. Finally, experimental and structural data suggest mechanisms that make proteins with N-terminal methionine bind very poorly to ClpS, explaining why these high-abundance proteins are not degraded via the N-end rule pathway in the cell.

  5. Comparison of Pollen Transfer Dynamics by Multiple Floral Visitors: Experiments with Pollen and Fluorescent Dye

    OpenAIRE

    ADLER, LYNN S.; Irwin, Rebecca E.

    2006-01-01

    • Background and Aims Most plant species are visited by a diversity of floral visitors. Pollen transfer of the four most common pollinating bee species and one nectar-robbing bee of the distylous plant Gelsemium sempervirens were compared.

  6. Changes in floral bouquets from compound-specific responses to increasing temperatures

    OpenAIRE

    Farré Armengol, Gerard; Filella Cubells, Iolanda; Niinemets, Ülo; Peñuelas, Josep

    2014-01-01

    We addressed the potential effects of changes in ambient temperature on the profiles of volatile emissions from flowers and tested whether warming could induce significant quantitative and qualitative changes in floral emissions, which would potentially interfere with plant-pollinator chemical communication. We measured the temperature responses of floral emissions of various common species of Mediterranean plants using dynamic headspace sampling and used GC-MS to identify and quantify the em...

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

    OpenAIRE

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

    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 m...

  8. The importance of floral signals in the establishment of plant-ant mutualisms

    OpenAIRE

    Vega, Clara de

    2009-01-01

    Visual and olfactory floral signals are essential for the establishment of plant-pollinator mutualisms. Different batteries of floral features attract different pollinators and may achieve specific relationships that are essential for the immediate plant reproductive success, and at an evolutionary time scale have been of vital importance in the radiation of Angiosperms. We have found that mutualistic services by ants, insects traditionally considered ineffective pollinators, are essential fo...

  9. How to be sweet? Extra floral nectar allocation by Gossypium hirsutum fits optimal defense theory predictions

    OpenAIRE

    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 categorization, in reality the functions may not be so discrete. Extrafloral nectar may serve a role in pollination, while floral nectar can be utilized by predators and parasitoids and thus can contribute to pl...

  10. Early spring floral foraging resources for pollinators in wet heathlands in Belgium

    OpenAIRE

    Moquet, Laura; Mayer, Carolin; Michez, Denis; Wathelet, Bernard; Jacquemart, Anne-Laure

    2015-01-01

    In temperate regions, foraging resources for pollinating insects are particularly important in early spring, especially for social insects like bumblebees that are initiating colonies. Heathlands, protected open habitats under EU law, provide floral resources (pollen and nectar) for a range of pollinating insects. In early spring, in Belgian heathlands, only two floral resources are available: willows Salix spp. (Salicaceae) and bilberry Vaccinium myrtillus (Ericaceae). Our objective was to a...

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

    OpenAIRE

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

    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...

  12. Explaining the effects of floral density on flower visitor species composition

    OpenAIRE

    Essenberg, Carla J.

    2013-01-01

    Floral density often influences the species composition of flower visitors. This variation in visitor species composition could have significant effects on pollination success and plant fitness but is poorly understood, especially in the many pollination guilds dominated by non-territorial species. This paper presents a foraging model that explores how flower visitors with diverse traits should distribute themselves across resource patches differing in floral density. The model predicts that ...

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

    OpenAIRE

    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 lev...

  14. Floral visitors and reproductive strategies in five melittophilous species of Bignoniaceae in Southeastern Brazil

    OpenAIRE

    Yuriko A. N. Pinto Yanagizawa; Rita de Cassia Sindrônia Maimoni-Rodella

    2007-01-01

    In order to evaluate the pollination strategies of Bignoniaceae, the floral biology and the floral visitors in five species, three cerrado shrubs (Arrabidaea brachypoda (DC.) Bor., Jacaranda decurrens Cham., and Jacaranda oxyphylla Cham.), and two lianas from the border of a semideciduous seasonal forest (Arrabidaea samydoides (Cham.) Sandw., and Arrabidaea triplinervia H. Baill.) were studied in Botucatu, São Paulo State, Southeastern Brazil. The flowering periods were partially overlapping,...

  15. Floral traits driving reproductive isolation of two co-flowering taxa that share vertebrate pollinators

    OpenAIRE

    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...

  16. Wild bees preferentially visit Rudbeckia flower heads with exaggerated ultraviolet absorbing floral guides

    OpenAIRE

    Lisa Horth; Laura Campbell; Rebecca Bray

    2014-01-01

    ABSTRACT Here, we report on the results of an experimental study that assessed the visitation frequency of wild bees to conspecific flowers with different sized floral guides. UV absorbent floral guides are ubiquitous in Angiosperms, yet surprisingly little is known about conspecific variation in these guides and very few studies have evaluated pollinator response to UV guide manipulation. This is true despite our rich understanding about learning and color preferences in bees. Historical dog...

  17. Floral traits influence pollen vectors’ choices in higher elevation communities in the Himalaya-Hengduan Mountains

    OpenAIRE

    Zhao, Yan-Hui; Ren, Zong-Xin; Lázaro, Amparo; Wang, Hong; Bernhardt, Peter; Li, Hai-Dong; Li, De-Zhu

    2016-01-01

    Background How floral traits and community composition influence plant specialization is poorly understood and the existing evidence is restricted to regions where plant diversity is low. Here, we assessed whether plant specialization varied among four species-rich subalpine/alpine communities on the Yulong Mountain, SW China (elevation from 2725 to 3910 m). We analyzed two factors (floral traits and pollen vector community composition: richness and density) to determine the degree of plant s...

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

    OpenAIRE

    Peter Kwapong; Andreas Kudom

    2010-01-01

    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 ins...

  19. Floral evolution in the Annonaceae: hypotheses of homeotic mutations and functional convergence.

    Science.gov (United States)

    Saunders, Richard M K

    2010-08-01

    The recent publication of hypotheses explaining the homeotic control of floral organ identity together with the availability of increasingly comprehensive and well-resolved molecular phylogenies presents an ideal opportunity for reassessing current knowledge of floral diversity and evolution in the Annonaceae. This review summarizes currently available information on selected aspects of floral structure and function, including: changes in the number of perianth whorls and the number of perianth parts per whorl; the evolution of sympetaly; the diversity and evolution of pollination chambers (with a novel classification of seven main structural forms of floral chamber based on the different arrangement, size and shape of petals); the evolution of perianth glands; floral unisexuality and hypotheses explaining the unexpectedly high frequency of occurrence of androdioecy; the origin and possible function of inner and outer staminodes; the evolution of stamen connective diversity and theca septation; and the origin of 'true' syncarpy and functionally equivalent extragynoecial compita. In each case, current ideas on the origin, evolution and function are discussed. The information presented in this review enables two main conclusions to be drawn. The first is that changes in the homeotic control of floral organ identity may have had a profound impact on floral structure in several disparate lineages in the family. This is most obvious in Fenerivia, in which a centrifugal shift of floral organ identity has occurred, and in Dasymaschalon, in which a reverse (centripetal) shift has occurred. Other genera that have gained or lost entire perianth whorls are likely to have undergone similar homeotic changes. Attention is also drawn to the extensive functional convergence in Annonaceae flowers, with widespread homoplasy in many characters that have previously been emphasized in higher-level classifications.

  20. Floral humidity and other indicators of energy rewards in pollination biology

    OpenAIRE

    von Arx, Martin

    2013-01-01

    Floral traits that correlate with nectar availability or are linked functionally to nectar production carry the potential to enable remote assessment of energy rewards by pollinators. Such floral traits can be considered “honest” in the sense that they convey information about the quality or profitability of a flower to a pollinator. Recently a new sensory channel used in plant-pollinator interactions was identified. We demonstrated that evaporation of water from the nectar itself and the pet...

  1. Floral and Seed Variability Patterns among Ethiopian Mustard (B. carinata A. Braun) of East Africa

    OpenAIRE

    Adeniji, OT.; A. Aloyce, A.

    2012-01-01

    In East Africa, Ethiopian mustard (Brassica carinata A. Braun) is cultivated primarily for its leaves, but in Ethiopia preference is high for oil in the seed. Dual purpose importance of the seeds for planting and for oil suggests the need to improve seed production efficiency through understanding variation pattern for floral morphology and seed characters. We investigated genetic diversity and correlations for floral and seed characteristics among 14 accessions of Ethiopian mustard to improv...

  2. Floral anatomy of Delphinieae (Ranunculaceae: comparing flower organization and vascular patterns

    Directory of Open Access Journals (Sweden)

    Andrew V. Novikoff

    2014-04-01

    Full Text Available Species of the tribe Delphinieae have dorsoventralized flowers; their pentamerous calyx and reduced corolla are dorsally spurred and inner spurs are nectariferous. Based on this common floral scheme, Delphinieae species exhibit a wide diversity of floral structures and morphologies. We present here the first investigation of the floral anatomy in Delphinieae. The organization of the floral vascular system has been studied in species representative of the floral morphological diversity of Delphinieae: Aconitum lasiocarpum, Delphinium elatum, and Consolida regalis. The three species show a similar vascularization of the calyx and of the reproductive organs, but exhibit distinct anatomical features in the corolla where the nectaries are borne. The sepals and the stamens have a trilacunar three-traced and a unilacunar one-traced vascularization, respectively. Three free carpels in D. elatum and A. lasiocarpum are basically supplied by six vascular bundles – three independent dorsal bundles and three fused lateral bundles. In C. regalis the single carpel is supplied by three independent vascular bundles (one dorsal and two ventral. Staminodes are not vascularized. The basic type of petal vascularization is unilacunar one-traced, but in the case of C. regalis the derived bilacunar two-traced type has been observed. This latter state arose as a result of the fusion of the two dorsal petal primordia. The results of this first comparative study of the floral anatomy of Delphinieae are discussed with the recent phylogenetic, morphological, and evo-devo findings concerning the tribe.

  3. Plant-pollinator interactions and floral convergence in two species of Heliconia from the Caribbean Islands.

    Science.gov (United States)

    Martén-Rodríguez, Silvana; Kress, W John; Temeles, Ethan J; Meléndez-Ackerman, Elvia

    2011-12-01

    Variation in interspecific interactions across geographic space is a potential driver of diversification and local adaptation. This study quantitatively examined variation in floral phenotypes and pollinator service of Heliconia bihai and H. caribaea across three Antillean islands. The prediction was that floral characters would correspond to the major pollinators of these species on each island. Analysis of floral phenotypes revealed convergence among species and populations of Heliconia from the Greater Antilles. All populations of H. caribaea were similar, characterized by long nectar chambers and short corolla tubes. In contrast, H. bihai populations were strongly divergent: on Dominica, H. bihai had flowers with short nectar chambers and long corollas, whereas on Hispaniola, H. bihai flowers resembled those of H. caribaea with longer nectar chambers and shorter corolla tubes. Morphological variation in floral traits corresponded with geographic differences or similarities in the major pollinators on each island. The Hispaniolan mango, Anthracothorax dominicus, is the principal pollinator of both H. bihai and H. caribaea on Hispaniola; thus, the similarity of floral phenotypes between Heliconia species suggests parallel selective regimes imposed by the principal pollinator. Likewise, divergence between H. bihai populations from Dominica and Hispaniola corresponded with differences in the pollinators visiting this species on the two islands. The study highlights the putative importance of pollinator-mediated selection as driving floral convergence and the evolution of locally-adapted plant variants across a geographic mosaic of pollinator species.

  4. Plant-pollinator interactions and floral convergence in two species of Heliconia from the Caribbean Islands.

    Science.gov (United States)

    Martén-Rodríguez, Silvana; Kress, W John; Temeles, Ethan J; Meléndez-Ackerman, Elvia

    2011-12-01

    Variation in interspecific interactions across geographic space is a potential driver of diversification and local adaptation. This study quantitatively examined variation in floral phenotypes and pollinator service of Heliconia bihai and H. caribaea across three Antillean islands. The prediction was that floral characters would correspond to the major pollinators of these species on each island. Analysis of floral phenotypes revealed convergence among species and populations of Heliconia from the Greater Antilles. All populations of H. caribaea were similar, characterized by long nectar chambers and short corolla tubes. In contrast, H. bihai populations were strongly divergent: on Dominica, H. bihai had flowers with short nectar chambers and long corollas, whereas on Hispaniola, H. bihai flowers resembled those of H. caribaea with longer nectar chambers and shorter corolla tubes. Morphological variation in floral traits corresponded with geographic differences or similarities in the major pollinators on each island. The Hispaniolan mango, Anthracothorax dominicus, is the principal pollinator of both H. bihai and H. caribaea on Hispaniola; thus, the similarity of floral phenotypes between Heliconia species suggests parallel selective regimes imposed by the principal pollinator. Likewise, divergence between H. bihai populations from Dominica and Hispaniola corresponded with differences in the pollinators visiting this species on the two islands. The study highlights the putative importance of pollinator-mediated selection as driving floral convergence and the evolution of locally-adapted plant variants across a geographic mosaic of pollinator species. PMID:21792557

  5. Visitantes florales diurnos del girasol (Helianthus annuus, Asterales: Asteraceae) en la Argentina Diurnal floral visitors of sunflower (Helianthus annuus, Asterales: Asteraceae) in Argentina

    OpenAIRE

    Juan P. Torretta; Diego Medan; Arturo Roig Alsina; Norberto H. Montaldo

    2010-01-01

    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 ...

  6. Biologia floral e polinização de Arrabidaea conjugata (Vell.) Mart. (Bignoniaceae) Floral and pollination biology of Arrabidaea conjugata (Vell.) Mart. (Bignoniaceae)

    OpenAIRE

    Maria Célia Rodrigues Correia; Maria Célia B. Pinheiro; Heloísa Alves de Lima

    2005-01-01

    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...

  7. Crystal structure of Toll-like receptor adaptor MAL/TIRAP reveals the molecular basis for signal transduction and disease protection

    OpenAIRE

    Valkov, Eugene; Stamp, Anna; DiMaio, Frank; Baker, David; Verstak, Brett; Roversi, Pietro; Kellie, Stuart; Sweet, Matthew J.; Mansell, Ashley; Gay, Nicholas J.; Jennifer L Martin; Kobe, Bostjan

    2011-01-01

    Initiation of the innate immune response requires agonist recognition by pathogen-recognition receptors such as the Toll-like receptors (TLRs). Toll/interleukin-1 receptor (TIR) domain-containing adaptors are critical in orchestrating the signal transduction pathways after TLR and interleukin-1 receptor activation. Myeloid differentiation primary response gene 88 (MyD88) adaptor-like (MAL)/TIR domain-containing adaptor protein (TIRAP) is involved in bridging MyD88 to TLR2 and TLR4 in response...

  8. Large scale interaction analysis predicts that the Gerbera hybrida floral E function is provided both by general and specialized proteins

    Directory of Open Access Journals (Sweden)

    Elomaa Paula

    2010-06-01

    Full Text Available Abstract Background The ornamental plant Gerbera hybrida bears complex inflorescences with morphologically distinct floral morphs that are specific to the sunflower family Asteraceae. We have previously characterized several MADS box genes that regulate floral development in Gerbera. To study further their behavior in higher order complex formation according to the quartet model, we performed yeast two- and three-hybrid analysis with fourteen Gerbera MADS domain proteins to analyze their protein-protein interaction potential. Results The exhaustive pairwise interaction analysis showed significant differences in the interaction capacity of different Gerbera MADS domain proteins compared to other model plants. Of particular interest in these assays was the behavior of SEP-like proteins, known as GRCDs in Gerbera. The previously described GRCD1 and GRCD2 proteins, which are specific regulators involved in stamen and carpel development, respectively, showed very limited pairwise interactions, whereas the related GRCD4 and GRCD5 factors displayed hub-like positions in the interaction map. We propose GRCD4 and GRCD5 to provide a redundant and general E function in Gerbera, comparable to the SEP proteins in Arabidopsis. Based on the pairwise interaction data, combinations of MADS domain proteins were further subjected to yeast three-hybrid assays. Gerbera B function proteins showed active behavior in ternary complexes. All Gerbera SEP-like proteins with the exception of GRCD1 were excellent partners for B function proteins, further implicating the unique role of GRCD1 as a whorl- and flower-type specific C function partner. Conclusions Gerbera MADS domain proteins exhibit both conserved and derived behavior in higher order protein complex formation. This protein-protein interaction data can be used to classify and compare Gerbera MADS domain proteins to those of Arabidopsis and Petunia. Combined with our reverse genetic studies of Gerbera, these

  9. Floral biology and breeding system of Psychotria tenuinervis Muell. Arg. (Rubiaceae) in the Atlantic rain forest, SE Brazil Biologia floral e sistema reprodutivo de Psychotria tenuinervis Muell. Arg. (Rubiaceae) na Floresta Atlântica, SE Brasil

    OpenAIRE

    Carolina Bernucci Virillo; Flavio Nunes Ramos; Cibele Cardoso de Castro; João Semir

    2007-01-01

    (Floral biology and breeding system oi Psychotria tenuinervis Muell. Arg. (Rubiaceae) in the Atlantic rain forest, SE Brazil). The aim of this study was to investigate pollination biology, floral morphometry, morph ratio and breeding system oiPsychotria tenuinervis in an area of Atlantic rain forest in southeastern Brazil. Pollination biology was studied based on focal observations and the breeding system was determined using controlled crosses; data on flower production and floral morphometr...

  10. DVC1 (C1orf124) is a DNA damage-targeting p97 adaptor that promotes ubiquitin-dependent responses to replication blocks.

    Science.gov (United States)

    Mosbech, Anna; Gibbs-Seymour, Ian; Kagias, Konstantinos; Thorslund, Tina; Beli, Petra; Povlsen, Lou; Nielsen, Sofie Vincents; Smedegaard, Stine; Sedgwick, Garry; Lukas, Claudia; Hartmann-Petersen, Rasmus; Lukas, Jiri; Choudhary, Chunaram; Pocock, Roger; Bekker-Jensen, Simon; Mailand, Niels

    2012-11-01

    Ubiquitin-mediated processes orchestrate critical DNA-damage signaling and repair pathways. We identify human DVC1 (C1orf124; Spartan) as a cell cycle-regulated anaphase-promoting complex (APC) substrate that accumulates at stalled replication forks. DVC1 recruitment to sites of replication stress requires its ubiquitin-binding UBZ domain and PCNA-binding PIP box motif but is independent of RAD18-mediated PCNA monoubiquitylation. Via a conserved SHP box, DVC1 recruits the ubiquitin-selective chaperone p97 to blocked replication forks, which may facilitate p97-dependent removal of translesion synthesis (TLS) DNA polymerase η (Pol η) from monoubiquitylated PCNA. DVC1 knockdown enhances UV light-induced mutagenesis, and depletion of human DVC1 or the Caenorhabditis elegans ortholog DVC-1 causes hypersensitivity to replication stress-inducing agents. Our findings establish DVC1 as a DNA damage-targeting p97 adaptor that protects cells from deleterious consequences of replication blocks and suggest an important role of p97 in ubiquitin-dependent regulation of TLS. PMID:23042605

  11. Involvement of Grb2 adaptor protein in nucleophosmin-anaplastic lymphoma kinase (NPM-ALK)-mediated signaling and anaplastic large cell lymphoma growth.

    Science.gov (United States)

    Riera, Ludovica; Lasorsa, Elena; Ambrogio, Chiara; Surrenti, Nadia; Voena, Claudia; Chiarle, Roberto

    2010-08-20

    Most anaplastic large cell lymphomas (ALCL) express oncogenic fusion proteins derived from chromosomal translocations or inversions of the anaplastic lymphoma kinase (ALK) gene. Frequently ALCL carry the t(2;5) translocation, which fuses the ALK gene to the nucleophosmin (NPM1) gene. The transforming activity mediated by NPM-ALK fusion induces different pathways that control proliferation and survival of lymphoma cells. Grb2 is an adaptor protein thought to play an important role in ALK-mediated transformation, but its interaction with NPM-ALK, as well as its function in regulating ALCL signaling pathways and cell growth, has never been elucidated. Here we show that active NPM-ALK, but not a kinase-dead mutant, bound and induced Grb2 phosphorylation in tyrosine 160. An intact SH3 domain at the C terminus of Grb2 was required for Tyr(160) phosphorylation. Furthermore, Grb2 did not bind to a single region but rather to different regions of NPM-ALK, mainly Tyr(152-156), Tyr(567), and a proline-rich region, Pro(415-417). Finally, shRNA knockdown experiments showed that Grb2 regulates primarily the NPM-ALK-mediated phosphorylation of SHP2 and plays a key role in ALCL cell growth.

  12. Src-Like adaptor protein (SLAP) binds to the receptor tyrosine kinase Flt3 and modulates receptor stability and downstream signaling.

    Science.gov (United States)

    Kazi, Julhash U; Rönnstrand, Lars

    2012-01-01

    Fms-like tyrosine kinase 3 (Flt3) is an important growth factor receptor in hematopoiesis. Gain-of-function mutations of the receptor contribute to the transformation of acute myeloid leukemia (AML). Src-like adaptor protein (SLAP) is an interaction partner of the E3 ubiquitin ligase Cbl that can regulate receptor tyrosine kinases-mediated signal transduction. In this study, we analyzed the role of SLAP in signal transduction downstream of the type III receptor tyrosine kinase Flt3. The results show that upon ligand stimulation SLAP stably associates with Flt3 through multiple phosphotyrosine residues in Flt3. SLAP constitutively interacts with oncogenic Flt3-ITD and co-localizes with Flt3 near the cell membrane. This association initiates Cbl-dependent receptor ubiquitination and degradation. Depletion of SLAP expression by shRNA in Flt3-transfected Ba/F3 cells resulted in a weaker activation of FL-induced PI3K-Akt and MAPK signaling. Meta-analysis of microarray data from patient samples suggests that SLAP mRNA is differentially expressed in different cancers and its expression was significantly increased in patients carrying the Flt3-ITD mutation. Thus, our data suggest a novel role of SLAP in different cancers and in modulation of receptor tyrosine kinase signaling apart from its conventional role in regulation of receptor stability.

  13. Src-Like adaptor protein (SLAP binds to the receptor tyrosine kinase Flt3 and modulates receptor stability and downstream signaling.

    Directory of Open Access Journals (Sweden)

    Julhash U Kazi

    Full Text Available Fms-like tyrosine kinase 3 (Flt3 is an important growth factor receptor in hematopoiesis. Gain-of-function mutations of the receptor contribute to the transformation of acute myeloid leukemia (AML. Src-like adaptor protein (SLAP is an interaction partner of the E3 ubiquitin ligase Cbl that can regulate receptor tyrosine kinases-mediated signal transduction. In this study, we analyzed the role of SLAP in signal transduction downstream of the type III receptor tyrosine kinase Flt3. The results show that upon ligand stimulation SLAP stably associates with Flt3 through multiple phosphotyrosine residues in Flt3. SLAP constitutively interacts with oncogenic Flt3-ITD and co-localizes with Flt3 near the cell membrane. This association initiates Cbl-dependent receptor ubiquitination and degradation. Depletion of SLAP expression by shRNA in Flt3-transfected Ba/F3 cells resulted in a weaker activation of FL-induced PI3K-Akt and MAPK signaling. Meta-analysis of microarray data from patient samples suggests that SLAP mRNA is differentially expressed in different cancers and its expression was significantly increased in patients carrying the Flt3-ITD mutation. Thus, our data suggest a novel role of SLAP in different cancers and in modulation of receptor tyrosine kinase signaling apart from its conventional role in regulation of receptor stability.

  14. The adaptor protein DCAF7 mediates the interaction of the adenovirus E1A oncoprotein with the protein kinases DYRK1A and HIPK2.

    Science.gov (United States)

    Glenewinkel, Florian; Cohen, Michael J; King, Cason R; Kaspar, Sophie; Bamberg-Lemper, Simone; Mymryk, Joe S; Becker, Walter

    2016-01-01

    DYRK1A is a constitutively active protein kinase that has a critical role in growth and development which functions by regulating cell proliferation, differentiation and survival. DCAF7 (also termed WDR68 or HAN11) is a cellular binding partner of DYRK1A and also regulates signalling by the protein kinase HIPK2. DCAF7 is an evolutionarily conserved protein with a single WD40 repeat domain and has no catalytic activity. We have defined a DCAF7 binding motif of 12 amino acids in the N-terminal domain of class 1 DYRKs that is functionally conserved in DYRK1 orthologs from Xenopus, Danio rerio and the slime mold Dictyostelium discoideum. A similar sequence was essential for DCAF7 binding to HIPK2, whereas the closely related HIPK1 family member did not bind DCAF7. Immunoprecipitation and pulldown experiments identified DCAF7 as an adaptor for the association of the adenovirus E1A protein with DYRK1A and HIPK2. Furthermore, DCAF7 was required for the hyperphosphorylation of E1A in DYRK1A or HIPK2 overexpressing cells. Our results characterize DCAF7 as a substrate recruiting subunit of DYRK1A and HIPK2 and suggest that it is required for the negative effect of DYRK1A on E1A-induced oncogenic transformation. PMID:27307198

  15. Involvement of β3A Subunit of Adaptor Protein-3 in Intracellular Trafficking of Receptor-like Protein Tyrosine Phosphatase PCP-2

    Institute of Scientific and Technical Information of China (English)

    Hui DONG; Hong YUAN; Weirong JIN; Yan SHEN; Xiaojing XU; Hongyang WANG

    2007-01-01

    PCP-2 is a human receptor-like protein tyrosine phosphatase and a member of the MAM domain family cloned in human pancreatic adenocarcinoma cells. Previous studies showed that PCP-2 directly interacted with β-catenin through the juxtamembrane domain, dephosphorylated β-catenin and played an important role in the regulation of cell adhesion. Recent study showed that PCP-2 was also involved in the repression of β-catenin-induced transcriptional activity. Here we describe the interactions of PCP-2 with the β3A subunit of adaptor protein (AP)-3 and sorting nexin (SNX) 3. These protein complexes were detected using the yeast two-hybrid assay with the juxtamembrane and membrane-proximal catalytic domain of PCP-2 as "bait". Both AP-3 and SNX3 are molecules involved in intracellular trafficking of membrane receptors. The association between the β3A subunit of AP-3 and PCP-2 was further confirmed in mammalian cells. Our results suggested a possible mechanism of intracellular trafficking of PCP-2 mediated by AP-3 and SNX3 which might participate in the regulation of PCP-2 functions.

  16. Floral biology of the Cunoniaceae in New Caledonia and the role of insects, birds and geckos as potential pollinators

    OpenAIRE

    Hopkins, H.C.F.; Bradford, J.C.; Donovan, B; Pillon, Y.; Munzinger, Jérôme; Fogliani, B.

    2015-01-01

    Cunoniaceae are represented in New Caledonia by some 90 species, all of them endemic, and the family is thus a significant element in this diverse island flora. We present a descriptive survey of floral biology for the seven genera present, covering floral structure and colour, inflorescence shape, sexual system and phenology, plus details of floral visitors, where known, based on field observations; individual records of potential pollinators are tabulated in appendices. The flowers are poly...

  17. Floral scent variation in two Antirrhinum majus subspecies influences the choice of naïve bumblebees

    OpenAIRE

    Dormont, Laurent; Schatz, Bertrand; Giurfa, Martin; Simon, Valérie; Raynaud, Christine; Chave, Jérôme

    2011-01-01

    Two wild subspecies of snapdragon, Antirrhinum majus, subspecies pseudomajus and striatum, differ in floral color and can be visually discriminated by insect visitors. The extent to which olfactory cues derived from floral scents contribute to discrimination between snapdragon subspecies is however unknown. We tested whether these two subspecies differ in floral scent and whether these olfactory differences are used by bumblebees (Bombus terrestris) to discriminate between them. We grew indiv...

  18. A ¤Terminal Flower-1¤-like gene from perennial ryegrass involved in floral transition and axillary meristem identity

    DEFF Research Database (Denmark)

    Jensen, C.S.; Salchert, K.; Nielsen, K.K.

    2001-01-01

    . To investigate the regulation of meristem identity and the control of floral transition in perennial ryegrass (Lolium perenne) we isolated a ryegrass TERMINAL FLOWER1-like gene, LpTFL1, and characterized it for its function in ryegrass flower development. Perennial ryegrass requires a cold treatment of at least...... spikelets. Arabidopsis plants overexpressing LpTFL1 were significantly delayed in flowering and exhibited dramatic changes in architecture such as extensive lateral branching, increased growth of all vegetative organs, and a highly increased trichome production. Furthermore, overexpression of LpTFL1...... and a controller of axillary meristem identity in ryegrass....

  19. Reduced transcription of a LEAFY-like gene in Alstroemeria sp. cultivar Green Coral that cannot develop floral meristems.

    Science.gov (United States)

    Hirai, Masayo; Yamagishi, Masumi; Kanno, Akira

    2012-04-01

    Alstroemeria sp. cv. Green Coral has numerous bracts instead of flowers, and its cyme structures are repeated eternally. Observations of the development and morphology of inflorescence in cv. Green Coral revealed that transition from inflorescence to floral meristem was restricted. We isolated and characterized floral meristem identity genes LEAFY-like (AlsLFY) and SQUAMOSA-like (AlsSQa and AlsSQb) genes from Alstroemeria ligtu. In situ hybridization results indicated that AlsSQa and AlsSQb were expressed in the dome-shaped floral meristems and all floral organ primordia in A. ligtu. Transcripts of AlsLFY accumulated early in the dome-shaped floral meristems; the signals were restricted later to the outer region of the floral meristem. These results indicate that AlsLFY, AlsSQa, and AlsSQb function as floral meristem identity genes. Expression profiles of AlsLFY, AlsSQa, AlsSQb, and other MADS-box genes were compared between A. ligtu and cv. Green Coral. AlsLFY, AlsDEFa, and AlsAGL6 transcripts were not detected at the shoot apices of cv. Green Coral but were detected in A. ligtu. The early induction and accumulation of AlsLFY transcripts in the inflorescence meristem of A. ligtu prior to development of the floral meristem suggest that downregulation of AlsLFY is likely to restrict the inflorescence-to-floral meristem transition in cv. Green Coral. PMID:22325893

  20. 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.

  1. Do honeybees shape the bacterial community composition in floral nectar?

    Directory of Open Access Journals (Sweden)

    Yana Aizenberg-Gershtein

    Full Text Available Floral nectar is considered the most important reward animal-pollinated plants offer to attract pollinators. Here we explore whether honeybees, which act as pollinators, affect the composition of bacterial communities in the nectar. Nectar and honeybees were sampled from two plant species: Amygdalus communis and Citrus paradisi. To prevent the contact of nectar with pollinators, C. paradisi flowers were covered with net bags before blooming (covered flowers. Comparative analysis of bacterial communities in the nectar and on the honeybees was performed by the 454-pyrosequencing technique. No significant differences were found among bacterial communities in honeybees captured on the two different plant species. This resemblance may be due to the presence of dominant bacterial OTUs, closely related to the Arsenophonus genus. The bacterial communities of the nectar from the covered and uncovered C. paradisi flowers differed significantly; the bacterial communities on the honeybees differed significantly from those in the covered flowers' nectar, but not from those in the uncovered flowers' nectar. We conclude that the honeybees may introduce bacteria into the nectar and/or may be contaminated by bacteria introduced into the nectar by other sources such as other pollinators and nectar thieves.

  2. Pollinators' mating rendezvous and the evolution of floral advertisement.

    Science.gov (United States)

    Fishman, Michael A; Hadany, Lilach

    2013-01-01

    Successful cross-fertilization in plant species that rely on animal pollinators depends not just on the number of pollinator visits, but also on these visits' duration. Furthermore, in non-deceptive pollination, a visit's duration depends on the magnitude of the reward provided to the pollinator. Accordingly, plants that rely on biotic pollination have to partition their investment in cross-fertilization assurance between attracting pollinator visits - advertisement, and rewarding visitors to assure that the visit is of productive duration. Here we analyze these processes by a combination of optimality methods and game theoretical modeling. Our results indicate that the optimality in such allocation of resources depends on the types of reward offered to the pollinators. More precisely, we show that plants that offer both food reward and mating rendezvous to pollinators will evolve to allocate a higher proportion of their cross-fertilization assurance budget to advertisement than plants that offer only food reward. That is, our results indicate that pollinators' mating habits may play a role in floral evolution. PMID:23023108

  3. Floral biology and a pollinator effectiveness test of the diurnal floral visitors of Tabernaemontana undulata Vahl. (Apocynaceae) in the understory of Amazon Rainforest, Brazil Biologia floral e teste da efetividade de polinização dos visitantes florais diurnos de Tabernaemontana undulata Vahl. (Apocynaceae) no sub-bosque da Amazônia Central, Brasil

    OpenAIRE

    Thaysa Nogueira de Moura; Antonio Carlos Webber; Liliane Noemia Melo Torres

    2011-01-01

    In this paper we examined the floral biology, per-visit effectiveness, frequency of visits and relative abundance of the diurnal floral visitor taxa of T. undulata (Apocynaceae) at two populations located in the primary forest and in a disturbed area connected to the continuous forest. Its hermaphrodite flowers show a long and narrow floral tube and introrse anthers form a cone around the apex of the style head where the pollen is deposited. The stigmatic head has three functional regions, in...

  4. 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.

  5. Divergence on floral traits and vertebrate pollinators of two endemic Encholirium bromeliads.

    Science.gov (United States)

    Christianini, A V; Forzza, R C; Buzato, S

    2013-03-01

    Shifts in pollen vectors favour diversification of floral traits, and differences in pollination strategies between congeneric sympatric species can contribute to reproductive isolation. Divergence in flowering phenology and selfing could also reduce interspecific crossing between self-compatible species. We investigated floral traits and visitation rates of pollinators of two sympatric Encholirium species on rocky outcrops to evaluate whether prior knowledge of floral characters could indicate actual pollinators. Data on flowering phenology, visitation rates and breeding system were used to evaluate reproductive isolation. Flowering phenology overlapped between species, but there were differences in floral characters, nectar volume and concentration. Several hummingbird species visited flowers of both Encholirium spp., but the endemic bat Lonchophylla bokermanni and an unidentified sphingid only visited E. vogelii. Pollination treatments demonstrated that E. heloisae and E. vogelii were partially self-compatible, with weak pollen limitation to seed set. Herbivores feeding on inflorescences decreased reproductive output of both species, but for E. vogelii the damage was higher. Our results indicate that actual pollinators can be known beforehand through floral traits, in agreement with pollination syndromes stating that a set of floral traits can be associated with the attraction of specific groups of pollinators. Divergence on floral traits and pollinator assemblage indicate that shifts in pollination strategies contribute to reproductive isolation between these Encholirium species, not divergence on flowering phenology or selfing. We suggest that hummingbird pollination might be the ancestral condition in Encholirium and that evolution of bat pollination made a substantial contribution to the diversification of this clade. PMID:22882351

  6. Geographic variation of floral traits in Nicotiana glauca : Relationships with biotic and abiotic factors

    Science.gov (United States)

    Nattero, Julieta; Sérsic, Alicia N.; Cocucci, Andrea A.

    2011-09-01

    Geographic pattern of phenotypic variation can appear in a clinal or a mosaic fashion and can evidence adaptive or non-adaptive variation. To shed light on the mechanisms underlying this variation, we studied the relationships between geographic variation of floral traits and both biotic and abiotic factors of the hummingbird-pollinated plant, Nicotiana glauca, across its natural range. We obtained floral measures of 38 populations from an area about 1600 km long and 1050 km wide and an altitude range from 7 to over 3400 m. We used a MANOVA to detect between-population differentiations in flower traits and a DFA to determine the traits that best discriminate between populations. To test for associations between floral traits and climatic variables we used correlation analysis. We explored any possible distance-based pattern of variation (either geographic or altitudinal) in floral traits or bill length of pollinators using Mantel tests. Finally, we used a multiple regression to analyze simultaneously the effects and relative importance of abiotic predictor variables and bill length on corolla length. We found a high variation in flower traits among populations. Morphometric traits were the ones that best discriminated across populations. There was a clinal pattern of floral phenotypic variation explained by climatic factors. Differences in floral phenotypic distances were structured by altitudinal distances but not by geographic distances. Bill length of the hummingbird pollinators was structured both by altitudinal and geographic distances. Differences in bill length of hummingbird pollinators explained differences in corolla length across populations. Our findings support the assumption of flower evolution at a broad geographic scale. Floral traits seem to be structured not only by altitude but also by climatic factors.

  7. Pollen limitation and variation in floral longevity in gynodioecious Potentilla tanacetifolia

    Institute of Scientific and Technical Information of China (English)

    Hong YAO; yi-Bo LUO

    2011-01-01

    Pollination limitation is common in flowering plants and is thought to be a factor driving the evolution of floral traits.The plasticity of floral longevity to pollination may be an adaptation of plants to pollen limitation.However,this adaptation is less critical in short-lived flowers.To evaluate pollen limitation and the plasticity of floral longevity to pollination in Potentilla tanacetifolia,a gynodioecious herb with short-lived flowers,we analyzed its breeding system,tested sex-differential pollen limitation,and compared variations in floral display size in natural populations in Duolun County,Inner Mongolia,China.Hand pollination experiments and pollinator exclusion treatments revealed that P tanacetifolia is self-compatible and non-autonomously apomictic and shows sex-differential pollen limitation.The plasticity of floral longevity to pollination was observed; the floral duration of female plants was prolonged by approximately 3-4 hours with pollination exclusion treatment.Moreover,the percentage of flowers displayed on female plants during pollination exclusion treatment was significantly higher than that during natural pollination.Under natural pollination conditions,the percentage of flowers displayed on female plants was significantly higher than on hermaphrodite plants.Furthermore,approximately 50% of the pollen grains spread out of the anthers of hermaphrodite flowers within 2 h of anthesis; the number of pollen grains adhering to the stigmas of hermaphrodite flowers was significantly higher than that adhering to female flowers when flowers shed their petals.These results indicate that variation in floral longevity may be an adaptive strategy to pollination conditions for gynodioecious P tanacetifolia.

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

    Science.gov (United States)

    Balasubramaniam, Vinod R M T; Hong Wai, Tham; Ario Tejo, Bimo; Omar, Abdul Rahman; Syed Hassan, Sharifah

    2013-01-01

    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.

  9. Probing heterobivalent binding to the endocytic AP-2 adaptor complex by DNA-based spatial screening.

    Science.gov (United States)

    Diezmann, F; von Kleist, L; Haucke, V; Seitz, O

    2015-08-01

    The double helical DNA scaffold offers a unique set of properties, which are particularly useful for studies of multivalency in biomolecular interactions: (i) multivalent ligand displays can be formed upon nucleic acid hybridization in a self-assembly process, which facilitates spatial screening (ii) valency and spatial arrangement of the ligand display can be precisely controlled and (iii) the flexibility of the ligand display can be adjusted by integrating nick sites and unpaired template regions. Herein we describe the use of DNA-based spatial screening for the characterization of the adaptor complex 2 (AP-2), a central interaction hub within the endocytic protein network in clathrin-mediated endocytosis. AP-2 is comprised of a core domain and two, so-called appendage domains, the α- and the β2-ear, which associate with cytoplasmatic proteins required for the formation or maturation of clathrin/AP-2 coated pits. Each appendage domain has two binding grooves which recognize distinct peptide motives with micromolar affinity. This provides opportunities for enhanced interactions with protein molecules that contain two (or more) different peptide motives. To determine whether a particular, spatial arrangement of binding motifs is required for high affinity binding we probed the distance-affinity relationships by means of DNA-programmed spatial screening with self-assembled peptide-DNA complexes. By using trimolecular and tetramolecular assemblies two different peptides were positioned in 2-22 nucleotide distance. The binding data obtained with both recombinant protein in well-defined buffer systems and native AP-2 in brain extract suggests that the two binding sites of the AP-2 α-appendage can cooperate to provide up to 40-fold enhancement of affinity compared to the monovalent interaction. The distance between the two recognized peptide motives was less important provided that the DNA duplex segments were connected by flexible, single strand segments. By

  10. Comparison Study on Finite Element Model for Structural Analysis of Lower CTS Cylinder Lifting Adaptor in ITER Assembly Tool

    International Nuclear Information System (INIS)

    The ITER tokamak assembly tools are purpose-built and specially designed to complete the ITER tokamak machine which includes; Vacuum Vessel (VV), VV Thermal Shield (VVTS) and Cryostat Thermal Shield (CTS), Toroidal Field Coil (TFC) and Poloidal Field (PF) coils, and other components contained in the cryostat. Based on the engineering design and design description documents prepared by the ITER organization (IO). In this paper, FE models to verify the structural integrity of the Lower Cryostat Thermal Shield (LCTS) Lifting Adaptor are prepared and compared with their structure analysis result. In the paper, each analysis result with difference BC applied was compared with the equivalent stress and the results of analysis were evaluated according to SM490YB's allowable stress. And the conclusions of this paper are summarized as following. - The structural stabilities of the LCTS lift adaptor have been studied using ANSYS codes for verifying structural strength for this tool

  11. Genetic interaction between GROWTH-REGULATING FACTOR and CUP-SHAPED COTYLEDON in organ separation

    OpenAIRE

    Lee, Byung Ha; Jeon, Jae Og; Lee, Myeong Min; Kim, Jeong Hoe

    2015-01-01

    The Arabidopsis thaliana GROWTH-REGULATING FACTOR (GRF) gene family comprises 9 members and encodes a class of transcription factors. We previously demonstrated that GRF genes played an essential role in formation of the boundary region between cotyledons, since their loss-of-function mutants developed fused cotyledons. Our present study shows that the grf mutants display fused floral organs as well. Such fusion phenotypes of embryonic and post-embryonic floral organs are highly reminiscent o...

  12. Chemical-genetic disruption of clathrin function spares adaptor complex 3–dependent endosome vesicle biogenesis

    OpenAIRE

    Zlatic, Stephanie A.; Grossniklaus, Emily J.; Ryder, Pearl V.; Salazar, Gloria; Mattheyses, Alexa L.; Peden, Andrew A.; Faundez, Victor

    2013-01-01

    A role for clathrin in AP-3–dependent vesicle biogenesis has been inferred from biochemical interactions and colocalization between this adaptor and clathrin. The functionality of these molecular associations, however, is controversial. We comprehensively explore the role of clathrin in AP-3–dependent vesicle budding, using rapid chemical-genetic perturbation of clathrin function with a clathrin light chain–FKBP chimera oligomerizable by the drug AP20187. We find that AP-3 interacts and coloc...

  13. Effect of exogenous GA3 and its inhibitor paclobutrazol on floral formation, endogenous hormones, and flowering-associated genes in 'Fuji' apple (Malus domestica Borkh.).

    Science.gov (United States)

    Zhang, Songwen; Zhang, Dong; Fan, Sheng; Du, Lisha; Shen, Yawen; Xing, Libo; Li, Youmei; Ma, Juanjuan; Han, Mingyu

    2016-10-01

    Gibberellins (GAs) reduce apple (Malus domestica) flowering rates; however, the mechanism of their action is not fully understood. To gain a better insight into gibberellin-regulated flowering, here, 5 year-old 'Fuji' apple trees were used to explore the responses of hormones [GA1+3, GA4+7, indole-3-acetic acid (IAA), zeatin-riboside (ZR), and abscisic acid (ABA)], and gibberellin- and flowering-associated genes, to applications of gibberellin acid (GA3) and paclobutrazol (PAC). Results showed that GA3 relatively stimulated vegetative growth and delayed floral induction. Moreover, GA3 spraying significantly affected contents of all endogenous hormones and all the genes tested in at least one time points: the content of endogenous GAs was increased instantly and that of ZR was reduced at 44 days after fullbloom (DAF), which might constitute an unfavorable factor for flower formation; MdKO (ent-kaurene oxidase gene) and MdGA20ox (GA20 oxidase gene) were significantly repressed by a high level of GAs through the negative feedback regulation of GA; additionally, the MdSPLs (SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE) in this study were all significantly repressed by GA3 but promoted by PAC; the expression of MdFT1/2 (FLOWERING LOCUS T), MdSOC1 (SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1) and MdAP1 (APETALA1) in GA3-treated buds changed in the same way, and they were repressed at 44 DAF. We suppose that GA3 spraying disrupts the balance between ZR and GAs, and inhibits floral induction, probably by suppressing MdSPLs and the floral integrators in flower induction, which ultimately contributed to inhibiting flower formation. PMID:27295342

  14. Effect of exogenous GA3 and its inhibitor paclobutrazol on floral formation, endogenous hormones, and flowering-associated genes in 'Fuji' apple (Malus domestica Borkh.).

    Science.gov (United States)

    Zhang, Songwen; Zhang, Dong; Fan, Sheng; Du, Lisha; Shen, Yawen; Xing, Libo; Li, Youmei; Ma, Juanjuan; Han, Mingyu

    2016-10-01

    Gibberellins (GAs) reduce apple (Malus domestica) flowering rates; however, the mechanism of their action is not fully understood. To gain a better insight into gibberellin-regulated flowering, here, 5 year-old 'Fuji' apple trees were used to explore the responses of hormones [GA1+3, GA4+7, indole-3-acetic acid (IAA), zeatin-riboside (ZR), and abscisic acid (ABA)], and gibberellin- and flowering-associated genes, to applications of gibberellin acid (GA3) and paclobutrazol (PAC). Results showed that GA3 relatively stimulated vegetative growth and delayed floral induction. Moreover, GA3 spraying significantly affected contents of all endogenous hormones and all the genes tested in at least one time points: the content of endogenous GAs was increased instantly and that of ZR was reduced at 44 days after fullbloom (DAF), which might constitute an unfavorable factor for flower formation; MdKO (ent-kaurene oxidase gene) and MdGA20ox (GA20 oxidase gene) were significantly repressed by a high level of GAs through the negative feedback regulation of GA; additionally, the MdSPLs (SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE) in this study were all significantly repressed by GA3 but promoted by PAC; the expression of MdFT1/2 (FLOWERING LOCUS T), MdSOC1 (SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1) and MdAP1 (APETALA1) in GA3-treated buds changed in the same way, and they were repressed at 44 DAF. We suppose that GA3 spraying disrupts the balance between ZR and GAs, and inhibits floral induction, probably by suppressing MdSPLs and the floral integrators in flower induction, which ultimately contributed to inhibiting flower formation.

  15. Molecular protein adaptor with genetically encoded interaction sites guiding the hierarchical assembly of plasmonically active nanoparticle architectures

    Science.gov (United States)

    Schreiber, Andreas; Huber, Matthias C.; Cölfen, Helmut; Schiller, Stefan M.

    2015-03-01

    The control over the defined assembly of nano-objects with nm-precision is important to create systems and materials with enhanced properties, for example, metamaterials. In nature, the precise assembly of inorganic nano-objects with unique features, for example, magnetosomes, is accomplished by efficient and reliable recognition schemes involving protein effectors. Here we present a molecular approach using protein-based ‘adaptors/connectors’ with genetically encoded interaction sites to guide the assembly and functionality of different plasmonically active gold nanoparticle architectures (AuNP). The interaction of the defined geometricaly shaped protein adaptors with the AuNP induces the self-assembly of nanoarchitectures ranging from AuNP encapsulation to one-dimensional chain-like structures, complex networks and stars. Synthetic biology and bionanotechnology are applied to co-translationally encode unnatural amino acids as additional site-specific modification sites to generate functionalized biohybrid nanoarchitectures. This protein adaptor-based nano-object assembly approach might be expanded to other inorganic nano-objects creating biohybrid materials with unique electronic, photonic, plasmonic and magnetic properties.

  16. Losses, Expansions, and Novel Subunit Discovery of Adaptor Protein Complexes in Haptophyte Algae.

    Science.gov (United States)

    Lee, Laura J Y; Klute, Mary J; Herman, Emily K; Read, Betsy; Dacks, Joel B

    2015-11-01

    The phylum Haptophyta (Diaphoratickes) contains marine algae that perform biomineralization, extruding large, distinctive calcium carbonate scales (coccoliths) that completely cover the cell. Coccolith production is an important part of global carbon cycling; however, the membrane trafficking pathway by which they are secreted has not yet been elucidated. In most eukaryotes, post-Golgi membrane trafficking involves five heterotetrameric adaptor protein (AP) complexes, which impart cargo selection specificity. To better understand coccolith secretion, we performed comparative genomic, phylogenetic, and transcriptomic analyses of the AP complexes in Emiliania huxleyi strains 92A, Van556, EH2, and CCMP1516, and related haptophytes Gephyrocapsa oceanica and Isochrysis galbana; the latter has lost the ability to biomineralize. We show that haptophytes have a modified membrane trafficking system (MTS), as we found both AP subunit losses and duplications. Additionally, we identified a single conserved subunit of the AP-related TSET complex, whose expression suggests a functional role in membrane trafficking. Finally, we detected novel alpha adaptin ear and gamma adaptin ear proteins, the first of their kind to be described outside of opisthokonts. These novel ear proteins and the sculpting of the MTS may support the capacity for biomineralization in haptophytes, enhancing their ability to perform this highly specialized form of secretion.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    Petr eDraber

    2012-01-01

    Full Text Available Aggregation of the high-affinity IgE receptor (FcεRI initiates a cascade of signaling events leading to release of preformed inflammatory and allergy mediators and de novo synthesis and secretion of cytokines and other compounds. The first biochemically well defined step of this signaling cascade is tyrosine phosphorylation of the FcεRI subunits by Src family kinase Lyn, followed by recruitment and activation of Syk kinase. Activity of Syk is decisive for the formation of multicomponent signaling assemblies, the signalosomes, in the vicinity of the receptors. Formation of the signalosomes is dependent on the presence of transmembrane adaptor proteins (TRAPs. These proteins are characterized by a short extracellular domain, a single transmembrane domain and a cytoplasmic tail with various motifs serving as anchors for cytoplasmic signaling molecules. In mast cells five TRAPs have been identified (LAT, NTAL, LAX, PAG and GAPT; engagement of four of them (LAT, NTAL, LAX and PAG in FcεRI signaling has been documented. Here we discuss recent progress in the understanding of how TRAPs affect FcεRI-mediated mast cell signaling. The combined data indicate that individual TRAPs have irreplaceable roles in important signaling events such as calcium response, degranulation, cytokines production and chemotaxis.

  2. Novel isoform of adaptor protein ITSN1 forms homodimers via its C-terminus

    Directory of Open Access Journals (Sweden)

    Skrypkina I. Ya.

    2011-06-01

    Full Text Available Aim. Previously we have identified a novel isoform of endocytic adaptor protein ITSN1 designated as ITSN122a. Western blot revealed two immunoreactive bands of 120 and 250 kDa that corresponded to ITSN1-22a. The goal of this study was to investigate the possibility of dimer formation by the novel isoform. Methods. Dimerization ability of ITSN1-22a was tested by immunoprecipitation and subsequent Western blot analysis. To specify the region responsible for dimerization, site-directed mutagenesis and truncation analysis were carried out. Inhibition of endocytosis by potassium depletion and EGF stimulation of HEK293 were performed. Results. We have found that ITSN1-22a forms dimers in HEK293 cells. The dimerization of ITSN1-22a was mediated by C-terminal domain. We showed that cysteines C1016 and C1019 were involved in homodimerization. Inhibition of clathrin-mediated endocytosis and mitogen stimulation did not affect ITSN1-22a dimer formation. Conclusions. ITSN1-22a is the only one known ITSN1 isoform, which is capable to form homodimers via disulphide bonds. This could be important for the formation of protein complexes containing ITSN1 molecules.

  3. Allostery mediates ligand binding to Grb2 adaptor in a mutually exclusive manner.

    Science.gov (United States)

    McDonald, Caleb B; El Hokayem, Jimmy; Zafar, Nawal; Balke, Jordan E; Bhat, Vikas; Mikles, David C; Deegan, Brian J; Seldeen, Kenneth L; Farooq, Amjad

    2013-02-01

    Allostery plays a key role in dictating the stoichiometry and thermodynamics of multi-protein complexes driving a plethora of cellular processes central to health and disease. Herein, using various biophysical tools, we demonstrate that although Sos1 nucleotide exchange factor and Gab1 docking protein recognize two non-overlapping sites within the Grb2 adaptor, allostery promotes the formation of two distinct pools of Grb2-Sos1 and Grb2-Gab1 binary signaling complexes in concert in lieu of a composite Sos1-Grb2-Gab1 ternary complex. Of particular interest is the observation that the binding of Sos1 to the nSH3 domain within Grb2 sterically blocks the binding of Gab1 to the cSH3 domain and vice versa in a mutually exclusive manner. Importantly, the formation of both the Grb2-Sos1 and Grb2-Gab1 binary complexes is governed by a stoichiometry of 2:1, whereby the respective SH3 domains within Grb2 homodimer bind to Sos1 and Gab1 via multivalent interactions. Collectively, our study sheds new light on the role of allostery in mediating cellular signaling machinery. PMID:23334917

  4. 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.

  5. Impairment of dendritic cell functions in patients with adaptor protein-3 complex deficiency.

    Science.gov (United States)

    Prandini, Alberto; Salvi, Valentina; Colombo, Francesca; Moratto, Daniele; Lorenzi, Luisa; Vermi, William; De Francesco, Maria Antonia; Notarangelo, Lucia Dora; Porta, Fulvio; Plebani, Alessandro; Facchetti, Fabio; Sozzani, Silvano; Badolato, Raffaele

    2016-06-30

    Hermansky-Pudlak syndrome type 2 (HPS2) is a primary immunodeficiency due to adaptor protein-3 (AP-3) complex deficiency. HPS2 patients present neutropenia, partial albinism, and impaired lysosomal vesicles formation in hematopoietic cells. Given the role of dendritic cells (DCs) in the immune response, we studied monocyte-derived DCs (moDCs) and plasmacytoid DCs (pDCs) in two HPS2 siblings. Mature HPS2 moDCs showed impaired expression of CD83 and DC-lysosome-associated membrane protein (LAMP), low levels of MIP1-β/CCL4, MIG/CXCL9, and severe defect of interleukin-12 (IL-12) secretion. DCs in lymph-node biopsies from the same patients showed a diffuse cytoplasm reactivity in a large fraction of DC-LAMP(+) cells, instead of the classical dot-like stain. In addition, analysis of pDC-related functions of blood-circulating mononuclear cells revealed reduced interferon-α secretion in response to herpes simplex virus-1 (HSV-1), whereas granzyme-B induction upon IL-3/IL-10 stimulation was normal. Finally, T-cell costimulatory activity, as measured by mixed lymphocyte reaction assay, was lower in patients, suggesting that function and maturation of DCs is abnormal in patients with HPS2.

  6. Transmembrane adaptor molecules: a new category of lymphoid-cell markers.

    Science.gov (United States)

    Tedoldi, Sara; Paterson, Jennifer C; Hansmann, Martin-Leo; Natkunam, Yasodha; Rüdiger, Thomas; Angelisova, Pavla; Du, Ming Q; Roberton, Helen; Roncador, Giovanna; Sanchez, Lydia; Pozzobon, Michela; Masir, Noraidah; Barry, Richard; Pileri, Stefano; Mason, David Y; Marafioti, Teresa; Horejsí, Václav

    2006-01-01

    Transmembrane adaptor proteins (of which 7 have been identified so far) are involved in receptor signaling in immune cells. They have only a short extracellular region, with most of the molecule comprising a substantial intracytoplasmic region carrying multiple tyrosine residues that can be phosphorylated by Src- or Syk-family kinases. In this paper, we report an immunohistologic study of 6 of these molecules in normal and neoplastic human tissue sections and show that they are restricted to subpopulations of lymphoid cells, being present in either T cells (LAT, LIME, and TRIM), B cells (NTAL), or subsets of both cell types (PAG and SIT). Their expression in neoplastic lymphoid cells broadly reflects that of normal lymphoid tissue, including the positivity of plasma cells and myeloma/plasmacytoma for LIME, NTAL, PAG, and SIT. However, this study also revealed some reactions that may be of diagnostic/prognostic value. For example, lymphocytic lymphoma and mantle-cell lymphoma showed similar profiles but differed clearly from follicle-center lymphoma, whereas PAG tended to be selectively expressed in germinal center-derived subsets of diffuse large B-cell lymphoma. These molecules represent a potentially important addition to the panel of immunophenotypic markers detectable in routine biopsies that can be used in hematopathologic studies. PMID:16160011

  7. 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. PMID:12506008

  8. 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

    2016-01-01

    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. PMID:27072926

  9. 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.

  10. Separating selection by diurnal and nocturnal pollinators on floral display and spur length in Gymnadenia conopsea.

    Science.gov (United States)

    Sletvold, Nina; Trunschke, Judith; Wimmergren, Carolina; Agren, Jon

    2012-08-01

    Most plants attract multiple flower visitors that may vary widely in their effectiveness as pollinators. Floral evolution is expected to reflect interactions with the most important pollinators, but few studies have quantified the contribution of different pollinators to current selection on floral traits. To compare selection mediated by diurnal and nocturnal pollinators on floral display and spur length in the rewarding orchid Gymnadenia conopsea, we manipulated the environment by conducting supplemental hand-pollinations and selective pollinator exclusions in two populations in central Norway. In both populations, the exclusion of diurnal pollinators significantly reduced seed production compared to open pollination, whereas the exclusion of nocturnal pollinators did not. There was significant selection on traits expected to influence pollinator attraction and pollination efficiency in both the diurnal and nocturnal pollination treatment. The relative strength of selection among plants exposed to diurnal and nocturnal visitors varied among traits and populations, but the direction of selection was consistent. The results suggest that diurnal pollinators are more important than nocturnal pollinators for seed production in the study populations, but that both categories contribute to selection on floral morphology. The study illustrates how experimental manipulations can link specific categories of pollinators to observed selection on floral traits, and thus improve our understanding of how species interactions shape patterns of selection. PMID:22928416

  11. Local adaptation: Mechanical fit between floral ecotypes of Nerine humilis (Amaryllidaceae) and pollinator communities.

    Science.gov (United States)

    Newman, Ethan; Manning, John; Anderson, Bruce

    2015-09-01

    Geographic variation in floral morphology is often assumed to reflect geographic variation in pollinator communities and associated divergence in selective pressures. We studied populations of Nerine humilis (Amaryllidaceae) to assess whether geographic variation in floral form is the result of local adaptation to different pollinator communities. We first tested for associations between floral traits and visitor communities, and found that populations with similar floral morphologies were visited by similar insect communities. Mean style length in each population was also closely associated with the mean body length of the local visitor community. A reciprocal translocation experiment demonstrated that native phenotypes set more seed than translocated phenotypes. Single visitation experiments showed that native flowers received more pollen, and set more seed per visit, than introduced phenotypes in both populations. This suggests that the effectiveness of pollinator visits is determined by the degree of mechanical fit between flowers and visitors. We provide strong evidence that the observed among-population variation in floral traits is an adaptive response to geographic variation in the pollinator community. PMID:26194119

  12. 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. PMID:25047026

  13. Experimental manipulation of floral scent bouquets restructures flower-visitor interactions in the field.

    Science.gov (United States)

    Larue, Anne-Amélie C; Raguso, Robert A; Junker, Robert R

    2016-03-01

    A common structural feature of natural communities is the non-random distribution of pairwise interactions between organisms of different trophic levels. For plant-animal interactions, it is predicted that both stochastic processes and functional plant traits that facilitate or prevent interactions are responsible for these patterns. However, unbiased manipulative field experiments that rigorously test the effects of individual traits on community structure are lacking. We address this gap by manipulating floral scent bouquets in the field. Manipulation of floral scent bouquets led to quantitative as well as qualitative restructuring of flower-visitor networks, making them more generalized. Olfactometer trials confirmed both positive and negative responses to scent bouquets. Our results clearly show that the distribution of insect visitors to the two abundant study plant species reflects the insects' species-specific preferences for floral scents, rather than for visual or morphological floral traits. Thus, floral scents may be of major importance in partitioning flower-visitor interactions. Integrating experimental manipulations of plant traits with field observations of interaction patterns thus represents a promising approach for revealing the processes that structure species assemblages in natural communities. PMID:26428739

  14. Changes in pollinator fauna affect altitudinal variation of floral size in a bumblebee-pollinated herb.

    Science.gov (United States)

    Nagano, Yusuke; Abe, Kota; Kitazawa, Tomoaki; Hattori, Mitsuru; Hirao, Akira S; Itino, Takao

    2014-09-01

    Geographic trait variations are often caused by locally different selection regimes. As a steep environmental cline along altitude strongly influences adaptive traits, mountain ecosystems are ideal for exploring adaptive differentiation over short distances. We investigated altitudinal floral size variation of Campanula punctata var. hondoensis in 12 populations in three mountain regions of central Japan to test whether the altitudinal floral size variation was correlated with the size of the local bumblebee pollinator and to assess whether floral size was selected for by pollinator size. We found apparent geographic variations in pollinator assemblages along altitude, which consequently produced a geographic change in pollinator size. Similarly, we found altitudinal changes in floral size, which proved to be correlated with the local pollinator size, but not with altitude itself. Furthermore, pollen removal from flower styles onto bees (plant's male fitness) was strongly influenced by the size match between flower style length and pollinator mouthpart length. These results strongly suggest that C. punctata floral size is under pollinator-mediated selection and that a geographic mosaic of locally adapted C. punctata exists at fine spatial scale.

  15. The role of abiotic environmental conditions and herbivory in shaping bacterial community composition in floral nectar.

    Directory of Open Access Journals (Sweden)

    Michal Samuni-Blank

    Full Text Available Identifying the processes that drive community assembly has long been a central theme in ecology. For microorganisms, a traditional prevailing hypothesis states that "everything is everywhere, but the environment selects". Although the bacterial community in floral nectar may be affected by both atmosphere (air-borne bacteria and animals as dispersal vectors, the environmental and geographic factors that shape microbial communities in floral nectar are unknown. We studied culturable bacterial communities in Asphodelus aestivus floral nectar and in its typical herbivorous bug Capsodes infuscatus, along an aridity gradient. Bacteria were sampled from floral nectar and bugs at four sites, spanning a geographical range of 200 km from Mediterranean to semi-arid conditions, under open and bagged flower treatments. In agreement with the niche assembly hypothesis, the differences in bacterial community compositions were explained by differences in abiotic environmental conditions. These results suggest that microbial model systems are useful for addressing macro-ecological questions. In addition, similar bacterial communities were found in the nectar and on the surface of the bugs that were documented visiting the flowers. These similarities imply that floral nectar bacteria dispersal is shaped not only by air borne bacteria and nectar consumers as previously reported, but also by visiting vectors like the mirid bugs.

  16. 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.

  17. How floral odours are learned inside the bumblebee ( Bombus terrestris) nest

    Science.gov (United States)

    Molet, Mathieu; Chittka, Lars; Raine, Nigel E.

    2009-02-01

    Recruitment in social insects often involves not only inducing nestmates to leave the nest, but also communicating crucial information about finding profitable food sources. Although bumblebees transmit chemosensory information (floral scent), the transmission mechanism is unknown as mouth-to-mouth fluid transfer (as in honeybees) does not occur. Because recruiting bumblebees release a pheromone in the nest that triggers foraging in previously inactive workers, we tested whether this pheromone helps workers learn currently rewarding floral odours, as found in food social learning in rats. We exposed colonies to artificial recruitment pheromone, paired with anise scent. The pheromone did not facilitate learning of floral scent. However, we found that releasing floral scent in the air of the colony was sufficient to trigger learning and that learning performance was improved when the chemosensory cue was provided in the nectar in honeypots; probably because it guarantees a tighter link between scent and reward, and possibly because gustatory cues are involved in addition to olfaction. Scent learning was maximal when anise-scented nectar was brought into the nest by demonstrator foragers, suggesting that previously unidentified cues provided by successful foragers play an important role in nestmates learning new floral odours.

  18. Variability and heritability of floral development in apple full-sib off springs

    Directory of Open Access Journals (Sweden)

    Atay Ayşe Nilgun

    2016-01-01

    Full Text Available The timing of blooming in spring is highly crucial for temperate zone tree fruit production. In this study, we aimed to investigate floral development using the all parents and full-sib offsprings of two different crossing combinations (‘Kaşel 37’ × ‘Delbarestivale’ and ‘Kaşel 41’ × ‘Williams’ Pride’. Assessments of variability in floral development have been done according to a numerical assessment scheme defined by ten stages (stage 0-9. The assessments were conducted three different dates, early (21 04, intermediate (28 04, and late (05 05. The results showed significant variations for floral development among the 273 genotypes. In particular, the genotypes 326, 340, 369, 88 and 146 were found as superiors for floral development. The broad sense heritability (h2 b for floral development was reliable on the first assessment date, with no reliability on the other assessment dates. Our results would be useful to geneticists and breeders. Key words: Amasya, breeding, F1, Malus slyvestris, new cultivar, progeny, spring frost.

  19. 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.

  20. Activation of EphA receptors mediates the recruitment of the adaptor protein Slap, contributing to the downregulation of N-methyl-D-aspartate receptors.

    Science.gov (United States)

    Semerdjieva, Sophia; Abdul-Razak, Hayder H; Salim, Sharifah S; Yáñez-Muñoz, Rafael J; Chen, Philip E; Tarabykin, Victor; Alifragis, Pavlos

    2013-04-01

    Regulation of the activity of N-methyl-d-aspartate receptors (NMDARs) at glutamatergic synapses is essential for certain forms of synaptic plasticity underlying learning and memory and is also associated with neurotoxicity and neurodegenerative diseases. In this report, we investigate the role of Src-like adaptor protein (Slap) in NMDA receptor signaling. We present data showing that in dissociated neuronal cultures, activation of ephrin (Eph) receptors by chimeric preclustered eph-Fc ligands leads to recruitment of Slap and NMDA receptors at the sites of Eph receptor activation. Interestingly, our data suggest that prolonged activation of EphA receptors is as efficient in recruiting Slap and NMDA receptors as prolonged activation of EphB receptors. Using established heterologous systems, we examined whether Slap is an integral part of NMDA receptor signaling. Our results showed that Slap does not alter baseline activity of NMDA receptors and does not affect Src-dependent potentiation of NMDA receptor currents in Xenopus oocytes. We also demonstrate that Slap reduces excitotoxic cell death triggered by activation of NMDARs in HEK293 cells. Finally, we present evidence showing reduced levels of NMDA receptors in the presence of Slap occurring in an activity-dependent manner, suggesting that Slap is part of a mechanism that homeostatically modulates the levels of NMDA receptors.

  1. 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.

  2. Floral morphogenesis: stochastic explorations of a gene network epigenetic landscape.

    Directory of Open Access Journals (Sweden)

    Elena R Alvarez-Buylla

    Full Text Available In contrast to the classical view of development as a preprogrammed and deterministic process, recent studies have demonstrated that stochastic perturbations of highly non-linear systems may underlie the emergence and stability of biological patterns. Herein, we address the question of whether noise contributes to the generation of the stereotypical temporal pattern in gene expression during flower development. We modeled the regulatory network of organ identity genes in the Arabidopsis thaliana flower as a stochastic system. This network has previously been shown to converge to ten fixed-point attractors, each with gene expression arrays that characterize inflorescence cells and primordial cells of sepals, petals, stamens, and carpels. The network used is binary, and the logical rules that govern its dynamics are grounded in experimental evidence. We introduced different levels of uncertainty in the updating rules of the network. Interestingly, for a level of noise of around 0.5-10%, the system exhibited a sequence of transitions among attractors that mimics the sequence of gene activation configurations observed in real flowers. We also implemented the gene regulatory network as a continuous system using the Glass model of differential equations, that can be considered as a first approximation of kinetic-reaction equations, but which are not necessarily equivalent to the Boolean model. Interestingly, the Glass dynamics recover a temporal sequence of attractors, that is qualitatively similar, although not identical, to that obtained using the Boolean model. Thus, time ordering in the emergence of cell-fate patterns is not an artifact of synchronous updating in the Boolean model. Therefore, our model provides a novel explanation for the emergence and robustness of the ubiquitous temporal pattern of floral organ specification. It also constitutes a new approach to understanding morphogenesis, providing predictions on the population dynamics of

  3. 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.

  4. Transgressive phenotypes and generalist pollination in the floral evolution of Nicotiana polyploids.

    Science.gov (United States)

    McCarthy, Elizabeth W; Chase, Mark W; Knapp, Sandra; Litt, Amy; Leitch, Andrew R; Le Comber, Steven C

    2016-01-01

    Polyploidy is an important driving force in angiosperm evolution, and much research has focused on genetic, epigenetic and transcriptomic responses to allopolyploidy. Nicotiana is an excellent system in which to study allopolyploidy because half of the species are allotetraploids of different ages, allowing us to examine the trajectory of floral evolution over time. Here, we study the effects of allopolyploidy on floral morphology in Nicotiana, using corolla tube measurements and geometric morphometrics to quantify petal shape. We show that polyploid morphological divergence from the intermediate phenotype expected (based on progenitor morphology) increases with time for floral limb shape and tube length, and that most polyploids are distinct or transgressive in at least one trait. In addition, we show that polyploids tend to evolve shorter and wider corolla tubes, suggesting that allopolyploidy could provide an escape from specialist pollination via reversion to more generalist pollination strategies. PMID:27501400

  5. The Effects of Diesel Exhaust Pollution on Floral Volatiles and the Consequences for Honey Bee Olfaction.

    Science.gov (United States)

    Lusebrink, Inka; Girling, Robbie D; Farthing, Emily; Newman, Tracey A; Jackson, Chris W; Poppy, Guy M

    2015-10-01

    There is growing evidence of a substantial decline in pollinators within Europe and North America, most likely caused by multiple factors such as diseases, poor nutrition, habitat loss, insecticides, and environmental pollution. Diesel exhaust could be a contributing factor to this decline, since we found that diesel exhaust rapidly degrades floral volatiles, which honey bees require for flower recognition. In this study, we exposed eight of the most common floral volatiles to diesel exhaust in order to investigate whether it can affect volatile mediated plant-pollinator interaction. Exposure to diesel exhaust altered the blend of common flower volatiles significantly: myrcene was considerably reduced, β-ocimene became undetectable, and β-caryophyllene was transformed into its cis-isomer isocaryophyllene. Proboscis extension response (PER) assays showed that the alterations of the blend reduced the ability of honey bees to recognize it. The chemically reactive nitrogen oxides fraction of diesel exhaust gas was identified as capable of causing degradation of floral volatiles.

  6. Floral scent of brazilian Passiflora: five species analised by dynamic headspace

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    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.

  7. Covariance of floral and vegetative traits in four species of Ranunculaceae: a comparison between specialized and generalized pollination systems.

    Science.gov (United States)

    Meng, Jin-Liu; Zhou, Xian-Hui; Zhao, Zhi-Gang; Du, Guo-Zhen

    2008-09-01

    Theory predicts that tighter correlation between floral traits and weaker relationship between floral and vegetative traits more likely occur in specialized flowers than generalized flowers, favoring by precise fit with pollinators. However, traits and trait correlations frequently vary under different environments. Through detecting spatiotemporal variation in phenotypic traits (floral organ size and vegetative size) and trait correlations in four Ranunculaceae species, we examined four predictions. Overall, our results supported these predictions to a certain degree. The mean coefficient of variation (CV) of floral traits in two specialized species (Delphinium kamaonense and Aconitum gymnandrum) was marginally significantly lower than that of another two generalized species (Trollius ranunculoides and Anemone obtusiloba). The two specialized species also showed marginally significantly smaller CV in floral traits than vegetative size across the two species. The absolute mean correlation between floral and vegetative traits, or that between floral traits in species with specialized flowers was not significantly lower, or higher than that in generalized plants, weakly supporting the predictions. Furthermore, we documented a large variation in trait correlations of four species among different seasons and populations. Study of covariance of floral and vegetative traits will benefit from the contrast of results obtained from generalized and specialized pollination systems.

  8. Covariance of Floral and Vegetative Traits in Four Species of Ranunculaceae: A Comparison between Specialized and Generalized Pollination Systems

    Institute of Scientific and Technical Information of China (English)

    Jin-Liu Meng; Xian-Hui Zhou; Zhi-Gang Zhao; Guo-Zhen Du

    2008-01-01

    Theory predicts that tighter correlation between floral traits and weaker relationship between floral and vegetative traits more likely occur in specialized flowers than generalized flowers,favoring by precise fit with pollinators.However,traits and trait correlations frequently vary under different environments.Through detecting spatiotemporal variation in phenotypic traits (floral organ size and vegetative size) and trait correlations in four Ranunculaceae species,we examined four predictions.Overall,our results supported these predictions to a certain degree.The mean coefficient of variation (CV) of floral traits in two specialized species (Delphinium kamaonense and Aconitum gymnandrum) was marginally significantly lower than that of another two generalized species (Trollius ranunculoides and Anemone obtusiloba).The two specialized species also showed marginally significantly smaller CV in floral traits than vegetative size across the two species.The absolute mean correlation between floral and vegetative traits,or that between floral traits in species with specialized flowers was not significantly lower,or higher than that in generalized plants,weakly supporting the predictions.Furthermore,we documented a large variation in trait correlations of four species among different seasons and populations.Study of covariance of floral and vegetative traits will benefit from the contrast of results obtained from generalized and specialized pollination systems.

  9. 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

  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. 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

  12. 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

  13. Simulation of organ patterning on the floral meristem using a polar auxin transport model.

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    Simon van Mourik

    Full Text Available An intriguing phenomenon in plant development is the timing and positioning of lateral organ initiation, which is a fundamental aspect of plant architecture. Although important progress has been made in elucidating the role of auxin transport in the vegetative shoot to explain the phyllotaxis of leaf formation in a spiral fashion, a model study of the role of auxin transport in whorled organ patterning in the expanding floral meristem is not available yet. We present an initial simulation approach to study the mechanisms that are expected to play an important role. Starting point is a confocal imaging study of Arabidopsis floral meristems at consecutive time points during flower development. These images reveal auxin accumulation patterns at the positions of the organs, which strongly suggests that the role of auxin in the floral meristem is similar to the role it plays in the shoot apical meristem. This is the basis for a simulation study of auxin transport through a growing floral meristem, which may answer the question whether auxin transport can in itself be responsible for the typical whorled floral pattern. We combined a cellular growth model for the meristem with a polar auxin transport model. The model predicts that sepals are initiated by auxin maxima arising early during meristem outgrowth. These form a pre-pattern relative to which a series of smaller auxin maxima are positioned, which partially overlap with the anlagen of petals, stamens, and carpels. We adjusted the model parameters corresponding to properties of floral mutants and found that the model predictions agree with the observed mutant patterns. The predicted timing of the primordia outgrowth and the timing and positioning of the sepal primordia show remarkable similarities with a developing flower in nature.

  14. 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

  15. Selection on floral characters in natural Spanish populations of Silene latifolia.

    Science.gov (United States)

    Wright, J W; Meagher, T R

    2004-03-01

    In insect-pollinated plants, floral characters are expected to play an important role in paternal and maternal reproductive success. Bateman's principle states that male reproductive success increases with more mating opportunities, while female reproductive success is limited by the amount of resources available to produce progeny, thus there should be greater selection on male floral characters than on female. In the case of the dioecious plant Silene latifolia, floral characters are likely to be influenced by its association within its native European range with moths of the genus Hadena, which serve as both pollinators and seed predators. The present study addresses relationships between male and female reproductive success, spatial location and floral characters (corolla, calyx and claw) over a 2-year period in two Spanish populations of S. latifolia in the presence of Hadena moths. A maximum likelihood paternity analysis using genetic variation at six allozyme markers showed heterogeneity in male reproductive success. There was much less variation in female reproductive success. When this analysis was extended to include interplant distance as a causal factor underlying variation in male success, we found that successful pollination tended to be limited to nearby females, in accordance with exponential decay of pollen dispersal with increasing distance. When the paternity analysis included floral characters as a causal factor underlying variation in male success, our data showed little evidence for directional selection, but there was stabilizing selection in one of the two years for calyx diameter. Selection on female characters varied widely between sites and years, in most of the site/year combinations there was little selection on female floral characters; however, in one site/year there was evidence for selection on all three floral characters. We conclude that pollinators visit flowers that are close together, and that while floral characters are

  16. 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

  17. Biophysical basis of the binding of WWOX tumor suppressor to WBP1 and WBP2 adaptors.

    Science.gov (United States)

    McDonald, Caleb B; Buffa, Laura; Bar-Mag, Tomer; Salah, Zaidoun; Bhat, Vikas; Mikles, David C; Deegan, Brian J; Seldeen, Kenneth L; Malhotra, Arun; Sudol, Marius; Aqeilan, Rami I; Nawaz, Zafar; Farooq, Amjad

    2012-09-01

    The WW-containing oxidoreductase (WWOX) tumor suppressor participates in a diverse array of cellular activities by virtue of its ability to recognize WW-binding protein 1 (WBP1) and WW-binding protein 2 (WBP2) signaling adaptors among a wide variety of other ligands. Herein, using a multitude of biophysical techniques, we provide evidence that while the WW1 domain of WWOX binds to PPXY motifs within WBP1 and WBP2 in a physiologically relevant manner, the WW2 domain exhibits no affinity toward any of these PPXY motifs. Importantly, our data suggest that while R25/W44 residues located within the binding pocket of a triple-stranded β-fold of WW1 domain are critical for the recognition of PPXY ligands, they are replaced by the chemically distinct E66/Y85 duo at structurally equivalent positions within the WW2 domain, thereby accounting for its failure to bind PPXY ligands. Predictably, not only does the introduction of E66R/Y85W double substitution within the WW2 domain result in gain of function but the resulting engineered domain, hereinafter referred to as WW2_RW, also appears to be a much stronger binding partner of WBP1 and WBP2 than the wild-type WW1 domain. We also show that while the WW1 domain is structurally disordered and folds upon ligand binding, the WW2 domain not only adopts a fully structured conformation but also aids stabilization and ligand binding to WW1 domain. This salient observation implies that the WW2 domain likely serves as a chaperone to augment the physiological function of WW1 domain within WWOX. Collectively, our study lays the groundwork for understanding the molecular basis of a key protein-protein interaction pertinent to human health and disease. PMID:22634283

  18. 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

  19. Floral biology, flowering phenology and floral visitors of five insect-pollinated tree species in a tropical lowland rainforest remnant of Pernambuco, Brazil

    OpenAIRE

    Krause, Leonhard

    2008-01-01

    Reproductive processes of frequent canopy tree species that persisted up to now in the few remnants of the Brazilian Atlantic forest might be thought to be robust. To test this hypothesis, the reproductive biology, flowering phenology, and the floral visitors of Tapirira guinanensis (Anacardiaceae), Ocotea glomerata (Lauraceae), Trichilia lepidota (Meliaceae), Sclerolobium densiflorum (Fabaceae), and Eschweilera ovata (Lecythidaceae) were studied in a 319 ha forest fragment 30 km north of Rec...

  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. Heliconia acuminata reproductive success is independent of local floral density O sucesso reprodutivo de Heliconia acuminata é independente da densidade floral local

    OpenAIRE

    Emilio M Bruna; W John Kress; Francisco Marques; Osmaildo Ferreira da Silva

    2004-01-01

    Reproductive plants in tropical forests are patchily distributed, with some in large aggregations of reproductive consepecifics while others are relatively isolated. This variation in floral density is hypothesized to have a major effect on plant reproductive success, since individuals in higher density neighborhoods can attract more or higher quality pollinators. We experimentally tested this hypothesis with populations of the understory herb Heliconia acuminata in central Amazonia. We creat...

  2. UIF, a New mRNA export adaptor that works together with REF/ALY, requires FACT for recruitment to mRNA.

    Science.gov (United States)

    Hautbergue, Guillaume M; Hung, Ming-Lung; Walsh, Matthew J; Snijders, Ambrosius P L; Chang, Chung-Te; Jones, Rachel; Ponting, Chris P; Dickman, Mark J; Wilson, Stuart A

    2009-12-01

    Messenger RNA (mRNA) export adaptors play an important role in the transport of mRNA from the nucleus to the cytoplasm. They couple early mRNA processing events such as 5' capping and 3' end formation with loading of the TAP/NXF1 export receptor onto mRNA. The canonical adaptor REF/ALY/Yra1 is recruited to mRNA via UAP56 and subsequently delivers the mRNA to NXF1 [1]. Knockdown of UAP56 [2, 3] and NXF1 [4-7] in higher eukaryotes efficiently blocks mRNA export, whereas knockdown of REF only causes a modest reduction, suggesting the existence of additional adaptors [8-10]. Here we identify a new UAP56-interacting factor, UIF, which functions as an export adaptor, binding NXF1 and delivering mRNA to the nuclear pore. REF and UIF are simultaneously found on the same mRNA molecules, and both proteins are required for efficient export of mRNA. We show that the histone chaperone FACT specifically binds UIF, but not REF, via the SSRP1 subunit, and this interaction is required for recruitment of UIF to mRNA. Together the results indicate that REF and UIF represent key human adaptors for the export of cellular mRNAs via the UAP56-NXF1 pathway.

  3. Evolutionary Genomics Suggests That CheV Is an Additional Adaptor for Accommodating Specific Chemoreceptors within the Chemotaxis Signaling Complex.

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    Davi R Ortega

    2016-02-01

    Full Text Available Escherichia coli and Salmonella enterica are models for many experiments in molecular biology including chemotaxis, and most of the results obtained with one organism have been generalized to another. While most components of the chemotaxis pathway are strongly conserved between the two species, Salmonella genomes contain some chemoreceptors and an additional protein, CheV, that are not found in E. coli. The role of CheV was examined in distantly related species Bacillus subtilis and Helicobacter pylori, but its role in bacterial chemotaxis is still not well understood. We tested a hypothesis that in enterobacteria CheV functions as an additional adaptor linking the CheA kinase to certain types of chemoreceptors that cannot be effectively accommodated by the universal adaptor CheW. Phylogenetic profiling, genomic context and comparative protein sequence analyses suggested that CheV interacts with specific domains of CheA and chemoreceptors from an orthologous group exemplified by the Salmonella McpC protein. Structural consideration of the conservation patterns suggests that CheV and CheW share the same binding spot on the chemoreceptor structure, but have some affinity bias towards chemoreceptors from different orthologous groups. Finally, published experimental results and data newly obtained via comparative genomics support the idea that CheV functions as a "phosphate sink" possibly to off-set the over-stimulation of the kinase by certain types of chemoreceptors. Overall, our results strongly suggest that CheV is an additional adaptor for accommodating specific chemoreceptors within the chemotaxis signaling complex.

  4. Evolutionary Genomics Suggests That CheV Is an Additional Adaptor for Accommodating Specific Chemoreceptors within the Chemotaxis Signaling Complex.

    Science.gov (United States)

    Ortega, Davi R; Zhulin, Igor B

    2016-02-01

    Escherichia coli and Salmonella enterica are models for many experiments in molecular biology including chemotaxis, and most of the results obtained with one organism have been generalized to another. While most components of the chemotaxis pathway are strongly conserved between the two species, Salmonella genomes contain some chemoreceptors and an additional protein, CheV, that are not found in E. coli. The role of CheV was examined in distantly related species Bacillus subtilis and Helicobacter pylori, but its role in bacterial chemotaxis is still not well understood. We tested a hypothesis that in enterobacteria CheV functions as an additional adaptor linking the CheA kinase to certain types of chemoreceptors that cannot be effectively accommodated by the universal adaptor CheW. Phylogenetic profiling, genomic context and comparative protein sequence analyses suggested that CheV interacts with specific domains of CheA and chemoreceptors from an orthologous group exemplified by the Salmonella McpC protein. Structural consideration of the conservation patterns suggests that CheV and CheW share the same binding spot on the chemoreceptor structure, but have some affinity bias towards chemoreceptors from different orthologous groups. Finally, published experimental results and data newly obtained via comparative genomics support the idea that CheV functions as a "phosphate sink" possibly to off-set the over-stimulation of the kinase by certain types of chemoreceptors. Overall, our results strongly suggest that CheV is an additional adaptor for accommodating specific chemoreceptors within the chemotaxis signaling complex.

  5. The AP-1A and AP-1B clathrin adaptor complexes define biochemically and functionally distinct membrane domains

    OpenAIRE

    Fölsch, Heike; Pypaert, Marc; Maday, Sandra; Pelletier, Laurence; Mellman, Ira

    2003-01-01

    Most epithelial cells contain two AP-1 clathrin adaptor complexes. AP-1A is ubiquitously expressed and involved in transport between the TGN and endosomes. AP-1B is expressed only in epithelia and mediates the polarized targeting of membrane proteins to the basolateral surface. Both AP-1 complexes are heterotetramers and differ only in their 50-kD μ1A or μ1B subunits. Here, we show that AP-1A and AP-1B, together with their respective cargoes, define physically and functionally distinct membra...

  6. Competitive and Cooperative Interactions Mediate RNA Transfer from Herpesvirus Saimiri ORF57 to the Mammalian Export Adaptor ALYREF

    OpenAIRE

    Tunnicliffe, Richard B.; Hautbergue, Guillaume M.; Wilson, Stuart A.; Priti Kalra; Golovanov, Alexander P.

    2014-01-01

    The essential herpesvirus adaptor protein HVS ORF57, which has homologs in all other herpesviruses, promotes viral mRNA export by utilizing the cellular mRNA export machinery. ORF57 protein specifically recognizes viral mRNA transcripts, and binds to proteins of the cellular transcription-export (TREX) complex, in particular ALYREF. This interaction introduces viral mRNA to the NXF1 pathway, subsequently directing it to the nuclear pore for export to the cytoplasm. Here we have used a range o...

  7. Additive effects of pollinators and herbivores result in both conflicting and reinforcing selection on floral traits.

    Science.gov (United States)

    Sletvold, Nina; Moritz, Kim K; Agren, Jon

    2015-01-01

    Mutualists and antagonists are known to respond to similar floral cues, and may thus cause opposing selection on floral traits. However, we lack a quantitative understanding of their independent and interactive effects. In a population of the orchid Gymnadenia conopsea, we manipulated the intensity of pollination and herbivory in a factorial design to examine whether both interactions influence selection on flowering phenology, floral display, and morphology. Supplemental hand-pollination increased female fitness by 31% and one-quarter of all plants were damaged by herbivores. Both interactions contributed to selection. Pollinators mediated selection for later flowering and herbivores for earlier flowering, while both selected for longer spurs. The strength of selection was similar for both agents, and their effects were additive. As a consequence, there was no. net selection on phenology, whereas selection on spur length was strong. The experimental results demonstrate that both pollinators and herbivores can markedly influence the strength of selection on flowering phenology and floral morphology, and cause both conflicting and reinforcing selection. They also indicate that the direction of selection on phenology will vary with the relative intensity of the mutualistic and antagonistic interaction, potentially resulting in both temporal and among-population variation in optimal flowering time.

  8. Attractiveness of binary blends of floral odorant compounds to moths in Florida, USA

    Science.gov (United States)

    Evaluation of combinations of flower odor compounds in the field revealed several chemicals that were attractive or co-attractive with phenylacetaldehyde (PAA) to pest noctuid and pyralid moths. A number of moth species responded positively to PAA. The floral odorants cis-jasmone, linalool, benzyl...

  9. 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.

  10. Flowering synchrony and floral display size affect pollination success in a deceit-pollinated tropical orchid

    Science.gov (United States)

    Parra-Tabla, Victor; Vargas, Carlos F.

    2007-07-01

    ue to frequency-dependent negative selection, a strong relationship between reproductive phenology traits and pollination success is expected in deceit-pollinated species. This paper assesses the effects of floral display size on both female (fruit production) and male (pollen removal) pollination success in a population of the deceit-pollinated tropical orchid Myrmecophila christinae during two consecutive years (1998-1999). Low pollen removal (˜9% of total flowers) and fruit production values (˜3% of total flowers) were recorded during both years. As expected, binary logistic regressions showed a significant negative effect of floral synchrony, and a positive effect of floral display size on both male and female success, although these effects varied across years. Pollination rates in the field and in hand pollinations suggest a doubling in pollinator abundance between years. Results suggest that floral display size and flowering synchrony are of adaptive value for M. christinae. However, between-year fluctuations might indicate that reproductive phenology traits in deceit-pollinated species undergo fluctuating selection regimes among years and are probably linked to short-term changes in environmental (abiotic and biotic) conditions.

  11. Attractiveness of floral compounds to male and female moths in Florida

    Science.gov (United States)

    Evaluation of combinations of flower odor compounds in the field revealed several chemicals that were attractive or co-attractive with phenylacetaldehyde (PAA) to pest noctuid and pyralid moths. A number of moth species responded positively to PAA. The floral odorants cis-jasmone, linalool, benzyl a...

  12. Floral Trait Associations in Hawkmoth-Specialized and Mixed Pollination Systems

    Science.gov (United States)

    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 (herbivo...

  13. Additive effects of pollinators and herbivores result in both conflicting and reinforcing selection on floral traits.

    Science.gov (United States)

    Sletvold, Nina; Moritz, Kim K; Agren, Jon

    2015-01-01

    Mutualists and antagonists are known to respond to similar floral cues, and may thus cause opposing selection on floral traits. However, we lack a quantitative understanding of their independent and interactive effects. In a population of the orchid Gymnadenia conopsea, we manipulated the intensity of pollination and herbivory in a factorial design to examine whether both interactions influence selection on flowering phenology, floral display, and morphology. Supplemental hand-pollination increased female fitness by 31% and one-quarter of all plants were damaged by herbivores. Both interactions contributed to selection. Pollinators mediated selection for later flowering and herbivores for earlier flowering, while both selected for longer spurs. The strength of selection was similar for both agents, and their effects were additive. As a consequence, there was no. net selection on phenology, whereas selection on spur length was strong. The experimental results demonstrate that both pollinators and herbivores can markedly influence the strength of selection on flowering phenology and floral morphology, and cause both conflicting and reinforcing selection. They also indicate that the direction of selection on phenology will vary with the relative intensity of the mutualistic and antagonistic interaction, potentially resulting in both temporal and among-population variation in optimal flowering time. PMID:26236906

  14. 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.

  15. 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 elim

  16. 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

  17. 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…

  18. TRL1 gene expression in tomato (Solanum lycopersicum) floral organs after γ-irradiation

    International Nuclear Information System (INIS)

    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)

  19. 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 categorization

  20. Floral Properties of Different Lucerne Varieties and Their Effects on Bee Visitation

    Institute of Scientific and Technical Information of China (English)

    Jiang; Hua; Shan; Guilian; Duan; Xinhui; Bi; Yufen; He; Chenggang

    2014-01-01

    Lucerne( Medicago sativa L.) is a plant of strict allogamy,and its pollination relies on bees mainly. Genetic variations of lucerne floral properties,including receptacle diameter,coronary length,number of flowers per raceme,number of racemes per twig,number of flowers per square metre,percentage of tripped flowers,nectar production,sugar concentration in nectar and contents of sucrose,fructose and glucose in nectar,have been studied with morphological markers,and floral properties of ten lucerne cultivars were also investigated to determine their role in number of visiting bees and to provide a basis for the evaluation of mutant flowers for visitation by bees. The results showed CV( coefficient of variation) of floral properties was from 0. 80% to 92. 30%,of which the content of glucose was the most significant one with variation from 0. 01 to 0. 53 μmol /L( P < 0. 05),and the sugar concentration was the most insignificant one( P > 0. 05). The significant order of floral properties affecting the number of visiting bees was that the nectar production per square metre( r = 0. 93,P < 0. 01) was in the first place,followed by the number of flowers per square metre( r = 0. 92,P < 0. 01),sucrose concentration of nectar sugar( r = 0. 82,P < 0. 05),coronary length( r = 0. 77,P < 0. 05) and nectar production per flower( r = 0. 71,P < 0. 05).

  1. Glufosinate does not affect floral morphology and pollen viability in glufosinate-resistant cotton (Gossypium hirsutum)

    Science.gov (United States)

    Studies were conducted to determine whether glufosinate treatments to glufosinate-resistant cotton caused changes in floral morphology, pollen viability, and seed set. Four glufosinate treatments were included: (1) glufosinate applied postemergence over the top (POST) at the four-leaf stage, (2) glu...

  2. Effects of temperature and nitrogen supply on post-floral growth of wheat; measurements and simulations

    NARCIS (Netherlands)

    Vos, J.

    1981-01-01

    Warmth accelerates the rate of grain growth in wheat, but the temperature coefficient expressed as Q 10 decreases gradually between 10 and 25°C. The rate of protein deposition responds more to temperature than the total grain dry matter accumulation rate. Warmth shortens the post-floral p

  3. 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.

  4. 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

  5. Floral divergence, pollinator partitioning and the spatiotemporal pattern of plant-pollinator interactions in three sympatric Adenophora species.

    Science.gov (United States)

    Liu, Chang-Qiu; Huang, Shuang-Quan

    2013-12-01

    Floral divergence among congeners may relate to differential utilization of pollinators and contribute to reducing overlap in pollination niches. To investigate whether and how floral differences are associated with differential utilization of pollinators in three sympatric Adenophora species, we analyzed floral traits and evaluated the contribution of different visitors to pollination. We compared visitation rates of different pollinator categories in different years and sites. A suite of floral traits differed among the three Adenophora species, suggesting adaptation to diurnal versus nocturnal pollination and an intermediate condition. However, many visitor species were shared among the three plant species, suggesting that floral traits did not rigorously filter visitors. Effective pollinators were large bees and moths. The importance of large bees as pollinators decreased whereas that of moths increased along the gradient from typically bee-pollinated to moth-pollinated flowers. The intermediate species (A. khasiana) differed substantially from the other two species in pollinator species but not in pollinator categories. The principal pollinator category of each species was constant across years and sites except in the intermediate species where it differed between two sites. Overall, the three sympatric species of Adenophora partition pollinators by floral divergence and the principal pollinators coincide with the predictions based on floral syndromes. PMID:23824141

  6. 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.

  7. Pollination syndromes in a Caatinga plant community in northeastern Brazil: seasonal availability of floral resources in different plant growth habits.

    Science.gov (United States)

    Quirino, Z G M; Machado, I C

    2014-02-01

    To describe plant phenological patterns and correlate functioning for the quantity and quality of resources available for the pollinator, it is crucial to understand the temporal dynamics of biological communities. In this way, the pollination syndromes of 46 species with different growth habits (trees, shrubs, herbs, and vines) were examined in an area of Caatinga vegetation, northeastern Brazil (7° 28' 45″ S and 36° 54' 18″ W), during two years. Flowering was monitored monthly in all the species, over two years (from January 2003 to December 2004). Pollination syndromes were characterised based on floral traits such as size, colour, morphology, symmetry, floral resources, as well as on direct visual observation of floral visitors on focal plants and published information. We observed differences among the plant growth habits with respect to floral traits, types of resources offered, and floral syndromes. The flowering periods of the species varied among floral syndrome groups. The majority of the melittophilous species flowered during the rainy season in the two study years, while the species of the other pollination syndroms flowered at the end of the dry season. An asynchrony of flowering was noted among the chiropterophilous species, while the phalenophilous group concentrated during the rainy season. The overall availability of floral resources was different during the rainy and the dry seasons, and also it varied among plants with different growth habits. The availability of oil-flowers coincided with the period of low nectar availability. We observed a relationship between the temporal distribution of the pollination syndromes and the availability of floral resources among each growth habits in this tropical ecosystem. Resource allocation in seasonal environments, such as the Caatinga, can function as a strategy for maintaining pollinators, facilitating therefore the reproductive success of plant species. The availability of floral resources during

  8. Combinação do paclobutrazol, sulfato de potássio e etefon na indução floral da mangueira cv. Tommy Atkins

    Directory of Open Access Journals (Sweden)

    José Algaci Lopes da Silva

    2011-04-01

    Full Text Available Amongst the techniques used for the regulation of the vegetative growth of mango trees withthe purpose in floral induction, is common the arranged use of the substances Paclobutrazol,Potassium Sulfate and Ethephon. Under conditions of semi-arid tropic the precipitated techniquehas persuaded an abundant flower induction, however has produced inconsistent effects in theconditions of warm and rainy climate. With the purpose to study that combination in the growth eflowering of mango trees, variety Tommy Atkins, it was experimented in the mesorgion of TeresinaCity, State of Piauí, under conditions of humid tropic, using an experimental design of randomizedcomplete blocks, with an factorial arrangement 4 x 3: four Paclobutrazol doses (zero; 0.7; 1.0 and 1.3g of a.i. m-1 of diameter tree canopy and three practices that combined applications of PotassiumSulfate (2%, Ethephon (240 ppm on three periods of floral induction, 90, 105 and 120 days, to thestart of application of dormancy-breaking, which was counted from the Paclobutrazol application.Plants untreated produced only vegetative branches and the various products and periods ofapplications combinations tested showed low rates flowering and high rates of dormant buds.

  9. 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. PMID:26440413

  10. Pollen Morphology and Boron Concentration in Floral Tissues as Factors Triggering Natural and GA-Induced Parthenocarpic Fruit Development in Grapevine.

    Directory of Open Access Journals (Sweden)

    Orlando Alva

    Full Text Available 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.

  11. Pollinator Competition as a Driver of Floral Divergence: An Experimental Test.

    Science.gov (United States)

    Temeles, Ethan J; Newman, Julia T; Newman, Jennifer H; Cho, Se Yeon; Mazzotta, Alexandra R; Kress, W John

    2016-01-01

    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.

  12. 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. PMID:25835570

  13. 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.

  14. Floral ontogeny of Pedicularis (Orobanchaceae),with an emphasis on the corolla upper lip

    Institute of Scientific and Technical Information of China (English)

    Wen-Bin YU; Jie CAI; De-Zhu LI; Robert R.MILL; Hong WANG

    2013-01-01

    Pedicularis shows high diversity in its corolla form,however,its floral ontogeny has been rarely investigated.In particular,the development of the highly variable upper lip (galea),three broad morphological types of which (beakless and toothless,beakless and toothed,beaked) can be discriminated,remains unknown.We used scanning electron microscopy to investigate the early stages of floral ontogeny in two beaked species,Pedicularis gruina and P.siphonantha.To compare the developmental processes of the three galea types,three species for each type were investigated.Initiations of floral organs in Pedicularis are consistent.Sepal initiations are successive from the lateral-adaxial primordia,followed by the lateral-abaxial ones (these sometimes missing),then the mid-adaxial one (again sometimes missing).The stamens are initiated prior to the petals,or development of petal primordia may be retarded at the early stages in comparison with that of stamen primordia.Four stamen primordia are initiated simultaneously.The five petal primordia are initiated almost simultaneously.Development processes of the upper lip among the three galea types differ in the expansion rates and directions of the cells of the two lobes and these differences govem whether or not a beak and/or teeth are formed on the upper lip.The floral ontogeny of Pedicularis is close to that of Agalinis,which supports the molecular assignment.Floral monosymmetry of Pedicularis is established at the beginning of sepal initiation and is maintained until flowering.The development of the upper lip provides some clues to the evolution of beaked and/or toothed galeas in Pedicularis.

  15. 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.

  16. Pollinator Competition as a Driver of Floral Divergence: An Experimental Test.

    Science.gov (United States)

    Temeles, Ethan J; Newman, Julia T; Newman, Jennifer H; Cho, Se Yeon; Mazzotta, Alexandra R; Kress, W John

    2016-01-01

    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. PMID:26814810

  17. 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.

  18. SmShb, the SH2-Containing Adaptor Protein B of Schistosoma mansoni Regulates Venus Kinase Receptor Signaling Pathways

    Science.gov (United States)

    Morel, Marion; Vanderstraete, Mathieu; Cailliau, Katia; Hahnel, Steffen; Grevelding, Christoph G.; Dissous, Colette

    2016-01-01

    Venus kinase receptors (VKRs) are invertebrate receptor tyrosine kinases (RTKs) formed by an extracellular Venus Fly Trap (VFT) ligand binding domain associated via a transmembrane domain with an intracellular tyrosine kinase (TK) domain. Schistosoma mansoni VKRs, SmVKR1 and SmVKR2, are both implicated in reproductive activities of the parasite. In this work, we show that the SH2 domain-containing protein SmShb is a partner of the phosphorylated form of SmVKR1. Expression of these proteins in Xenopus oocytes allowed us to demonstrate that the SH2 domain of SmShb interacts with the phosphotyrosine residue (pY979) located in the juxtamembrane region of SmVKR1. This interaction leads to phosphorylation of SmShb on tyrosines and promotes SmVKR1 signaling towards the JNK pathway. SmShb transcripts are expressed in all parasite stages and they were found in ovary and testes of adult worms, suggesting a possible colocalization of SmShb and SmVKR1 proteins. Silencing of SmShb in adult S. mansoni resulted in an accumulation of mature sperm in testes, indicating a possible role of SmShb in gametogenesis. PMID:27636711

  19. SmShb, the SH2-Containing Adaptor Protein B of Schistosoma mansoni Regulates Venus Kinase Receptor Signaling Pathways.

    Science.gov (United States)

    Morel, Marion; Vanderstraete, Mathieu; Cailliau, Katia; Hahnel, Steffen; Grevelding, Christoph G; Dissous, Colette

    2016-01-01

    Venus kinase receptors (VKRs) are invertebrate receptor tyrosine kinases (RTKs) formed by an extracellular Venus Fly Trap (VFT) ligand binding domain associated via a transmembrane domain with an intracellular tyrosine kinase (TK) domain. Schistosoma mansoni VKRs, SmVKR1 and SmVKR2, are both implicated in reproductive activities of the parasite. In this work, we show that the SH2 domain-containing protein SmShb is a partner of the phosphorylated form of SmVKR1. Expression of these proteins in Xenopus oocytes allowed us to demonstrate that the SH2 domain of SmShb interacts with the phosphotyrosine residue (pY979) located in the juxtamembrane region of SmVKR1. This interaction leads to phosphorylation of SmShb on tyrosines and promotes SmVKR1 signaling towards the JNK pathway. SmShb transcripts are expressed in all parasite stages and they were found in ovary and testes of adult worms, suggesting a possible colocalization of SmShb and SmVKR1 proteins. Silencing of SmShb in adult S. mansoni resulted in an accumulation of mature sperm in testes, indicating a possible role of SmShb in gametogenesis.

  20. 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

    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.

  1. 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

  2. The Ras suppressor Rsu-1 binds to the LIM 5 domain of the adaptor protein PINCH1 and participates in adhesion-related functions

    International Nuclear Information System (INIS)

    Rsu-1 is a highly conserved leucine rich repeat (LRR) protein that is expressed ubiquitously in mammalian cells. Rsu-1 was identified based on its ability to inhibit transformation by Ras, and previous studies demonstrated that ectopic expression of Rsu-1 inhibited anchorage-independent growth of Ras-transformed cells and human tumor cell lines. Using GAL4-based yeast two-hybrid screening, the LIM domain protein, PINCH1, was identified as the binding partner of Rsu-1. PINCH1 is an adaptor protein that localizes to focal adhesions and it has been implicated in the regulation of adhesion functions. Subdomain mapping in yeast revealed that Rsu-1 binds to the LIM 5 domain of PINCH1, a region not previously identified as a specific binding domain for any other protein. Additional testing demonstrated that PINCH2, which is highly homologous to PINCH1, except in the LIM 5 domain, does not interact with Rsu-1. Glutathione transferase fusion protein binding studies determined that the LRR region of Rsu-1 interacts with PINCH1. Transient expression studies using epitope-tagged Rsu-1 and PINCH1 revealed that Rsu-1 co-immunoprecipitated with PINCH1 and colocalized with vinculin at sites of focal adhesions in mammalian cells. In addition, endogenous P33 Rsu-1 from 293T cells co-immunoprecipitated with transiently expressed myc-tagged PINCH1. Furthermore, RNAi-induced reduction in Rsu-1 RNA and protein inhibited cell attachment, and while previous studies demonstrated that ectopic expression of Rsu-1 inhibited Jun kinase activation, the depletion of Rsu-1 resulted in activation of Jun and p38 stress kinases. These studies demonstrate that Rsu-1 interacts with PINCH1 in mammalian cells and functions, in part, by altering cell adhesion

  3. The cell signaling adaptor protein EPS-8 is essential for C. elegans epidermal elongation and interacts with the ankyrin repeat protein VAB-19.

    Directory of Open Access Journals (Sweden)

    Mei Ding

    Full Text Available The epidermal cells of the C. elegans embryo undergo coordinated cell shape changes that result in the morphogenetic process of elongation. The cytoskeletal ankyrin repeat protein VAB-19 is required for cell shape changes and localizes to cell-matrix attachment structures. The molecular functions of VAB-19 in this process are obscure, as no previous interactors for VAB-19 have been described.In screens for VAB-19 binding proteins we identified the signaling adaptor EPS-8. Within C. elegans epidermal cells, EPS-8 and VAB-19 colocalize at cell-matrix attachment structures. The central domain of EPS-8 is necessary and sufficient for its interaction with VAB-19. eps-8 null mutants, like vab-19 mutants, are defective in epidermal elongation and in epidermal-muscle attachment. The eps-8 locus encodes two isoforms, EPS-8A and EPS-8B, that appear to act redundantly in epidermal elongation. The function of EPS-8 in epidermal development involves its N-terminal PTB and central domains, and is independent of its C-terminal SH3 and actin-binding domains. VAB-19 appears to act earlier in the biogenesis of attachment structures and may recruit EPS-8 to these structures.EPS-8 and VAB-19 define a novel pathway acting at cell-matrix attachments to regulate epithelial cell shape. This is the first report of a role for EPS-8 proteins in cell-matrix attachments. The existence of EPS-8B-like isoforms in Drosophila suggests this function of EPS-8 proteins could be conserved among other organisms.

  4. Analysis of Phosphorylation-dependent Protein Interactions of Adhesion and Degranulation Promoting Adaptor Protein (ADAP) Reveals Novel Interaction Partners Required for Chemokine-directed T cell Migration.

    Science.gov (United States)

    Kuropka, Benno; Witte, Amelie; Sticht, Jana; Waldt, Natalie; Majkut, Paul; Hackenberger, Christian P R; Schraven, Burkhart; Krause, Eberhard; Kliche, Stefanie; Freund, Christian

    2015-11-01

    Stimulation of T cells leads to distinct changes of their adhesive and migratory properties. Signal propagation from activated receptors to integrins depends on scaffolding proteins such as the adhesion and degranulation promoting adaptor protein (ADAP)(1). Here we have comprehensively investigated the phosphotyrosine interactome of ADAP in T cells and define known and novel interaction partners of functional relevance. While most phosphosites reside in unstructured regions of the protein, thereby defining classical SH2 domain interaction sites for master regulators of T cell signaling such as SLP76, Fyn-kinase, and NCK, other binding events depend on structural context. Interaction proteomics using different ADAP constructs comprising most of the known phosphotyrosine motifs as well as the structured domains confirm that a distinct set of proteins is attracted by pY571 of ADAP, including the ζ-chain-associated protein kinase of 70 kDa (ZAP70). The interaction of ADAP and ZAP70 is inducible upon stimulation either of the T cell receptor (TCR) or by chemokine. NMR spectroscopy reveals that the N-terminal SH2 domains within a ZAP70-tandem-SH2 construct is the major site of interaction with phosphorylated ADAP-hSH3(N) and microscale thermophoresis (MST) indicates an intermediate binding affinity (Kd = 2.3 μm). Interestingly, although T cell receptor dependent events such as T cell/antigen presenting cell (APC) conjugate formation and adhesion are not affected by mutation of Y571, migration of T cells along a chemokine gradient is compromised. Thus, although most phospho-sites in ADAP are linked to T cell receptor related functions we have identified a unique phosphotyrosine that is solely required for chemokine induced T cell behavior.

  5. 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

  6. A membrane-tethered transcription factor ANAC089 negatively regulates floral initiation in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The plant-specific NAC (NAM, ATAF1/2,and CUC2) transcription factors have a regulatory function in developmental processes and stress responses. Notably a group of NAC members named NTLs (NTM1-Like) are membrane-tethered, ensuring plants rapidly respond to developmental changes and environmental stimuli. Our results indicated that ANAC089 was a membrane-tethered transcription factor and its truncated form was responsible for the physiological function in flowering time control.

  7. The NR-radon intensity impact on floral environment around NAPP

    International Nuclear Information System (INIS)

    The nuclear radiation level around Narora Atomic Power Plant (NAPP), District Buladshehar (Uttar Pradesh) has been observed by experimental irradiation of CR-39 plastic track detectors, mounted in a self assembled box installed at height from the ground level 10, 20, 40, 60, 80 and 100 cm. The plants being most sensitive to nuclear radiation, constituting the floral component of bio-diversity, look more frequent and effective means to regulate the nuclear radiation and hence employed as potential alternative to SSNTD, named as BSNTD (the Bio-Species-Nuclear Track Detector) after appropriate calibrations. The five sites selected with similar settings of NR experimental 45 days exposures for Radon alpha, also accompanied by vegetable plants, oil yielding and ornamental plants such as radish, onion, mustard and marigold (under various physical as well as chemical treatments such as magnetic fields, fertilizers) placed at: (1)The open space nearly ∼ 100 meter away from NAPP Reactor Unit No. 1, (2) Village Ratanpur about 10 Km from NAPP, (3) Village Shehdol near Atrauli about 20 Km from NAPP, (4) Kasimpur Thermal power Plant near Aligarh, about 40 Km from NAPP and (5) The D.S. College, Physics research laboratory at Aligarh proper. The isolated and mixed treated plants were grown under controlled favourable conditions and their regular biological growth like total shoot yield, flowers/fruits and seed yield were recorded and these were correlated with the observed radioactive data. The experimental findings seem to match with all these parameters proportionally to CR-39 recording and thus proposing much cheaper Bio-Species Nuclear Track Detection as dynamical physiological changes but not as rigid geometrical damages recorded in SSNTD under cumbersome experimental procedures. The plant growth performance under different environmental conditions such as presence of track elements and heavy metals, our research group had set an unique experimentation relating complex bio

  8. 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

  9. 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

  10. Anatomía floral comparativa del género Polianthes (Agavaceae Comparative floral anatomy of the genus Polianthes (Agavaceae

    Directory of Open Access Journals (Sweden)

    Héctor Serrano-Casas

    2011-03-01

    Full Text Available Se realizó un estudio anatómico de las flores de algunas especies en los subgéneros Polianthes y Bravoa del género Polianthes L. (Agavaceae, con el propósito de investigar si la actual clasificación subgenérica es adecuada. Los taxa analizados del subgénero Polianthes fueron P. densiflora, P. nelsonii y P. platyphylla, y del subgénero Bravoa, P. geminiflora var. geminiflora, P. howardii y P. multicolor. Las características anatómicas florales entre las especies son similares y comparten con otros miembros de la familia Agavaceae los nectarios septales y los óvulos anátropos, bitégmicos y crasinucelados. En los taxa del subgénero Bravoa, los filamentos se originan en la base del tubo floral, mientras que en el subgénero Polianthes se originan por debajo de los tépalos internos del perianto. Anteriormente, sin considerar la anatomía de las flores, se planteaba que los filamentos se originaban en ambos subgéneros desde la base del tubo del perianto y que éstos permanecían adnados al mismo, separándose a diferentes niveles. En el nivel interespecífico, P. howardii presenta nectarios de mayor longitud que los lóculos, en relación con los de las otras especies estudiadas.An anatomical floral study of some species of the genus Polianthes (Agavaceae, of both subgenus Polianthes and subgenus Bravoa (Agavaceae was carried out, with the aim of testing the adequacy of the present subgeneric classification. The taxa studied of subgenus Polianthes were P. densiflora, P. nelsonii and P. platyphylla; and P. geminiflora var. geminiflora, P. howardii and P. multicolor of subgenus Bravoa. The anatomical characters between these species are similar, sharing with other members of the Agavaceae family the septal nectaries and the anatropous, bitegmic, and crassinucellated ovules. In the taxa of subgenus Bravoa, the filaments originate from the floral tube base, while in subgenus Polianthes they originate near the base of the internal tepals

  11. Classificação do mel em floral ou mel de melato Classification of honey as floral or honeydew honey

    Directory of Open Access Journals (Sweden)

    G. Campos

    2003-04-01

    Full Text Available O mel é um produto natural de abelhas fabricado a partir do néctar das flores (mel floral e de secreções de partes vivas das plantas, ou de excreções de insetos sugadores de partes vivas das plantas (mel de melato. O melato é uma fonte alternativa de alimento bastante utilizada pela abelha. Em Santa Catarina, o mel de melato é muito conhecido, sendo produzido nos meses de janeiro a abril, em ciclos bianuais. Foram colhidas aleatoriamente 25 amostras de mel, no período de janeiro/93 a junho/96, de diferentes apiários e datas de colheita. Foram determinados os teores de umidade, pH, cinzas e açúcares redutores. Os resultados foram utilizados na aplicação da equação de Kirkwood para classificar o mel como floral ou de melato. As amostras também foram analisadas quanto à rotação óptica para classificação de acordo com White. Das 25 amostras analisadas, 11 foram classificadas como mel de melato de acordo com Kirkwood e White. O estudo estatístico, feito pela aplicação do teste exato de Fisher, indicou que, apesar da divergência em 4 amostras, estes métodos são equivalentes e ambos podem ser usados.Honey is a natural product made by bees using flower's nectar (floral honey or excretion of alive parts of plants or either excretion produced by sucking insects from alive parts of plants (honeydew honey. Honeydew is an alternative food source used by bees. In Santa Catarina state, honeydew honey is produced from january to april, each two years. In order to identify the presence of honeydew honey, 25 samples were sampled randomly from january/93 to june/96. They were colected from different apiaries in different periods of time and tested for moisture, pH, ash, reducing sugars, and the results were used in the application of Kirkwood equation to classify honey as floral or honeydew. They were analised for polarimetry, to classify them according to Kirkwood and White. The statistical study was done by the application of exact

  12. 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

  13. When looks can kill: the evolution of sexually dimorphic floral display and the extinction of dioecious plants.

    OpenAIRE

    Vamosi, Jana C; Otto, Sarah P.

    2002-01-01

    Dioecious plants (with separate male and female individuals) more often have drab, inconspicuous flowers than related bisexual plants. Models indicate, however, that similar conditions favour the evolution of showy floral displays in dioecious and bisexual plants. One difference, however, is that dioecious plants may evolve floral displays that are sexually dimorphic. We show that males are more likely to evolve showy flowers than females in animal-pollinated plants, especially when pollinato...

  14. Floral visitors of Aechmea constantinii (Mez) L. B. Sm. (Bromeliaceae) in a remnant of the Brazilian Northeast Atlantic Rainforest

    OpenAIRE

    Petrúcio Alexandre Fonseca Rios J; uliana Braga da Silva; Flávia de Barros Prado Moura

    2010-01-01

    This study aims to determine the floral visitors and potential pollinators of Aechmea constantinii (Mez) L. B. Sm. (Bromeliaceae), a bromeliad endemic to the Brazilian Northeast Atlantic Rainforest. Reproductively-active individuals were observed systematically and their visitors were recorded and determined. The main recorded fl oral visitors were Glaucis hirsutus, Phaethornis ruber and Phaethornis pretrei (hummingbirds) which executed frontal functional floral visits in which they touched t...

  15. Ants as flower visitors : floral ant-repellence and the impact of ant scent-marks on pollinator behaviour

    OpenAIRE

    Ballantyne, Gavin

    2011-01-01

    As flower visitors, ants rarely benefit a plant, commonly disrupting pollination by deterring other flower visitors, or stealing nectar. This thesis examines three aspects of ant-flower interactions, focusing on the occurrence of floral traits that prevent disruption of pollination and a novel means by which ants may influence pollinator behaviour. To assess which types of plant species possess ant-repelling floral traits I carried out a survey of 49 Neotropical plant species. ...

  16. 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

    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...

  17. 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. PMID:11526079

  18. 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.

  19. Amyloplast to chromoplast conversion in developing ornamental tobacco floral nectaries provides sugar for nectar and antioxidants for protection.

    Science.gov (United States)

    Horner, H T; Healy, R A; Ren, G; Fritz, D; Klyne, A; Seames, C; Thornburg, R W

    2007-01-01

    Tobacco floral nectaries undergo changes in form and function. As nectaries change from green to orange, a new pigment is expressed. Analysis demonstrated that it is β-carotene. Plastids undergo dramatic changes. Early in nectary development, they divide and by stage 9 (S9) they are engorged with starch. About S9, nectaries shift from quiescent anabolism to active catabolism resulting in starch breakdown and production of nectar sugars. Starch is replaced by osmiophilic bodies, which contain needle-like carotenoid crystals. Between S9 and S12, amyloplasts are converted to chromoplasts. Changes in carotenoids and ascorbate were assayed and are expressed at low levels early in development; however, following S9 metabolic shift, syntheses of β-carotene and ascorbate greatly increase in advance of expression of nectar redox cycle. Transcript analysis for carotenoid and ascorbate biosynthetic pathways showed that these genes are significantly expressed at S6, prior to the S9 metabolic shift. Thus, formation of antioxidants β-carotene and ascorbate after the metabolic shift is independent of transcriptional regulation. We propose that biosynthesis of these antioxidants is governed by availability of substrate molecules that arise from starch breakdown. These processes and events may be amenable to molecular manipulation to provide a better system for insect attraction, cross pollination, and hybridization.

  20. The Arabidopsis Floral Repressor BFT DelaysFlowering by Competing with FT for FD Bindingunder High Salinity

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    Soil salinity is one of the most serious agricultural problems that significantly reduce crop yields in the aridand semi-arid regions. It influences various phases of plant growth and developmental processes, such as seed germina-tion, leaf and stem growth, and reproductive propagation. Salt stress delays the onset of flowering in many plant spe-cies. We have previously reported that the Arabidopsis BROTHER OF FT AND TFL1 (BFT) acts as a floral repressor undersalt stress. However, the molecular mechanisms underlying the BFT function in the salt regulation of flowering inductionis unknown. In this work, we found that BFT delays flowering under high salinity by competing with FLOWERING LOCUST (FT) for binding to the FD transcription factor. The flowering time of FD-deficient fd-2 mutant was insensitive to highsalinity. BFT interacts with FD in the nucleus via the C-terminal domain of FD, which is also required for the interactionof FD with FT, and interferes with the FT-FD interaction. These observations indicate that BFT constitutes a distinct saltstress signaling pathway that modulates the function of the FT-FD module and possibly provides an adaptation strategythat fine-tunes photoperiodic flowering under high salinity.

  1. Floral Biology of Chinese Jujube (Ziziphus jujube Mill. I: The Formation of Microspores and Development of Male Gametes

    Directory of Open Access Journals (Sweden)

    Feng Zou

    2015-08-01

    Full Text Available Ziziphus jujube Mill is an economically important fruit tree, cultivated on marginal lands on a commercial scale, especially in China. In order to elucidate the microsporogenesis and male gametogenesis formation in Chinese jujube, a cultivar named ‘Lizao’ was employed for microscopy analysis. The results are showed that ‘Lizao’ was four ventricles in each anther and the anther wall was 4 to 5 layers. Its primary anther wall consisted of the epidermis, 1-2 layers endothecium, middle and glandular tapetum layers. The development of the anther wall conformed to the basic type. The meiosis in the microspore mother cells were belonged to a simultaneous type and most of the microspores were arranged in a tetrahedron shape in the tetrads. In the later May, the shape of pollen was a triangular germination vale with three germinal furrow and the mature pollen was of 2-cell type. Floral emergence and development lasted for 1 months-from later April to later May. Based our results, we did not find the abnormal male flower in the Z. jujube ‘Lizao’, suggesting that microsporogensis development may not be factors in the low seed production in the Z. jujube. This study provides the basis for understanding the biological mechanism regulating sexual reproduction, thus expanding the prospects for Z. jujube breeding programs and for further molecular and genetic studies of this species.

  2. Effect of floral cluster pruning on anthocyanin levels and anthocyanain-related gene expression in 'Houman' grape.

    Science.gov (United States)

    Zhang, Lei; Xu, Yan-Shuai; Jia, Yue; Wang, Ji-Yuan; Yuan, Yue; Yu, Yang; Tao, Jian-Min

    2016-01-01

    Lateral floral clusters were removed from the main axis of the floral clusters of 'Houman' grape plants, leaving only 3-5-cm-long region of flowers at the end of the central axis. The floral clusters were pruned at 7 days prior to flowering. The effect of the pruning on fruit quality was assessed by determining the composition and levels of anthocyanins in the fruit and anthocyanin-related gene expression. Results indicated that floral cluster pruning significantly improved the quality of the fruit by increasing berry size, fruit weight and the total content of soluble solids. Floral cluster pruning also decreased the level of titratable acidity. Sixteen different anthocyanins were detected in fruit of the pruned clusters, while only 15 were detected in fruit from unpruned clusters. The level of anthocyanins was also significantly higher in fruit of the pruned clusters than in the unpruned clusters. Anthocyanin-related gene expression was also significantly upregulated to a higher level in fruit from pruned floral clusters as compared with unpruned clusters. The upregulation was closely associated with increases in anthocyanin biosynthesis. PMID:27555920

  3. Effect of floral cluster pruning on anthocyanin levels and anthocyanain-related gene expression in ‘Houman’ grape

    Science.gov (United States)

    Zhang, Lei; Xu, Yan-shuai; Jia, Yue; Wang, Ji-yuan; Yuan, Yue; Yu, Yang; Tao, Jian-min

    2016-01-01

    Lateral floral clusters were removed from the main axis of the floral clusters of ‘Houman’ grape plants, leaving only 3–5-cm-long region of flowers at the end of the central axis. The floral clusters were pruned at 7 days prior to flowering. The effect of the pruning on fruit quality was assessed by determining the composition and levels of anthocyanins in the fruit and anthocyanin-related gene expression. Results indicated that floral cluster pruning significantly improved the quality of the fruit by increasing berry size, fruit weight and the total content of soluble solids. Floral cluster pruning also decreased the level of titratable acidity. Sixteen different anthocyanins were detected in fruit of the pruned clusters, while only 15 were detected in fruit from unpruned clusters. The level of anthocyanins was also significantly higher in fruit of the pruned clusters than in the unpruned clusters. Anthocyanin-related gene expression was also significantly upregulated to a higher level in fruit from pruned floral clusters as compared with unpruned clusters. The upregulation was closely associated with increases in anthocyanin biosynthesis. PMID:27555920

  4. 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.

  5. Floral aroma improvement of Muscat spirits by packed column distillation with variable internal reflux.

    Science.gov (United States)

    Matias-Guiu, Pau; Rodríguez-Bencomo, Juan José; Orriols, Ignacio; Pérez-Correa, José Ricardo; López, Francisco

    2016-12-15

    The organoleptic quality of wine distillates depends on raw materials and the distillation process. Previous work has shown that rectification columns in batch distillation with fixed reflux rate are useful to obtain distillates or distillate fractions with enhanced organoleptic characteristics. This study explores variable reflux rate operating strategies to increase the levels of terpenic compounds in specific distillate fractions to emphasize its floral aroma. Based on chemical and sensory analyses, two distillate heart sub-fractions obtained with the best operating strategy found, were compared with a distillate obtained in a traditional alembic. Results have shown that a drastic reduction of the reflux rate at an early stage of the heart cut produced a distillate heart sub-fraction with a higher concentration of terpenic compounds and lower levels of negative aroma compounds. Therefore, this sub-fraction presented a much more noticeable floral aroma than the distillate obtained with a traditional alembic. PMID:27451153

  6. 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. PMID:27539950

  7. Cloning and characterization of PhPI9 involved in floral development from Phalaenopsis Orchid

    Institute of Scientific and Technical Information of China (English)

    GUO Bin; DAI Wei; CHEN Donghong; WEI Xing; MING Feng

    2007-01-01

    In the attempt to discover new genes involved in the floral development in monoeotyledonousin species,we have cloned and characterized the homologous PISTALLATA-like (PI-like) gone from Phalaenopsis hybrid cultivar named PhPI9 (Phalaenopsis PI STILLATA # 9).The eDNA of PhPI9 has a fragment of 834 bp and has 60% identity with the PISTILATA from Arabidopsis.The deduced amino acid sequence of PhPI9 had the typical PI-motif.It also formed a subelade with other monoeot PI-type genes in phylogenetie analysis.Southern analysis showed that PhPI9 was present in the Phalaenopsis orchid genome as a single copy.Furthermore,it was expressed only in the lip of the Phalaenopsis flower and no expression was detected in vegetative organs.Thus,as a B-function MADS-box gone,PhP19 specifies floral organ identity in orchids.

  8. Association between receptor protein-tyrosine phosphatase RPTPalpha and the Grb2 adaptor. Dual Src homology (SH) 2/SH3 domain requirement and functional consequences

    DEFF Research Database (Denmark)

    Su, J; Yang, L T; Sap, J

    1996-01-01

    Receptor protein-tyrosine phosphatase RPTPalpha is found associated in vivo with the adaptor protein Grb2. Formation of this complex, which contains no detectable levels of Sos, is known to depend on a C-terminal phosphorylated tyrosine residue (Tyr798) in RPTPalpha and on the Src homology (SH) 2...

  9. Disruption of adaptor protein 2mu (AP-2mu) in cochlear hair cells impairs vesicle reloading of synaptic release sites and hearing

    NARCIS (Netherlands)

    Jung, S.; Maritzen, T.; Wichmann, C.; Jing, Z.; Neef, A.; Revelo, N.H.; Al-Moyed, H.; Meese, S.; Wojcik, S.M.; Panou, I.; Bulut, H.; Schu, P.; Ficner, R.; Reisinger, E.; Rizzoli, S.O.; Neef, J.; Strenzke, N.; Haucke, V.; Moser, T.

    2015-01-01

    Active zones (AZs) of inner hair cells (IHCs) indefatigably release hundreds of vesicles per second, requiring each release site to reload vesicles at tens per second. Here, we report that the endocytic adaptor protein 2mu (AP-2mu) is required for release site replenishment and hearing. We show that

  10. Ubc2, an Ortholog of the Yeast Ste50p Adaptor, Possesses a Basidiomycete-Specific Carboxy terminal Extension Essential for Pathogenicity Independent of Pheromone Response.

    Science.gov (United States)

    Proteins involved in the MAP kinase pathway controlling mating, morphogenesis and pathogenicity have been identified previously in the fungus Ustilago maydis. One of these, the Ubc2 adaptor protein, possesses a basidiomycete-specific structure. In addition to containing SAM and RA domains typical of...

  11. Enigma interacts with adaptor protein with PH and SH2 domains to control insulin-induced actin cytoskeleton remodeling and glucose transporter 4 translocation

    DEFF Research Database (Denmark)

    Barres, Romain; Grémeaux, Thierry; Gual, Philippe;

    2006-01-01

    APS (adaptor protein with PH and SH2 domains) initiates a phosphatidylinositol 3-kinase-independent pathway involved in insulin-stimulated glucose transport. We recently identified Enigma, a PDZ and LIM domain-containing protein, as a partner of APS and showed that APS-Enigma complex plays...

  12. Optimum temperature for floral terpene emissions tracks the mean temperature of the flowering season

    OpenAIRE

    Farré Armengol, Gerard; Filella Cubells, Iolanda; Llusià Benet, Joan; Peñuelas, Josep; Niinemets, Ülo

    2015-01-01

    Emissions of volatiles from leaves exhibit temperature dependence on maximums, but the optimum temperatures for the release of floral volatiles and the mechanism(s) of optimising these emissions have not been determined. We hypothesised that flowers have an optimum temperature for the emission of volatiles and, because the period of flowering varies highly among species, that this optimum is adapted to the temperatures prevailing during flowering. To test these hypotheses, we characterised th...

  13. Divergent genetic mechanisms underlie reversals to radial floral symmetry from diverse zygomorphic flowered ancestors

    OpenAIRE

    Zhang, Wenheng; Steinmann, Victor W.; Nikolov, Lachezar; Kramer, Elena M.; Davis, Charles C.

    2013-01-01

    Malpighiaceae possess flowers with a unique bilateral symmetry (zygomorphy), which is a hypothesized adaptation associated with specialization on neotropical oil bee pollinators. Gene expression of two representatives of the CYC2 lineage of floral symmetry TCP genes, CYC2A and CYC2B, demarcate the adaxial (dorsal) region of the flower in the characteristic zygomorphic flowers of most Malpighiaceae. Several clades within the family, however, have independently lost their specialized oil bee po...

  14. 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...

  15. Compostos voláteis em méis florais Volatile compounds in floral honeys

    OpenAIRE

    Carlos Alberto Bastos De Maria; Ricardo Felipe Alves Moreira

    2003-01-01

    A review about origin, composition and importance of volatile compounds in floral honeys is presented. Hydrocarbons, aromatic components, acids, diacids, terpenoids, ketones, aldehydes, esters and alcohols have been found in honey aroma of different botanical origin. Cis-rose oxide has been proposed as an indicator for Tilia cordata honey. Citrus honeys are known to contain methyl anthranilate, a compound which other honeys virtually lack. Linalool, phenylethylalcohol, phenylacetaldehyde, p-a...

  16. Nectar sugar production across floral phases in the gynodioecious protandrous plant Geranium sylvaticum

    OpenAIRE

    Sandra Varga; Carolin Nuortila; Minna-Maarit Kytöviita

    2013-01-01

    Many zoophilous plants attract their pollinators by offering nectar as a reward. In gynodioecious plants (i.e. populations are composed of female and hermaphrodite individuals) nectar production has been repeatedly reported to be larger in hermaphrodite compared to female flowers even though nectar production across the different floral phases in dichogamous plants (i.e. plants with time separation of pollen dispersal and stigma receptivity) has rarely been examined. In this study, sugar prod...

  17. Adaptive plasticity of floral display size in animal-pollinated plants

    OpenAIRE

    Harder, Lawrence D.; JOHNSON, STEVEN D.

    2005-01-01

    Plants need not participate passively in their own mating, despite their immobility and reliance on pollen vectors. Instead, plants may respond to their recent pollination experience by adjusting the number of flowers that they display simultaneously. Such responsiveness could arise from the dependence of floral display size on the longevity of individual flowers, which varies with pollination rate in many plant species. By hand-pollinating some inflorescences, but not others, we demonstrate ...

  18. Floral Biology of Aconitum heterophyllum Wall.: A Critically Endangered Alpine Medicinal Plant of Himalaya, India

    OpenAIRE

    NAUTIYAL, Bhagwati P.; NAUTIYAL, Mohan C.

    2009-01-01

    Aconitum heterophyllum Wall. is a critically endangered wild medicinal herb of alpine Himalaya and cultivation is recommended owing to its large demand in the herbal market and to ensure the conservation of wild habitats. Therefore, observations on floral biology, pollen germination, pollination, and fruit and seed setting after implying different breeding systems were carried out for its successful domestication and improvement in cultivation practices. The study reveals that the plants grow...

  19. Floral and pollination biology of three sympatric Vaccinium (Ericaceae) species in the Upper Ardennes, Belgium

    OpenAIRE

    Jacquemart, Anne-Laure; Thompson, JD

    1996-01-01

    Comparative studies of the reproductive biology and pollination ecology of closely related species allow us to test several ideas related to the evolution of selfing taxa from outcrossing ancestors. The existence of closely related species in the same habitat provides a particularly useful opportunity to examine this issue. A variety of floral traits likely to be associated with the reproductive system of three sympatric Vaccinium species (V. myrtillus, V. vitis-idaea, and V. uliginosum) were...

  20. Floral syndrome and secondary pollen presentation in Codonopsis clem-atidea (Campanulaceae)

    OpenAIRE

    Li Wang; Dunyan Tan

    2011-01-01

    Secondary pollen presentation has been described as a reproductive strategy that enhances the ef-ficiency and accuracy of pollen exportation and pollen reception, thereby promoting outcrossing. Codonopsis clematidea is characterized by secondary pollen presentation. The objective of this research is to study the floral syndrome and the procedure of secondary pollen presentation of this species, with special reference to the adaptive significance of these features based on the field observatio...

  1. Floral colour diversity in plant communities, bee colour space and a null model

    OpenAIRE

    Gumbert, A; Kunze, J.; Chittka, L.

    1999-01-01

    Evolutionary biologists have long hypothesized that the diversity of flower colours we see is in part a strategy to promote memorization by pollinators, pollinator constancy, and therefore, a directed and efficient pollen transfer between plants. However, this hypothesis has never been tested against a biologically realistic null model, nor were colours assessed in the way pollinators see them. Our intent here is to fill these gaps. Throughout one year, we sampled floral species compositions ...

  2. A Morphological and Quantitative Characterization of Early Floral Development in Apple (Malus × domestica Borkh.)

    OpenAIRE

    Foster, Toshi; JOHNSTON, ROBYN; SELEZNYOVA, ALLA

    2003-01-01

    Apple is an important crop and a focus of research worldwide. However, some aspects of floral commitment and morphogenesis remain unclear. A detailed characterization of bourse shoot apex development was undertaken to provide a framework for future genetic, molecular and physiological studies. Eight morphologically distinct stages of shoot apex development, prior to winter dormancy, were defined. Based on measurements of meristem diameter, two stages of vegetative development were recognized....

  3. FLORAL VISITORS IN SALVIA RHOMBIFOLIA RUIZ & PAVON (LAMIACEAE) IN LIMA, PERU: A BEE-POLLINATED SPECIES

    OpenAIRE

    Lianka Cairampoma; Carlos Martel

    2012-01-01

    We study the mechanisms, rates and agents involved in pollination and subsequent reproduction of Salvia rhombifolia. It characterized its floral visitors by recorded their visit frequency, also wemeasured its reproductive success by the percentage of seed production. Four bee species, one dipterous species and two hummingbird species were seen visiting flowers. Due hummingbirds were not actively carry pollen during their visits, they were classified as opportunistic; on the other hand, three ...

  4. 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; Paulo A V Borges

    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...

  5. Nectar sugars and bird visitation define a floral niche for basidiomycetous yeast on the Canary Islands

    OpenAIRE

    Mittelbach, Moritz; Yurkov, Andrey M; Nocentini, Daniele; Nepi, Massimo; Weigend, Maximilian; Begerow, Dominik

    2015-01-01

    Background Studies on the diversity of yeasts in floral nectar were first carried out in the late 19th century. A narrow group of fermenting, osmophilous ascomycetes were regarded as exclusive specialists able to populate this unique and species poor environment. More recently, it became apparent that microorganisms might play an important role in the process of plant pollination. Despite the importance of these nectar dwelling yeasts, knowledge of the factors that drive their diversity and s...

  6. Putting pollination quality into analyses of floral ecology: testing syndromes through pollinator performance

    OpenAIRE

    King, Caroline

    2012-01-01

    Over recent years, the extent of specialised and generalised plant-pollinator relationships, and the predictive powers of floral traits (often grouped into “pollination syndromes”) as indicators of the most effective pollinators of plant species, have been questioned. Such studies, however, have used proxies such as visitation frequency rather than direct measurements of pollinator effectiveness (PE). The main objective of this thesis was to test the predictive powers of various p...

  7. Variación intraestacional en los visitantes florales de Erysimum mediohispanicum en Sierra Nevada

    Directory of Open Access Journals (Sweden)

    J. Valverde

    2014-01-01

    Full Text Available Las interacciones planta-polinizador han sido tradicionalmente un tema de gran interés en el área de la ecología y la biología evolutiva, tanto por los servicios ecosistémicos que ofrecen como por la complejidad que presentan como sistema. La comunidad de visitantes florales de una especie vegetal puede ser muy diversa en plantas generalistas pero muy reducida en plantas especialistas, siendo los sistemas generalistas una realidad más común de lo que tradicionalmente se ha pensado. Además, esta comunidad puede presentar importantes fluctuaciones espacio-temporales en composición y abundancia. Esta variabilidad está sujeta a factores intrínsecos y extrínsecos a la planta, y podría afectar notoriamente a diversos aspectos poblacionales. En el presente trabajo estudiamos la variación temporal de la comunidad de visitantes florales en composición, abundancia y diversidad en dos parcelas experimentales de Erysimum mediohispanicum Polatschek (Brassicaceae, una especie típicamente generalista. Para centrarnos en las variaciones temporales en la comunidad hemos homogeneizado la distribución espacial y las condiciones microambientales de las plantas. Durante el periodo de floración censamos diariamente los insectos a nivel de morfoespecie, agrupándolos en 16 grupos funcionales basándonos en características morfológicas y comportamentales. Nuestros resultados muestran una gran diversidad en la comunidad de visitantes florales para ambas parcelas así como importantes fluctuaciones temporales en composición y abundancia relativa tanto para morfoespecies como para grupos funcionales. Esta variación temporal en abundancia de los visitantes florales de E. mediohispanicum puede tener importantes implicaciones ecológicas y evolutivas.

  8. 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.

  9. Exploring potential new floral organ morphogenesis genes of Arabidopsis thaliana using systems biology approach

    OpenAIRE

    Xie, Wenchuan; Huang, Junfeng; Liu, Yang; Rao, Jianan; Luo, Da; He, Miao

    2015-01-01

    Flowering is one of the important defining features of angiosperms. The initiation of flower development and the formation of different floral organs are the results of the interplays among numerous genes. But until now, just fewer genes have been found linked with flower development. And the functions of lots of genes of Arabidopsis thaliana are still unknown. Although, the quartet model successfully simplified the ABCDE model to elaborate the molecular mechanism by introducing protein-prote...

  10. Floral reward, advertisement and attractiveness to honey bees in dioecious Salix caprea.

    Science.gov (United States)

    Dötterl, Stefan; Glück, Ulrike; Jürgens, Andreas; Woodring, Joseph; Aas, Gregor

    2014-01-01

    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. PMID:24676333

  11. Simulation of Organ Patterning on the Floral Meristem Using a Polar Auxin Transport Model

    OpenAIRE

    Simon van Mourik; Kerstin Kaufmann; Aalt D J van Dijk; Angenent, Gerco C.; Merks, Roeland M H; Jaap Molenaar

    2012-01-01

    An intriguing phenomenon in plant development is the timing and positioning of lateral organ initiation, which is a fundamental aspect of plant architecture. Although important progress has been made in elucidating the role of auxin transport in the vegetative shoot to explain the phyllotaxis of leaf formation in a spiral fashion, a model study of the role of auxin transport in whorled organ patterning in the expanding floral meristem is not available yet. We present an initial simulation app...

  12. Variation in floral scent compounds recognized by honeybees in Brassicaceae crop species

    Science.gov (United States)

    Kobayashi, Kiwa; Arai, Miyako; Tanaka, Atsushi; Matsuyama, Shigeru; Honda, Hiroshi; Ohsawa, Ryo

    2012-01-01

    Floral scent attracts pollinators. We investigated the floral scent compounds recognized by pollinators in six Brassica crop species, including allogamous species with different genomes and autogamous species with two parental genomes and radish (Raphanus sativus). Biologically active compounds recognized by honeybees were screened from all floral compounds by combined gas chromatography–electroantennogram analysis and their profiles were determined by gas chromatography–mass spectrometry. Fourteen of the 52 compounds were active. All accessions had more than two active compounds, but the compounds greatly differed between the two genera. On the basis of similarities in whether active compounds were presence or absence, their amount and their composition ratio, we divided the Brassica accessions into three to five groups by cluster analyses. Most groups were composed of a mixture of allogamous and autogamous species sharing same genome, indicating that the variation depended on genome, not species. These results suggest that all species require pollinator visits for reproduction, despite their different reproductive systems. However, the inter-genus and intra-specific variations shown by the multiple groups within a species might cause different visitation frequencies by pollinators between genera and among accessions within a species, resulting in insufficient seed production in some accessions or species. PMID:23341742

  13. 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; Ovando-Medina, Isidro

    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

  14. Pollination, mating and reproductive fitness in a plant population with bimodal floral-tube length.

    Science.gov (United States)

    Anderson, B; Pauw, A; Cole, W W; Barrett, S C H

    2016-08-01

    Mating patterns and natural selection play important roles in determining whether genetic polymorphisms are maintained or lost. Here, we document an atypical population of Lapeirousia anceps (Iridaceae) with a bimodal distribution of floral-tube length and investigate the reproductive mechanisms associated with this pattern of variation. Flowers were visited exclusively by the long-proboscid fly Moegistorhynchus longirostris (Nemestrinidae), which exhibited a unimodal distribution of proboscis length and displayed a preference for long-tubed phenotypes. Despite being visited by a single pollinator species, allozyme markers revealed significant genetic differentiation between open-pollinated progeny of long- and short-tubed phenotypes suggesting mating barriers between them. We obtained direct evidence for mating barriers between the floral-tube phenotypes through observations of pollinator foraging, controlled hand pollinations and measurements of pollen competition and seed set. Intermediate tube-length phenotypes produced fewer seeds in the field than either long- or short-tubed phenotypes. Although floral-tube length bimodality may not be a stable state over long timescales, reproductive barriers to mating and low 'hybrid' fitness have the potential to contribute to the maintenance of this state in the short term. PMID:27206242

  15. Forget-me-not:Complex floral displays,inter-signal interactions,and pollinator cognition

    Institute of Scientific and Technical Information of China (English)

    Anne S.LEONARD; Anna DORNHAUS; Daniel R.PAPAJ

    2011-01-01

    Flowers are multisensory displays used by plants to influence the behavior of pollinators.Although we know a great deal about how individual signal components are preduced by plants and detected or learned by pollinators,very few experiments directly address the function of floral signal complexity,I.e.how the multicompenent nature of these signals benefits plant or pollinator.Yet,experimental psychology suggests that increasing complexity can enhance subjects'ability to deteCt,learn and remember stimuli,and the plant,sreproductive success depends upon ensuring that pollinators learn their signals and so transport pollen to other similar(conspecific)flowers.Here we explore functional hypotheses for why plants invest in complex floral displays focusing on hypotheses in which floral signals interact to promote pollinator learning and memory'Specifically,we discuss how an attention-altering or context-providing function of one signal may promote acquisition or recall of a second signal.Although we focus on communication between plants and poilinators,these process-based hypotheses should apply to any situation where a sender benefits from enhancing a receiver's acquisition or recall of informtion.

  16. A simple floral fragrance and unusual osmophore structure in Cyclopogon elatus (Orchidaceae).

    Science.gov (United States)

    Wiemer, A P; Moré, M; Benitez-Vieyra, S; Cocucci, A A; Raguso, R A; Sérsic, A N

    2009-07-01

    We studied gland morphology, anatomy and the chemical composition of the floral fragrance in the sweat bee-pollinated orchid Cyclopogon elatus. This is apparently the first such analysis for any Cyclopogon species, and one of very few studies in which both odour and osmophore are characterised in a nectar-rewarding orchid. Structures responsible for floral scent production were localised with neutral red staining and histochemical assays for lipids and starch. Their morphology and anatomy were studied with scanning electron microscopy and light microscopy thin sections, respectively. Fragrance samples were collected using SPME fibres and analysed with GC-MS. Anatomical evidence suggests that two parallel oval-shaped patches of unicellular trichomes on the abaxial surface of the labellum are osmophores. These are rich in stored lipids, while the parenchyma surrounding the vascular bundles contains starch. Only freshly opened flowers produced odours, while buds and withered flowers lacked scent. The chemical composition of the odour was dominated (>99.8%) by a single compound, trans-4,8-dimethyl-nona-1,3,7-triene (DMNT). Gland anatomy and position on the outside of the perianth are unusual for scent glands in general. The presence of DMNT, a nearly ubiquitous compound in herbivore-induced vegetative emissions and one of the major floral volatiles of Yucca, is not surprising in view of hypotheses on the evolutionary origin of flower scents, suggesting that wound volatiles are utilised as kairomonal attractants by florivores whose activities result in pollination. PMID:19538389

  17. 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.

  18. Floral development in Tribe Detarieae (Leguminosae: Caesalpinioideae): Amherstia, Brownea, and Tamarindus.

    Science.gov (United States)

    Tucker, S C

    2000-10-01

    Floral development was compared among three taxa in caesalpinioid tribe Detarieae sensu lato: Amherstia nobilis and Tamarindus indica have racemose, helically arranged inflorescences, while Brownea latifolia has cauliflorous capitate flower clusters that arise as racemes. All have acropetal flower order; initiation and development are sequential in all except Brownea, which is synchronous. All have paired persistent showy bracteoles. Floral symmetry is dorsiventral (zygomorphic) in all except Brownea, with radial symmetry at anthesis. Sepals initiate helically on a circular floral apex, starting with a median abaxial sepal, in all. Petals are initiated helically in Brownea, and unidirectionally in Amherstia and Tamarindus. Stamens are initiated unidirectionally in each stamen whorl in all except Amherstia, in which the outer whorl is bidirectional. The carpel initiates concurrently with the petals in Brownea, and with the outer stamens in the other taxa. The two upper (adaxial) sepal primordia become fused during development in all, so that the calyx appears tetramerous. Some reduced petals occur in Amherstia and Tamarindus, and some reduced stamens occur in all. All produce a hypanthium by zonal growth, and all except Tamarindus have the gynoecium attached adaxially to the hypanthial rim. PMID:11034916

  19. Palynological and physicochemical characteristics of three uni floral honey types from central Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Naab, O. A.; Tamame, M. A.; Caccavari, M. A.

    2008-07-01

    The characteristics of 59 uni floral honeys of Condalia microphylla Cav. (piquillin), Centaurea solstitialis L. (yellow star thistle) and Prosopis spp., from La Pampa, Argentina, were studied. Pollen features (abundance and frequency of pollen types) and some physicochemical parameters (colour, electrical conductivity, free acidity, glucose content, glucose: water ratio, moisture and pH) were determined. Two different but related sets of calculations were done: the first involved single-factor variance analysis, while the second set involved two multivariate methods, principal component analysis and cluster analysis. Variance and multivariate analysis allowed differentiation of the three honey types according to their physicochemical properties. The variables that best explained this differentiation were pH, electrical conductivity, colour, glucose content and the glucose:water ratio. Pollen analysis showed that the pollen frequency traditionally used (> 45%) for a botanical origin assignment in honey was not valid for the uni floral honeys studied. Therefore, pollen analysis should be combined with the above physicochemical analysis order to obtain a successful classification of these uni floral honeys. Additional key words: botanical origin, Centaurea solstitialis, Condalia microphylla, melissopalynology, multivariate analysis, pollen analysis, Prosopis spp. (Author) 60 refs.

  20. The Effects of Diesel Exhaust Pollution on Floral Volatiles and the Consequences for Honey Bee Olfaction.

    Science.gov (United States)

    Lusebrink, Inka; Girling, Robbie D; Farthing, Emily; Newman, Tracey A; Jackson, Chris W; Poppy, Guy M

    2015-10-01

    There is growing evidence of a substantial decline in pollinators within Europe and North America, most likely caused by multiple factors such as diseases, poor nutrition, habitat loss, insecticides, and environmental pollution. Diesel exhaust could be a contributing factor to this decline, since we found that diesel exhaust rapidly degrades floral volatiles, which honey bees require for flower recognition. In this study, we exposed eight of the most common floral volatiles to diesel exhaust in order to investigate whether it can affect volatile mediated plant-pollinator interaction. Exposure to diesel exhaust altered the blend of common flower volatiles significantly: myrcene was considerably reduced, β-ocimene became undetectable, and β-caryophyllene was transformed into its cis-isomer isocaryophyllene. Proboscis extension response (PER) assays showed that the alterations of the blend reduced the ability of honey bees to recognize it. The chemically reactive nitrogen oxides fraction of diesel exhaust gas was identified as capable of causing degradation of floral volatiles. PMID:26424685