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Sample records for stomata

  1. leaf epidermal members of the epidermal structures and stomata

    African Journals Online (AJOL)

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    temperate regions of the world. ... Indeed, it can be fair accurately stated that ... Journal of Pure and Applied Sciences, 10(1): 670 - 675 ... lopment were examined and to estimate stomata frequency, stoma uated. .... examined under microscope.

  2. AKUMULASI TIMBAL (PB DAN STRUKTUR STOMATA DAUN PURING (CODIAEUM VARIEGATUM LAM. BLUME

    Directory of Open Access Journals (Sweden)

    Susi Sulistiana

    2016-12-01

    Full Text Available Tanaman mempunyai kemampuan untuk mengatasi atau mengeliminir pencemaran udara yang terjadi di kota, salah satunya adalah tanaman puring. Stomata adalah salah satu organ tumbuhan yang digunakan untuk berinteraksi dengan lingkungannya. Fungsi utama stomata adalah sebagai tempat pertukaran gas, seperti CO2 yang diperlukan oleh tumbuhan dalam proses fotosintesis. Namun, stomata juga bertindak sebagai salah satu jalur masuknya polutan khususnya polutan yang berasal dari udara. Untuk mempertegas pengaruh akumulasi timbal terhadap daun tanaman puring secara morfologi yang telah dilakukan oleh Sulistiana dan Setijorini tahun 2014, perlu dilakukan penelitian lanjutan dengan melakukan pengamatan anatomi daun terutama struktur stomata daun tanaman puring. Penelitian bertujuan membandingkan struktur stomata antar kultivar puring dan membuktikan adanya hubungan antara akumulasi timbal (Pb dengan struktur stomata daun dari beberapa kultivar puring. Bahan penelitian yang digunakan adalah daun segar dari 13 kultivar tanaman puring yang ditanam di Perumahan Batan Indah, Kecamatan Kademangan, Tangerang Selatan. Pengamatan struktur stomata daun dilakukan dengan cara pembuatan preparat paradermal Parameter yang diamati dalam penelitian meliputi jumlah stomata, jumlah sel epidermis, panjang stomata, lebar stomata, indeks stomata, dan kerapatan stomata. Hasil yang diperoleh adanya korelasi positif antara kadar Pb dan struktur stomata daun kultivar puring melalui parameter-paramater yang diamati terutama jumlah stomata, lebar stomata, indeks stomata, dan kerapatan stomata.

  3. Effects of stomata clustering on leaf gas exchange.

    Science.gov (United States)

    Lehmann, Peter; Or, Dani

    2015-09-01

    A general theoretical framework for quantifying the stomatal clustering effects on leaf gaseous diffusive conductance was developed and tested. The theory accounts for stomatal spacing and interactions among 'gaseous concentration shells'. The theory was tested using the unique measurements of Dow et al. (2014) that have shown lower leaf diffusive conductance for a genotype of Arabidopsis thaliana with clustered stomata relative to uniformly distributed stomata of similar size and density. The model accounts for gaseous diffusion: through stomatal pores; via concentration shells forming at pore apertures that vary with stomata spacing and are thus altered by clustering; and across the adjacent air boundary layer. Analytical approximations were derived and validated using a numerical model for 3D diffusion equation. Stomata clustering increases the interactions among concentration shells resulting in larger diffusive resistance that may reduce fluxes by 5-15%. A similar reduction in conductance was found for clusters formed by networks of veins. The study resolves ambiguities found in the literature concerning stomata end-corrections and stomatal shape, and provides a new stomata density threshold for diffusive interactions of overlapping vapor shells. The predicted reduction in gaseous exchange due to clustering, suggests that guard cell function is impaired, limiting stomatal aperture opening. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  4. Stomata: key players in the earth system, past and present.

    Science.gov (United States)

    Berry, Joseph A; Beerling, David J; Franks, Peter J

    2010-06-01

    Stomata have played a key role in the Earth System for at least 400 million years. By enabling plants to control the rate of evaporation from their photosynthetic organs, stomata helped to set in motion non-linear processes that led to an acceleration of the hydrologic cycle over the continents and an expansion of climate zones favorable for plant life. Global scale modeling of land-atmosphere interactions provides a way to explore parallels between the influence of vegetation on climate over time, and the influence of spatial and temporal variation in the activities of vegetation in the current Earth System on climate and weather. We use the logic in models that simulate land-atmosphere interactions to illustrate the central role played by stomatal conductance in the Earth System. In the modeling context, most of the activities of plants and their manifold interactions with their genomes and with the environment are communicated to the atmosphere through a single property: the aperture or conductance of their stomata. We tend to think of the controls on vegetation responses in the real world as being distributed among factors such as seasonal patterns of growth, the changing availability of soil water, or changes in light intensity and leaf water potential over a day. However, the impact of these controls on crucial exchanges of energy and water vapor with the atmosphere are also largely mediated by stomata. The decisions 'made by' stomata emerge as an important and inadequately understood component of these models. At the present time we lack effective ways to link advances in the biology of stomata to this decision making process. While not unusual, this failure to connect between disciplines, introduces uncertainty in modeling studies being used to predict weather and climate change and ultimately to inform policy decisions. This problem is also an opportunity.

  5. The use of pure carbon stomata (Biocarbon) in urinary diversion.

    Science.gov (United States)

    Harzmann, R; Bichler, K H; Ideler, V

    1978-12-01

    A new synthetic material, Biocarbon, has the advantages of tissue compatibility and chemical inactivity, so that there is minimal salt sedimentation. Experiments with animals extending over a period of more than 2 years showed good healing after various surgical and urological operations. Biocarbon stomata were then used for vesicostomies in 6 patients. The period of follow-up has been months. We conclude that Biocarbon implants used for ureterocutaneostomies and for various conduit operations can improve tthe care of stomapatients.

  6. Development of immature stomata: evidence for epigenetic selection of a spacing pattern.

    Science.gov (United States)

    Kagan, M L; Sachs, T

    1991-07-01

    In Sansevieria trifasciata as many as half the potential stomata remain immature. The development of all stomatal structures started at the same time and the early stages of the development of immature stomata had no special characteristics. Statistical analysis showed that the mature stomata were more evenly spaced than all potential stomata, both mature and immature. Furthermore, the distribution of mature stomata per unit area was more predictable or orderly than comparable structures of a random model that developed in the same way. These facts indicate that a nonrandom loss of many stomata by "immaturity" is a major determinant, acting during rather than preceding development, of the distribution of the mature, functional stomata. Thus in Sansevieria there is a selection of an epidermal pattern from an excess of cells that undergo the early stages of stomatal development.

  7. Microscope image based fully automated stomata detection and pore measurement method for grapevines

    Directory of Open Access Journals (Sweden)

    Hiranya Jayakody

    2017-11-01

    Full Text Available Abstract Background Stomatal behavior in grapevines has been identified as a good indicator of the water stress level and overall health of the plant. Microscope images are often used to analyze stomatal behavior in plants. However, most of the current approaches involve manual measurement of stomatal features. The main aim of this research is to develop a fully automated stomata detection and pore measurement method for grapevines, taking microscope images as the input. The proposed approach, which employs machine learning and image processing techniques, can outperform available manual and semi-automatic methods used to identify and estimate stomatal morphological features. Results First, a cascade object detection learning algorithm is developed to correctly identify multiple stomata in a large microscopic image. Once the regions of interest which contain stomata are identified and extracted, a combination of image processing techniques are applied to estimate the pore dimensions of the stomata. The stomata detection approach was compared with an existing fully automated template matching technique and a semi-automatic maximum stable extremal regions approach, with the proposed method clearly surpassing the performance of the existing techniques with a precision of 91.68% and an F1-score of 0.85. Next, the morphological features of the detected stomata were measured. Contrary to existing approaches, the proposed image segmentation and skeletonization method allows us to estimate the pore dimensions even in cases where the stomatal pore boundary is only partially visible in the microscope image. A test conducted using 1267 images of stomata showed that the segmentation and skeletonization approach was able to correctly identify the stoma opening 86.27% of the time. Further comparisons made with manually traced stoma openings indicated that the proposed method is able to estimate stomata morphological features with accuracies of 89.03% for area

  8. A study on the stomata mutation of peanut leaves and its relationship with drought resistance

    International Nuclear Information System (INIS)

    Qiu Qingshu; Li Zhengchao; Hu Wenguang; Wu Lanrong

    1999-12-01

    Stomata mutation of leaves and its relationship with drought resistance were studied with four peanut mutants as well as original variety Baisha 1016. Results showed that irradiation was able to cause peanut leaf stoma to mutate. By comparing with original variety Baisha 1016, some of the mutants have more stomas, and some have less ones; some mutants have bigger stomas, some have smaller ones. The stomata numbers of peanut leaf have close relation to the drought resistance, while the stomata size seems to have no relation to it. It's possible that more drought-resistant variety or line could be elected among peanut mutants

  9. [Study of Chinese herbal medicine in treating ascites and their mechanism in regulating lymphatic stomata].

    Science.gov (United States)

    Wu, Y; Li, J C; Mao, L G

    2001-09-01

    To study the therapeutic effect of Chinese herbal medicines (CHM) in treating ascites to elucidate its mechanism in regulating the lymphatic stomata and promoting the absorption of ascites from the peritoneal cavity. Using scanning electron microscope (SEM) and computerized image processing and quantitative analysis assays, the CHM extract consisting of Atractylodes macrocephala, Salvia miltiorrhiza, Codonopsis pilosula, Alismatis orientale and Leonurus heterophyllus were studied. Intraperitoneal injection of nitric oxide (NO) supplier or CHM administration could cause the average area of lymphatic stomata obviously enlarged (P inverted obviously, i.e. the average area and the density of lymphatic stomata were markedly reduced (P < 0.01). CHM might treat ascites through increasing the endogenous NO concentration to open the lymphatic stomata and in turn to conduct the peritoneal water through lymphatic path.

  10. Density, size and distribution of stomata in 35 rainforest trees species in Central Amazonia

    OpenAIRE

    Miguel Angelo Branco Camargo; Ricardo Antonio Marenco

    2011-01-01

    Stomata are turgor-operated valves that control water loss and CO2 uptake during photosynthesis, and thereby water relation and plant biomass accumulation is closely related to stomatal functioning. The aims of this work were to document how stomata are distributed on the leaf surface and to determine if there is any significant variation in stomatal characteristics among Amazonian tree species, and finally to study the relationship between stomatal density (S D) and tree height. Thirty five ...

  11. Density, size and distribution of stomata in 35 rainforest tree species in Central Amazonia

    OpenAIRE

    Camargo, Miguel Angelo Branco; Marenco, Ricardo Antonio

    2011-01-01

    Stomata are turgor-operated valves that control water loss and CO2 uptake during photosynthesis, and thereby water relation and plant biomass accumulation is closely related to stomatal functioning. The aims of this work were to document how stomata are distributed on the leaf surface and to determine if there is any significant variation in stomatal characteristics among Amazonian tree species, and finally to study the relationship between stomatal density (S D) and tree height. Thirty five ...

  12. Stomata character and chlorophyll content of tomato in response to Zn application under drought condition

    Science.gov (United States)

    Sakya, A. T.; Sulistyaningsih, E.; Indradewa, D.; Purwanto, B. H.

    2018-03-01

    This experiment was performed in order to evaluate the effects of Zn application under drought condition on tomato, especially its chlorophyll content and stomata character. This experiment was arranged in factorial using randomized complete block design with three replications. The treatment consisted of the Zn application method, namely: soil and foliar, the Zn dosage, namely: 0, 40 and 60 mg ZnSO4 kg-1 soil and two cultivars of tomato, namely: ‘Tyrana’ F1 and ‘Permata’ F1. The stress condition was induced by watering every 12 days of 3 weeks after transplanting until harvesting. The results showed that the soil with a Zn application under drought conditions increased the aperture stomata, chlorophyll b and chlorophyll a/b ratio. The response of stomata character, chlorophyll a and total chlorophyll in both cultivars was similar.

  13. Effects of radiation quality on the opening of stomata in intact Phaseolus vulgaris leaves

    International Nuclear Information System (INIS)

    Sikorska, K.; Kozłowska, B.; Ciereszko, I.; Maleszewski, S.

    1997-01-01

    In intact French bean (Phaseolus vulgaris L.) leaves blue radiation enhanced opening of stomata both when it was used individually and when it was used as preirradiation before ''white light'' irradiation. Effects of red radiation were just the contrary

  14. How does the nectar of stomata-free nectaries cross the cuticle?

    Directory of Open Access Journals (Sweden)

    Elder Antônio Sousa Paiva

    Full Text Available ABSTRACT In many glandular structures, departure from the cell is only one step in the process of exudate release to the plant surface. Here the set of events that lead nectar to the external environment is presented and discussed mainly for stomata-free nectaries. After being synthesized, the nectar or some of its component needs to be released to the environment where it performs its functions. Nectar precursors derived from cell metabolism need to cross several barriers, such as the cell membrane and cell wall, in order to become nectar. Then the nectar must cross the cuticle or pass through stomata in order to be offered to plant mutualists. Release through stomata is a simple mechanism, but the ways by which nectar crosses the cuticle is still controversial. Hydrophilic pathways in the cuticle and repetitive cycles of rupture or cuticle detachment are the main routes for nectar release in stomata-free nectaries. In addition to nectar, there are other exogenous secretions that must leave the protoplast and reach the plant surface to perform their function. The ways by which nectar is released discussed herein are likely relevant to understanding the release of other hydrophilic products of the secretory process of plants.

  15. A role for stomata in regulating water use efficiency in Populus x ...

    African Journals Online (AJOL)

    A role for stomata in regulating water use efficiency in Populus x euramericana and characterization of a related gene, PdERECTA. P Guo, X Xia, WL Yin. Abstract. The physiological mechanism of water use efficiency (WUE) remains elucidated, especially in poplar. We studied WUEi (instantaneous leaf transpiration ...

  16. Stomata of the CAM plant Tillandsia recurvata respond directly to humidity.

    Science.gov (United States)

    Lange, O L; Medina, E

    1979-01-01

    Under controlled conditions, CO 2 exchange of Tillandsia recurvata showed all characteristics of CAM. During the phase of nocturnal CO 2 fixation stomata of the plant responded sensitively to changes in ambient air humidity. Dry air resulted in an increase, moist air in a decrease of diffusion resistance. The evaporative demand of the air affected the level of stomatal resistance during the entire night period. Due to stomatal closure, the total nocturnal water loss of T. recurvata was less at low than at high humidity. It is concluded that stomata respond directly to humidity and not via bulk tissue water conditions of the leaves. Such control of transpiration may optimize water use efficiency for this almost rootless, extreme epiphyte.

  17. Elevated-CO2 Response of Stomata and Its Dependence on Environmental Factors

    Science.gov (United States)

    Xu, Zhenzhu; Jiang, Yanling; Jia, Bingrui; Zhou, Guangsheng

    2016-01-01

    Stomata control the flow of gases between plants and the atmosphere. This review is centered on stomatal responses to elevated CO2 concentration and considers other key environmental factors and underlying mechanisms at multiple levels. First, an outline of general responses in stomatal conductance under elevated CO2 is presented. Second, stomatal density response, its development, and the trade-off with leaf growth under elevated CO2 conditions are depicted. Third, the molecular mechanism regulating guard cell movement at elevated CO2 is suggested. Finally, the interactive effects of elevated CO2 with other factors critical to stomatal behavior are reviewed. It may be useful to better understand how stomata respond to elevated CO2 levels while considering other key environmental factors and mechanisms, including molecular mechanism, biochemical processes, and ecophysiological regulation. This understanding may provide profound new insights into how plants cope with climate change. PMID:27242858

  18. [Carbon polymer stomata in vesicostomy and other urinary diversion procedures (author's transl)].

    Science.gov (United States)

    Harzmann, R; Bichler, K H

    1979-01-01

    Implants of pure carbon are ideal for prosteses because of their tissue acceptability and lack of incrustation. Animal experiments with biocarbon implants were tested as subfascial implantations, coeco-, ileo-, and vesicostomies, (n = 37). The results showed lack of reaction and good healing of the stomata, lack of incrustation, and water tight urinary diversion. Based on these animal experiments biocarbon vesicostomies were carried out successfully in six patients. The follow up period was 3--16 months.

  19. Epicuticular wax on stomata of damaged silver fir trees (Abies alba Mili.)

    OpenAIRE

    Tomislav Bačić; Ljiljana Krstin; Jadranka Roša; Željko Popović

    2011-01-01

    Condition of epistomatal wax on the abaxial surface of the current and previous-year needles of damaged silver fir trees (Abies alba Mill.), both from the polluted Risnjak and "clean" Donja Dobra sites in Gorski Kotar region, both influenced by pollutants coming from Europe, during two years, three times a year, were examined with Scanning Electron Microscope. In the course of time the wax tubules on the epistomatal rims of stomata in polluted, but also in "clean" needles surface, become fuse...

  20. Gamma-aminobutyric acid depletion affects stomata closure and drought tolerance of Arabidopsis thaliana.

    Science.gov (United States)

    Mekonnen, Dereje Worku; Flügge, Ulf-Ingo; Ludewig, Frank

    2016-04-01

    A rapid accumulation of γ-aminobutyric acid (GABA) during biotic and abiotic stresses is well documented. However, the specificity of the response and the primary role of GABA under such stress conditions are hardly understood. To address these questions, we investigated the response of the GABA-depleted gad1/2 mutant to drought stress. GABA is primarily synthesized from the decarboxylation of glutamate by glutamate decarboxylase (GAD) which exists in five copies in the genome of Arabidopsis thaliana. However, only GAD1 and GAD2 are abundantly expressed, and knockout of these two copies dramatically reduced the GABA content. Phenotypic analysis revealed a reduced shoot growth of the gad1/2 mutant. Furthermore, the gad1/2 mutant was wilted earlier than the wild type following a prolonged drought stress treatment. The early-wilting phenotype was due to an increase in stomata aperture and a defect in stomata closure. The increase in stomata aperture contributed to higher stomatal conductance. The drought oversensitive phenotype of the gad1/2 mutant was reversed by functional complementation that increases GABA level in leaves. The functionally complemented gad1/2 x pop2 triple mutant contained more GABA than the wild type. Our findings suggest that GABA accumulation during drought is a stress-specific response and its accumulation induces the regulation of stomatal opening thereby prevents loss of water. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. Cross-scale modelling of transpiration from stomata via the leaf boundary layer

    Science.gov (United States)

    Defraeye, Thijs; Derome, Dominique; Verboven, Pieter; Carmeliet, Jan; Nicolai, Bart

    2014-01-01

    Background and Aims Leaf transpiration is a key parameter for understanding land surface–climate interactions, plant stress and plant structure–function relationships. Transpiration takes place at the microscale level, namely via stomata that are distributed discretely over the leaf surface with a very low surface coverage (approx. 0·2–5 %). The present study aims to shed more light on the dependency of the leaf boundary-layer conductance (BLC) on stomatal surface coverage and air speed. Methods An innovative three-dimensional cross-scale modelling approach was applied to investigate convective mass transport from leaves, using computational fluid dynamics. The gap between stomatal and leaf scale was bridged by including all these scales in the same computational model (10−5–10−1 m), which implies explicitly modelling individual stomata. Key Results BLC was strongly dependent on stomatal surface coverage and air speed. Leaf BLC at low surface coverage ratios (CR), typical for stomata, was still relatively high, compared with BLC of a fully wet leaf (hypothetical CR of 100 %). Nevertheless, these conventional BLCs (CR of 100 %), as obtained from experiments or simulations on leaf models, were found to overpredict the convective exchange. In addition, small variations in stomatal CR were found to result in large variations in BLCs. Furthermore, stomata of a certain size exhibited a higher mass transfer rate at lower CRs. Conclusions The proposed cross-scale modelling approach allows us to increase our understanding of transpiration at the sub-leaf level as well as the boundary-layer microclimate in a way currently not feasible experimentally. The influence of stomatal size, aperture and surface density, and also flow-field parameters can be studied using the model, and prospects for further improvement of the model are presented. An important conclusion of the study is that existing measures of conductances (e.g. from artificial leaves) can be

  2. Bottle gourd rootstock-grafting promotes photosynthesis by regulating the stomata and non-stomata performances in leaves of watermelon seedlings under NaCl stress.

    Science.gov (United States)

    Yang, Yanjuan; Yu, Li; Wang, Liping; Guo, Shirong

    2015-08-15

    Previously, we found that the amelioration of photosynthetic capacity by bottle gourd (Lagenaria siceraria Standl.) rootstock in watermelon seedlings (Citrullus lanatus [Thunb.] Mansf.) with salt treatment might be closely related to the enzymes in Calvin cycle such as ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) (Yang et al., 2012). We confirmed this and showed more details in this study that improved photosynthesis of watermelon plants by bottle gourd rootstock was associated with the decreased stomata resistance and the increased photochemical activity and photosynthetic metabolism with or without 100mM NaCl stress for 3 days. The analysis of gas exchange parameters showed that self-grafted plants suffered serious non-stomatal limitation to photosynthesis under salt stress while rootstock-grafted plants were mainly affected by stomata limitation in stress conditions. Further, results showed that NaCl stress markedly reduced the chlorophyll content, damaged the structure of photosynthetic apparatus, and inhibited photochemical activity and CO2 assimilation in self-grafted plants. In contrast, rootstock-grafting increased the chlorophyll content, especially chlorophyll b, and minimized the harmful effects on photosystem II (PSII) reaction center and the thylakoids structure induced by NaCl stress. Furthermore, rootstock-grafting enhanced the content and activity of Rubisco and thus elevated carbon fixation in the leaves of watermelon scions under salt stress. The gene expressions of enzymes related to ribulose-1,5-bisphosphate (RuBP) regeneration were also up-regulated by rootstock and this probably guaranteed the sufficient supply of RuBP for the operation of Calvin cycle in watermelon scions under salt stress. Thus, bottle gourd rootstock promoted photosynthesis by the activation of stomatal and non-stomatal abilities, especially the regulation of a variety of photosynthetic enzymes, including Rubisco in grafted watermelon plants under NaCl stress

  3. Size and Density of Artemisia annua Stomata Soaked in Water Extract of Gloriosa superba Seeds

    Directory of Open Access Journals (Sweden)

    Sri Indah Rahmawati

    2017-12-01

    Full Text Available Artemisia annua is a herbaceous plant that produces artemisinin as a malaria drug, haemorrhoids therapy, aromatherapy, antiviral, anticancer and antibacterial. Gloriosa superba is a plant that contains high colchicine compounds, especially on the seeds. Gloriosa superba extracts of tubers, stems, seeds, and leaves were used as biomutagen for many plants. Colchicine contains of these plants as antimitotic have been studied and proven by the mitotic index plants. Water extracts of Gloriosa superba seeds was used as a mutagen for Artemisia annua. The aim of this study was to determine the size and density of Artemisia annua stomata soaked in water extract of Gloriosa superba seeds as a mutagen. Extraction of Gloriosa superba seeds obtained naturally on Krakal Beach, Gunung Kidul by using a maceration method with water solvent (1:1. Artemisia annua sprouts were obtained from B2P2TOOT Tawangmangu. Variables treatment on sprouts using water extract concentration of Gloriosa superba seeds and soaking time of Artemisia annua sprouts. Measurements of stomatal length, width and density were conducted in epidermis of Artemisia annua leaf. Observation and measurements of the stomata were conducted by using a light microscope. The results showed that the length and width of stomata were 0.025 mm and 0.017 mm respectively. The stomatal density of the control leaf (174.69 amount/mm2 was lower than the other treated plants. Stomatal size and density has increased with the increasing concentration extracts on treated plants. Water extracts of Gloriosa superba seeds proved the effects on stomatal size and density of treated plants.  

  4. Pengaruh Stomata dan Klorofil pada Ketahanan Beberapa Varietas Jagung terhadap Penyakit Bulai

    Directory of Open Access Journals (Sweden)

    Christine Agustamia

    2016-12-01

    Full Text Available Resistant varieties are more advisable for controlling maize downy mildew compared with fungicides which is not effective and not environmentally friendly. This study is aimed to determine resistance of some varieties of maize against downy mildew. The maize varieties used were BS 0114, BS 0214, BS 0314, PAC 105, Sweet Corn and BISI 2. The parameters measured were disease incidence and intensity, chlorophyll content of leaves, stomatal density and plants dry weight. Data were analyzed by using analysis of variance (ANOVA and Duncan's Multiple Range Test (DMRT. The results indicated that PAC 105, BS 0214 and BS 0314 were resistant varieties, while BS 0114, Sweet Corn and BISI 2 were susceptible. PAC 105 variety has the lowest stomatal density (65.353/mm2, and Sweet Corn variety has the highest stomatal density (110.79/mm2. Stomatal density was positively correlated with the disease intensity. Higher disease intensity has lower chlorophyll content compared with the lower intensity. PAC 105 variety has the highest chlorophyll content and plant dry weight, while Sweet Corn variety has the lowest chlorophyll content and plant dry weight.   INTISARI   Penggunaan varietas tahan bulai lebih dianjurkan digunakan dalam pengendalian penyakit bulai pada jagung dibandingkan dengan penggunaan fungisida karena tidak efektif dan tidak ramah lingkungan. Penelitian ini bertujuan untuk mengetahui ketahanan beberapa varietas jagung terhadap penyakit bulai. Varietas yang digunakan meliputi BS 0114, BS 0214, BS 0314, PAC 105, jagung manis, dan BISI 2. Parameter yang diamati adalah insidensi dan intensitas penyakit, kandungan klorofil setelah inokulasi, kerapatan stomata dan berat kering tanaman. Data yang diperoleh diuji dengan analisis varians (ANOVA dan uji lanjut dengan Duncan’s Multiple Range Test (DMRT. Hasil penelitian rumah kaca menunjukkan bahwa varietas PAC 105, BS 0214 dan BS 0314 merupakan varietas tahan, sedangkan varietas BS 0114, jagung manis dan

  5. MAPK phosphatase AP2C3 induces ectopic proliferation of epidermal cells leading to stomata development in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Julija Umbrasaite

    2010-12-01

    Full Text Available In plant post-embryonic epidermis mitogen-activated protein kinase (MAPK signaling promotes differentiation of pavement cells and inhibits initiation of stomata. Stomata are cells specialized to modulate gas exchange and water loss. Arabidopsis MAPKs MPK3 and MPK6 are at the core of the signaling cascade; however, it is not well understood how the activity of these pleiotropic MAPKs is constrained spatially so that pavement cell differentiation is promoted only outside the stomata lineage. Here we identified a PP2C-type phosphatase termed AP2C3 (Arabidopsis protein phosphatase 2C that is expressed distinctively during stomata development as well as interacts and inactivates MPK3, MPK4 and MPK6. AP2C3 co-localizes with MAPKs within the nucleus and this localization depends on its N-terminal extension. We show that other closely related phosphatases AP2C2 and AP2C4 are also MAPK phosphatases acting on MPK6, but have a distinct expression pattern from AP2C3. In accordance with this, only AP2C3 ectopic expression is able to stimulate cell proliferation leading to excess stomata development. This function of AP2C3 relies on the domains required for MAPK docking and intracellular localization. Concomitantly, the constitutive and inducible AP2C3 expression deregulates E2F-RB pathway, promotes the abundance and activity of CDKA, as well as changes of CDKB1;1 forms. We suggest that AP2C3 downregulates the MAPK signaling activity to help maintain the balance between differentiation of stomata and pavement cells.

  6. Homologue Structure of the SLAC1 Anion Channel for Closing Stomata in Leaves

    Energy Technology Data Exchange (ETDEWEB)

    Y Chen; L Hu; M Punta; R Bruni; B Hillerich; B Kloss; B Rost; J Love; S Siegelbaum; W Hendrickson

    2011-12-31

    The plant SLAC1 anion channel controls turgor pressure in the aperture-defining guard cells of plant stomata, thereby regulating the exchange of water vapour and photosynthetic gases in response to environmental signals such as drought or high levels of carbon dioxide. Here we determine the crystal structure of a bacterial homologue (Haemophilus influenzae) of SLAC1 at 1.20 {angstrom} resolution, and use structure-inspired mutagenesis to analyse the conductance properties of SLAC1 channels. SLAC1 is a symmetrical trimer composed from quasi-symmetrical subunits, each having ten transmembrane helices arranged from helical hairpin pairs to form a central five-helix transmembrane pore that is gated by an extremely conserved phenylalanine residue. Conformational features indicate a mechanism for control of gating by kinase activation, and electrostatic features of the pore coupled with electrophysiological characteristics indicate that selectivity among different anions is largely a function of the energetic cost of ion dehydration.

  7. Smaller stomata require less severe leaf drying to close: A case study in Rosa hydrida

    DEFF Research Database (Denmark)

    Gebraegziabher, Habtamu Giday; Kjær, Katrine Heinsvig; Fanourakis, D.

    2013-01-01

    Stomata formed at high relative air humidity (RH) close less as leaf dries; an effect that varies depending on the genotype. We here quantified the contribution of each stomatal response characteristic to the higher water loss of high RH-grown plants, and assessed the relationship between response...... characteristics and intraspecific variation in stomatal size. Stomatal size (length multiplied by width), density and responsiveness to desiccation, as well as pore dimensions were analyzed in ten rose cultivars grown at moderate (60%) or high (85%) RH. Leaf morphological components and transpiration at growth...... conditions were also assessed. High growth RH resulted in thinner (11%) leaves with larger area. A strong positive genetic correlation of daytime and nighttime transpiration at either RH was observed. Stomatal size determined pore area (r = 0.7) and varied by a factor of two, as a result of proportional...

  8. Closing plant stomata requires a homolog of an aluminum-activated malate transporter.

    Science.gov (United States)

    Sasaki, Takayuki; Mori, Izumi C; Furuichi, Takuya; Munemasa, Shintaro; Toyooka, Kiminori; Matsuoka, Ken; Murata, Yoshiyuki; Yamamoto, Yoko

    2010-03-01

    Plant stomata limit both carbon dioxide uptake and water loss; hence, stomatal aperture is carefully set as the environment fluctuates. Aperture area is known to be regulated in part by ion transport, but few of the transporters have been characterized. Here we report that AtALMT12 (At4g17970), a homolog of the aluminum-activated malate transporter (ALMT) of wheat, is expressed in guard cells of Arabidopsis thaliana. Loss-of-function mutations in AtALMT12 impair stomatal closure induced by ABA, calcium and darkness, but do not abolish either the rapidly activated or the slowly activated anion currents previously identified as being important for stomatal closure. Expressed in Xenopus oocytes, AtALMT12 facilitates chloride and nitrate currents, but not those of organic solutes. Therefore, we conclude that AtALMT12 is a novel class of anion transporter involved in stomatal closure.

  9. Epicuticular wax on stomata of damaged silver fir trees (Abies alba Mili.

    Directory of Open Access Journals (Sweden)

    Tomislav Bačić

    2011-01-01

    Full Text Available Condition of epistomatal wax on the abaxial surface of the current and previous-year needles of damaged silver fir trees (Abies alba Mill., both from the polluted Risnjak and "clean" Donja Dobra sites in Gorski Kotar region, both influenced by pollutants coming from Europe, during two years, three times a year, were examined with Scanning Electron Microscope. In the course of time the wax tubules on the epistomatal rims of stomata in polluted, but also in "clean" needles surface, become fused and agglomerated rapidly to various extents of morphologically different types of amorphous wax crusts, primarily compact and particulate ones. This process begins very early, especially in polluted Risnjak site, and may be interpreted as a possible result of air pollution. However, the recrystalization, or production of new tubules, also appears relatively quickly in mostly cases. Quantitative estimations indicate a very large total amount of amorphous wax crusts in the current-year needles, and a very high percentage of the same wax in previous-year needles. Amorphous wax crusts cover stomatal pores, as well as the rims, disturbing the normal gas exchange. Statistically there is a signicant tendency of increase in wax degradation in the needles of the polluted site in comparison with those of the unpolluted one, but there is an insignificant wax degradation among the needles of damaged trees within each site. These results confirmed most of the research done in our preliminary report.

  10. Persistent drought monitoring using a microfluidic-printed electro-mechanical sensor of stomata in planta.

    Science.gov (United States)

    Koman, Volodymyr B; Lew, Tedrick T S; Wong, Min Hao; Kwak, Seon-Yeong; Giraldo, Juan P; Strano, Michael S

    2017-11-21

    Stomatal function can be used effectively to monitor plant hydraulics, photosensitivity, and gas exchange. Current approaches to measure single stomatal aperture, such as mold casting or fluorometric techniques, do not allow real time or persistent monitoring of the stomatal function over timescales relevant for long term plant physiological processes, including vegetative growth and abiotic stress. Herein, we utilize a nanoparticle-based conducting ink that preserves stomatal function to print a highly stable, electrical conductometric sensor actuated by the stomata pore itself, repeatedly and reversibly for over 1 week. This stomatal electro-mechanical pore size sensor (SEMPSS) allows for real-time tracking of the latency of single stomatal opening and closing times in planta, which we show vary from 7.0 ± 0.5 to 25.0 ± 0.5 min for the former and from 53.0 ± 0.5 to 45.0 ± 0.5 min for the latter in Spathiphyllum wallisii. These values are shown to correlate with the soil water potential and the onset of the wilting response, in quantitative agreement with a dynamic mathematical model of stomatal function. A single stoma of Spathiphyllum wallisii is shown to distinguish between incident light intensities (up to 12 mW cm -2 ) with temporal latency slow as 7.0 ± 0.5 min. Over a seven day period, the latency in opening and closing times are stable throughout the plant diurnal cycle and increase gradually with the onset of drought. The monitoring of stomatal function over long term timescales at single stoma level will improve our understanding of plant physiological responses to environmental factors.

  11. Open or close the gate – stomata action under the control of phytohormones in drought stress conditions

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    Agata eDaszkowska-Golec

    2013-05-01

    Full Text Available Two highly specialized cells, the guard cells that surround the stomatal pore, are able to integrate environmental and endogenous signals in order to control the stomatal aperture and thereby the gas exchange. The uptake of CO2 is associated with a loss of water by leaves. Control of the size of the stomatal aperture optimizes the efficiency of water use through dynamic changes in the turgor of the guard cells. The opening and closing of stomata is regulated by the integration of environmental signals and endogenous hormonal stimuli. The various different factors to which the guard cells respond translates into the complexity of the network of signaling pathways that control stomatal movements. The perception of an abiotic stress triggers the activation of signal transduction cascades that interact with or are activated by phytohormones. Among these, abscisic acid (ABA, is the best-known stress hormone that closes the stomata, although other phytohormones, such as jasmonic acid, brassinosteroids, cytokinins or ethylene are also involved in the stomatal response to stresses. As a part of the drought response, ABA may interact with jasmonic acid and nitric oxide in order to stimulate stomatal closure. In addition, the regulation of gene expression in response to ABA involves genes that are related to ethylene, cytokinins and auxin signaling. In this paper, recent findings on phytohormone crosstalk, changes in signaling pathways including the expression of specific genes and their impact on modulating stress response through the closing or opening of stomata, together with the highlights of gaps that need to be elucidated in the signaling network of stomatal regulation, are reviewed.

  12. Plant water use efficiency over geological time--evolution of leaf stomata configurations affecting plant gas exchange.

    Science.gov (United States)

    Assouline, Shmuel; Or, Dani

    2013-01-01

    Plant gas exchange is a key process shaping global hydrological and carbon cycles and is often characterized by plant water use efficiency (WUE - the ratio of CO2 gain to water vapor loss). Plant fossil record suggests that plant adaptation to changing atmospheric CO2 involved correlated evolution of stomata density (d) and size (s), and related maximal aperture, amax . We interpreted the fossil record of s and d correlated evolution during the Phanerozoic to quantify impacts on gas conductance affecting plant transpiration, E, and CO2 uptake, A, independently, and consequently, on plant WUE. A shift in stomata configuration from large s-low d to small s-high d in response to decreasing atmospheric CO2 resulted in large changes in plant gas exchange characteristics. The relationships between gas conductance, gws , A and E and maximal relative transpiring leaf area, (amax ⋅d), exhibited hysteretic-like behavior. The new WUE trend derived from independent estimates of A and E differs from established WUE-CO2 trends for atmospheric CO2 concentrations exceeding 1,200 ppm. In contrast with a nearly-linear decrease in WUE with decreasing CO2 obtained by standard methods, the newly estimated WUE trend exhibits remarkably stable values for an extended geologic period during which atmospheric CO2 dropped from 3,500 to 1,200 ppm. Pending additional tests, the findings may affect projected impacts of increased atmospheric CO2 on components of the global hydrological cycle.

  13. Prechilling of Xanthium strumarium L. Reduces Net Photosynthesis and, Independently, Stomatal Conductance, While Sensitizing the Stomata to CO(2).

    Science.gov (United States)

    Drake, B; Raschke, K

    1974-06-01

    Greenhouse-grown plants of Xanthium strumarium L. were exposed in a growth cabinet to 10 C during days and 5 C during nights for periods of up to 120 hours. Subsequently, CO(2) exchange, transpiration, and leaf temperature were measured on attached leaves and in leaf sections at 25 or 30 C, 19 C dew point of the air, 61 milliwatts per square centimeter irradiance, and CO(2) concentrations between 0 and 1000 microliters per liter ambient air. Net photosynthesis and stomatal conductance decreased and dark respiration increased with increasing duration of prechilling. The reduction in net photosynthesis was not a consequence of decreased stomatal conductance because the intercellular CO(2) concentration in prechilled leaves was equal to or greater than that in greenhouse-grown controls. The intercellular CO(2) concentration at which one-half maximum net photosynthesis occurred remained the same in prechilled leaves and controls (175 to 190 microliters per liter). Stomata of the control plants responded to changes in the CO(2) concentration of the air only slightly. Prechilling for 24 hours or more sensitized stomata to CO(2); they responded to changes in CO(2) concentration in the range from 100 to 1000 microliters per liter.

  14. Prechilling of Xanthium strumarium L. Reduces Net Photosynthesis and, Independently, Stomatal Conductance, While Sensitizing the Stomata to CO21

    Science.gov (United States)

    Drake, B.; Raschke, K.

    1974-01-01

    Greenhouse-grown plants of Xanthium strumarium L. were exposed in a growth cabinet to 10 C during days and 5 C during nights for periods of up to 120 hours. Subsequently, CO2 exchange, transpiration, and leaf temperature were measured on attached leaves and in leaf sections at 25 or 30 C, 19 C dew point of the air, 61 milliwatts per square centimeter irradiance, and CO2 concentrations between 0 and 1000 microliters per liter ambient air. Net photosynthesis and stomatal conductance decreased and dark respiration increased with increasing duration of prechilling. The reduction in net photosynthesis was not a consequence of decreased stomatal conductance because the intercellular CO2 concentration in prechilled leaves was equal to or greater than that in greenhouse-grown controls. The intercellular CO2 concentration at which one-half maximum net photosynthesis occurred remained the same in prechilled leaves and controls (175 to 190 microliters per liter). Stomata of the control plants responded to changes in the CO2 concentration of the air only slightly. Prechilling for 24 hours or more sensitized stomata to CO2; they responded to changes in CO2 concentration in the range from 100 to 1000 microliters per liter. PMID:16658795

  15. [Coordination effect between vapor water loss through plant stomata and liquid water supply in soil-plant-atmosphere continuum (SPAC): a review].

    Science.gov (United States)

    Liu, Li-Min; Qi, Hua; Luo, Xin-Lan; Zhang, Xuan

    2008-09-01

    Some important phenomena and behaviors concerned with the coordination effect between vapor water loss through plant stomata and liquid water supply in SPAC were discussed in this paper. A large amount of research results showed that plants show isohydric behavior when the plant hydraulic and chemical signals cooperate to promote the stomatal regulation of leaf water potential. The feedback response of stomata to the change of environmental humidity could be used to explain the midday depression of stomatal conductance and photosynthesis under drought condition, and also, to interpret the correlation between stomatal conductance and hydraulic conductance. The feed-forward response of stomata to the change of environmental humidity could be used to explain the hysteresis response of stomatal conductance to leaf-atmosphere vapor pressure deficit. The strategy for getting the most of xylem transport requires the rapid stomatal responses to avoid excess cavitation and the corresponding mechanisms for reversal of cavitation in short time.

  16. Co-ordination of physiological and morphological responses of stomata to elevated [CO2] in vascular plants.

    Science.gov (United States)

    Haworth, Matthew; Elliott-Kingston, Caroline; McElwain, Jennifer C

    2013-01-01

    Plant stomata display a wide range of short-term behavioural and long-term morphological responses to atmospheric carbon dioxide concentration ([CO(2)]). The diversity of responses suggests that plants may have different strategies for controlling gas exchange, yet it is not known whether these strategies are co-ordinated in some way. Here, we test the hypothesis that there is co-ordination of physiological (via aperture change) and morphological (via stomatal density change) control of gas exchange by plants. We examined the response of stomatal conductance (G(s)) to instantaneous changes in external [CO(2)] (C(a)) in an evolutionary cross-section of vascular plants grown in atmospheres of elevated [CO(2)] (1,500 ppm) and sub-ambient [O(2)] (13.0 %) compared to control conditions (380 ppm CO(2), 20.9 % O(2)). We found that active control of stomatal aperture to [CO(2)] above current ambient levels was not restricted to angiosperms, occurring in the gymnosperms Lepidozamia peroffskyana and Nageia nagi. The angiosperm species analysed appeared to possess a greater respiratory demand for stomatal movement than gymnosperm species displaying active stomatal control. Those species with little or no control of stomatal aperture (termed passive) to C(a) were more likely to exhibit a reduction in stomatal density than species with active stomatal control when grown in atmospheres of elevated [CO(2)]. The relationship between the degree of stomatal aperture control to C(a) above ambient and the extent of any reduction in stomatal density may suggest the co-ordination of physiological and morphological responses of stomata to [CO(2)] in the optimisation of water use efficiency. This trade-off between stomatal control strategies may have developed due to selective pressures exerted by the costs associated with passive and active stomatal control.

  17. Characterization of the photosynthetic induction response in a Populus species with stomata barely responding to light changes.

    Science.gov (United States)

    Tang, Y; Liang, N

    2000-08-01

    The photosynthetic induction response is constrained by stomatal and biochemical limitations. However, leaves in some plants like Populus koreana x trichocarpa cv. Peace (a hybrid clone) may have little stomatal limitation because their stomata barely respond to changes in photon flux density (PFD). We examined the induction responses of leaves of well-watered and dehydrated P. koreana x trichocarpa plants grown in a high-light or a low-light regime. With an increase in PFD from 50 to 500 micromol m(-2) s(-1), steady-state stomatal conductance (g(s)) increased by only 0.25-8.2%, regardless of the initial g(s), but steady-state assimilation rate (A) increased by 550-1810%. Photosynthetic induction times required to reach 50% (IT50) and 90% (IT90) of A at high PFD were 60-90 s and 210-360 s, respectively. Examination of the dynamic relationships between A and g(s), and between A and intercellular CO2 concentration, indicated that the induction limitation was imposed completely by the biochemical components within 30-40 s after the PFD increase. Values of IT50 and IT90 were significantly higher in low-light leaves than in high-light leaves, whereas the induction state at 60 s and the induction efficiency at 60 and 120 s after the increase in PFD were lower in low-light leaves than in high-light leaves. Dehydration reduced leaf water potential (psi) significantly, resulting in a significantly decreased initial g(s). Leaf water potential had no significant effects on induction time in high-light leaves, but a low psi significantly reduced the induction time in low-light leaves. We conclude that the photosynthetic induction response was limited almost completely by biochemical components because the stomata barely responded to light changes. The biochemical limitation appeared to be higher in low-light leaves than in high-light leaves. Mild water stress may have reduced steady-state A and g(s), but it had little effect on the photosynthetic induction response in high

  18. Stomata open at night in pole-sized and mature ponderosa pine: implications for O{sub 3} exposure metrics

    Energy Technology Data Exchange (ETDEWEB)

    Grulke, N. E.; Alonso, R.; Nguyen, T.; Dobrowolski, W. [USDA Forest Service, Pacific Southwest Station, Riverside, CA (United States); Cascio, C. [University of Florence, Firenze (Italy)

    2004-09-01

    Nighttime stomatal behaviour in two tree size stands of ponderosa pine are described. Ponderosa pine is one of the most ozone-sensitive conifers in western North America. The study involved measurement of time required to reach equilibrium in response to small increases in low irradiances at sites differing in environmental stressors. The contribution of nighttime ozone uptake to total daily ozone uptake in early and later summer was also investigated. Nighttime stomata conductance ranged between one tenth and one fifth that of maximum day-time values. Pole-size trees (i.e. less than 40 years old) showed greater ozone conductance than mature trees (i.e. over 250 years old). In June, nighttime ozone uptake accounted for 9, 5, and 3 per cent of the total daily ozone uptake of pole-sized trees. In late summer, ozone uptake at night was less than two percent of daily uptake at all sites. It is suspected that nighttime uptake of oxidants may have harmful physiological effects, such as contributing to the declining health of forest trees, owing to the fact that oxidants absorbed at night are not detoxified as well during the day. 67 refs.,1 tab., 8 figs.

  19. Effects of salinity stress on chlorophyll and carotenoid contents and stomata size of grafted and ungrafted galia c8 melon cultivar

    International Nuclear Information System (INIS)

    Yarsi, G.; Sivaci, A.; Dasgan, H.Y.; Altuntas, O.

    2017-01-01

    Salinity is known as the most important abiotic stress that decreases crop production and plant growth, and changes the anatomy and morphology of plants. In this study, the growth rate of grafted and ungrafted melon plants were studied under salinity stress. Maximus F1, Shintoza F-90 F1 and Nun 9075 F1 (Cucurbita maxima x Cucurbita moschata) were used as a rootstock and Galia C8 melon cultivar was used as a scion. In this study, the stomata size and chlorophyll and carotenoid contents were investigated. According to the results, chlorophyll and carotenoid contents and stomata length and width of upper and lower surface of leaf were generally reduced under salinity stress. (author)

  20. A method to identify important dynamical states in Boolean models of regulatory networks: application to regulation of stomata closure by ABA in A. thaliana.

    Science.gov (United States)

    Bugs, Cristhian A; Librelotto, Giovani R; Mombach, José C M

    2011-12-22

    We introduce a method to analyze the states of regulatory Boolean models that identifies important network states and their biological influence on the global network dynamics. It consists in (1) finding the states of the network that are most frequently visited and (2) the identification of variable and frozen nodes of the network. The method, along with a simulation that includes random features, is applied to the study of stomata closure by abscisic acid (ABA) in A. thaliana proposed by Albert and coworkers. We find that for the case of study, that the dynamics of wild and mutant networks have just two states that are highly visited in their space of states and about a third of all nodes of the wild network are variable while the rest remain frozen in True or False states. This high number of frozen elements explains the low cardinality of the space of states of the wild network. Similar results are observed in the mutant networks. The application of the method allowed us to explain how wild and mutants behave dynamically in the SS and determined an essential feature of the activation of the closure node (representing stomata closure), i.e. its synchronization with the AnionEm node (representing anion efflux at the plasma membrane). The dynamics of this synchronization explains the efficiency reached by the wild and each of the mutant networks. For the biological problem analyzed, our method allows determining how wild and mutant networks differ 'phenotypically'. It shows that the different efficiencies of stomata closure reached among the simulated wild and mutant networks follow from a dynamical behavior of two nodes that are always synchronized. Additionally, we predict that the involvement of the anion efflux at the plasma membrane is crucial for the plant response to ABA. The algorithm used in the simulations is available upon request.

  1. Carbon dioxide diffusion across stomata and mesophyll and photo-biochemical processes as affected by growth CO2 and phosphorus nutrition in cotton.

    Science.gov (United States)

    Singh, Shardendu K; Badgujar, Girish; Reddy, Vangimalla R; Fleisher, David H; Bunce, James A

    2013-06-15

    Nutrients such as phosphorus may exert a major control over plant response to rising atmospheric carbon dioxide concentration (CO2), which is projected to double by the end of the 21st century. Elevated CO2 may overcome the diffusional limitations to photosynthesis posed by stomata and mesophyll and alter the photo-biochemical limitations resulting from phosphorus deficiency. To evaluate these ideas, cotton (Gossypium hirsutum) was grown in controlled environment growth chambers with three levels of phosphate (Pi) supply (0.2, 0.05 and 0.01mM) and two levels of CO2 concentration (ambient 400 and elevated 800μmolmol(-1)) under optimum temperature and irrigation. Phosphate deficiency drastically inhibited photosynthetic characteristics and decreased cotton growth for both CO2 treatments. Under Pi stress, an apparent limitation to the photosynthetic potential was evident by CO2 diffusion through stomata and mesophyll, impairment of photosystem functioning and inhibition of biochemical process including the carboxylation efficiency of ribulose-1,5-bisphosphate carboxylase/oxyganase and the rate of ribulose-1,5-bisphosphate regeneration. The diffusional limitation posed by mesophyll was up to 58% greater than the limitation due to stomatal conductance (gs) under Pi stress. As expected, elevated CO2 reduced these diffusional limitations to photosynthesis across Pi levels; however, it failed to reduce the photo-biochemical limitations to photosynthesis in phosphorus deficient plants. Acclimation/down regulation of photosynthetic capacity was evident under elevated CO2 across Pi treatments. Despite a decrease in phosphorus, nitrogen and chlorophyll concentrations in leaf tissue and reduced stomatal conductance at elevated CO2, the rate of photosynthesis per unit leaf area when measured at the growth CO2 concentration tended to be higher for all except the lowest Pi treatment. Nevertheless, plant biomass increased at elevated CO2 across Pi nutrition with taller plants

  2. Unveiling stomata 24/7: can we use carbonyl sulfide (COS) and oxygen isotopes (18O) to constrain estimates of nocturnal transpiration across different evolutionary plant forms?

    Science.gov (United States)

    Gimeno, Teresa E.; Ogee, Jerome; Bosc, Alexander; Genty, Bernard; Wohl, Steven; Wingate, Lisa

    2015-04-01

    Numerous studies have reported a continued flux of water through plants at night, suggesting that stomata are not fully closed. Growing evidence indicates that this nocturnal flux of transpiration might constitute an important fraction of total ecosystem water use in certain environments. However, because evaporative demand is usually low at night, nocturnal transpiration fluxes are generally an order of magnitude lower than rates measured during the day and perilously close to the measurement error of traditional gas-exchange porometers. Thus estimating rates of stomatal conductance in the dark (gnight) precisely poses a significant methodological challenge. As a result, we lack accurate field estimates of gnight and how it responds to different atmospheric drivers, indicating the need for a different measurement approach. In this presentation we propose a novel method to obtain detectable and robust estimates of gnight. We will demonstrate using mechanistic theory how independent tracers including the oxygen isotope composition of CO2 (δ18O) and carbonyl sulfide (COS) can be combined to obtain robust estimates of gnight. This is because COS and CO18O exchange within leaves are controlled by the light insensitive enzyme carbonic anhydrase. Thus, if plant stomata are open in the dark we will continue to observe COS and CO18O exchange. Using our theoretical model we will demonstrate that the exchange of these tracers can now be measured using advances in laser spectrometry techniques at a precision high enough to determine robust estimates of gnight. We will also present our novel experimental approach designed to measure simultaneously the exchange of CO18O and COS alongside the conventional technique that relies on measuring the total water flux from leaves in the dark. Using our theoretical approach we will additionally explore the feasibility of our proposed experimental design to detect variations in gnight during drought stress and across a variety of plant

  3. Compound Synthesis or Growth and Development of Roots/Stomata Regulate Plant Drought Tolerance or Water Use Efficiency/Water Uptake Efficiency.

    Science.gov (United States)

    Meng, Lai-Sheng

    2018-04-11

    Water is crucial to plant growth and development because it serves as a medium for all cellular functions. Thus, the improvement of plant drought tolerance or water use efficiency/water uptake efficiency is important in modern agriculture. In this review, we mainly focus on new genetic factors for ameliorating drought tolerance or water use efficiency/water uptake efficiency of plants and explore the involvement of these genetic factors in the regulation of improving plant drought tolerance or water use efficiency/water uptake efficiency, which is a result of altered stomata density and improving root systems (primary root length, hair root growth, and lateral root number) and enhanced production of osmotic protectants, which is caused by transcription factors, proteinases, and phosphatases and protein kinases. These results will help guide the synthesis of a model for predicting how the signals of genetic and environmental stress are integrated at a few genetic determinants to control the establishment of either water use efficiency or water uptake efficiency. Collectively, these insights into the molecular mechanism underpinning the control of plant drought tolerance or water use efficiency/water uptake efficiency may aid future breeding or design strategies to increase crop yield.

  4. Evolution of the bHLH genes involved in stomatal development: implications for the expansion of developmental complexity of stomata in land plants.

    Directory of Open Access Journals (Sweden)

    Jin-Hua Ran

    Full Text Available Stomata play significant roles in plant evolution. A trio of closely related basic Helix-Loop-Helix (bHLH subgroup Ia genes, SPCH, MUTE and FAMA, mediate sequential steps of stomatal development, and their functions may be conserved in land plants. However, the evolutionary history of the putative SPCH/MUTE/FAMA genes is still greatly controversial, especially the phylogenetic positions of the bHLH Ia members from basal land plants. To better understand the evolutionary pattern and functional diversity of the bHLH genes involved in stomatal development, we made a comprehensive evolutionary analysis of the homologous genes from 54 species representing the major lineages of green plants. The phylogenetic analysis indicated: (1 All bHLH Ia genes from the two basal land plants Physcomitrella and Selaginella were closely related to the FAMA genes of seed plants; and (2 the gymnosperm 'SPCH' genes were sister to a clade comprising the angiosperm SPCH and MUTE genes, while the FAMA genes of gymnosperms and angiosperms had a sister relationship. The revealed phylogenetic relationships are also supported by the distribution of gene structures and previous functional studies. Therefore, we deduce that the function of FAMA might be ancestral in the bHLH Ia subgroup. In addition, the gymnosperm "SPCH" genes may represent an ancestral state and have a dual function of SPCH and MUTE, two genes that could have originated from a duplication event in the common ancestor of angiosperms. Moreover, in angiosperms, SPCHs have experienced more duplications and harbor more copies than MUTEs and FAMAs, which, together with variation of the stomatal development in the entry division, implies that SPCH might have contributed greatly to the diversity of stomatal development. Based on the above, we proposed a model for the correlation between the evolution of stomatal development and the genes involved in this developmental process in land plants.

  5. A novel-type phosphatidylinositol phosphate-interactive, Ca-binding protein PCaP1 in Arabidopsis thaliana: stable association with plasma membrane and partial involvement in stomata closure.

    Science.gov (United States)

    Nagata, Chisako; Miwa, Chika; Tanaka, Natsuki; Kato, Mariko; Suito, Momoe; Tsuchihira, Ayako; Sato, Yori; Segami, Shoji; Maeshima, Masayoshi

    2016-05-01

    The Ca(2+)-binding protein-1 (PCaP1) of Arabidopsis thaliana is a new type protein that binds to phosphatidylinositol phosphates and Ca(2+)-calmodulin complex as well as free Ca(2+). Although biochemical properties, such as binding to ligands and N-myristoylation, have been revealed, the intracellular localization, tissue and cell specificity, integrity of membrane association and physiological roles of PCaP1 are unknown. We investigated the tissue and intracellular distribution of PCaP1 by using transgenic lines expressing PCaP1 linked with a green fluorescence protein (GFP) at the carboxyl terminus of PCaP1. GFP fluorescence was obviously detected in most tissues including root, stem, leaf and flower. In these tissues, PCaP1-GFP signal was observed predominantly in the plasma membrane even under physiological stress conditions but not in other organelles. The fluorescence was detected in the cytosol when the 25-residue N-terminal sequence was deleted from PCaP1 indicating essential contribution of N-myristoylation to the plasma membrane anchoring. Fluorescence intensity of PCaP1-GFP in roots was slightly decreased in seedlings grown in medium supplemented with high concentrations of iron for 1 week and increased in those grown with copper. In stomatal guard cells, PCaP1-GFP was strictly, specifically localized to the plasma membrane at the epidermal-cell side but not at the pore side. A T-DNA insertion mutant line of PCaP1 did not show marked phenotype in a life cycle except for well growth under high CO2 conditions. However, stomata of the mutant line did not close entirely even in high osmolarity, which usually induces stomata closure. These results suggest that PCaP1 is involved in the stomatal movement, especially closure process, in leaves and response to excessive copper in root and leaf as a mineral nutrient as a physiological role.

  6. Identification of Open Stomata1-Interacting Proteins Reveals Interactions with Sucrose Non-fermenting1-Related Protein Kinases2 and with Type 2A Protein Phosphatases That Function in Abscisic Acid Responses1[OPEN

    Science.gov (United States)

    Waadt, Rainer; Manalansan, Bianca; Rauniyar, Navin; Munemasa, Shintaro; Booker, Matthew A.; Brandt, Benjamin; Waadt, Christian; Nusinow, Dmitri A.; Kay, Steve A.; Kunz, Hans-Henning; Schumacher, Karin; DeLong, Alison; Yates, John R.; Schroeder, Julian I.

    2015-01-01

    The plant hormone abscisic acid (ABA) controls growth and development and regulates plant water status through an established signaling pathway. In the presence of ABA, pyrabactin resistance/regulatory component of ABA receptor proteins inhibit type 2C protein phosphatases (PP2Cs). This, in turn, enables the activation of Sucrose Nonfermenting1-Related Protein Kinases2 (SnRK2). Open Stomata1 (OST1)/SnRK2.6/SRK2E is a major SnRK2-type protein kinase responsible for mediating ABA responses. Arabidopsis (Arabidopsis thaliana) expressing an epitope-tagged OST1 in the recessive ost1-3 mutant background was used for the copurification and identification of OST1-interacting proteins after osmotic stress and ABA treatments. These analyses, which were confirmed using bimolecular fluorescence complementation and coimmunoprecipitation, unexpectedly revealed homo- and heteromerization of OST1 with SnRK2.2, SnRK2.3, OST1, and SnRK2.8. Furthermore, several OST1-complexed proteins were identified as type 2A protein phosphatase (PP2A) subunits and as proteins involved in lipid and galactolipid metabolism. More detailed analyses suggested an interaction network between ABA-activated SnRK2-type protein kinases and several PP2A-type protein phosphatase regulatory subunits. pp2a double mutants exhibited a reduced sensitivity to ABA during seed germination and stomatal closure and an enhanced ABA sensitivity in root growth regulation. These analyses add PP2A-type protein phosphatases as another class of protein phosphatases to the interaction network of SnRK2-type protein kinases. PMID:26175513

  7. Efeito de sistemas de consórcio e inseticida na formação dos estômatos em plântulas de erva-doce (Foeniculum vulgare Mill. Effects of intercropping systems and insecticide in formation of stomata in fennel seedlings

    Directory of Open Access Journals (Sweden)

    C.F. Azevedo

    2012-01-01

    fennel and has great medicinal and commercial importance, both in Brazil and in several other countries. The objective of this research was to study the development of stomata of F. vulgare seedlings grown from seeds produced in intercropping systems fennel and cotton, with application of insecticide monocrotophos. The fennel was grown in association with colored cotton BRS Safira, with the following treatments: 1A2E, one rows of cotton and two fennel; 2A1E, two rows of cotton and one fennel; ES, fennel single; were distributed with and without application of insecticide, total six treatments. The seeds were sown in sand and kept in a greenhouse for 25 days. Parts of seedlings (transition zone, stem, cotyledons and leaves were cut freehand, stained and mounted on slides with glycerol for observation under microscope. Were evaluated the following characteristics: stomata number, polar and equatorial diameter of the stomata and chloroplasts number in guard cells. The data were analyzed in completely randomized and distributed in factorial 3x2, being conducted Tukey test at 5% probability. The transition zone and stem showed an increase of the stomata number and polar diameter the when consortium systems were used. In cotyledons, fennel single provided the highest stomata number, but with smaller diameter and fewer chloroplasts. In leaf, the consortia have positively influenced the stomata and chloroplasts number. In general, the intercropping systems and insecticide positively influenced the development of stomata in fennel plants.

  8. Variação do número de estômatos e micropêlos em Paspalum vaginatum Sw: em relação às condições abióticas numa marisma do estuário da Lagoa dos Patos, RS-Brasil Variation in the number of stomata and microhairs of Paspalum vaginatum Sw: en relation to abiotic conditions in a breakwater in the Lagoa dos Patos estuary, RS-Brazil

    Directory of Open Access Journals (Sweden)

    Eleci de Oliveria Bastos

    1992-12-01

    Full Text Available Paspalum vaginatum Sw., gramínea perene, estolonífera, com folhas anfistomáticas e pequenas é característica de pântanos salgados, crescendo em condições estressantes na marisma da lagoa dos Patos, molhe oeste da Barra do Rio Grande, RS. Foram feitas contagens mensais de estômatos e micropêlos nas superfícies adaxial e abaxial das lâminas e relacionadas às características abióticas do ambiente. O número de micropêlos da superfície foliar abaxial variou significativamente e diretamente com a temperatura da água intersticial junto às rizosferas. Estes, porém, não mantiveram correlação com a salinidade intersticial. Os resultados sugerem que a espécie seja uma halófita facultativa. O número de estômatos da superfície abaxial manteve um relacionamento inverso com a pluviosidade. Paspalum vaginatum, apresenta-se como uma espécie com características xeromórficas.Paspalum vaginatum Sw., a perennial, stoloniferous grass with small leaves presenting stomata on both epidermises is characteristic of salt marshes, growing under stressful conditions near the west breakwater of the Rio Grande outlet, Lagoa dos Patos, Rio Grande do Sul, Brazil. Monthly counts of stomata and microhairs on the adaxial and abaxial surfaces were related to the abiotic characteristics of the enviroment. The number of microhairs of the abaxial leaf surface varied significantly and directly with interstitial water temperature close to the rhyzosphere. However, these counts did not correlate with the interstitial salinity. The results suggest that the species is a facultative halophyte. Stomata counts of the abaxial surface showed an inverse relation to precipitation. Paspalum vaginatum appears to be a species with xeromorphic characteristics.

  9. Drought tolerance studies through WSSI and stomata in upland cotton

    International Nuclear Information System (INIS)

    Baloch, M.J.; Jatoi, W.A.; Soomro, Z.A.; Khan, N.U.; Hassan, G.; Khakwani, A.A.; Veesar, N.F.

    2011-01-01

    Water stress susceptibility index (WSSI) and stomatal conductance were used to determine the stress tolerance of 10 upland cotton cultivars during 2009 at Sindh Agriculture University, Tandojam, Pakistan. The experiment was conducted in spilt plot design with irrigations as main plots and cultivars as sub-plots. Two irrigation treatments were used i.e. one has two irrigations (water stress) and other has eight irrigations (non-stress). Analysis of variance revealed significant genotypic differences about WSSI for all the traits. Non-significant interaction between irrigations and cultivars for seed cotton yield and boll weight exhibited varietals stability over irrigation regimes, whereas significant interactions between above parameters for plant height and bolls per plant suggested genotypic instability over irrigation treatments for these traits. Overall, cultivars mean performance for all the traits in stress conditions was poor as compared to non-stress conditions, nevertheless some cultivars exhibited nonsignificant mean differences in both irrigation regimes, thus showing higher stress tolerance. The WSSI values of seed cotton yield as displayed in bi plot revealed that cultivars CRIS-477, CRIS-483 and CRIS-486 were found highly susceptible to water stress. Cultivars CRIS-476, CRIS-482, CRIS-487 and NIAB-78 were characterized as highly susceptible with minimum production even under optimum irrigation conditions. Cultivar CRIS-9 was moderately tolerant as produced low production. However, cultivars CRIS-485 and CRIS-484 were found highly stress tolerant because of minimum WSSI value and lower stomatal conductance. Negative correlations between water stress and WSSI for seed cotton yield and plant height revealed that any increase in the degree of stress caused a corresponding decrease in WSSI. (author)

  10. Hydraulic patterns and safety margins, from stem to stomata, in three eastern US tree species

    Science.gov (United States)

    D.M. Johnson; K.A. McCulloh; F.C. Meinzer; D.R. Woodruff; D.M. Eissenstat

    2011-01-01

    Adequate water transport is necessary to prevent stomatal closure and allow for photosynthesis. Dysfunction in the water transport pathway can result in stomatal closure, and can be deleterious to overall plant health and survival. Although much is known about small branch hydraulics, little is known about the coordination of leaf and stem hydraulic function....

  11. Superimposed behaviour of g(m) under ABA-induced stomata closing and low CO2

    Czech Academy of Sciences Publication Activity Database

    Tazoe, Y.; Šantrůček, Jiří

    2015-01-01

    Roč. 38, č. 3 (2015), s. 385-387 ISSN 0140-7791 R&D Projects: GA ČR(CZ) GAP501/12/1261 Institutional support: RVO:60077344 Keywords : Mesophyll conductance * Carbon-isotope discrimination * Photosnthesis * Plants Subject RIV: CE - Biochemistry Impact factor: 6.169, year: 2015

  12. A possible CO2 conducting and concentrating mechanism in plant stomata SLAC1 channel.

    Directory of Open Access Journals (Sweden)

    Qi-Shi Du

    Full Text Available BACKGROUND: The plant SLAC1 is a slow anion channel in the membrane of stomatal guard cells, which controls the turgor pressure in the aperture-defining guard cells, thereby regulating the exchange of water vapour and photosynthetic gases in response to environmental signals such as drought, high levels of carbon dioxide, and bacterial invasion. Recent study demonstrated that bicarbonate is a small-molecule activator of SLAC1. Higher CO(2 and HCO(3(- concentration activates S-type anion channel currents in wild-type Arabidopsis guard cells. Based on the SLAC1 structure a theoretical model is derived to illustrate the activation of bicarbonate to SLAC1 channel. Meanwhile a possible CO(2 conducting and concentrating mechanism of the SLAC1 is proposed. METHODOLOGY: The homology structure of Arabidopsis thaliana SLAC1 (AtSLAC1 provides the structural basis for study of the conducting and concentrating mechanism of carbon dioxide in SLAC1 channels. The pK(a values of ionizable amino acid side chains in AtSLAC1 are calculated using software PROPKA3.0, and the concentration of CO(2 and anion HCO(3(- are computed based on the chemical equilibrium theory. CONCLUSIONS: The AtSLAC1 is modeled as a five-region channel with different pH values. The top and bottom layers of channel are the alkaline residue-dominated regions, and in the middle of channel there is the acidic region surrounding acidic residues His332. The CO(2 concentration is enhanced around 10(4 times by the pH difference between these regions, and CO(2 is stored in the hydrophobic region, which is a CO(2 pool. The pH driven CO(2 conduction from outside to inside balances the back electromotive force and maintain the influx of anions (e.g. Cl(- and NO(3(- from inside to outside. SLAC1 may be a pathway providing CO(2 for photosynthesis in the guard cells.

  13. A role for stomata in regulating water use efficiency in Populus ...

    African Journals Online (AJOL)

    Jane

    2011-07-18

    Jul 18, 2011 ... Institute, agricultural water use will increase by 17% in. 2025. However, competition ..... Plasticity to soil water deficit in. Arabidopsis thaliana: ... repeats in gonadotropin receptors determine hormone specificity. EMBO J. 10: ...

  14. Unique responsiveness of angiosperm stomata to elevated CO2 explained by calcium signalling.

    Directory of Open Access Journals (Sweden)

    Timothy J Brodribb

    Full Text Available Angiosperm and conifer tree species respond differently when exposed to elevated CO2, with angiosperms found to dynamically reduce water loss while conifers appear insensitive. Such distinct responses are likely to affect competition between these tree groups as atmospheric CO2 concentration rises. Seeking the mechanism behind this globally important phenomenon we targeted the Ca(2+-dependent signalling pathway, a mediator of stomatal closure in response to elevated CO2, as a possible explanation for the differentiation of stomatal behaviours. Sampling across the diversity of vascular plants including lycophytes, ferns, gymnosperms and angiosperms we show that only angiosperms possess the stomatal behaviour and prerequisite genetic coding, linked to Ca(2+-dependent stomatal signalling. We conclude that the evolution of Ca(2+-dependent stomatal signalling gives angiosperms adaptive benefits in terms of highly efficient water use, but that stomatal sensitivity to high CO2 may penalise angiosperm productivity relative to other plant groups in the current era of soaring atmospheric CO2.

  15. Biometry of stomata in Blechnum species (Blechnaceae with some taxonomic and ecological implications for the ferns

    Directory of Open Access Journals (Sweden)

    José María Gabriel y Galán

    2011-03-01

    Full Text Available Morphological stomatal traits, such as size, form and frequency, have been subject of much literature, including their relationships with environmental factors. However, little effort have focused on ferns, and very few in the genus Blechnum. Stomatal length, width and frequency (as stomatal index of a number of specimens of fourteen Neotropical species of Blechnum were measured in adult pinnae. The aim of the work was to find biometrical relationships between stomatal traits and between stomatal traits and habit, habitat and ecosystem of the plants. Statistical analyses of data were conducted using Exploratory Data Analysis and Multivariate Statistical Methods. Stomatal length and width showed a very high correlation, suggesting an endogenous, genetic control, thus giving these traits a considerable diagnostic utility. With respect to the relationships between stomatal traits and environment, we found significant statistical relationships between altitude and stomatal index. We also addressed the interpretation of the ecological- selective significance of various assemblages of stomatal traits in a diverse conjunction of habits, habitats and ecosystems. Rev. Biol. Trop. 59 (1: 403-415. Epub 2011 March 01.Los caracteres morfológicos estomáticos, tales como tamaño, forma y frecuencia, han sido objeto de abundante investigación, incluyendo su relación con los factores ambientales. Sin embargo, poco esfuerzo se ha realizado en esta materia en helechos y menos todavía en el género Blechnum. En este trabajo se midieron la longitud, anchura y frecuencia (como índice estomático de estomas de pinnas adultas de un número de individuos en catorce especies de Blechnum neotropicales. El objetivo fue encontrar relaciones biométricas entre los caracteres estomáticos, y entre los caracteres estomáticos y el hábito, hábitat y ecosistema de las plantas. Se realizaron análisis estadísticos como Análisis Exploratorios de Datos y Métodos Estadísticos Multivariantes. La longitud y la anchura de los estomas mostraron una muy fuerte correlación, sugiriendo un control genético endógeno que otorga a estos caracteres un considerable valor diagnóstico. Con respecto a las relaciones entre los caracteres estomáticos y el ambiente, encontramos una relación estadísticamente significativa entre la altitud y el índice estomático. También se incluyen interpretaciones de la significación ecológico- selectiva de un conjunto de caracteres estomáticos en diferentes conjuntos de hábitos, hábitats y ecosistemas.

  16. QTL mapping provides evidence for lack of association of the avoidance of leaf rust in Hordeum chilense with stomata density

    NARCIS (Netherlands)

    Vaz Patto, M.C.; Rubiales, D.; Martin, A.; Hernandez, P.; Lindhout, W.H.; Niks, R.E.; Stam, P.

    2003-01-01

    In cereals, rust fungi are among the most harmful pathogens. Breeders usually rely on short-lived hypersensitivity resistance. As an alternative, "avoidance" may be a more durable defence mechanism to protect plants to rust fungi. In Hordeum chilense avoidance is based on extensive wax covering of

  17. Responses of air humidity and light quality on growth and stomata function of greenhouse grown Rosa*hybrida

    OpenAIRE

    Poudel, Madhu Sudhan

    2013-01-01

    Single node stem segment with one mature leaf of Rosa x hybrida, cv. Toril were grown in chambers. Plants were exposed to 100 μmol m-2 s-1 for 20 h day-1 followed by a 4 h dark period and supplementary light was provided by LED (20% blue light and 80% red light), HPS and HPS+UV-B Lamp. Each light source was provided by moderate (60%) and high (90) RH in different chambers. The UV-B light was provided 1 hour twice a day, in the middle of the dark period and in the middle of ligh...

  18. Effects of soil flooding on photosynthesis and growth of Zea mays L ...

    African Journals Online (AJOL)

    user

    2012-04-12

    Apr 12, 2012 ... most important responses of plants to soil flooding which could be caused by ... by monitoring stomata morphometric, intercellular CO2 (Ci) and stomata ..... absorb water and nutrients, then decrease root growth rate and dry ...

  19. Anatomical indications of fume resistance in certain woody plants

    Energy Technology Data Exchange (ETDEWEB)

    Ninova, D.

    1970-01-01

    An attempt is made to describe studies on seven species of fruit and forest trees close to or far from a Bulgarian factory emitting fumes containing S. The most resistant species (Quercus borealis, Gleditsia triacanthos, Morus alba) had the smallest stomata and the greatest number of stomata per unit leaf area. Changes observed in leaf anatomy as a result of exposure to the fumes were: decreased leaf aeration, elongated palisade cells, thicker cuticles, and more stomata.

  20. LEAF SURFACE COMPARISON OF THREE GENERA OF ARACEAE IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Ina Erlinawati

    2013-07-01

    Full Text Available Alocasia, Colocasia and Remusatia are the genera of Araceae family which have high economic value, such as for food and ornamental plants. Those three genera, previously treated as Colocasieae tribe. Later, based on Nauheimer, L. et al. study in 2012, using plastid and nuclear DNA, Alocasia is placed in different tribe. Study on leaf anatomy of Araceae is still poor known. Comparison of three genera of Araceae, indicates a difference in the epidermis. Alocasia and Colocasia have stomata on both leaf surfaces (amphistomatic but Remusatia has stomata only limited on the lower surface. The three genera can be distinguished from epidermal cell shape, stomata complex and the presence of stomata.

  1. Stomatal characterization of five species of the genus Vanilla.

    Directory of Open Access Journals (Sweden)

    Delfino Reyes-López

    2015-06-01

    Full Text Available The objective was to characterize the stomata of five species of vanilla. Throughout 2012, leaf samples of V. planifolia G. Jackson, V. pompona Schiede, V. indora Schiede, V. insignis Ames and V. odorota Presl were taken from the vanilla germplasm bank at the Benemérita Universidad Autónoma de Puebla. The stomata size was obtained considering their length and width, as well as the index and stomata number of the abaxial and adaxial leaf surfaces in a randomized complete block design with three replications. V. pompona Schiede and V. inodora Schiede showed the highest stomatal index with 8713 and 8246 stomata per mm2, respectively, followed by V. odorata Presl with 4412 stomata per mm2. V. insignis Ames and V. planifolia G. Jackson showed the lowest stomata index with 2968 and 1378 stomata per mm2, respectively, in the abaxial leaf surface, these differences were statistically significant (P≤0.05. According to the position of the leaf stomata, V. planifolia G. Jackson and V. inodora Schiede can be considered to be hypostomatics since they showed stomata only in the abaxial leaf surface. V. insignis Ames, V. inodora Schiede and V. odorata Presl. can be considered to be anfiestomatic because they showed stomata in both the abaxial and adaxial leaf surfaces. V. inodora Schiede had smaller stomata compared with the other species.That is an important feature to be included in the genetic improvement of the genus Vanilla, because due to climate change, temperature will increase and precipitation will decrease, so Vainilla will require more efficient genotypes for water use.

  2. Stomatal characterization of five species of the genus Vanilla

    International Nuclear Information System (INIS)

    Reyes-Lopez, Delfino; Quiroz-Valentin, Jonathan; Kelso-Bucio, Henry Arturo; Huerta-Lara, Manuel; Avendano-Arrazate, Carlos Hugo; Lobato-Ortiz, Ricardo

    2015-01-01

    The stomata of five species of vanilla were characterized. Throughout 2012, leaf samples of V. planifolia G. Jackson, V. pompona Schiede, V. inodora Schiede, V. insignis Ames and V. odorota Presl were taken from the vanilla germplasm bank at the Benemerita Universidad Autonoma de Puebla, throughout 2012. The stomata size was obtained considering their length and width, as well as the index and stomata number of the abaxial and adaxial leaf surfaces in a randomized complete block design with three replications. The highest stomatal index with 8713 and 8246 stomata per mm"2, was showed in V. pompona Schiede an V. inodora Schiede respectively, followed by V. odorata Presl with 4412 stomata per mm"2. The lowest stomata index with 2968 and 1378 stomata per mm"2, was showed by V. insignis Ames and V. planifolia G. Jackson respectively, in the abaxial leaf surface, these differences were statistically significant (p≤0,05). According to the position of the leaf stomata, V. planifolia G. Jackson and V. inodora Schiede can be considered to be hypostomatics since they showed stomata only in the abaxial leaf surface. V. insignis Ames, V. inodora Schiede and V. odorata Presl. can be considered to be anfiestomatic because they showed stomata in both the abaxial and adaxial leaf surfaces. V. inodora Schiede has had smaller stomata compared with the other species. That is an important feature to be included in the genetic improvement of the genus Vanilla, because due to climate change, temperature will increase and precipitation will decrease, so Vainilla will require more efficient genotypes for water use. (author) [es

  3. Morphology and AFLP markers suggest three Hordeum chilense ecotypes that differ in avoidance to rust fungi

    NARCIS (Netherlands)

    Vaz Patto, M.C.; Aardse, A.; Buntjer, J.; Rubiales, D.; Martin, A.; Niks, R.E.

    2001-01-01

    In Hordeum chilense Roem. & Schult., a high variation in the level of avoidance to infection of barley leaf rust (Puccinia hordei Otth) occurs. Probably resulting from the properties of the stomata, the rust germ tube overgrows stomata, and the infection process fails in an early stage. In the

  4. Microscopic, physicochemical and chromatographic fingerprints of ...

    African Journals Online (AJOL)

    Polygonal epidermal cells and numerous uniseriate, unicellular trichomes were also present. Quantitative leaf analysis revealed the following: stomata number on abaxial surface 445, stomata index 30.7, palisade ratio 17.1, vein- islet number 17.3 and vein- termination number 14.2. Chemomicroscopic characters present ...

  5. Does Size Matter? Atmospheric CO2 May Be a Stronger Driver of Stomatal Closing Rate Than Stomatal Size in Taxa That Diversified under Low CO2.

    Science.gov (United States)

    Elliott-Kingston, Caroline; Haworth, Matthew; Yearsley, Jon M; Batke, Sven P; Lawson, Tracy; McElwain, Jennifer C

    2016-01-01

    One strategy for plants to optimize stomatal function is to open and close their stomata quickly in response to environmental signals. It is generally assumed that small stomata can alter aperture faster than large stomata. We tested the hypothesis that species with small stomata close faster than species with larger stomata in response to darkness by comparing rate of stomatal closure across an evolutionary range of species including ferns, cycads, conifers, and angiosperms under controlled ambient conditions (380 ppm CO2; 20.9% O2). The two species with fastest half-closure time and the two species with slowest half-closure time had large stomata while the remaining three species had small stomata, implying that closing rate was not correlated with stomatal size in these species. Neither was response time correlated with stomatal density, phylogeny, functional group, or life strategy. Our results suggest that past atmospheric CO2 concentration during time of taxa diversification may influence stomatal response time. We show that species which last diversified under low or declining atmospheric CO2 concentration close stomata faster than species that last diversified in a high CO2 world. Low atmospheric [CO2] during taxa diversification may have placed a selection pressure on plants to accelerate stomatal closing to maintain adequate internal CO2 and optimize water use efficiency.

  6. Water retention capacity of tissue cultured plants

    NARCIS (Netherlands)

    Klerk, de G.J.M.; Wijnhoven, F.

    2005-01-01

    Leaves rapidly close their stomata after detachment resulting in a strong reduction of water loss. It has been reported that detached leaves of in vitro produced plants show continuous water loss indicating that they are unable to close the stomata properly and/or that their cuticle is

  7. Abnormal germling development by brown rust and powdery mildew on cer barley mutants

    NARCIS (Netherlands)

    Rubiales, D.; Ramirez, M.C.; Carver, T.L.W.; Niks, R.E.

    2001-01-01

    The barley leaf rust fungus forms appressoria over host leaf stomata and penetrates via the stomatal pore. High levels of avoidance to leaf rust fungi have been described in some wild accessions of Hordeum species where a prominent wax layer on the stomata inhibits triggering of fungal appressorium

  8. Study of anatomy of the genus Hura L. (Euphorbiaceae) | Kadiri | Ife ...

    African Journals Online (AJOL)

    Typical paracytic and anomocytic stomata of the Euphorbiaceae were recorded in the genus. The amphibrachyparacytic stomatal type found on the abaxial surface may be diagnostic. The range of interstomatal distance between any two paracytic and amphibrachyparacytic stomata is 35-45μm and 100-160 μm respectively.

  9. Pharmacognostic Evaluation of the Leaves of Secamone afzelii ...

    African Journals Online (AJOL)

    Erah

    numerical (palisade ratio, stomata number, stomata index, vein–islet number and veinlet termination number ... 2,000 species distributed all over the world. Some of them are ... Chemomicroscopic examination ... Quantitative leaf microscopy to determine palisade ... experiment. .... the Nigerian College of Arts, Science and.

  10. Novel insights on the structure and composition of pseudostomata of Sphagnum.

    Science.gov (United States)

    Merced, Amelia

    2015-03-01

    The occurrence of stomata on sporophytes of mosses and hornworts is congruent with a single origin in land plants. Although true stomata are absent in early-divergent mosses, Sphagnum has specialized epidermal cells, pseudostomata, that partially separate but do not open to the inside. This research examined two competing hypotheses that explain the origin of pseudostomata: (1) they are modified stomata, or (2) they evolved from epidermal cells independently from stomata.• Capsule anatomy and ultrastructure of pseudostomata were studied using light and electron microscopy, including immunolocalization of pectins.• Cell walls in pseudostomata are thin, two-layered, and rich in pectins, similar to young moss stomata, including the presence of cuticle on exterior walls. Outer and ventral walls have a thick cuticle that suggests that initial separation of ventral walls involves cuticle deposition as in true stomata. Further mechanical separation between ventral walls does not form a pore and occurs as the capsule dries.• As in moss stomata, pseudostomata wall architecture and behavior facilitate capsule dehydration, shape change, and dehiscence, supporting a common function. The divergent structure and fate of pseudostomata may be explained by the retention of Sphagnum sporophytes within protective leaves until nearly mature. Ultrastructural and immunocytological data suggest that pseudostomata are related to stomata but do not conclusively support either hypothesis. Solving the relationship of early land plants is critical to understanding stomatal evolution. Pseudostomata are structurally and anatomically unique, but their relationship to true stomata remains to be determined. © 2015 Botanical Society of America, Inc.

  11. Regulation of stomatal tropism and infection by light in Cercospora zeae-maydis: evidence for coordinated host/pathogen responses to photoperiod?

    OpenAIRE

    Hun Kim; John B Ridenour; Larry D Dunkle; Burton H Bluhm

    2011-01-01

    Cercospora zeae-maydis causes gray leaf spot of maize, which has become one of the most widespread and destructive diseases of maize in the world. C. zeae-maydis infects leaves through stomata, which is predicated on the ability of the pathogen to perceive stomata and reorient growth accordingly. In this study, the discovery that light was required for C. zeae-maydis to perceive stomata and infect leaves led to the identification of CRP1, a gene encoding a putative blue-light photoreceptor ho...

  12. Pharmacognostic Evaluation of the Leaves of Secamone afzelii ...

    African Journals Online (AJOL)

    Stomata arrangement was paracytic, with numerous unicellular uniseriate covering trichomes on both surfaces. Chemomicroscopic characters present included lignin, cellulose, mucilage, suberin and cutin, while phytochemical evaluation revealed the presence of alkaloids, tannins, cardiac glycosides and saponins.

  13. Oladipo and Ayo-Ayinde (7).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Result also reveals that simple hooked bicellular and unicellular non glandular trichome is diagnostic of Commelinabenghalensisand Aneilema aequinoctialerespectively. Similarities exist in foliar epidermal characters like the trichome and stomata types among other characters between the genera Commelina and ...

  14. Browse Title Index

    African Journals Online (AJOL)

    Items 101 - 150 of 193 ... Vol 13, No 2 (2011), Leaf stomata conductance, leaf water potential and soil ... Vol 14, No 2 (2012), Nanotechnology: The magic bullet towards ... for the treatment of malaria in Oshogbo, south-western Nigeria, Abstract.

  15. Somatic polyploidization and characterization of induced polyploids ...

    African Journals Online (AJOL)

    Rukevwe S. Abraka

    2016-09-21

    Sep 21, 2016 ... 3International Institute of Tropical Agriculture, Ibadan, Oyo State, Nigeria. 4Japan International .... Photos of stomata were taken using a digital camera (DP71, Olympus) attached to the ..... In. Marketing. Opportunities for ...

  16. Arogundade and Adedeji (22)

    African Journals Online (AJOL)

    USER

    complex, elliptic stomata shape, polygonal to irregular epidermal cell shape as well as straight to wavy anticlinal cell wall ... other species in this study which are amphistomatic in nature. ..... Benedetto A. D., Molinari J., Boschi C., Benedicto.

  17. Foliar epidermal characters of some Sterculiaceae species in Nigeria

    African Journals Online (AJOL)

    DR. AWORINDE D.O

    curve and slightly curved. All the species except Cola nitida (Vent) Schott, Malachanta alnifolia (Bak) Pierre, Mansonia altissima (A.Chev) R.Capuron, Theobroma cacao Linn and Waltheria indica Linn are amphistomatic. Stomata types included ...

  18. Identifying the tundra-forest border in the stomate record: an analysis of lake surface samples from the Yellowknife area, Northwest Territories, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, B.C.S. [Minnesota Univ., Minneapolis, MN (United States). Limnological Research Center; MacDonald, G.M. [California Univ., Los Angeles, CA (United States). Dept. of Botanical Sciences; Moser, K.A. [McMaster Univ., Hamilton, ON (Canada)

    1996-05-01

    The relationship between conifer stomata and existing vegetation across tundra, forest-tundra, and closed zones in the Yellowknife area of the Northwest Territories was studied. Conifer stomata were identified in surface samples from lakes in the treeline zone, but were absent in samples from tundra lakes. Stomate analysis was recorded and the results were presented in a concentration diagram plotting stomate concentrations according to vegetation zone. Conifer stomate analysis was not able to resolve differences between forest-tundra and closed forest. Nevertheless, it was suggested that stomate analysis will become an important technique supplementing pollen analysis for reconstructing past tree-line changes since the presence of stomata in lakes make it possible to separate the tundra from forest-tundra and closed forest. The limited dispersal of conifer stomata permitted a better resolution of tree-line boundaries than did pollen. 13 refs., 3 figs.

  19. Leaf development and photosynthetic properties of three tropical tree species with delayed greening

    NARCIS (Netherlands)

    Cai, Z.Q.; Slot, M.; Fan, Z.X.

    2005-01-01

    Leaf developmental patterns were characterized for three tropical tree species with delayed greening. Changes in the pigment contents, photosynthetic capacity, stomata development, photosystem 2 efficiency, rate of energy dissipation, and the activity of partial protective enzymes were followed in

  20. Quantitative trait loci mapping for stomatal traits in interspecific ...

    Indian Academy of Sciences (India)

    M. Sumathi

    2018-02-23

    Feb 23, 2018 ... Journal of Genetics, Vol. ... QTL analysis was carried out to identify the chromosomal regions affecting ... Keywords. linkage map; quantitative trait loci; stomata; stress ..... of India for providing financial support for the project.

  1. Lotus-Inspired Nanotechnology Applications

    Indian Academy of Sciences (India)

    user

    studied in the lotus, it has come to be known as the 'Lotus effect'. Barthlott and his ... would interfere with gas exchange through the stomata located on the .... greenhouses avoiding their expensive and cumbersome cleaning, water repellant ...

  2. Effects of ventilation and sucrose concentrations on the growth and plantlet anatomy of micropropagated persian walnut plants

    Science.gov (United States)

    Plantlets grown in conventional tissue culture systems usually encounter physiological and anatomical abnormalities including inability to photosynthesize, low chlorophyll content, open stomata, lack of a cuticle layer in the leaf, abnormal xylem parenchyma etc. Photoautotrophic and photomixotrophic...

  3. Improving the eco-environment in the western-China by applying ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... than exotic species in terms of the physiological and adaptation aspects. .... as needle-shaped leaves, sunken stomata and thick, .... the coniferous tree, there is only tracheid in the wood- iness ..... Seasonal Variations of Water.

  4. Morphological Characters, Occurrence and Distribution among ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Key words: Solanaceae, Solanum, Stomata, trichomes, Complements, Comparative. .... kind of oil secretory function which gave the leaves and stems glossary outlook. .... 25. 96. 20.66%. Anomocyti c. CWO13. Capsicum frutescens. Linn. 5. 78.

  5. Reference: 614 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available native promoter were found to produce excessive stomata, consistent with the recently described role of MPK...s determined using a YFP-MPK6 fusion construct, and expression was observed throughout most plant tissues, consistent

  6. Leaf surface anatomy in some woody plants from northeastern Mexico

    International Nuclear Information System (INIS)

    Maiti, R.; Rodriguez, H.G.; Balboa, P.C.R.; Kumari, A

    2016-01-01

    Studies on leaf surface anatomy of woody plants and its significance are rare. The present study was undertaken in the Forest Science Faculty Experimental Research Station, UANL, Mexico, with objectives to determine the variability in leaf surface anatomy in the woody plants of the Tamaulipan thornscrub and its utility in taxonomy and possible adaptation to the prevailing semiarid conditions. The results show the presence of large variability in several leaf anatomical traits viz., waxy leaf surface, type of stomata, its size, and distribution. The species have been classified on the basis of various traits which can be used in species delimitation and adaptation to the semiarid condition such as waxy leaf surface, absence sparse stomata on the leaf surface, sunken stomata. The species identified as better adapters to semi-arid environments on the basis of the presence and absence of stomata on both adaxial and abaxial surface viz., Eysenhardtia texana, Parkinsonia texana, Gymnosperma glutinosum, Celtis laevigata, Condalia hookeri and Karwinskia humboldtiana. (author)

  7. MICROSCOPIC, PHYSICOCHEMICAL AND CHROMATOGRAPHIC ...

    African Journals Online (AJOL)

    Peters

    carbohydrates, vitamins and organic acid) have been incinerated at ... cleaned using forceps and carmel hair brush. .... D) Diacytic stomata (s) and palisade cells on adaxial surface E) unicellular ... photosynthesis and water loss (opening and.

  8. Foliar Epidermal Studies of Plants in Euphorbiaceae

    Directory of Open Access Journals (Sweden)

    H. A. Thakur

    2014-03-01

    Full Text Available This paper describes foliar epidermal structure in 17 species belonging to 17 genera of the family Euphoprbiaceae. Anomocytic stomata is predominant, rarely they are anisocytic, paracytic on the same foliar surface with different combinations. Leaves are hypostomatic and rarely amphistomatic. The foliar surface is smooth, rarely striated. The foliar epidermal cell walls are straight or undulate. Distribution of stomata, stomatal index, stomatal frequency, stomatal size and other cell wall contours are described in detail.

  9. Optimal allocation of leaf epidermal area for gas exchange

    OpenAIRE

    de Boer, Hugo J.; Price, Charles A.; Wagner-Cremer, Friederike; Dekker, Stefan C.; Franks, Peter J.; Veneklaas, Erik J.

    2016-01-01

    Summary A long?standing research focus in phytology has been to understand how plants allocate leaf epidermal space to stomata in order to achieve an economic balance between the plant's carbon needs and water use. Here, we present a quantitative theoretical framework to predict allometric relationships between morphological stomatal traits in relation to leaf gas exchange and the required allocation of epidermal area to stomata. Our theoretical framework was derived from first principles of ...

  10. Stomatal responses to flooding of the intercellular air spaces suggest a vapor-phase signal between the mesophyll and the guard cells.

    Science.gov (United States)

    Sibbernsen, Erik; Mott, Keith A

    2010-07-01

    Flooding the intercellular air spaces of leaves with water was shown to cause rapid closure of stomata in Tradescantia pallida, Lactuca serriola, Helianthus annuus, and Oenothera caespitosa. The response occurred when water was injected into the intercellular spaces, vacuum infiltrated into the intercellular spaces, or forced into the intercellular spaces by pressurizing the xylem. Injecting 50 mm KCl or silicone oil into the intercellular spaces also caused stomata to close, but the response was slower than with distilled water. Epidermis-mesophyll grafts for T. pallida were created by placing the epidermis of one leaf onto the exposed mesophyll of another leaf. Stomata in these grafts opened under light but closed rapidly when water was allowed to wick between epidermis and the mesophyll. When epidermis-mesophyll grafts were constructed with a thin hydrophobic filter between the mesophyll and epidermis stomata responded normally to light and CO(2). These data, when taken together, suggest that the effect of water on stomata is caused partly by dilution of K(+) in the guard cell and partly by the existence of a vapor-phase signal that originates in the mesophyll and causes stomata to open in the light.

  11. Stomatal Responses to Flooding of the Intercellular Air Spaces Suggest a Vapor-Phase Signal Between the Mesophyll and the Guard Cells1[OA

    Science.gov (United States)

    Sibbernsen, Erik; Mott, Keith A.

    2010-01-01

    Flooding the intercellular air spaces of leaves with water was shown to cause rapid closure of stomata in Tradescantia pallida, Lactuca serriola, Helianthus annuus, and Oenothera caespitosa. The response occurred when water was injected into the intercellular spaces, vacuum infiltrated into the intercellular spaces, or forced into the intercellular spaces by pressurizing the xylem. Injecting 50 mm KCl or silicone oil into the intercellular spaces also caused stomata to close, but the response was slower than with distilled water. Epidermis-mesophyll grafts for T. pallida were created by placing the epidermis of one leaf onto the exposed mesophyll of another leaf. Stomata in these grafts opened under light but closed rapidly when water was allowed to wick between epidermis and the mesophyll. When epidermis-mesophyll grafts were constructed with a thin hydrophobic filter between the mesophyll and epidermis stomata responded normally to light and CO2. These data, when taken together, suggest that the effect of water on stomata is caused partly by dilution of K+ in the guard cell and partly by the existence of a vapor-phase signal that originates in the mesophyll and causes stomata to open in the light. PMID:20472750

  12. Guard cell photosynthesis is critical for stomatal turgor production, yet does not directly mediate CO2 - and ABA-induced stomatal closing.

    Science.gov (United States)

    Azoulay-Shemer, Tamar; Palomares, Axxell; Bagheri, Andisheh; Israelsson-Nordstrom, Maria; Engineer, Cawas B; Bargmann, Bastiaan O R; Stephan, Aaron B; Schroeder, Julian I

    2015-08-01

    Stomata mediate gas exchange between the inter-cellular spaces of leaves and the atmosphere. CO2 levels in leaves (Ci) are determined by respiration, photosynthesis, stomatal conductance and atmospheric [CO2 ]. [CO2 ] in leaves mediates stomatal movements. The role of guard cell photosynthesis in stomatal conductance responses is a matter of debate, and genetic approaches are needed. We have generated transgenic Arabidopsis plants that are chlorophyll-deficient in guard cells only, expressing a constitutively active chlorophyllase in a guard cell specific enhancer trap line. Our data show that more than 90% of guard cells were chlorophyll-deficient. Interestingly, approximately 45% of stomata had an unusual, previously not-described, morphology of thin-shaped chlorophyll-less stomata. Nevertheless, stomatal size, stomatal index, plant morphology, and whole-leaf photosynthetic parameters (PSII, qP, qN, FV '/FM' ) were comparable with wild-type plants. Time-resolved intact leaf gas-exchange analyses showed a reduction in stomatal conductance and CO2 -assimilation rates of the transgenic plants. Normalization of CO2 responses showed that stomata of transgenic plants respond to [CO2 ] shifts. Detailed stomatal aperture measurements of normal kidney-shaped stomata, which lack chlorophyll, showed stomatal closing responses to [CO2 ] elevation and abscisic acid (ABA), while thin-shaped stomata were continuously closed. Our present findings show that stomatal movement responses to [CO2 ] and ABA are functional in guard cells that lack chlorophyll. These data suggest that guard cell CO2 and ABA signal transduction are not directly modulated by guard cell photosynthesis/electron transport. Moreover, the finding that chlorophyll-less stomata cause a 'deflated' thin-shaped phenotype, suggests that photosynthesis in guard cells is critical for energization and guard cell turgor production. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  13. Stomatal cell wall composition: distinctive structural patterns associated with different phylogenetic groups.

    Science.gov (United States)

    Shtein, Ilana; Shelef, Yaniv; Marom, Ziv; Zelinger, Einat; Schwartz, Amnon; Popper, Zoë A; Bar-On, Benny; Harpaz-Saad, Smadar

    2017-04-01

    Stomatal morphology and function have remained largely conserved throughout ∼400 million years of plant evolution. However, plant cell wall composition has evolved and changed. Here stomatal cell wall composition was investigated in different vascular plant groups in attempt to understand their possible effect on stomatal function. A renewed look at stomatal cell walls was attempted utilizing digitalized polar microscopy, confocal microscopy, histology and a numerical finite-elements simulation. The six species of vascular plants chosen for this study cover a broad structural, ecophysiological and evolutionary spectrum: ferns ( Asplenium nidus and Platycerium bifurcatum ) and angiosperms ( Arabidopsis thaliana and Commelina erecta ) with kidney-shaped stomata, and grasses (angiosperms, family Poaceae) with dumbbell-shaped stomata ( Sorghum bicolor and Triticum aestivum ). Three distinct patterns of cellulose crystallinity in stomatal cell walls were observed: Type I (kidney-shaped stomata, ferns), Type II (kidney-shaped stomata, angiosperms) and Type III (dumbbell-shaped stomata, grasses). The different stomatal cell wall attributes investigated (cellulose crystallinity, pectins, lignin, phenolics) exhibited taxon-specific patterns, with reciprocal substitution of structural elements in the end-walls of kidney-shaped stomata. According to a numerical bio-mechanical model, the end walls of kidney-shaped stomata develop the highest stresses during opening. The data presented demonstrate for the first time the existence of distinct spatial patterns of varying cellulose crystallinity in guard cell walls. It is also highly intriguing that in angiosperms crystalline cellulose appears to have replaced lignin that occurs in the stomatal end-walls of ferns serving a similar wall strengthening function. Such taxon-specific spatial patterns of cell wall components could imply different biomechanical functions, which in turn could be a consequence of differences in

  14. Regulation of stomatal tropism and infection by light in Cercospora zeae-maydis: evidence for coordinated host/pathogen responses to photoperiod?

    Directory of Open Access Journals (Sweden)

    Hun Kim

    2011-07-01

    Full Text Available Cercospora zeae-maydis causes gray leaf spot of maize, which has become one of the most widespread and destructive diseases of maize in the world. C. zeae-maydis infects leaves through stomata, which is predicated on the ability of the pathogen to perceive stomata and reorient growth accordingly. In this study, the discovery that light was required for C. zeae-maydis to perceive stomata and infect leaves led to the identification of CRP1, a gene encoding a putative blue-light photoreceptor homologous to White Collar-1 (WC-1 of Neurospora crassa. Disrupting CRP1 via homologous recombination revealed roles in multiple aspects of pathogenesis, including tropism of hyphae to stomata, the formation of appressoria, conidiation, and the biosynthesis of cercosporin. CRP1 was also required for photoreactivation after lethal doses of UV exposure. Intriguingly, putative orthologs of CRP1 are central regulators of circadian clocks in other filamentous fungi, raising the possibility that C. zeae-maydis uses light as a key environmental input to coordinate pathogenesis with maize photoperiodic responses. This study identified a novel molecular mechanism underlying stomatal tropism in a foliar fungal pathogen, provides specific insight into how light regulates pathogenesis in C. zeae-maydis, and establishes a genetic framework for the molecular dissection of infection via stomata and the integration of host and pathogen responses to photoperiod.

  15. Regulation of stomatal tropism and infection by light in Cercospora zeae-maydis: evidence for coordinated host/pathogen responses to photoperiod?

    Science.gov (United States)

    Kim, Hun; Ridenour, John B; Dunkle, Larry D; Bluhm, Burton H

    2011-07-01

    Cercospora zeae-maydis causes gray leaf spot of maize, which has become one of the most widespread and destructive diseases of maize in the world. C. zeae-maydis infects leaves through stomata, which is predicated on the ability of the pathogen to perceive stomata and reorient growth accordingly. In this study, the discovery that light was required for C. zeae-maydis to perceive stomata and infect leaves led to the identification of CRP1, a gene encoding a putative blue-light photoreceptor homologous to White Collar-1 (WC-1) of Neurospora crassa. Disrupting CRP1 via homologous recombination revealed roles in multiple aspects of pathogenesis, including tropism of hyphae to stomata, the formation of appressoria, conidiation, and the biosynthesis of cercosporin. CRP1 was also required for photoreactivation after lethal doses of UV exposure. Intriguingly, putative orthologs of CRP1 are central regulators of circadian clocks in other filamentous fungi, raising the possibility that C. zeae-maydis uses light as a key environmental input to coordinate pathogenesis with maize photoperiodic responses. This study identified a novel molecular mechanism underlying stomatal tropism in a foliar fungal pathogen, provides specific insight into how light regulates pathogenesis in C. zeae-maydis, and establishes a genetic framework for the molecular dissection of infection via stomata and the integration of host and pathogen responses to photoperiod.

  16. Impact of solid waste burning air pollution on some physio-anatomical characteristics of some plants

    International Nuclear Information System (INIS)

    Laghari, S.K.; Zaidi, M.A.

    2015-01-01

    Present study evaluated the effect of solid waste burning pollution on carbohydrate, stomata and chlorophyll contents of seven different plant species. Leaf samples of Artemisia maritima L., Fraxinus excelsior L., Amaranthus viridis L., Cynodon dactylon L., Chenopodium album L., Robinia pseudoacacia L., and Sophora mollis (Royle) Baker, growing in the (1m, 500m and 1000m distance) vicinity of burning points at residential colony, University of Baluchistan Quetta were collected. Results revealed that the carbohydrate, chlorophyll a and b and total chlorophyll contents in the leaves of selected plant species were found to be significantly low at 1m distance, but as the distance from the source of pollution increased (500m and 1000m) these contents increased accordingly. Generally the percentage of completely and partially clogged stomata was found higher near the pollution source (1m distance). The percentage of open stomata in all investigated plant species was noticed lower near the pollution source (1m distance), while with the increase of distance (500m-1000m) the percentage of open stomata increased accordingly. As regard to carbohydrate and chlorophyll contents, the Artemisia maritima L., were found most sensitive to air pollution in all four directions at 1m distances as compared to the other species. While plant species, Cynodon dactylon L. showed more resistant to air pollution effect as regard to carbohydrate contents and high percentage of open stomata at 1m distances with respect to other species. (author)

  17. Stomatal clustering in Begonia associates with the kinetics of leaf gaseous exchange and influences water use efficiency.

    Science.gov (United States)

    Papanatsiou, Maria; Amtmann, Anna; Blatt, Michael R

    2017-04-01

    Stomata are microscopic pores formed by specialized cells in the leaf epidermis and permit gaseous exchange between the interior of the leaf and the atmosphere. Stomata in most plants are separated by at least one epidermal pavement cell and, individually, overlay a single substomatal cavity within the leaf. This spacing is thought to enhance stomatal function. Yet, there are several genera naturally exhibiting stomata in clusters and therefore deviating from the one-cell spacing rule with multiple stomata overlaying a single substomatal cavity. We made use of two Begonia species to investigate whether clustering of stomata alters guard cell dynamics and gas exchange under different light and dark treatments. Begonia plebeja, which forms stomatal clusters, exhibited enhanced kinetics of stomatal conductance and CO2 assimilation upon light stimuli that in turn were translated into greater water use efficiency. Our findings emphasize the importance of spacing in stomatal clusters for gaseous exchange and plant performance under environmentally limited conditions. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  18. KORELASI KARAKTER ANATOMI DAUN UBI JALAR (Ipomoea batatas L. KULTIVAR TAHAN DAN TIDAK TAHAN TERHADAP INTENSITAS PENYAKIT KUDIS DAUN

    Directory of Open Access Journals (Sweden)

    Ade Winda Pradana

    2017-03-01

    Full Text Available Sweet potato (Ipomoea batatas L. is one of alternative food sources beside than rice. Sweet potatoes are contains minerals, nutrients, sources of energy, protein, vitamins A and C. Sweet potatoes have lower productivity than rice and cassava. The low productivity of sweet potatoes due to several factors, which one of them is a leaf scab disease caused by pathogens Sphaceloma batatas Saw. The purpose of this study is to determine the character of the anatomy of sweet potato leaf cultivars that resistant and unresistant to the intensity of leaf scab disease, as well as the correlations between the anatomy character of sweet potato leaves with leaf scab disease intensity. The method used in this study is an experimental method with factorial completely randomized design. The first factor is the character of the anatomy of four cultivars sweet potato leaves, Cangkuang and Sukuh cultivars (cultivars resistant, cultivars Cilembu and Beta (unresistant cultivars. The second factor is the inoculation treatment S. batatas Saw. The parameters were observed thickness of cuticle, epidermis, mesophyll, the size (length and width stomata, density of stomata and trikomata as well as the intensity of the disease were analyzed using analysis of variance (ANOVA. To determine the correlation between the anatomy character leaves with disease intensity using regression correlation analysis. The results showed that Cangkuang cultivar has cuticle, epidermis and mesophyll thickest. Beta cultivars have stomata size of the longest and widest. Cilembu cultivar has the highest density of stomata. Sukuh cultivars has the highest density. The anatomy characters include of a thick cuticle, epidermis, stomata size (length and width, as well as the density of stomata and trikomata correlated with intensity of leaf scab disease.

  19. Identification of water use strategies at early growth stages in durum wheat from shoot phenotyping and physiological measurements.

    Directory of Open Access Journals (Sweden)

    ALIREZA NAKHFOROOSH

    2016-08-01

    Full Text Available Modern imaging technology provides new approaches to plant phenotyping for traits relevant to crop yield and resource efficiency. Our objective was to investigate water use strategies at early growth stages in durum wheat genetic resources using shoot imaging at the ScreenHouse phenotyping facility combined with physiological measurements. 12 durum landraces from different pedoclimatic backgrounds were compared to three modern check cultivars in a greenhouse pot experiment under well watered (75 % plant available water, PAW and drought (25 % PAW conditions. Transpiration rate was analyzed for the underlying main morphological (leaf area duration and physiological (stomata conductance factors. Combining both morphological and physiological regulation of transpiration, four distinct water use types were identified. Most landraces had high transpiration rates either due to extensive leaf area (area types or both large leaf areas together with high stomata conductance (spender types. All modern cultivars were distinguished by high stomata conductance with comparatively compact canopies (conductance types. Only few landraces were water saver types with both small canopy and low stomata conductance. During early growth, genotypes with large leaf area had high dry-matter accumulation under both well watered and drought conditions compared to genotypes with compact stature. However, high stomata conductance was the basis to achieve high dry matter per unit leaf area, indicating high assimilation capacity as a key for productivity in modern cultivars. We conclude that the identified water use strategies based on early growth shoot phenotyping combined with stomata conductance provide an appropriate framework for targeted selection of distinct pre-breeding material adapted to different types of water limited environments.

  20. Identification of Water Use Strategies at Early Growth Stages in Durum Wheat from Shoot Phenotyping and Physiological Measurements

    Science.gov (United States)

    Nakhforoosh, Alireza; Bodewein, Thomas; Fiorani, Fabio; Bodner, Gernot

    2016-01-01

    Modern imaging technology provides new approaches to plant phenotyping for traits relevant to crop yield and resource efficiency. Our objective was to investigate water use strategies at early growth stages in durum wheat genetic resources using shoot imaging at the ScreenHouse phenotyping facility combined with physiological measurements. Twelve durum landraces from different pedoclimatic backgrounds were compared to three modern check cultivars in a greenhouse pot experiment under well-watered (75% plant available water, PAW) and drought (25% PAW) conditions. Transpiration rate was analyzed for the underlying main morphological (leaf area duration) and physiological (stomata conductance) factors. Combining both morphological and physiological regulation of transpiration, four distinct water use types were identified. Most landraces had high transpiration rates either due to extensive leaf area (area types) or both large leaf areas together with high stomata conductance (spender types). All modern cultivars were distinguished by high stomata conductance with comparatively compact canopies (conductance types). Only few landraces were water saver types with both small canopy and low stomata conductance. During early growth, genotypes with large leaf area had high dry-matter accumulation under both well-watered and drought conditions compared to genotypes with compact stature. However, high stomata conductance was the basis to achieve high dry matter per unit leaf area, indicating high assimilation capacity as a key for productivity in modern cultivars. We conclude that the identified water use strategies based on early growth shoot phenotyping combined with stomata conductance provide an appropriate framework for targeted selection of distinct pre-breeding material adapted to different types of water limited environments. PMID:27547208

  1. Influence of Environmental Pollution on Leaf Properties of Urban Plane Trees, Platanus orientalis L.

    Science.gov (United States)

    Pourkhabbaz, Alireza; Rastin, Nayerah; Olbrich, Andrea; Langenfeld-Heyser, Rosemarie

    2010-01-01

    To investigate whether leaves of plane trees (Platanus orientalis) are damaged by traffic pollution, trees from a megacity (Mashhad, Iran) and a rural area were investigated. Soil and air from the urban centre showed enrichment of several toxic elements, but only lead was enriched in leaves. Leaf size and stomata density were lower at the urban site. At the urban site leaf surfaces were heavily loaded by dust particles but the stomata were not occluded; the cuticle was thinner; other anatomical properties were unaffected suggesting that plane trees can cope with traffic exhaust in megacities. PMID:20577871

  2. Macromorphological and micromorphological studies of four selected passiflora species in peninsular malaysia

    International Nuclear Information System (INIS)

    Veeramohan, R.; Haron, N.W.

    2015-01-01

    Taxonomic studies of four selected Passiflora species; Passiflora edulis Sims (Passion fruit), Passiflora coccinea Aubl. (Scarlet passion flower), Passiflora foetida L. (Stinking passion flower) and Passiflora incarnata L. (Fragrant passion flower) were carried out to distinguish their morphological characteristics. Macromorphological characters on the leaves, flowers and fruits of all four Passiflora species were observed under a binocular microscope and they varied characteristically in terms of colour, texture and shape of flowers, leaves and fruits. Jeol JSM-7500F Scanning Electron Microscope was used to observe the micromorphological characters such as stomata, trichomes, and leaf surface indumentum of each Passiflora species. Micromorphologically, each species varied in types and sizes of stomata, epidermal. (author)

  3. Effects of water stress on the root and shoot behaviour of rain-fed rice

    International Nuclear Information System (INIS)

    Bois, J.F.; Couchat, P.

    1983-01-01

    Application of the neutron technique to the roots of rain-fed rice seedlings during water stress has shown that there is a noticeable decrease in root diameter because of water loss and a slowing down of growth. At the leaf level the water deficiency results in modified gas exchanges due to closure of the stomata. Transpiration and photosynthesis appear to be independent of the soil-water potential above a threshold value in the neighbourhood of -600 mbar. Below this critical potential the closure of the stomata is progressive and proportional to the drop in water potential. (author)

  4. New method for study of injurious effect of dust pollution on leaves

    Energy Technology Data Exchange (ETDEWEB)

    Nyomarky, K.M.; Szasz, J.

    1980-01-01

    Polluted leaf samples of Acer negundo and Acer platanoides were collected from plants grown in industrial areas of Budapest. At the same time leaves of the chosen species were collected from plants grown at an experimental station. These were used as controls. The plant species used for sampling were at the same development stage. The leaf samples were subjected to light microscopic and scanning electronmicroscopic observations. An active stomatal index was derived, using the number of stomata and epidermal cells per mm of leaf area, and the number of dust clogged stomata per mm of leaf area. Data are shown illustrating use of the index to assess the effects of dust pollution.

  5. Responce of leaves of three plant species to aluminium stress

    Directory of Open Access Journals (Sweden)

    Agata Konarska

    2012-12-01

    Full Text Available Water culture experiments were undertaken for 14 days to examine the effect of increasing aluminum level (0, 10, 20 40 mg·dm-3 AlCl3·6 H2O on growth of sunflower, red pepper and radish leaves. The early stage of Al toxicity was characterized by curling or rolling of young leaves, marginal and veinal chlorosis, dark green leaves as soon as purpling of margins and veins of leaves. Reduction of leaf size and increased stomata density were observed with increasing Al concentration. Additionally, length of stomata cells decreased after Al-treatment.

  6. Stomatal kinetics and photosynthetic gas exchange along a continuum of isohydric to anisohydric regulation of plant water status

    Science.gov (United States)

    Frederick C. Meinzer; Duncan D. Smith; David R. Woodruff; Danielle E. Marias; Katherine A. McCulloh; Ava R. Howard; Alicia L. Magedman

    2017-01-01

    Species’ differences in the stringency of stomatal control of plant water potential represent a continuum of isohydric to anisohydric behaviours. However, little is known about how quasi-steady-state stomatal regulation of water potential may relate to dynamic behaviour of stomata and photosynthetic gas exchange in species operating at different positions along this...

  7. Orientation of Germ Tubes of Puccinia hordei on the Hordeum chilense Leaf Surface

    NARCIS (Netherlands)

    Vaz Patto, M.C.; Niks, R.E.

    2000-01-01

    The directional growth of urediospores germ tubes along the transverse axis of a cereal's leaf is considered to be a response to stimuli from the plant surface. In order to find out if the germ tube growth is directed towards stomata, and if the cuticular wax layer plays a role in this orientated

  8. Comparative analysis of drought resistance genes in Arabidopsis and rice

    NARCIS (Netherlands)

    Trijatmiko, K.R.

    2005-01-01

    Keywords: rice, Arabidopsis, drought, genetic mapping,microarray, transcription factor, AP2/ERF, SHINE, wax, stomata, comparative genetics, activation tagging, Ac/Ds, En/IThis thesis describes the use of genomics information and tools from Arabidopsis and

  9. Comparison of arabidopsis stomatal density mutants indicates variation in water stress responses and potential epistatic effects

    Science.gov (United States)

    Shaneka S. Lawson; Paula M. Pijut; Charles H. Michler

    2014-01-01

    Recent physiological analysis of Arabidopsis stomatal density (SD) mutants indicated that SD was not the major factor controlling aboveground biomass accumulation. Despite the general theory that plants with fewer stomata have limited biomass acquisition capabilities, epf1 and several other Arabidopsis mutants varied significantly in leaf fresh...

  10. Effect of Particulates Generated from Asphalt Production on the ...

    African Journals Online (AJOL)

    PROF HORSFALL

    in air, including dust, soot, dirt, smoke and liquid droplets. Particulate matter is of localized importance near roads, cement works, and other industrial areas. Apart from screening out sunlight, dust on leaf blocks stomata and lowers their conductants to Carbon iv oxide (Jitin and Manish, 2014). Asphalt, which is also referred ...

  11. Effect of nitrogen supply on transpiration and stomatal behaviour of beans (Phaseolus vulgaris L. )

    Energy Technology Data Exchange (ETDEWEB)

    Shimshi, D

    1970-01-01

    The effect of nitrogen supply on the transpiration rate and stomatal opening of potted bean plants was studied in a series of experiments. The transpiration rates of N-supplied plants were higher than those of N-deficient plants when soil moisture was relatively high; as soil moisture approached the wilting range, the transpiration rates of N-supplied plants dropped to below those of N-deficient plants. In spite of the marked differences in transpiration rates, as influenced by soil moisture and nitrogen supply, the stomata appeared closed. By coating the upper or lower surfaces of the leaves with a vapor-impervious compound it was shown that stomatal apertures below the limit of microscopic resolution control the rate of transpiration. Under conditions that encourage stomatal opening (covering the plants with transparent plastic bags), the stomata of the N-deficient plants opened to a lesser degree than those of N-supplied plants. There was some evidence that when stomata were visibly open, transpiration rates were regulated by the degree of plant hydration rather than by the degree of stomatal opening. It is concluded that N-deficient plants fail to open their stomata as widely and to close them as tightly as N-supplied plants. 8 references, 2 tables.

  12. Abscisic acid (ABA) and key proteins in its perception and signaling pathways are ancient, but their roles have changed through time.

    Science.gov (United States)

    Sussmilch, Frances C; Atallah, Nadia M; Brodribb, Timothy J; Banks, Jo Ann; McAdam, Scott A M

    2017-09-02

    Homologs of the Arabidopsis core abscisic acid (ABA) signaling component OPEN STOMATA1 (OST1) are best known for their role in closing stomata in angiosperm species. We recently characterized a fern OST1 homolog, GAMETOPHYTES ABA INSENSITIVE ON ANTHERDIOGEN 1 (GAIA1), which is not required for stomatal closure in ferns, consistent with physiologic evidence that shows the stomata of these plants respond passively to changes in leaf water status. Instead, gaia1 mutants reveal a critical role in ABA signaling for spore dormancy and sex determination, in a system regulated by antagonism between ABA and the gibberellin (GA)-derived fern hormone antheridiogen (A CE ). ABA and key proteins, including ABA receptors from the PYR/PYL/RCAR family and negative regulators of ABA-signaling from Group A of the type-2C protein phosphatases (PP2Cs), in addition to OST1 homologs, can be found in all terrestrial land plant lineages, ranging from liverworts that lack stomata, to angiosperms. As land plants have evolved and diversified over the past 450 million years, so too have the roles of this important plant hormone and the genes involved in its signaling and perception.

  13. Stomatal and pavement cell density linked to leaf internal CO2 concentration

    Czech Academy of Sciences Publication Activity Database

    Šantrůček, Jiří; Vráblová, M.; Šimková, Marie; Hronková, Marie; Drtinová, M.; Květoň, J.; Vrábl, D.; Kubásek, J.; Macková, J.; Wiesnerová, Dana; Neuwithová, J.; Schreiber, L.

    2014-01-01

    Roč. 114, č. 2 (2014), s. 191-202 ISSN 0305-7364 R&D Projects: GA ČR(CZ) GAP501/12/1261 Institutional support: RVO:60077344 Keywords : Stomatal density * Stomata development * Pavement cells Subject RIV: CE - Biochemistry Impact factor: 3.654, year: 2014

  14. MACROSCOPICAL AND MICROSCOPICAL STUDIES ON THE ...

    African Journals Online (AJOL)

    Caesalpinia crista leaves are bipinnate of about six pairs with alternate leaflets while the stem us fibrous, cylindrical hollow and prickly. Microscopical examination revealed the presence of strained cuticle, straight-walled epidermal cells, paracytic stomata, unicellular covering trichomes, fibres, prisms as well as cluster of ...

  15. Pharmacognostic evaluation of the leaves and stem-bark of ...

    African Journals Online (AJOL)

    The microscopy revealed the dorsiventral nature of the leaf and was observed to be hypostomatic with anomocytic type of stomata, with numerous unicellular covering and glandular trichomes on the abaxial surface. Chemomicroscopic characters present include; lignin, starch, cellulose, tannin, suberin and calcium oxalate ...

  16. Pharmacognostic studies and elemental analysis of the aerial parts ...

    African Journals Online (AJOL)

    Findings from this study revealed the presence of some diagnostic microscopical features such as paracytic stomata, unicellular covering trichomes with cystoliths, prismatic calcium oxalate crystals and annular xylem vessels. Quantitative physical constants include moisture contents (5.5 %), ash value (17 %), acid insoluble ...

  17. Relationship between canopy structure, microclimate, and Swiss needle cast severity among different ages of Douglas-fir forests

    Science.gov (United States)

    Swiss needle cast (SNC) is an endemic disease of Douglas-fir caused by Phaeocryptopus gaeumannii. The fungus infects newly emerged needles between May and August. As the fungus develops, its fruiting bodies (pseudothecia) block the stomata and inhibit gas exchange, reducing the p...

  18. Cultivar Differences in Plant Transpiration Rate at High Relative Air Humidity Are Not Related to Genotypic Variation in Stomatal Responsiveness

    DEFF Research Database (Denmark)

    Gebraegziabher, Habtamu Giday; Kjær, Katrine Heinsvig; Ottosen, Carl-Otto

    2015-01-01

    Plants grown at high relative air humidity (RH) often show disturbed water relations due to less responsive stomata. The attenuation of stomatal responsiveness as a result of high RH during leaf expansion depends on the cultivar. We hypothesized that tolerant cultivars to high RH experience a low...

  19. KERAGAMAN DAN ANALISIS KEKERABATAN Hoya spp. BERTIPE DAUN NON SUKULEN BERDASARKAN KARAKTER ANATOMI DAUN

    Directory of Open Access Journals (Sweden)

    Aldi Rahman Hakim

    2013-01-01

    Full Text Available Hoya spp. (Apocynaceae: Asclepiadoideae has differences in leaf type, there are succulent and non succulent leaf types.  Anatomical structure of Hoya spp. leaf has not been widely studied, especially for the non succulent type. The aims of this research were to explore the diversity and relationship of non succulent Hoya, based on leaf anatomical characters represented by eight species i.e. H. bandaensis, H. campanulata, H. chlorantha, H. cilliata, H. coriacea, H. coronaria, H. densifolia and H. multiflora. Hoya leaf anatomical characters were observed on the paradermal and transversal section and analyzed by using IBM SPSS version 19 sotfware for cluster analysis. According to the paradermal observation, stomata were present at lower surface (hypostomatic for all species, and amphistomatic (both surface for H. densifolia.  The type of stomata is cyclocytic for all species. Clustered stomata were found in H. coriacea.  Observation on transversal section showed that all of species has the normal structure i.e cuticula, upper and lower epidermis, palisade parenchyma and spongy parenchyma with the variation in the layer thickness.  The cluster analysis resulted four groups at distance scale 19. Each group has specific characters. The first group has trichomes on both sides of the leaf surface. The second group has amphistomatic stomatal. The third group has thin leaves. The fourth group has the widest stomata.

  20. water deficit effects on morpho-physiologicals parameters in durum ...

    African Journals Online (AJOL)

    S. Chahbar

    1 sept. 2016 ... ABSTRACT. Various morpho-physiological characters r rate water loss, stomatal density, stomata genotypes under two hydrous conditions strategies develops by each genotype have present an appreciable variability intrasp related to the adaptation to the water defici for relative water content who is ...

  1. Comparative genomics of pseudomonas syringae pathovar tomato reveals novel chemotaxis pathways associated with motility and plant pathogenicity

    Science.gov (United States)

    The majority of bacterial foliar plant pathogens must invade the apoplast of host plants through points of ingress, such as stomata or wounds, replicate to high population density and cause disease. How pathogens navigate plant surfaces to locate invasion sites remains poorly understood. Many bacter...

  2. Comparative leaf morpho-anatomical studies of two South American species of Cardiospermum (Sapindaceae) with special reference to adaxial domatia

    NARCIS (Netherlands)

    Solís, S.M.; Ferrucci, M.S.

    2006-01-01

    Morphological and anatomical studies of leaves of two closely related Cardiospermum species from South America, C. procumbens and C. pterocarpum, were assayed. Both species have amphistomatic leaves, anomocytic stomata, non-glandular and glandular trichomes, secretory cells present in the epidermis

  3. Anatomical and histochemical analysis of vegetative organs of ...

    African Journals Online (AJOL)

    Samples of V. ferruginea vegetative organs were collected and submitted to the usual plant anatomy and histochemical techniques. The leaves are anfihipoestomática with anomocytic stomata; have tector and glandular trichomes that store essential oils. The stem has collateral-type vascular bundles arranged in a eustele ...

  4. Xeromorphic traits help to maintain photosynthesis in the perhumid climate of a Taiwanese cloud forest.

    Science.gov (United States)

    Pariyar, Shyam; Chang, Shih-Chieh; Zinsmeister, Daniel; Zhou, Haiyang; Grantz, David A; Hunsche, Mauricio; Burkhardt, Juergen

    2017-07-01

    Previous flux measurements in the perhumid cloud forest of northeastern Taiwan have shown efficient photosynthesis of the endemic tree species Chamaecyparis obtusa var. formosana even under foggy conditions in which leaf surface moisture would be expected. We hypothesized this to be the result of 'xeromorphic' traits of the Chamaecyparis leaves (hydrophobicity, stomatal crypts, stomatal clustering), which could prevent coverage of stomata by precipitation, fog, and condensation, thereby maintaining CO 2 uptake. Here we studied the amount, distribution, and composition of moisture accumulated on Chamaecyparis leaf surfaces in situ in the cloud forest. We studied the effect of surface tension on gas penetration to stomata using optical O 2 microelectrodes in the laboratory. We captured the dynamics of condensation to the leaf surfaces with an environmental scanning electron microscope (ESEM). In spite of substantial surface hydrophobicity, the mean water film thickness on branchlets under foggy conditions was 80 µm (upper surface) and 40 µm (lower surface). This amount of water could cover stomata and prevent CO 2 uptake. This is avoided by the clustered arrangement of stomata within narrow clefts and the presence of Florin rings. These features keep stomatal pores free from water due to surface tension and provide efficient separation of plant and atmosphere in this perhumid environment. Air pollutants, particularly hygroscopic aerosol, may disturb this functionality by enhancing condensation and reducing the surface tension of leaf surface water.

  5. Fruit photosynthesis in Satsuma mandarin.

    Science.gov (United States)

    Hiratsuka, Shin; Suzuki, Mayu; Nishimura, Hiroshi; Nada, Kazuyoshi

    2015-12-01

    To clarify detailed characteristics of fruit photosynthesis, possible gas exchange pathway and photosynthetic response to different environments were investigated in Satsuma mandarin (Citrus unshiu). About 300 mm(-2) stomata were present on fruit surface during young stages (∼10-30 mm diameter fruit) and each stoma increased in size until approximately 88 days after full bloom (DAFB), while the stomata collapsed steadily thereafter; more than 50% stomata deformed at 153 DAFB. The transpiration rate of the fruit appeared to match with stoma development and its intactness rather than the density. Gross photosynthetic rate of the rind increased gradually with increasing CO2 up to 500 ppm but decreased at higher concentrations, which may resemble C4 photosynthesis. In contrast, leaf photosynthesis increased constantly with CO2 increment. Although both fruit and leaf photosynthesis were accelerated by rising photosynthetic photon flux density (PPFD), fruit photosynthesis was greater under considerably lower PPFD from 13.5 to 68 μmolm(-2)s(-1). Thus, Satsuma mandarin fruit appears to incorporate CO2 through fully developed and non-collapsed stomata, and subject it to fruit photosynthesis, which may be characterized as intermediate status among C3, C4 and shade plant photosynthesis. The device of fruit photosynthesis may develop differently from its leaf to capture CO2 efficiently. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Les caractéristiques des stomates des feuilles de Ficus benjamina L ...

    African Journals Online (AJOL)

    Objective: The main objective of this study is to assess the potential of Ficus benjamina stomata to be used as indicators of local air pollution. Methodology: Stomatal prints were taken from the species of study in the vicinity of roads, in residential and industrial areas and parks. Density, pore surface and stomatal resistance ...

  7. Fingerprints of a forest fungus: Swiss needle cast, carbon isotopes, carbohydrates, and growth in Douglas-fir

    Science.gov (United States)

    Andrea Watts; Frederick Meinzer; Brandy J. Saffell

    2014-01-01

    Swiss needle cast is caused by a fungus native to the Pacific Northwest. Its host is Douglas-fir, an iconic evergreen tree in the region. The fungus does not kill its host, but it adversely affects the tree's growth. The fungal fruiting bodies block the stomata, small openings on the underside of the needle where carbon dioxide, water vapor, and other gases are...

  8. No carbon “bet hedging” in pine seedlings under prolonged summer drought and elevated CO2

    NARCIS (Netherlands)

    Bachofen, Christoph; Moser, Barbara; Hoch, Günter; Ghazoul, Jaboury; Wohlgemuth, Thomas

    2018-01-01

    © 2017 The Authors. Journal of Ecology © 2017 British Ecological Society More frequent drought episodes are expected to cause higher mortality in isohydric tree species such as pines, because individuals close their stomata early during drought in order to maintain constant needle water potentials.

  9. A dynamic leaf gas-exchange strategy is conserved in woody plants under changing ambient CO2: evidence from carbon isotope discrimination in paleo and CO2 enrichment studies

    Science.gov (United States)

    Rising atmospheric [CO2], ca, is expected to affect stomatal regulation of leaf gas-exchange of woody plants, thus influencing energy fluxes as well as carbon (C), water and nutrient cycling of forests. Researchers have reported that stomata regulate leaf gas-exchange around “set...

  10. MORPHOLOGICAL AND ANATOMICAL STUDY OF SHOOTS OF JUNIPERUS COMMUNIS L. FROM CUPRESSACEAE FAMILY

    Directory of Open Access Journals (Sweden)

    F. K. Serebryanaya

    2015-01-01

    Full Text Available We have conducted morphological and anatomical studies of Juniperus communis, revealed diagnostic indices of the stamina, stalk, and needle. The leaf is sessile, linear awe shaped, pointed. Stalk form at cross section is cylindrical. Needles are lanceolar with one whitish vertical stripe, with paracytic stomata

  11. (Benth.) Benth. and Megaphrynium macrostachyum

    African Journals Online (AJOL)

    The aim is to determine ... observations were made using Light Microscope (LM). ... and stomata index on the abaxial surfaces. ... cells and thick cuticle in M. macrostachyum, presence of crystals of calcium oxalate and carbonate in M. macrostachyum. ... into an edible berry containing high amount of ..... Scale = 30 µm.

  12. Water stress detection using radar

    NARCIS (Netherlands)

    van Emmerik, T.H.M.

    2017-01-01

    Vegetation is a crucial part of the water and carbon cycle. Through photosynthesis carbon is assimilated for biomass production, and oxygen is released into the atmosphere. During this process, water is transpired through the stomata, and is redistributed in the plant. Transpired water is refilled

  13. Interactions between climate and vegetation during the Lateglacial period as recorded by lake and mire sediment archives in Northern Italy and Southern Switzerland

    NARCIS (Netherlands)

    Vescovi, E.; Ravazzi, C.; Arpenti, E.; Finsinger, W.; Pini, R.; Valsecchi, V.; Wick, L.; Ammann, B.; Tinner, W.

    2007-01-01

    We reconstruct the vegetational history of the southern side of the Alps at 18,000–10,000 cal yr BP using previous and new AMS-dated stratigraphic records of pollen, stomata, and macrofossils. To address potential effects of climatic change on vegetation, we compare our results with independent

  14. A 15,000 year record of vegetation and climate change from a treeline lake in the Rocky Mountains, Wyoming, USA

    Science.gov (United States)

    Scott A. Mensing; John L. Korfmacher; Thomas Minckley; Robert C. Musselman

    2012-01-01

    Future climate projections predict warming at high elevations that will impact treeline species, but complex topographic relief in mountains complicates ecologic response, and we have a limited number of long-term studies examining vegetation change related to climate. In this study, pollen and conifer stomata were analyzed from a 2.3 m sediment core extending to 15,...

  15. Tree and forest effects on air quality and human health in the United States

    Science.gov (United States)

    David J. Nowak; Satoshi Hirabayashi; Allison Bodine; Eric. Greenfield

    2014-01-01

    Trees remove air pollution by the interception of particulate matter on plant surfaces and the absorption of gaseous pollutants through the leaf stomata. However, the magnitude and value of the effects of trees and forests on air quality and human health across the United States remains unknown. Computer simulations with local environmental data reveal that trees and...

  16. Final Scientific Report DE-FGO3-97ER62460 Stomatal Responses to CO2: A Comparison of Woody and Herbaceous Species in Arid and Humid Climates

    Energy Technology Data Exchange (ETDEWEB)

    Koch, George W.

    2003-12-19

    OAK-B135 The project involved a study of a fundamental response of terrestrial vegetation to rising atmospheric carbon dioxide (CO2) concentration, namely, the change in leaf conductance to gas diffusion associated with a change in the aperture of the microscopic pores (stomata) on the surface of leaves.

  17. Outside-xylem pathways, not xylem embolism, drive leaf hydraulic decline with dehydration

    Science.gov (United States)

    Leaf hydraulic supply is crucial to enable the maintenance of open stomata for CO2 capture and plant growth. During drought-induced leaf dehydration, the capacity for water flow through the leaf (Kleaf) declines, a phenomenon surprisingly attributed for the past fifty years solely to the formation o...

  18. Acclimation to Chronic O3 in Field-grown Soybean is Characterized by Increased Levels of TCA Cycle Transcripts and ROS Scavenging Compounds in Addition to Decreased Photosynthetic Capacity

    Science.gov (United States)

    Tropospheric ozone (O3) is a pollutant that is generated by volatile organic compounds, nitrogen oxides and sunlight. When plants take in O3 through stomata, harmful reactive oxygen species (ROS) are produced that induce the production of ROS scavenging antioxidants. Climate change predictions indic...

  19. Does homeostasis or disturbance of homeostasis in minimum leaf water potential explain the isohydric versus anisohydric behavior of Vitis vinifera L. cultivars?

    Science.gov (United States)

    Jean-Christophe Domec; Daniel M. Johnson

    2012-01-01

    Due to the diurnal and seasonal fluctuations in leaf-to-air vapor pressure deficit (D), one of the key regulatory roles played by stomata is to limit transpiration-induced leaf water deficit. Different types of plants are known to vary in the sensitivity of stomatal conductance (gs) to D with important consequences for their survival and growth. Plants that minimize...

  20. Air pollution removal by urban forests in Canada and its effect on air quality and human health

    Science.gov (United States)

    David J. Nowak; Satoshi Hirabayashi; Marlene Doyle; Mark McGovern; Jon Pasher

    2018-01-01

    Urban trees perform a number of ecosystem services including air pollution removal, carbon sequestration, cooling air temperatures and providing aesthetic beauty to the urban landscape. Trees remove air pollution by intercepting particulate matter on plant surfaces and absorbing gaseous pollutants through the leaf stomata. Computer simulations with local environmental...

  1. Plant Physiology: Redefining the Enigma of Metabolism in Stomatal Movement.

    Science.gov (United States)

    Blatt, Michael R

    2016-02-08

    Stomata open at the leaf epidermis, driven by solute accumulation in the surrounding guard cells. Transmembrane ion transport has long been recognised to contribute to this process. A new study makes it clear that guard cells also metabolise starch to accelerate opening. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. 75 Easy Life Science Demonstrations. Teacher Book.

    Science.gov (United States)

    Kardos, Thomas

    This book is a collection of life science classroom demonstrations. Explanations that review key concepts are included. Topics are: stimulus and response; gravitropism; phototropism; living organisms; carbon dioxide; gases emitted by plants; greenhouse effect; stomata; transpiration; leaf skeletons; seed growth; water evaporation in plants; carbon…

  3. Acclimation of morphology and physiology in turf grass to low light ...

    African Journals Online (AJOL)

    Jane

    2011-08-29

    Aug 29, 2011 ... ... under low light. As such, changes take place in its internal ... structure changes enhance the cell ability to capture light, which is an ... increased, stomata conductance decreased, intercellular ... Thylakoid of shade plants takes up nearly the whole .... photosynthesis or respiration (Huppe and Turpin, 1994).

  4. Journal of Genetics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    linkage map; quantitative trait loci; stomata; stress tolerance; eucalyptus ... Correlation of stomatal traits when combined with growth and wood properties would have greater implications for generation of stress tolerant eucalypt hybrids with higher ... Institute of Forest Genetics and Tree Breeding, Coimbatore 641 002, India ...

  5. 1709-IJBCS-Article-Abayomi Folrunso

    African Journals Online (AJOL)

    Dr GATSING

    resulting in significant loss in the economic value, biodiversity and function of the invaded ecosystem .... pattern is actinodromous, marginal to basal. Stomata anomocytic, elliptical to circular in shape (Figure 1a). ... circular in shape (Figure 1c), stomatal size ranges between 303.60 - 806.50 µm2 and the stomatal index ...

  6. Seasonal carbohydrate dynamics and growth in Douglas-fir trees experiencing chronic, fungal-mediated reduction in functional leaf area

    Science.gov (United States)

    B. J. Saffell; F. C. Meinzer; D. R. Woodruff; D. C. Shaw; S. L. Voelker; B. Lachenbruch; K. Falk

    2014-01-01

    Stored non-structural carbohydrates (NSCs) could play an important role in tree survival in the face of a changing climate and associated stress-related mortality. We explored the effects of the stomata-blocking and defoliating fungal disease called Swiss needle cast on Douglas-fir carbohydrate reserves and growth to evaluate the extent to which NSCs can be mobilized...

  7. Investigating the Role of the Arabidopsis Homologue of the Human G3BP in RNA Metabolism, Cellular Stress Responses and Innate Immunity

    KAUST Repository

    Abulfaraj, Aala A.

    2018-01-01

    immunity and defense immune responses. Atg3bp1 mutant lines show constitutive stomata closure, expression of a number of key defense marker genes, and accumulate salicylic acid but not jasmonic acid. Furthermore, Atg3bp1 plants exhibit enhanced resistance

  8. Morphological characters of the flowers and the structure of the nectaries of Acer platanoides L.

    Directory of Open Access Journals (Sweden)

    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available The micromorphology of the nectaries and of other elements of the flower was examined by scanning electron microscopy (SEM. The anatomy of the nectaries was determined using light microscopy (LM. The inflorescences of A. platanoides comprise flowers included in two categories: functionally male and female. Nectaries of similar structure are found in both types of these flowers. The nectary gland located on the surface of the receptacle belongs to interstaminal nectaries. It has the form of a fleshy ring situated between the petals and the pistil. The bases of the staminal filaments are located in the depressions of the nectary. The outer diameter of the nectary reaches ca. 5 mm, while the thickness of this gland's tissues is 400-700 μm. In the epidermis of the nectary gland, there are numerous, evenly distributed stomata through which nectar release occurs. The stomata function asynchronously. In some stomata, we could observe nectar drops flowing out and a layer of this secretion around the stomata. The secretory parenchyma of the nectary is composed of several layers of thick-walled cells, whereas the ends of the vascular bundles with xylem and phloem elements are situated in the subglandular parenchyma. Chloroplasts are found both in the epidermal cells and in the glandular parenchyma cells and photosynthesis can take place in them due to the nectary's good exposure to light. The presence of starch grains was found in the chloroplasts; they can be energy material for nectar production.

  9. photoautotrophic, photomixotrophic

    African Journals Online (AJOL)

    Dion Daniels

    on the adaptation of papaya plants, strengthening the function of the stomata and with this, allowing .... culture vessels with a total volume of 250 mL with 30 mL of liquid ..... scaling. Physiological parameters: Chlorophyll a, b and carotenoids. In terms ..... Soluble sugars mediate .... Yu TA, Yeh SD, Cheng YH, Yang JS (2000).

  10. Structure-function relationships in sapwood water transport and storage.

    Science.gov (United States)

    Barbara L. Gartner; Frederick C. Meinzer

    2005-01-01

    Primary production by plants requires the loss of substantial quantities of water when the stomata are open for carbon assimilation. The delivery of that water to the leaves occurs through the xylem. The structure, condition, and quantity of the xylem control not only the transport efficiency but also the release of water from storage. For example, if there is high...

  11. Polyploidization effect in two diploid cotton (Gossypium herbaceum ...

    African Journals Online (AJOL)

    SERVER

    2008-01-18

    Jan 18, 2008 ... 2Department of Biology, Gorgan University of Agricultural Sciences and Natural ... examined the effects of different doses of colchicine on polyploidy ... number of stomata are generally increased in the poly- ... species; one comprising the New World (D-genome ... used for preparation of microscopic slides.

  12. Download this PDF file

    African Journals Online (AJOL)

    AISA

    1UFR Sciences et Gestion de l'Environnement, Université Nangui Abrogoua, 02 BP 801 Abidjan 02, Côte d'Ivoire. ... microscope and compared. .... examined fish specimens were collected and ... localization and distribution of stomata (Garcia- ... PT = Taxa common to all tropical countries of the world, SZ = Taxa of the.

  13. Envi

    African Journals Online (AJOL)

    USER

    2017-03-13

    Mar 13, 2017 ... Biology and Biotechnology, University of Benin, Benin City, Nigeria ... Stomata number was more on the abaxial surface than adaxial surface in all ... world were significant gas flaring ... The entire project site was radially ... Slides were examined with top-view light ... measurements in light microscope (LM).

  14. Parthenium Weed (Parthenium hysterophorus L.) Research in

    African Journals Online (AJOL)

    symptoms with pustule development and also by microscopic examination of ..... infection or deposition of polyphenols around penetrated stomata in many of the test ... experiment, samples of air-dried and fresh phyllody diseased Parthenium .... world. The susceptibility of Parthenium to phyllody disease suggests that it ...

  15. 937-IJBCS-Article-Mrs Adiukwu Chukwuemeka

    African Journals Online (AJOL)

    DR GATSING

    Methods used include standard procedure for macroscopic and microscopic ... presence of calcium oxalates and animocytic stomata. ... World Health Organization (WHO) to be used by 80% ... Biology Department, Faculty of Science, ... of the leaf was examined after clearing with ... for the experiment were inoculated using.

  16. Download this PDF file

    African Journals Online (AJOL)

    cadewumi

    Then the sections were placed on clean glass slides with 1-2 drops of sterile distilled water, ... using JEOL (JSM-6390LV) SEM, operated at 10 – 15 kV acceleration voltage. ... in fixing the botanical identity of medicinal plants in traditional systems arises ... The shape, size, distribution and orientation of the stomata and the.

  17. Reference: 498 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available Lynn Jo et al. 2007 Feb. Nature 445(7127):501-5. Stomata consist of a pair of guard cells that mediate gas ...a. 7127 501-5 17183267 2007 Feb Nature Bogenschutz Naomi L|Pillitteri Lynn Jo|Sloan Daniel B|Torii Keiko U

  18. Adaptative changes of leaf surface of tropical orchid Cattleya gaskelliana (N.E.Br. B.S. Williams after transferring from in vitro to ex vitro conditions

    Directory of Open Access Journals (Sweden)

    Lyudmila I. Buyun

    2013-04-01

    Full Text Available The leaf surface micromorphology of Cattleya gaskellianajuvenile plants, propagated in vitrofrom seeds, as well as of adult plants, cultivated in glasshouse, was analyzed by scanning electron microscopy (SEM. The leaves of both juvenile and adult plants are hypostomatic, their stomata are of tetracytic type. It was found that development of single stomata on the adaxial leaf surface of juvenile plants was induced byin vitro conditions. During the acclimation of in vitro propagated plants to glasshouse conditions the following changes of leaf surface micromorphology have been observed: 1 configuration of epidermal cells changed; 2 dimensions of typical epidermal cells reduced; 3 stomata density and their dimensions increased. The results suggest that structural changes, probably, can be regarded as an adaptation to avoid excessive rate leaf transpiration during a period of C. gaskelliana juvenile plants acclimation to glasshouse conditions. In the case when micromorphological leaf characteristics (stomata density per mm2, stomatal index, epidermal cells number per mm 2 of in vitro propagated plants of C. gaskelliana were comparable to those of adult plants, survival rate was more than 95%.

  19. Stomatal responses to CO2 during a diel Crassulacean acid metabolism cycle in Kalanchoe daigremontiana and Kalanchoe pinnata.

    Science.gov (United States)

    von Caemmerer, Susanne; Griffiths, Howard

    2009-05-01

    To investigate the diurnal variation of stomatal sensitivity to CO2, stomatal response to a 30 min pulse of low CO2 was measured four times during a 24 h time-course in two Crassulacean acid metabolism (CAM) species Kalanchoe daigremontiana and Kalanchoe pinnata, which vary in the degree of succulence, and hence, expression and commitment to CAM. In both species, stomata opened in response to a reduction in pCO2 in the dark and in the latter half of the light period, and thus in CAM species, chloroplast photosynthesis is not required for the stomatal response to low pCO2. Stomata did not respond to a decreased pCO2 in K. daigremontiana in the light when stomata were closed, even when the supply of internal CO2 was experimentally reduced. We conclude that stomatal closure during phase III is not solely mediated by high internal pCO2, and suggest that in CAM species the diurnal variability in the responsiveness of stomata to pCO2 could be explained by hypothesizing the existence of a single CO2 sensor which interacts with other signalling pathways. When not perturbed by low pCO2, CO2 assimilation rate and stomatal conductance were correlated both in the light and in the dark in both species.

  20. Overexpression of an ABA biosynthesis gene using a stress inducible promoter enhances drought resistance in petunia

    Science.gov (United States)

    Plants respond to drought stress by closing their stomata and reducing transpirational water loss. The plant hormone abscisic acid (ABA) regulates growth and stomatal closure particularly when the plant is under environmental stresses. One of the key enzymes in the ABA biosynthesis of higher plants ...

  1. High atmospheric demand for water can limit forest carbon uptake and transpiration as severely as dry soil

    Science.gov (United States)

    Benjamin N. Sulman; Daniel Tyler Roman; Koong Yi; Lixin Wang; Richard P. Phillips; Kimberly A. Novick

    2016-01-01

    When stressed by low soil water content (SWC) or high vapor pressure deficit (VPD), plants close stomata, reducing transpiration and photosynthesis. However, it has historically been difficult to disentangle the magnitudes of VPD compared to SWC limitations on ecosystem-scale fluxes. We used a 13 year record of eddy covariance measurements from a forest in south...

  2. Climate forcing due to optimization of maximal leaf conductance in subtropical vegetation under rising CO2

    NARCIS (Netherlands)

    Boer, H.J. de; Lammertsma, E.I.; Wagner-Cremer, F.; Dilcher, D.L.; Wassen, M.J.; Dekker, S.C.

    2011-01-01

    Plant physiological adaptation to the global rise in atmospheric CO 2 concentration (CO2) is identified as a crucial climatic forcing. To optimize functioning under rising CO2, plants reduce the diffusive stomatal conductance of their leaves (gs) dynamically by closing stomata and structurally by

  3. Providing Some Pharmacopoeial Standards for Nigerian Allium ...

    African Journals Online (AJOL)

    Microscopical evaluation of the bulb showed distinct cell-walls devoid of nucleus while the inner epidermis possessed well delineated cell-walls, transparent cytoplasm containing nucleus but without stomata. Histochemical experiments showed lignified, suberized and cellulosic cell-walls, starch grains, oils, resins, tannins ...

  4. The effect of elevated CO2 on the vegetative and generative growth of Phalaenopsis

    NARCIS (Netherlands)

    Kromwijk, J.A.M.; Meinen, E.; Dueck, T.A.

    2014-01-01

    Phalaenopsis is a crassulacean acid metabolism (CAM) plant which absorbs and binds CO2 as malate during the night. During daytime the stomata close and the CO2 stored in the vacuole is released and used for photosynthesis. Because the CO2 taken up by CAM plants was assumed to be unaffected by the

  5. Near-optimal response of instantaneous transpiration efficiency to vapour pressure deficit, temperature and [CO2] in cotton (Gossypium hirsutum L.).

    Science.gov (United States)

    The instantaneous transpiration efficiency (ITE, the ratio of photosynthesis rate to transpiration) is an important variable for crops, because it ultimately affects dry mass production per unit of plant water lost to the atmosphere. The theory that stomata optimize carbon uptake per unit water used...

  6. Fern Stomatal Responses to ABA and CO2 Depend on Species and Growth Conditions.

    Science.gov (United States)

    Hõrak, Hanna; Kollist, Hannes; Merilo, Ebe

    2017-06-01

    Changing atmospheric CO 2 levels, climate, and air humidity affect plant gas exchange that is controlled by stomata, small pores on plant leaves and stems formed by guard cells. Evolution has shaped the morphology and regulatory mechanisms governing stomatal movements to correspond to the needs of various land plant groups over the past 400 million years. Stomata close in response to the plant hormone abscisic acid (ABA), elevated CO 2 concentration, and reduced air humidity. Whether the active regulatory mechanisms that control stomatal closure in response to these stimuli are present already in mosses, the oldest plant group with stomata, or were acquired more recently in angiosperms remains controversial. It has been suggested that the stomata of the basal vascular plants, such as ferns and lycophytes, close solely hydropassively. On the other hand, active stomatal closure in response to ABA and CO 2 was found in several moss, lycophyte, and fern species. Here, we show that the stomata of two temperate fern species respond to ABA and CO 2 and that an active mechanism of stomatal regulation in response to reduced air humidity is present in some ferns. Importantly, fern stomatal responses depend on growth conditions. The data indicate that the stomatal behavior of ferns is more complex than anticipated before, and active stomatal regulation is present in some ferns and has possibly been lost in others. Further analysis that takes into account fern species, life history, evolutionary age, and growth conditions is required to gain insight into the evolution of land plant stomatal responses. © 2017 American Society of Plant Biologists. All Rights Reserved.

  7. Morphology, Physiology, and Anatomy of Penny Fern (Drymoglossum phyloselloidesand Its Effect on Cocoa

    Directory of Open Access Journals (Sweden)

    Fitria Yuliasmara

    2013-08-01

    Full Text Available This study aims to determine the anatomy, physiology and morphology of penny fern (Drimoglosum phylloseloides and its effect on cocoa. Morphological observation of penny fern used microscope to observe the roots, stems, leaves and spores. Physiology of penny fern was observed based on number of stomata and stomatal conductance using stomata printing method, while the amount of chlorophyll based on spectrophotometric method and rate of transpiration used cobalt chloride paper. Penny fern anatomy on cross-sectional and longitudinal in roots, stems and leaves. Penny fern growth was observed based the length of tendrils once a week during rainy and dry season. While the effect of penny fern invasion was observed based on variable leaf area with gravimetric method, the cross-section of attacked cacao branch using microtom and microscope and chlorophyll content by chlorophyll meter. Results showed that penny fern is a epiphytic weed which was crassulaceae acid metabolism plants that have the ability to absorb carbon dioxide at night and carry out photosynthesis during the day with closed stomata. Penny ferns reproduce using spores. The growth rate of penny fern 2.18 cm/week during the dry season and while in rainy season 3.89 cm/week. Penny fern leaf contains 0.0212 mg/g chlorophyll. Penny fern stomata density was 18.33/mm 2 with a width of opening stomata at night 26.3 µm which caused a veryslow rate of transpiration of 0.69 mm 2 /seconds. The existence penny fern on cocoa decreased leaf area and chlorophyll content decreased crop productivity which was indicated by decreasing in number of flowers, number of small, medium fruit, and large pods. However it had no effect on the number of leaves on one side flush cocoa. Key words: Drimoglosum phylloseloides, weeds, decrease productivity, Theobroma cacao

  8. Effects of SO/sub 2/ pollution on stomatal movements in Vicia faba

    Energy Technology Data Exchange (ETDEWEB)

    Majernik, O; Mansfield, T A

    1971-01-01

    Leaves of broad bean Vicia faba L. exposed to controlled levels of SO/sub 2/ pollution in the range 0.25 to 9.0 ppm had much wider stomatal openings than control plants. The stimulation of opening relative to the controls was proportional to SO/sub 2/ concentration over the range 0.25 to 1.0 ppm. The ability of the stomata to close at night was not appreciably affected. The possible implications of this unnatural reaction of the stomata are discussed. Abnormal opening could lead to the plant's losing its usual control over transpiration, with resulting water stress. The main disadvantage, however, is that SO/sub 2/ will gain easier access to the interior of the leaf.

  9. MEDITERRANEAN FOREST TREE DECLINE IN ITALY: RELATIONSHIPS BETWEEN DROUGHT, POLLUTANTS AND THE WAX STRUCTURE OF LEAVES

    Directory of Open Access Journals (Sweden)

    E. PAOLETTI

    1996-04-01

    Full Text Available After presenting the situation of forest decline in Italy and analyzing the factors that play a contributing role, tbis paper studies the response of the epicuticular wax structures and the stomata in ten broadleaf species and one conifer to fog-like treatments with acids andlor surfactants and to severe water stress. The main results are that wax structure alterations vary in intensity in the different species studied and that the microstructural alterations observed in field conditions cannot be attributed only to severe drought. since sample trccs put through water stress simulations do nol differ significantly from controls. In the artificial surfactant treatment, a positive relationship between structural damage to tbe stomata and transpiration suggests possible synergies between the effects of drought and those of pollutants in inducing stress conditions in Mediterranean vegetation.

  10. [Facilitators of the transition process for the self-care of the person with stoma: subsidies for Nursing].

    Science.gov (United States)

    Mota, Marina Soares; Gomes, Giovana Calcagno; Petuco, Vilma Madalosso; Heck, Rita Maria; Barros, Edaiane Joana Lima; Gomes, Vera Lúcia de Oliveira

    2015-02-01

    To know the facilitating factors of the transition process from dependency to the self-care of people with a stoma. This is a descriptive study of qualitative approach, including 27 people with permanent stomas due to cancer. The data were collected through semi-structured interviews and submitted to content analysis based on the Transition Theory as theoretical reference. The self-care facilitators related to the person were the positive significance of ostomy; the preparation for this experience already in the preoperative period; emotional stability; faith; religiousness; and a sense of normalcy acquired from a next image similar to the previous one. The facilitators related to the community were the following: receiving equipment for free from the government; support from family and the multidisciplinary team, especially the nurses; and having contact with other people with stomata. The results allow that nurses develop strategies to help people with stomata to resume their self-care.

  11. Studies on anatomical characters indicating C3 and C4 photosynthetic metabolism in the genus Boerhavia L. (Nyctaginaceae

    Directory of Open Access Journals (Sweden)

    Abdulwakeel Ayokun-nun Ajao

    2017-08-01

    Full Text Available The C3 and C4 photosynthetic pathways in dicotyledons were investigated with the four species of Boerhavia occurring in Nigeria using light microscopy. The study is not yet well reported on dicotyledons as done for monocotyledons. The features cross-examined were stomata index, stomata size, inter-stomatal distance, stomatal density, interveinal distance, intercellular air spaces, leaf thickness, mesophyll thickness, Kranz tissue, one cell distant count criterion, maximum lateral cell count criterion, vein density and vein distance. Based on these features, these species (B. erecta, B. coccinea and B. repens were grouped into C4 while B. diffusa was grouped as a C3 plant. In particular, interveinal distance less than 166µm and maximum lateral count ranging 2 to 6 will help in grouping C4 dicotyledons species while those that were greater than these values are useful in grouping C3 and plants.

  12. Genotypic difference in salinity tolerance in quinoa is determined by differential control of xylem Na+ loading and stomatal density

    DEFF Research Database (Denmark)

    Shabala, Sergey; Hariadi, Yuda; Jacobsen, Sven-Erik

    2013-01-01

    old seedlings. Six weeks after the treatment commenced, leaf sap Na and K content and osmolality, stomatal density, chlorophyll fluorescence characteristics, and xylem sap Na and K composition were measured. Responses to salinity differed greatly among the varieties. All cultivars had substantially...... increased K+ concentrations in the leaf sap, but the most tolerant cultivars had lower xylem Na+ content at the time of sampling. Most tolerant cultivars had lowest leaf sap osmolality. All varieties reduced stomata density when grown under saline conditions. All varieties clustered into two groups...... to the xylem, and reduced stomata density are important physiological traits contributing to genotypic differences in salinity tolerance in quinoa, a halophyte species from Chenopodium family....

  13. Anatomical Basis for Optimal Use of Water for Maintenance of Three Xerophytic Plants

    Directory of Open Access Journals (Sweden)

    Abdullahi Alanamu ABDULRAHAMAN

    2012-05-01

    Full Text Available Three xerophytic plant species namely Agave americana Linn., Aloe vera Tourn. and Linn. and Euphorbia milii Des Moul. were propagated in a greenhouse each with 5 varying soil moisture contents i.e. 1.25%, 2.5%, 5%, 10%, and 20% and subjected to 4 watering frequencies i.e. daily, weekly, biweekly and monthly. Euphorbia milii was the most xerophytic species having relatively lower rate of transpiration than Aloe vera and Agave americana. It was suggested that the high rate of transpiration in Aloe vera and Agave americana may be due to the large tetracytic stomata as compared to the small paracytic stomata of Euphorbia milii. It was also observed that Aloe vera was least tolerant of high soil moisture in daily watering as well as low soil moisture in monthly regime. Agave americana and Euphorbia milii were species that were more robust with capacity to cope well with low and high watering regimes than Aloe vera.

  14. EPIDERMAL CHARACTERS OF BACCHARIS (ASTERACEAE SPECIES USED IN TRADITIONAL MEDICINE

    Directory of Open Access Journals (Sweden)

    FREIRE SUSANA E.

    2007-06-01

    Full Text Available A morphological study of 38 species of Baccharis used in traditional medicinewas carried out to provide some epidermal characters that will contribute to theknowledge of the genus. The present study revealed: 1 seven different types oftrichomes: conical, aseptate fl agellate, fi liform fl agellate, 1-armed, 2-4-armed,bulbiferous fl agellate, and glandular biseriate; 2 that 28 of the total of 38 specieshave trichomes in tufts; 3 six different types of stomata: anomocytic, anisocytic,cyclocytic, actinocytic, tetracytic, and staurocytic; 4 that some trichome types,such as 2-4-armed (B. dracunculifolia and aseptate fl agellate branched (B. trinervis,show a high diagnostic value; 5 that the stomata types can be used to differentiatespecies with similar trichomes type (e.g. B. trimera and B. articulata.Illustrations of the studied characters are provided.

  15. Opinion: the red-light response of stomatal movement is sensed by the redox state of the photosynthetic electron transport chain.

    Science.gov (United States)

    Busch, Florian A

    2014-02-01

    Guard cells regulate CO2 uptake and water loss of a leaf by controlling stomatal movement in response to environmental factors such as CO2, humidity, and light. The mechanisms by which stomata respond to red light are actively debated in the literature, and even after decades of research it is still controversial whether stomatal movement is related to photosynthesis or not. This review summarizes the current knowledge of the red-light response of stomata. A comparison of published evidence suggests that stomatal movement is controlled by the redox state of photosynthetic electron transport chain components, in particular the redox state of plastoquinone. Potential consequences for the modeling of stomatal conductance are discussed.

  16. STUDI STRUKTUR EPIDERMIS DAUN Dasymaschalon blumei Finet & Ganep. (Annonaceae DI JAWA DAN SUMATERA

    Directory of Open Access Journals (Sweden)

    Subekti Nurmawati

    2016-09-01

    Full Text Available Dasymaschalon blumei Finet & Gagnep. Is one of the species from the genus Dasymaschalon (Hook. F & Thomson Dalla Torre & Harms which can be recognized from its peculiar moniliform fruits. It widespread in Java and Sumatera. An anatomical of leaves from herbarium specimens of D. blumei collected from Java and Sumatera has been carried out by using light microscope in Herbarium Bogoriense. The objectives of this study is to observe the leaves anatomy of D. blumei and to support the classification of  the species concept of D. blumei.  The specimens are divided into three categories based on the elevation, those were: specimens collected from 500 m of sea level. The result showed that from the epidermal section, the type of the stomata from the three categories were similar, and also the number and the index of the stomata. Variations however exists because of the environment factors.

  17. Reevaluation of the plant "gemstones": Calcium oxalate crystals sustain photosynthesis under drought conditions.

    Science.gov (United States)

    Tooulakou, Georgia; Giannopoulos, Andreas; Nikolopoulos, Dimosthenis; Bresta, Panagiota; Dotsika, Elissavet; Orkoula, Malvina G; Kontoyannis, Christos G; Fasseas, Costas; Liakopoulos, Georgios; Klapa, Maria I; Karabourniotis, George

    2016-09-01

    Land plants face the perpetual dilemma of using atmospheric carbon dioxide for photosynthesis and losing water vapors, or saving water and reducing photosynthesis and thus growth. The reason behind this dilemma is that this simultaneous exchange of gases is accomplished through the same minute pores on leaf surfaces, called stomata. In a recent study we provided evidence that pigweed, an aggressive weed, attenuates this problem exploiting large crystals of calcium oxalate as dynamic carbon pools. This plant is able to photosynthesize even under drought conditions, when stomata are closed and water losses are limited, using carbon dioxide from crystal decomposition instead from the atmosphere. Abscisic acid, an alarm signal that causes stomatal closure seems to be implicated in this function and for this reason we named this path "alarm photosynthesis." The so-far "enigmatic," but highly conserved and widespread among plant species calcium oxalate crystals seem to play a crucial role in the survival of plants.

  18. Study on the doubling effect of colchicine on leaves in vitro of apple seedlings

    International Nuclear Information System (INIS)

    Wang Changquan; Li Yazhi; Cui Decai; Su Huairui

    1997-01-01

    Leaves in vitro of two diploid apple cultivars were treated with different concentrations of colchicine and 2% DMSO solution. Among all treatments, 0.5% of colchicine treating for 4 days showed the best effect with variation frequency of 56.1%. Obvious changes occurred in the morphological and cytological aspects of the induced tetraploidy apple plants. In comparison with normal plants, variant plants showed the following features: the stem became dwarf and thick; node was shorten; the leaves' colour appeared dark green. The stomata cell size was larger than that of diploid plants. The number of the stomata per unit area of the leaves in variant plants distinctly reduced. The chromosome number were determined to be 2n = 2x = 34 for diploid plants and 2n = 4x = 68 for variant plants. The nucleolus number of variant plants increased. By the means of section of paraffin-embedded shoot auspices, 86% of variant plants have been identified as solid tetraploidy

  19. Comparative SEM and LM foliar epidermal and palyno-morphological studies of Amaranthaceae and its taxonomic implications.

    Science.gov (United States)

    Hussain, Amara Noor; Zafar, Muhammad; Ahmad, Mushtaq; Khan, Raees; Yaseen, Ghulam; Khan, Muhammad Saleem; Nazir, Abdul; Khan, Amir Muhammad; Shaheen, Shabnum

    2018-05-01

    Palynological features as well as comparative foliar epidermal using light and scanning electron microscope (SEM) of 17 species (10genera) of Amaranthaceae have been studied for its taxonomic significance. Different foliar and palynological micro-morphological characters were examined to explain their value in resolving the difficulty in identification. All species were amphistomatic but stomata on abaxial surface were more abundant. Taxonomically significant epidermal character including stomata type, trichomes (unicellular, multicellular, and capitate) and epidermal cells shapes (polygonal and irregular) were also observed. Pollens of this family are Polypantoporate, pores large, spheroidal, mesoporous region is sparsely to scabrate, densely psilate, and spinulose. All these characters can be active at species level for identification purpose. This study indicates that at different taxonomic levels, LM and SEM pollen and epidermal morphology is explanatory and significant to identify species and genera. © 2018 Wiley Periodicals, Inc.

  20. Protocol for the ostomized person in the trans-hospital and outpatient period: Integrative Review

    Directory of Open Access Journals (Sweden)

    Stella Godoy Silva Lima

    2017-06-01

    Full Text Available Objective: To review the literature about the application of the evidence-based protocol concept for clinical assessment and interventions in nursing consultation to ostomized people. Method: integrative review to increase the knowledge about stomata. A search was made in the databases BIREME, CINAHL, SCOPUS, WEB OF SCIENCE and PUBMED with descriptors Ostomy OR Colostomy OR Colonic Pouches OR Surgical Stomata OR Colorectal Neoplasms OR Colorectal Cancer AND Protocols. It was selected 21 articles in the period of 2011-2015. Results: The articles were systematized into five categories: quality of life, nursing assistance, protocols, complications and surgery. The categories are complementary and demonstrate a work carried out by a multiprofessional team. Conclusion: the themes analysis made it possible to identify the need for expansion in research that addresses specific aspects such as teaching strategies in the levels of assistance in the trans-operative, postoperative and in the outpatient phase in nursing consultations.

  1. Facilitators of the transition process for the self-care of the person with stoma: subsidies for Nursing

    Directory of Open Access Journals (Sweden)

    Marina Soares Mota

    2015-02-01

    Full Text Available OBJECTIVE To know the facilitating factors of the transition process from dependency to the self-care of people with a stoma. METHOD This is a descriptive study of qualitative approach, including 27 people with permanent stomas due to cancer. The data were collected through semi-structured interviews and submitted to content analysis based on the Transition Theory as theoretical reference. RESULTS The self-care facilitators related to the person were the positive significance of ostomy; the preparation for this experience already in the preoperative period; emotional stability; faith; religiousness; and a sense of normalcy acquired from a next image similar to the previous one. The facilitators related to the community were the following: receiving equipment for free from the government; support from family and the multidisciplinary team, especially the nurses; and having contact with other people with stomata. CONCLUSION The results allow that nurses develop strategies to help people with stomata to resume their self-care.

  2. Mix-and-match: ligand-receptor pairs in stomatal development and beyond.

    Science.gov (United States)

    Torii, Keiko U

    2012-12-01

    Stomata are small valves on the plant epidermis balancing gas exchange and water loss. Stomata are formed according to positional cues. In Arabidopsis, two EPIDERMAL PATTERNING FACTOR (EPF) peptides, EPF1 and EPF2, are secreted from stomatal precursors enforcing proper stomatal patterning. Here, I review recent studies revealing the ligand-receptor pairs and revising the previously predicted relations between receptors specifying stomatal patterning: ERECTA-family and TOO MANY MOUTHS (TMM). Furthermore, EPF-LIKE9 (EPFL9/Stomagen) promotes stomatal differentiation from internal tissues. Two EPFL peptides specify inflorescence architecture, a process beyond stomatal development, as ligands for ERECTA. Thus, broadly expressed receptor kinases may regulate multiple developmental processes through perceiving different peptide ligands, each with a specialized expression pattern. TMM in the epidermis may fine-tune multiple EPF/EPFL signals to prevent signal interference. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Longevity of guard cell chloroplasts in falling leaves: implication for stomatal function and cellular aging.

    Science.gov (United States)

    Zeiger, E; Schwartz, A

    1982-11-12

    Guard cell chloroplasts in senescing leaves from 12 species of perennial trees and three species of annual plants survived considerably longer than their mesophyll counterparts. In Ginkgo biloba, stomata from yellow leaves opened during the day and closed at night; guard cell chloroplasts from these leaves showed fluorescence transients associated with electron transport and photophosphorylation. These findings indicate that guard cell chloroplasts are highly conserved throughout the life-span of the leaf and that leaves retain stomatal control during senescence.

  4. Micromorphological studies on petals of spiraea l. species (rosaceae) from pakistan

    International Nuclear Information System (INIS)

    Omer, S.A.

    2017-01-01

    Epidermal micromorphology of petals of 10 species of Spiraea L. of the family Rosaceae from Pakistan has been examined with Scanning Electron Microscope (SEM). Micromorphological attributes observed in petals and their reliability as a taxonomic marker is discussed. The epidermal cells exhibit definite geometrical patterns, where cell wall boundaries are more or less elevated and cell surface generally marked with striae. Stomata are completely absent. (author)

  5. TRAORE S..mdi

    African Journals Online (AJOL)

    AISA

    lte. Figure 2 : Régression entre la densité stomatique de la partie proximale de la face supérieure de la feuille et l'indice d'infection. Regression between stomata density of proximal area of upper surface of the limb and infection index. A : à 6 mois; B : à la floraison ; C : à la récolte. A: at 6 months; B: at flowering; C: at harvest ...

  6. Derivation of the canopy conductance from surface temperature and spectral indices for estimating evapotranspiration in semiarid vegetation; Monitorizacion de conductancia en vegetacion semiarida a partir de indices espectrales y temperatura de supeficie

    Energy Technology Data Exchange (ETDEWEB)

    Morillas, L.; Garcia, M.; Zarco-Tejada, P.; Ladron de Guevara, M.; Villagarcia, L.; Were, A.; Domingo, F.

    2009-07-01

    This work evaluates the possibilities for estimating stomata conductance (C) and leaf transpiration (Trf) at the ecosystem scale from radiometric indices and surface temperature. The relationships found between indices and the transpiration component of the water balance in a semiarid tussock ecosystem in SE Spain are discussed. Field data were collected from spring 2008 until winter 2009 in order to observe the annual variability of the relationships and the behaviour of spectral indices and surface temperature. (Author) 11 refs.

  7. Derivation of the canopy conductance from surface temperature and spectral indices for estimating evapotranspiration in semiarid vegetation

    International Nuclear Information System (INIS)

    Morillas, L.; Garcia, M.; Zarco-Tejada, P.; Ladron de Guevara, M.; Villagarcia, L.; Were, A.; Domingo, F.

    2009-01-01

    This work evaluates the possibilities for estimating stomata conductance (C) and leaf transpiration (Trf) at the ecosystem scale from radiometric indices and surface temperature. The relationships found between indices and the transpiration component of the water balance in a semiarid tussock ecosystem in SE Spain are discussed. Field data were collected from spring 2008 until winter 2009 in order to observe the annual variability of the relationships and the behaviour of spectral indices and surface temperature. (Author) 11 refs.

  8. Coupling between the continental carbon and water cycles

    Science.gov (United States)

    Gentine, P.; Lemordant, L. A.; Green, J. K.

    2017-12-01

    The continental carbon adn water cycles are fundamentally coupled through leaf gas exchange at the stomata level. IN this presnetation we will emphasize the importance of this coupling for the future of the water cycle (runoff, evaporation, soil moisture) and in turn the implications for the carbon cycle and the capacity of continents to act as a carbon dioxyde sink in the future. Opprtunites from coupled carbon-water monitoring platforms will be then emphasized.

  9. Stomatal vs. genome size in angiosperms: the somatic tail wagging the genomic dog?

    Science.gov (United States)

    Hodgson, J G; Sharafi, M; Jalili, A; Díaz, S; Montserrat-Martí, G; Palmer, C; Cerabolini, B; Pierce, S; Hamzehee, B; Asri, Y; Jamzad, Z; Wilson, P; Raven, J A; Band, S R; Basconcelo, S; Bogard, A; Carter, G; Charles, M; Castro-Díez, P; Cornelissen, J H C; Funes, G; Jones, G; Khoshnevis, M; Pérez-Harguindeguy, N; Pérez-Rontomé, M C; Shirvany, F A; Vendramini, F; Yazdani, S; Abbas-Azimi, R; Boustani, S; Dehghan, M; Guerrero-Campo, J; Hynd, A; Kowsary, E; Kazemi-Saeed, F; Siavash, B; Villar-Salvador, P; Craigie, R; Naqinezhad, A; Romo-Díez, A; de Torres Espuny, L; Simmons, E

    2010-04-01

    Genome size is a function, and the product, of cell volume. As such it is contingent on ecological circumstance. The nature of 'this ecological circumstance' is, however, hotly debated. Here, we investigate for angiosperms whether stomatal size may be this 'missing link': the primary determinant of genome size. Stomata are crucial for photosynthesis and their size affects functional efficiency. Stomatal and leaf characteristics were measured for 1442 species from Argentina, Iran, Spain and the UK and, using PCA, some emergent ecological and taxonomic patterns identified. Subsequently, an assessment of the relationship between genome-size values obtained from the Plant DNA C-values database and measurements of stomatal size was carried out. Stomatal size is an ecologically important attribute. It varies with life-history (woody species < herbaceous species < vernal geophytes) and contributes to ecologically and physiologically important axes of leaf specialization. Moreover, it is positively correlated with genome size across a wide range of major taxa. Stomatal size predicts genome size within angiosperms. Correlation is not, however, proof of causality and here our interpretation is hampered by unexpected deficiencies in the scientific literature. Firstly, there are discrepancies between our own observations and established ideas about the ecological significance of stomatal size; very large stomata, theoretically facilitating photosynthesis in deep shade, were, in this study (and in other studies), primarily associated with vernal geophytes of unshaded habitats. Secondly, the lower size limit at which stomata can function efficiently, and the ecological circumstances under which these minute stomata might occur, have not been satisfactorally resolved. Thus, our hypothesis, that the optimization of stomatal size for functional efficiency is a major ecological determinant of genome size, remains unproven.

  10. Epidermal characters of Tamarix L. (Tamaricaceae) from Northwest China and their taxonomic and palaeogeographic implications

    OpenAIRE

    Jian-Wei Zhang; Ashalata D'Rozario; Shi-Min Duan; Xi-Yong Wang; Xiao-Qing Liang; Bo-Rong Pan

    2018-01-01

    The taxonomical position of species of the genus Tamarix (Tamaricaceae) has been criticized because of their gross morphological similarities (such as slender, smooth and reddish–brown branches, grey–green foliage and scale leaves), and their systematic relationships remain unclear. In this paper, the leaf epidermal features of 17 species from China are studied based on the micro-morphological characters of the epidermal cells, stomata, salt glands, papillae and epidermal hairs. According to ...

  11. The effects of UV radiation on the content of phenolic acid and flavonoid, stomatal conductance and taste in red lettuce 'Lollo Rosso'

    OpenAIRE

    Almeida De Oliveira, Dinalva

    2016-01-01

    The use of supplementary light to improve the quality of red lettuce is common practice in today’s greenhouse production. Fluorescent lamps that emit Ultraviolet (UV) radiation have been shown to increase the synthesis of phenolic acids and flavonoids as well to control stomata movements in red lettuce. In the work presented here, I ran experiments which showed that the use of UV treatments lead to higher concentrations of these health-promoting compounds. The objective was to evaluate the ef...

  12. Responses of seedlings of tropical woody plants to environmental stresses with emphasis on Theobroma cacao and Hevea brasiliensis

    Energy Technology Data Exchange (ETDEWEB)

    Sena Gomes, A.R.

    1987-01-01

    Relative humidity, flooding, temperature, wind, and SO/sub 2/ variously influenced physiological processes and growth of tropical woody plants, with emphasis on three Theobroma cacao varieties and three Hevea brasiliensis families. Stomata were smaller and more numerous in Theobroma than in Hevea. In Theobroma, but not Heavea, stomatal frequency decreased from the leaf base to the apex and from the midrib outward. Stomata of Theobroma cacao var. Catongo opened in high relative humidity (RH) and closed in low RH. The more open stomata in high RH were associated with high rates of photosynthesis, low leaf water potential, high water use efficiency (WUE), and low transpiration rate (TR). Variations in TR and WUE were correlated with changes in vapor pressure deficit. Other responses included stomatal closure, decreased chlorophyll content, leaf epinasty, production of hypertrophied lenticels and adventitious roots, and acceleration of ethylene production. Responses to flooding varied with species, Theobroma varieties and Hevea families. Effects of temperature regimes on growth varied with species, varieties and families, plant parts, growth parameters, and time of harvesting. Optimal temperatures for dry weight increase of stems or roots of Theobroma cacao var. Comum were 22.2 C; and 33.3 C for dry weight increase or relative growth rates of leaves or seedlings. Optimal temperatures for growth varied for Hevea families. Wind injured leaves of Theobroma cacao, with more injury by wind of 6.0 than 3.0 m s/sup -1/. Stomata were more open on windy than on calm days, but tended to close at high wind speeds. Wind lowered transpiration rate but the reduction was not correlated with leaf dehydration. SO/sub 2/ at 0.5, 1.0, or 1.5 ppm for 24 h did not injure Theobroma leaves but reduced dry weight increment of leaves of var. Catongo but not Catongo/Sial.

  13. Rectum-conserving surgery in the era of chemoradiotherapy.

    LENUS (Irish Health Repository)

    Smith, F M

    2012-01-31

    BACKGROUND: A complete pathological response occurs in 10-30 per cent of patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy (CRT). The standard of care has been radical surgery with high morbidity risks and the challenges of stomata despite the favourable prognosis. This review assessed minimalist approaches (transanal excision or observation alone) to tumours with a response to CRT. METHODS: A systematic review was performed using PubMed and Embase databases. Keywords included: \\'rectal\\

  14. A rate equation model of stomatal responses to vapour pressure deficit and drought

    Directory of Open Access Journals (Sweden)

    Shanahan ST

    2002-08-01

    Full Text Available Abstract Background Stomata respond to vapour pressure deficit (D – when D increases, stomata begin to close. Closure is the result of a decline in guard cell turgor, but the link between D and turgor is poorly understood. We describe a model for stomatal responses to increasing D based upon cellular water relations. The model also incorporates impacts of increasing levels of water stress upon stomatal responses to increasing D. Results The model successfully mimics the three phases of stomatal responses to D and also reproduces the impact of increasing plant water deficit upon stomatal responses to increasing D. As water stress developed, stomata regulated transpiration at ever decreasing values of D. Thus, stomatal sensitivity to D increased with increasing water stress. Predictions from the model concerning the impact of changes in cuticular transpiration upon stomatal responses to increasing D are shown to conform to experimental data. Sensitivity analyses of stomatal responses to various parameters of the model show that leaf thickness, the fraction of leaf volume that is air-space, and the fraction of mesophyll cell wall in contact with air have little impact upon behaviour of the model. In contrast, changes in cuticular conductance and membrane hydraulic conductivity have significant impacts upon model behaviour. Conclusion Cuticular transpiration is an important feature of stomatal responses to D and is the cause of the 3 phase response to D. Feed-forward behaviour of stomata does not explain stomatal responses to D as feedback, involving water loss from guard cells, can explain these responses.

  15. 14CO2 studies in isoproturon treated crop and weed species

    International Nuclear Information System (INIS)

    Rao, K.R.; Balakrishna Reddy, R.

    1986-01-01

    Isoproturon, a selective herbiside inhibited the photosynthetic carbon assimilation in the weeds with the progress of time. In the crop plant, however, there was a gradual recovery in the carbon assimilation due to the progressive reopening of the stomata. The 14 Co 2 fixation of in vivo and in vitro chloroplasts was also drastically inhibited in the susceptible weeds when compared to the resistant crop plants. (author). 5 refs

  16. Leaf stomatal traits variation within and among black poplar native populations in Serbia

    OpenAIRE

    Cortan, Dijana; Vilotic, Dragica; Sijacic-Nikolic, Mirjana; Miljkovic, Danijela

    2017-01-01

    Populus nigra as a keystone riparian pioneer tree species is one of the rarest and most endangered species in Europe due to the loss of its natural habitats. Genetic diversity existence is a key factor in survival of one species, and stomata as genetically controlled trait could be used for differentiation studies. With the aim of proving stomatal phenotypic variation of the four native populations of Populus nigra located on the banks of three biggest river valleys (Dunabe, Tisa and Sava) in...

  17. Sobre la presencia de estomas en la cara adaxial de las hojas en las vainas de Equisetum L. e Hippochaete Milde

    OpenAIRE

    Estrelles, Elena; Iranzo Reig, Julio; Martínez Solís, Isabel; Ibáñez, M. V.

    1995-01-01

    [ES] Se describe la morfología, disposición y posible función de los estomas presentes en la zona interna de la vaina en Equisetum e Hippochaete. Palabras clave: Equisetum, Hippochaete, vaina, estoma, adaxial, hidatodo. [EN] In this paper the morphology, arrangement and possible function of the stomata present on the adaxial face of the sheath in Equisetum and Hippochaete are described.

  18. Stomatal behavior in fruits and leaves of the purple passion fruit (Passiflora edulis Sims and fruits and cladodes of the yellow pitaya [Hylocereus megalanthus (K. Schum. ex Vaupel Ralf Bauer

    Directory of Open Access Journals (Sweden)

    Camilo Sánchez

    2013-04-01

    Full Text Available Plants as C3 and CAM react photosynthetically different but both can grow in the same agroecological zone in the tropics. Therefore we studied the behavior of stomatal opening in fruits and leaves of the purple passion fruit and fruits and cladodes of the yellow pitaya was studied under natural growing conditions in Granada and Fusagasuga, Cundinamarca (Colombia. Imprints were made on the surface of leaves, fruits and cladodes using cosmetic enamel impressions. Three cycles were carried out, each cycle took 72 hours, obtaining three different samples every 3 hours; then the impressions were observed by microscope and the opened and closed stomata were counted in each species. In each sampling, data of solar radiation, temperature and relative humidity (RH were measured. The purple passion fruit had the typical behavior of a C3 plant in the leaves as well as the fruits, and a positive correlation between the stomatal aperture and radiation and temperature was found, along with a negative correlation between stomatal aperture and RH. The pitaya showed the typical behavior of a CAM plant with a negative correlation between the stomatal opening and radiation and temperature, as well as a positive correlation between stomatal opening and RH. Radiation, temperature and RH affected the stomatal opening in the fruits and cladodes. Stomatal densities differed greatly between the species and plant organs. In the purple passion fruit, 106.53 stomata per mm² leaf surface were found, but only 12.64 stomata per mm² fruit surface; whereas in the pitaya, 11.28 and 1.43 stomata per mm² were found on the cladodes and fruits, respectively

  19. BIOMONITORING OF URBAN AREA BY ANATOMICAL LEAF CHANGES

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    Elena IRIZA

    2012-01-01

    Full Text Available Plants play a vital role as indicators of pollution. The automobile emissions are high particularly at the traffic intersections. Plants growing under the stress of air pollution show differences in leaf surface characteristics. Light microscopic studies of leaf surface revealed an increase in the number of stomata and trichomes of polluted populations in comparison to control populations of Plantago major and Plantago lanceolata. These changes can be considered as indicators of environmental stress.

  20. Coronatine Facilitates Pseudomonas syringae Infection of Arabidopsis Leaves at Night

    Science.gov (United States)

    Panchal, Shweta; Roy, Debanjana; Chitrakar, Reejana; Price, Lenore; Breitbach, Zachary S.; Armstrong, Daniel W.; Melotto, Maeli

    2016-01-01

    In many land plants, the stomatal pore opens during the day and closes during the night. Thus, periods of darkness could be effective in decreasing pathogen penetration into leaves through stomata, the primary sites for infection by many pathogens. Pseudomonas syringae pv. tomato (Pst) DC3000 produces coronatine (COR) and opens stomata, raising an intriguing question as to whether this is a virulence strategy to facilitate bacterial infection at night. In fact, we found that (a) biological concentration of COR is effective in opening dark-closed stomata of Arabidopsis thaliana leaves, (b) the COR defective mutant Pst DC3118 is less effective in infecting Arabidopsis in the dark than under light and this difference in infection is reduced with the wild type bacterium Pst DC3000, and (c) cma, a COR biosynthesis gene, is induced only when the bacterium is in contact with the leaf surface independent of the light conditions. These findings suggest that Pst DC3000 activates virulence factors at the pre-invasive phase of its life cycle to infect plants even when environmental conditions (such as darkness) favor stomatal immunity. This functional attribute of COR may provide epidemiological advantages for COR-producing bacteria on the leaf surface. PMID:27446113

  1. Improving respiration measurements with gas exchange analyzers.

    Science.gov (United States)

    Montero, R; Ribas-Carbó, M; Del Saz, N F; El Aou-Ouad, H; Berry, J A; Flexas, J; Bota, J

    2016-12-01

    Dark respiration measurements with open-flow gas exchange analyzers are often questioned for their low accuracy as their low values often reach the precision limit of the instrument. Respiration was measured in five species, two hypostomatous (Vitis Vinifera L. and Acanthus mollis) and three amphistomatous, one with similar amount of stomata in both sides (Eucalyptus citriodora) and two with different stomata density (Brassica oleracea and Vicia faba). CO 2 differential (ΔCO 2 ) increased two-fold with no change in apparent R d , when the two leaves with higher stomatal density faced outside. These results showed a clear effect of the position of stomata on ΔCO 2 . Therefore, it can be concluded that leaf position is important to guarantee the improvement of respiration measurements increasing ΔCO 2 without affecting the respiration results by leaf or mass units. This method will help to increase the accuracy of leaf respiration measurements using gas exchange analyzers. Copyright © 2016 Elsevier GmbH. All rights reserved.

  2. Ethylene limits abscisic acid- or soil drying-induced stomatal closure in aged wheat leaves.

    Science.gov (United States)

    Chen, Lin; Dodd, Ian C; Davies, William J; Wilkinson, Sally

    2013-10-01

    The mechanism of age-induced decreased stomatal sensitivity to abscisic acid (ABA) and soil drying has been explored here. Older, fully expanded leaves partly lost their ability to close stomata in response to foliar ABA sprays, and soil drying which stimulated endogenous ABA production, while young fully expanded leaves closed their stomata more fully. However, ABA- or soil drying-induced stomatal closure of older leaves was partly restored by pretreating plants with 1-methylcyclopropene (1-MCP), which can antagonize ethylene receptors, or by inoculating soil around the roots with the rhizobacterium Variovorax paradoxus 5C-2, which contains 1-aminocyclopropane-1-carboxylic acid (ACC)-deaminase. ACC (the immediate biosynthetic precursor of ethylene) sprays revealed higher sensitivity of stomata to ethylene in older leaves than younger leaves, despite no differences in endogenous ACC concentrations or ethylene emission. Taken together, these results indicate that the relative insensitivity of stomatal closure to ABA and soil drying in older leaves is likely due to altered stomatal sensitivity to ethylene, rather than ethylene production. To our knowledge, this is the first study to mechanistically explain diminished stomatal responses to soil moisture deficit in older leaves, and the associated reduction in leaf water-use efficiency. © 2013 John Wiley & Sons Ltd.

  3. PATH-ANALYSIS ON SEVERAL CHARACTERS IN POTENTIAL OF CORN PRODUCTION AND RESISTANCE TO DOWNY MILDEW

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    Eko Hary Pudjiwati

    2013-06-01

    Full Text Available This research was aimed at investigating both direct and indirect impacts, and heritability values of characters regarding the potential of corn production and resistance to downy mildew. The result of this investigation is required to determine some criteria taken into account for selection process of downy mildew-resistant corn breeding with high yield. The field experiment was conducted at Research Centre of Agriculture Faculty, Brawijaya University from January to April 2012. Five varieties of hybrid crown and five inbreeding lines were employed, and Randomised Block Design was applied with two replications. As observed, the characters held heritability ranging from average to high, except for heritability of length and width of stomata on the lower surface of the leaves which was categorised as low. Moreover, the stomata density found on lower surface of the leaves was directly and positively correlated to the intensity of attack by downy mildew, which, then, was used as criteria selection in downy mildew-resistance. The intensity of disease and the density of the stomata on lower surface of the leaves accounted for direct and negative correlation to corn production, while the length and diameter of corncob was responsible for direct and positive correlation to corn production. The betterment of corn production can be coped by improving the plant resistance to downy mildew and characters of corncob diameter.

  4. The mechanism of improved aeration due to gas films on leaves of submerged rice.

    Science.gov (United States)

    Verboven, Pieter; Pedersen, Ole; Ho, Quang Tri; Nicolai, Bart M; Colmer, Timothy D

    2014-10-01

    Some terrestrial wetland plants, such as rice, have super-hydrophobic leaf surfaces which retain a gas film when submerged. O2 movement through the diffusive boundary layer (DBL) of floodwater, gas film and stomata into leaf mesophyll was explored by means of a reaction-diffusion model that was solved in a three-dimensional leaf anatomy model. The anatomy and dark respiration of leaves of rice (Oryza sativa L.) were measured and used to compute O2 fluxes and partial pressure of O2 (pO2 ) in the DBL, gas film and leaf when submerged. The effects of floodwater pO2 , DBL thickness, cuticle permeability, presence of gas film and stomatal opening were explored. Under O2 -limiting conditions of the bulk water (pO2  gas film significantly increases the O2 flux into submerged leaves regardless of whether stomata are fully or partly open. With a gas film, tissue pO2 substantially increases, even for the slightest stomatal opening, but not when stomata are completely closed. The effect of gas films increases with decreasing cuticle permeability. O2 flux and tissue pO2 decrease with increasing DBL thickness. The present modelling analysis provides a mechanistic understanding of how leaf gas films facilitate O2 entry into submerged plants. © 2014 John Wiley & Sons Ltd.

  5. The morphology and ultrastructure of the nectaries of marrow (Cucurbita pepo L. convar. giromontiina

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    Marta Dmitruk

    2013-10-01

    Full Text Available The present study investigated the size and structure of the nectaries in flowers of marrow – Cucurbita pepo convar. giromontiina cv. ‘Weiser Busch’. The diameter and thickness of nectariferous layer were compared in female and male flowers of this taxon. The micromorphology as well as the anatomical and ultrastructural characters of the nectary from the female flower were observed using light, scanning and transmission electron microscopy. The density and size of stomata of the nectary epidermis from both types of flowers were examined using light microscopy. The nectaries in female flowers were found to have a larger size than in male flowers. The stomata occurring in the nectary epidermis of both types of flowers have a similar size and density. We observed that nectar was released onto the surface of the nectary not only via the stomata, but also through the walls of the epidermal cells. In TEM examination, large nuclei, different-shaped plastids, ER tubules, dictyosomes, and ribosomes were observed in the nectariferous tissue cells. A large number of mitochondria accompanying the plastids were found in the parenchyma cells of the nectary. The degradation of the nectary parenchyma cells in the flowers living for about 6 hours was asynchronous.

  6. Anatomy of leaf and stem of Erythrina velutina

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    Márcia M. B. da Silva

    2013-04-01

    Full Text Available Erythrina velutina Willd., Fabaceae, known as "mulungu", is a tree of tropical regions, as northeastern Brazil. Its bark is used in folk medicine as tranquilizer, sedative and insomnia. This study aimed to characterize the stem and leaf anatomy and to provide subsidies to quality control of the plant drug due to its wide use in folk medicine as well as its differentiation from other species with the same popular name. Samples were collected at Cuité, in Paraíba State, Brazil, fixed in FAA50, semipermanent slides were made, following usual procedures in plant anatomy. The stem shows a cylindrical contour, covered by a uniseriate epidermis covered by a thickened cuticle. It shows claviform glandular and branched trichomes with uniseriate stalk. Secretory cavities are into the phloem. The leaf epidermis has branched and glandular trichomes and anisocytic and paracytic stomata, on both sides, with predominance of branched trichomes and stomata on abaxial surface. Secretory cavities in stem and leaf, types of trichomes and stomata, its location and distribution constitute diagnostic characters for this specie. The structural characterization of the stem and leaf allows its distinction from other ones of this genus, ensuring safety for commercial pharmacological uses, allowing certification of the authenticity of raw material.

  7. Anatomy of leaf and stem of Erythrina velutina

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    Márcia M. B. da Silva

    2013-02-01

    Full Text Available Erythrina velutina Willd., Fabaceae, known as "mulungu", is a tree of tropical regions, as northeastern Brazil. Its bark is used in folk medicine as tranquilizer, sedative and insomnia. This study aimed to characterize the stem and leaf anatomy and to provide subsidies to quality control of the plant drug due to its wide use in folk medicine as well as its differentiation from other species with the same popular name. Samples were collected at Cuité, in Paraíba State, Brazil, fixed in FAA50, semipermanent slides were made, following usual procedures in plant anatomy. The stem shows a cylindrical contour, covered by a uniseriate epidermis covered by a thickened cuticle. It shows claviform glandular and branched trichomes with uniseriate stalk. Secretory cavities are into the phloem. The leaf epidermis has branched and glandular trichomes and anisocytic and paracytic stomata, on both sides, with predominance of branched trichomes and stomata on abaxial surface. Secretory cavities in stem and leaf, types of trichomes and stomata, its location and distribution constitute diagnostic characters for this specie. The structural characterization of the stem and leaf allows its distinction from other ones of this genus, ensuring safety for commercial pharmacological uses, allowing certification of the authenticity of raw material.

  8. Coronatine Facilitates Pseudomonas syringae Infection of Arabidopsis Leaves at Night.

    Science.gov (United States)

    Panchal, Shweta; Roy, Debanjana; Chitrakar, Reejana; Price, Lenore; Breitbach, Zachary S; Armstrong, Daniel W; Melotto, Maeli

    2016-01-01

    In many land plants, the stomatal pore opens during the day and closes during the night. Thus, periods of darkness could be effective in decreasing pathogen penetration into leaves through stomata, the primary sites for infection by many pathogens. Pseudomonas syringae pv. tomato (Pst) DC3000 produces coronatine (COR) and opens stomata, raising an intriguing question as to whether this is a virulence strategy to facilitate bacterial infection at night. In fact, we found that (a) biological concentration of COR is effective in opening dark-closed stomata of Arabidopsis thaliana leaves, (b) the COR defective mutant Pst DC3118 is less effective in infecting Arabidopsis in the dark than under light and this difference in infection is reduced with the wild type bacterium Pst DC3000, and (c) cma, a COR biosynthesis gene, is induced only when the bacterium is in contact with the leaf surface independent of the light conditions. These findings suggest that Pst DC3000 activates virulence factors at the pre-invasive phase of its life cycle to infect plants even when environmental conditions (such as darkness) favor stomatal immunity. This functional attribute of COR may provide epidemiological advantages for COR-producing bacteria on the leaf surface.

  9. Removal of trimethylamine (fishy odor) by C₃ and CAM plants.

    Science.gov (United States)

    Boraphech, Phattara; Thiravetyan, Paitip

    2015-08-01

    From screening 23 plant species, it was found that Pterocarpus indicus (C3) and Sansevieria trifasciata (crassulacean acid metabolism (CAM)) were the most effective in polar gaseous trimethylamine (TMA) uptake, reaching up to 90% uptake of initial TMA (100 ppm) within 8 h, and could remove TMA at cycles 1-4 without affecting photosystem II (PSII) photochemistry. Up to 55 and 45% of TMA was taken up by S. trifasciata stomata and leaf epicuticular wax, respectively. During cycles 1-4, interestingly, S. trifasciata changed its stomata apertures, which was directly induced by gaseous TMA and light treatments. In contrast, for P. indicus the leaf epicuticular wax and stem were the major pathways of TMA removal, followed by stomata; these pathways accounted for 46, 46, and 8%, respectively, of TMA removal percentages. Fatty acids, particularly tetradecanoic (C14) acid and octadecanoic (C18) acid, were found to be the main cuticular wax components in both plants, and were associated with TMA removal ability. Moreover, the plants could degrade TMA via multiple metabolic pathways associated with carbon/nitrogen interactions. In CAM plants, one of the crucial pathways enabled 78% of TMA to be transformed directly to dimethylamine (DMA) and methylamine (MA), which differed from C3 plant pathways. Various metabolites were also produced for further detoxification and mineralization so that TMA was completely degraded by plants.

  10. Conifer species adapt to low-rainfall climates by following one of two divergent pathways.

    Science.gov (United States)

    Brodribb, Timothy J; McAdam, Scott A M; Jordan, Gregory J; Martins, Samuel C V

    2014-10-07

    Water stress is one of the primary selective forces in plant evolution. There are characters often cited as adaptations to water stress, but links between the function of these traits and adaptation to drying climates are tenuous. Here we combine distributional, climatic, and physiological evidence from 42 species of conifers to show that the evolution of drought resistance follows two distinct pathways, both involving the coordinated evolution of tissues regulating water supply (xylem) and water loss (stomatal pores) in leaves. Only species with very efficient stomatal closure, and hence low minimum rates of water loss, inhabit dry habitats, but species diverged in their apparent mechanism for maintaining closed stomata during drought. An ancestral mechanism found in Pinaceae and Araucariaceae species relies on high levels of the hormone abscisic acid (ABA) to close stomata during water stress. A second mechanism, found in the majority of Cupressaceae species, uses leaf desiccation rather than high ABA levels to close stomata during sustained water stress. Species in the latter group were characterized by xylem tissues with extreme resistance to embolism but low levels of foliar ABA after 30 d without water. The combination of low levels of ABA under stress with cavitation-resistant xylem enables these species to prolong stomatal opening during drought, potentially extending their photosynthetic activity between rainfall events. Our data demonstrate a surprising simplicity in the way conifers evolved to cope with water shortage, indicating a critical interaction between xylem and stomatal tissues during the process of evolution to dry climates.

  11. Systematic significance of leaf epidermal features in holcoglossum (orchidaceae).

    Science.gov (United States)

    Fan, Jie; He, Runli; Zhang, Yinbo; Jin, Xiaohua

    2014-01-01

    Determining the generic delimitations within Aeridinae has been a significant issue in the taxonomy of Orchidaceae, and Holcoglossum is a typical case. We investigated the phylogenetic utility of the morphological traits of leaf epidermis in the taxonomy of Holcoglossum s.l. by using light and scanning electron microscopy to analyze 38 samples representing 12 species of Holcoglossum, with five species from five closely related genera, such as Ascocentrum, Luisia, Papilionanthe, Rhynchostylis and Vanda. Our results indicated that Holcoglossum can be distinguished from the related genera based on cuticular wax characteristics, and the inclusion of Holcoglossum himalaicum in Holcoglossum is supported by the epidermis characteristics found by LM and SEM. The percentage of the tetracytic, brachyparacytic, and laterocytic stomata types as well as the stomata index and certain combinations of special wax types support infrageneric clades and phylogenetic relationships that have been inferred from molecular data. Laterocytic and polarcytic stomata are perhaps ecological adaptations to the strong winds and ample rains in the alpine region of the Hengduanshan Mountains.

  12. Systematic significance of leaf epidermal features in holcoglossum (orchidaceae.

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    Jie Fan

    Full Text Available Determining the generic delimitations within Aeridinae has been a significant issue in the taxonomy of Orchidaceae, and Holcoglossum is a typical case. We investigated the phylogenetic utility of the morphological traits of leaf epidermis in the taxonomy of Holcoglossum s.l. by using light and scanning electron microscopy to analyze 38 samples representing 12 species of Holcoglossum, with five species from five closely related genera, such as Ascocentrum, Luisia, Papilionanthe, Rhynchostylis and Vanda. Our results indicated that Holcoglossum can be distinguished from the related genera based on cuticular wax characteristics, and the inclusion of Holcoglossum himalaicum in Holcoglossum is supported by the epidermis characteristics found by LM and SEM. The percentage of the tetracytic, brachyparacytic, and laterocytic stomata types as well as the stomata index and certain combinations of special wax types support infrageneric clades and phylogenetic relationships that have been inferred from molecular data. Laterocytic and polarcytic stomata are perhaps ecological adaptations to the strong winds and ample rains in the alpine region of the Hengduanshan Mountains.

  13. The effect of tetraploidy induction on morphology and anatomy characteristics of Cannabis sativa L.

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    Hakimeh Mansouri

    2014-12-01

    Full Text Available The production of tetraploid plant was studied in Cannabis sativa L. with colchicine at three different concentrations (i.e., 0.0, 0.1 and 0.2% for about 24 and 48 h through dropping method. Flow cytometry analyses were used to confirm the ploidy level. Morphologic and anatomic characteristics between tetraploid and diploid control plants were compared. The results showed that 0.2% colchicine for 24 h had the best effect. The percentage of tetraploid plants and the survival rate were lowered by increasing the treatment time. In addition, the leaf index and height of tetraploid plants exhibited a significant decrease compared to the diploid plants. The size of leaves' epidermis stomata were larger in tetraploid plant compared to the diploid ones, in spite of their less density of stomata. However, the amount of total chlorophyll and carotenoids were almost the same in both of tetraploid and diploid plants. In addition, some differences were also observed in the cross section of stem of these plants from the descriptive structure point of view. On the whole, the results introduced usage of the stomata parameters as an effective and convenient method for detecting the tetraploid plants however, the flow cytometry analysis was more effective in assessing the ploidy percentage.

  14. Characterization and Molecular Interpretation of the Photosynthetic Traits of Lonicera confusa in Karst Environment

    Science.gov (United States)

    Gan, Lu; Fu, Chunhua; Zhang, Libin; Yu, Longjiang; Li, Maoteng

    2014-01-01

    Lonicera confusa was a medical plant which could adapt to the Ca-rich environment in the karst area of China. The photosynthesis, relative chlorophyll content,differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) of L. confusa that cultivated in calcareous and sandstone soils were investigated. The results showed that the relative chlorophyll content and net photosynthesis rate of L. confusa in calcareous soil are much higher than that planted in sandstone soil, the higher content of calcium might play a role in keeping the chloroplast from harm and showed higher photosynthesis rate. The transpiration and stomata conductance were decreased in calcareous soil, which might result from the closure of stomata. The GeneFishing and proteomic results showed that the expression of DEGs and DEPs were critical for photosynthesis and stomata closure, such as RuBisCO, photosynthetic electron transfer c and malate dehydrogenase varied in the leaves of L. confusa that cultivated in different soils. These DEGs or DEPs were further found to be directly or indirectly regulated by calcium sensor proteins. This study enriched our knowledge of the molecular mechanism of high net photosynthesis rate and lower transpiration of L. confusa that cultivated in the calcareous soil in some degree. PMID:24959829

  15. Acclimatization and leaf anatomy of micropropagated fig plantlets

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    Chrystiane Fráguas Chirinéa

    2012-12-01

    Full Text Available The survival of micropropagated plants during and after acclimatization is a limiting process to plant establishment. There is little information on how the anatomy of vegetative organs of Ficus carica can be affected by culture conditions and acclimatization. The present research aimed to study the effects of time on culture medium and substrates during the acclimatization of fig tree plantlets produced in vitro, characterizing some leaf anatomy aspects of plantlets cultured in vitro and of fig trees produced in field. Plantlets previously multiplied in vitro were separated and transferred into Wood Plant Medium (WPM where they were kept for 0, 15, 30, 45 and 60 days. Different substrates were tested and studies on leaf anatomy were performed in order to compare among plantlets grown in vitro, plantlets under 20, 40 and 60 days of acclimatization, and field grown plants. Keeping plantlets for 30 days in WPM allowed better development in Plantmax during acclimatization. Field grown plants presented higher number of stomata, greater epicuticular wax thickness and greater leaf tissue production compared to in vitro ones. The leaf tissues of in vitro plantlets show little differentiation and have great stomata number compared with acclimatized plants, which reduce the number of stomata during the acclimatization process.

  16. Integrating transient heterogeneity of non-photochemical quenching in shade-grown heterobaric leaves of avocado (Persea americana L.): responses to CO2 concentration, stomatal occlusion, dehydration and relative humidity.

    Science.gov (United States)

    Takayama, Kotaro; King, Diana; Robinson, Sharon A; Osmond, Barry

    2013-11-01

    Long-lived shade leaves of avocado had extremely low rates of photosynthesis. Gas exchange measurements of photosynthesis were of limited use, so we resorted to Chl fluorescence imaging (CFI) and spot measurements to evaluate photosynthetic electron transport rates (ETRs) and non-photochemical quenching (NPQ). Imaging revealed a remarkable transient heterogeneity of NPQ during photosynthetic induction in these hypostomatous, heterobaric leaves, but was adequately integrated by spot measurements, despite long-lasting artifacts from repeated saturating flashes during assays. Major veins (mid-vein, first- and second-order veins) defined areas of more static large-scale heterogeneous NPQ, with more dynamic small-scale heterogeneity most strongly expressed in mesophyll cells between third- and fourth-order veins. Both responded to external CO2 concentration ([CO2]), occlusion of stomata with Vaseline™, leaf dehydration and relative humidity (RH). We interpreted these responses in terms of independent behavior of stomata in adjacent areoles that was largely expressed through CO2-limited photosynthesis. Heterogeneity was most pronounced and prolonged in the absence of net CO2 fixation in 100 p.p.m. [CO2] when respiratory and photorespiratory CO2 cycling constrained the inferred ETR to ~75% of values in 400 or 700 p.p.m. [CO2]. Likewise, sustained higher NPQ under Vaseline™, after dehydration or at low RH, also restricted ETR to ~75% of control values. Low NPQ in chloroplast-containing cells adjacent to major veins but remote from stomata suggested internal sources of high [CO2] in these tissues.

  17. An ancestral stomatal patterning module revealed in the non-vascular land plant Physcomitrella patens

    Science.gov (United States)

    Chater, Caspar C.; Kamisugi, Yasuko

    2016-01-01

    The patterning of stomata plays a vital role in plant development and has emerged as a paradigm for the role of peptide signals in the spatial control of cellular differentiation. Research in Arabidopsis has identified a series of epidermal patterning factors (EPFs), which interact with an array of membrane-localised receptors and associated proteins (encoded by ERECTA and TMM genes) to control stomatal density and distribution. However, although it is well-established that stomata arose very early in the evolution of land plants, until now it has been unclear whether the established angiosperm stomatal patterning system represented by the EPF/TMM/ERECTA module reflects a conserved, universal mechanism in the plant kingdom. Here, we use molecular genetics to show that the moss Physcomitrella patens has conserved homologues of angiosperm EPF, TMM and at least one ERECTA gene that function together to permit the correct patterning of stomata and that, moreover, elements of the module retain function when transferred to Arabidopsis. Our data characterise the stomatal patterning system in an evolutionarily distinct branch of plants and support the hypothesis that the EPF/TMM/ERECTA module represents an ancient patterning system. PMID:27407102

  18. Immunity at Cauliflower Hydathodes Controls Systemic Infection by Xanthomonas campestris pv campestris.

    Science.gov (United States)

    Cerutti, Aude; Jauneau, Alain; Auriac, Marie-Christine; Lauber, Emmanuelle; Martinez, Yves; Chiarenza, Serge; Leonhardt, Nathalie; Berthomé, Richard; Noël, Laurent D

    2017-06-01

    Hydathodes are water pores found on leaves of a wide range of vascular plants and are the sites of guttation. We report here on the detailed anatomy of cauliflower ( Brassica oleracea ) and Arabidopsis ( Arabidopsis thaliana ) hydathodes. Hydathode surface presents pores resembling stomata giving access to large cavities. Beneath, the epithem is composed of a lacunar and highly vascularized parenchyma offering a direct connection between leaf surface and xylem vessels. Arabidopsis hydathode pores were responsive to ABA and light similar to stomata. The flg22 flagellin peptide, a well-characterized elicitor of plant basal immunity, did not induce closure of hydathode pores in contrast to stomata. Because hydathodes are natural infection routes for several pathogens, we investigated hydathode infection by the adapted vascular phytopathogenic bacterium Xanthomonas campestris pv campestris ( Xcc ), the causal agent of black rot disease of Brassicaceae. Microscopic observations of hydathodes six days postinoculation indicated a digestion of the epithem cells and a high bacterial multiplication. Postinvasive immunity was shown to limit pathogen growth in the epithem and is actively suppressed by the type III secretion system and its effector proteins. Altogether, these results give a detailed anatomic description of Brassicaceae hydathodes and highlight the efficient use of this tissue as an initial niche for subsequent vascular systemic dissemination of Xcc in distant plant tissues. © 2017 American Society of Plant Biologists. All Rights Reserved.

  19. Immunity at Cauliflower Hydathodes Controls Systemic Infection by Xanthomonas campestris pv campestris1

    Science.gov (United States)

    Cerutti, Aude; Jauneau, Alain; Auriac, Marie-Christine; Lauber, Emmanuelle; Martinez, Yves; Chiarenza, Serge

    2017-01-01

    Hydathodes are water pores found on leaves of a wide range of vascular plants and are the sites of guttation. We report here on the detailed anatomy of cauliflower (Brassica oleracea) and Arabidopsis (Arabidopsis thaliana) hydathodes. Hydathode surface presents pores resembling stomata giving access to large cavities. Beneath, the epithem is composed of a lacunar and highly vascularized parenchyma offering a direct connection between leaf surface and xylem vessels. Arabidopsis hydathode pores were responsive to ABA and light similar to stomata. The flg22 flagellin peptide, a well-characterized elicitor of plant basal immunity, did not induce closure of hydathode pores in contrast to stomata. Because hydathodes are natural infection routes for several pathogens, we investigated hydathode infection by the adapted vascular phytopathogenic bacterium Xanthomonas campestris pv campestris (Xcc), the causal agent of black rot disease of Brassicaceae. Microscopic observations of hydathodes six days postinoculation indicated a digestion of the epithem cells and a high bacterial multiplication. Postinvasive immunity was shown to limit pathogen growth in the epithem and is actively suppressed by the type III secretion system and its effector proteins. Altogether, these results give a detailed anatomic description of Brassicaceae hydathodes and highlight the efficient use of this tissue as an initial niche for subsequent vascular systemic dissemination of Xcc in distant plant tissues. PMID:28184011

  20. Optimal allocation of leaf epidermal area for gas exchange.

    Science.gov (United States)

    de Boer, Hugo J; Price, Charles A; Wagner-Cremer, Friederike; Dekker, Stefan C; Franks, Peter J; Veneklaas, Erik J

    2016-06-01

    A long-standing research focus in phytology has been to understand how plants allocate leaf epidermal space to stomata in order to achieve an economic balance between the plant's carbon needs and water use. Here, we present a quantitative theoretical framework to predict allometric relationships between morphological stomatal traits in relation to leaf gas exchange and the required allocation of epidermal area to stomata. Our theoretical framework was derived from first principles of diffusion and geometry based on the hypothesis that selection for higher anatomical maximum stomatal conductance (gsmax ) involves a trade-off to minimize the fraction of the epidermis that is allocated to stomata. Predicted allometric relationships between stomatal traits were tested with a comprehensive compilation of published and unpublished data on 1057 species from all major clades. In support of our theoretical framework, stomatal traits of this phylogenetically diverse sample reflect spatially optimal allometry that minimizes investment in the allocation of epidermal area when plants evolve towards higher gsmax . Our results specifically highlight that the stomatal morphology of angiosperms evolved along spatially optimal allometric relationships. We propose that the resulting wide range of viable stomatal trait combinations equips angiosperms with developmental and evolutionary flexibility in leaf gas exchange unrivalled by gymnosperms and pteridophytes. © 2016 The Authors New Phytologist © 2016 New Phytologist Trust.

  1. Effect of Salinity Stress and Foliar Application of Methyl Jasmonate on Photosynthetic Rate, Stomatal Conductance, Water Use Efficiency and Yield of German Chamomile

    Directory of Open Access Journals (Sweden)

    fatemeh Salimi

    2014-09-01

    Full Text Available Jasmonate is new plant growth regulator that plays an essential role at increasing plants resistance to the environmental stresses like salinity stress. Hence, in this research the effect of foliar application of methyl jasmonate on some physiological indices and yield of German chamomile under salinity conditions was studied. A factorial experiment was laid out based on randomized complete block design (RCBD with three replications in the greenhouse condition. Foliar application of methyl jasmonate was five levels (MJ1; 0, MJ2; 75, MJ3; 150, MJ4; 225 and MJ5; 300 μM and salinity stress was four levels (S1; 2, S2; 6, S3; 10, S4; 14 dS m-1. The effect of methyl jasmonate, salinity condition treatments and their interaction was significant for traits of photosynthesis rate, stomata conductance, transpiration rate, carboxylation efficiency, intercellular CO2 concentration and yield of flower. The highest values of photosynthetic rate, stomata conductance, transpiration rate, carboxylation efficiency and yield of flower (3.76 g pot-1 and the lowest intercellular CO2 concentration were achieved at MJ×S treatment. Maximum value of photosynthetic water use efficiency was revealed at MJ5×S2 treatment. With decreasing stomata conductance, photosynthetic water use efficiency and intercellular CO2 concentration were increased. In general, it seems that application of methyl jasmonate by lower dose (MJ2 under salinity conditions especially mild salinity stress (S2 can improve physiological indices and yield of chamomile.

  2. Effects of Foliar Application of Nano Zinc Chelate and Zinc Sulfate on Zinc Content, Pigments and Photosynthetic Indices of Holy Basil (Ocimum sanctum(

    Directory of Open Access Journals (Sweden)

    Zohreh Moghimi pour

    2017-02-01

    Full Text Available Introduction: Holy basil is a perennial plant belongs to Lamiaceae family. The plant is a perennial and thrives well in the hot and humid climate. Its aerial parts have been in use for food, pharmaceuticals, cosmetics and perfumery industries. Leaves contain 0.5-1.5% essential oil and main oil components are eugenol, methyl eugenol, carvacrol, methyl chavicol and1,8-cineole. A balanced fertilization program with macro and micronutrients is very important in producing high quality yield. Zinc is involved in IAA production, chlorophyll biosynthesis, carbon assimilation, saccharids accumulation, reactive oxygen radicals scavenging and finally carbon utilization in volatile oil biosynthesis. Material and methods: In order to evaluate the effect on zinc foliar application on zinc content of leaves, photosynthetic indices and pigments of holy basil, an experiment was carried out in 2013 at a research farm of Horticultural Science, Shahid Chamran University (31°20'N latitude and 48°40'E longitude and 22.5 m mean sea level, Ahvaz (Iran, a region characterized by semi-dry climate. The experiment was arranged based on Randomized Complete Block Design (RCBD with six treatments and three replications. The treatments were nano zinc chelate (0, 0.5, 1 and 1.5 g.l-1 and zinc sulfate (1 and 1.5 g.l-1 fertilizers. Land preparation includes disking and the formation of raising beds (15cm high and 45cm wide across the top using a press-pan-type bed shaper. Holy basil seeds were sown on two rows on each bed, with 15 cm in-row and 40 cm between-row spacing. The plants were irrigated weekly as needed. Foliar application of zinc fertilizers was done at six-eight leaf stage and were repeated with interval 15 days until full bloom stage. Zinc content, stomata conductance (gs, CO2 under stomata (Ci, transpiration rate (E, net photosynthesis (Pn, light use efficiency (LUE, water use efficiency (WUE and also chlorophyll a, chlorophyll b, chlorophyll a+b and carotenoid

  3. Observations of leaf stomatal conductance at the canopy scale: an atmospheric modeling perspective

    International Nuclear Information System (INIS)

    Avissar, R.

    1993-01-01

    Plant stomata play a key role in the redistribution of energy received on vegetated land into sensible and latent heat. As a result, they have a considerable impact on the atmospheric planetary boundary layer, the hydrologic cycle, the climate, and the weather. Current parameterizations of the stomatal mechanism in state-of-the-art atmospheric models are based on empirical relations that are established at the leaf scale between stomatal conductance and environmental conditions. In order to evaluate these parameterizations, an experiment was carried out on a potato field in New Jersey during the summer of 1989. Stomatal conductances were measured within a small homogeneous area in the middle of the potato field and under a relatively broad range of atmospheric conditions. A large variability of stomatal conductances was observed. This variability, which was associated with the variability of micro-environmental and physiological conditions that is found even in a homogeneous canopy, cannot be simulated explicitly on the scale of a single agricultural field and,a fortiori, on the scale of atmospheric models. Furthermore, this variability could not be related to the environmental conditions measured at a height of 2 m above the plant canopy simultaneously with the conductances, reinforcing the concept of scale decoupling suggested by Jarvis and McNaughton (1986) and McNaughton and Jarvis (1991). Thus, for atmospheric modeling purposes, a parameterization of stomatal conductance at the canopy scale using external environmental forcing conditions seems more appropriate than a parameterization based on leaf-scale stomatal conductance, as currently adopted in state-of-the-art atmospheric models. The measured variability was characterized by a lognormal probability density function (pdf) that remained relatively stable during the entire measuring period. These observations support conclusions by McNaughton and Jarvis (1991) that, unlike current parameterizations, a

  4. Leaf, stem bark and fruit anatomy of zanthoxylum armatum dc. (rutaceae)

    International Nuclear Information System (INIS)

    Barkatullah, A.; Ibrar, M.; Jelani, G.; Ahmad, I.

    2014-01-01

    Zanthoxylum armatum DC. (Rutaceae) is an important medicinal plant. The present study deals with anatomical exploration of the leaf, stem bark and fruit of this plant. Leaf of Z. armatum is bifacial, compound and punctate with glabrous surfaces having a single layer of epidermis and palisade mesophyll. The leaf has a Palisade ratio ranged from 6.00 to 9.00 (8.2 +- 0.32). Vein islets and vein termination number were 14-21 (16.8 +- 0.64) and 17-21 (19.1 +- 0.43) per mm2 respectively. The vein-islets were quite distinct with squaresh, elongated, polygonal or irregular in shape bounding many forked and unforked vascular branches. Adaxial surface of Z. armatum leaf midrib was planoconvex while the abaxial surface was semicircular in appearance. The diagnostic feature of the leaf was the complete absence of any kind of trichomes or any other appendages. The leaf showed prominent oil cavities. Nine types of stomata with different frequencies and other dimensions were observed. Brachparatetracytic stomata was the most frequent stoma (80%) followed by actinostephanocytic (40%) and then straucytic and brachyparacytic (30%) each. Hemiparacytic and stomatal cluster were the rarely occurring stomata (10% each) present on the lower epidermis of the leaf. Stomatal cluster, which is considered to be a special leaf epidermal feature and reported only in few genera of vascular plants, was also recorded in this plant. Bark and fruit anatomy of Z. armatum showed different tissue arrangement. The seed was non endospermic and contains an elongated embryo. The present study will be helpful in the phylogeny and taxonomic description of this important medicinal plant. (author)

  5. Observations of leaf stomatal conductance at the canopy scale: an atmospheric modeling perspective

    International Nuclear Information System (INIS)

    Avissar, R.

    1993-01-01

    Plant stomata play a key role in the redistribution of energy received on vegetated land into sensible and latent heat. As a result, they have a considerable impact on the atmospheric planetary boundary layer, the hydrologic cycle, the climate, and the weather. Current parameterizations of the stomatal mechanism in state-of-the-art atmospheric models are based on empirical relations that are established at the leaf scale between stomatal conductance and environmental conditions. In order to evaluate these parameterizations, an experiment was carried out on a potato field in New Jersey during the summer of 1989. Stomatal conductances were measured within a small homogeneous area in the middle of the potato field and under a relatively broad range of atmospheric conditions. A large variability of stomatal conductances was observed. This variability, which was associated with the variability of micro-environmental and physiological conditions that is found even in a homogeneous canopy, cannot be simulated explicitly on the scale of a single agricultural field and, a fortiori, on the scale of atmospheric models. Furthermore, this variability could not be related to the environmental conditions measured at a height of 2 m above the plant canopy simultaneously with the conductances, reinforcing the concept of scale decoupling suggested by Jarvis and McNaughton (1986) and McNaughton and Jarvis (1991). Thus, for atmospheric modeling purposes, a parameterization of stomatal conductance at the canopy scale using external environmental forcing conditions seems more appropriate than a parameterization based on leaf-scale stomatal conductance, as currently adopted in state-of-the-art atmospheric models. The measured variability was characterized by a lognormal probability density function (pdf) that remained relatively stable during the entire measuring period. These observations support conclusions by McNaughton and Jarvis (1991) that, unlike current parameterizations, a

  6. Ozone and Water Stress: Effects on the Behaviour of Two White Clover Biotypes

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    Massimo Fagnano

    Full Text Available ozone pollution, water stress, stomata conductance, ozone uptake, clover, OTC.Ozone is a strong oxidizing pollutant which derives by alteration of the photolytic NOx cycle and it accumulates in the troposphere spreading in rural areas and therefore determining injuries on natural vegetation and crops. Since its penetration occurs mainly through stomata, all factors which alter plant-atmosphere relations could be able to modify plant response to ozone. Interaction between ozone and water stress in Mediterranean environment was studied on ozone resistant and sensitive biotypes of white clover, which were grown in charcoal filtered and notfiltered Open Top Chambers in factorial combination with different levels of water supply. Measurements of biomass, leaf area and stomatal conductance were made during the growth period. Ozone injuries were estimated as not-filtered/filtered OTC yield ratio; the stomatal flux of ozone was estimated multiplying stomata conductance x diffusivity ratio between ozone and water vapour (0.613 x ozone hourly concentrations. The hourly values of ozone uptake were cumulated throughout the cropping periods of the two years. In the sensitive biotype, water stress reduced yield losses due to ozone from 38% to 22%, as well as yield losses due to water stress were reduced by the presence of ozone from 43% to 29%, while no interaction between ozone and water stress was observed in the resistant biotype. Biomass yield losses of the sensitive biotype were strictly correlated to cumulated ozone uptake (R2 = 0.99, while biomass yield losses of the resistant biotype were not affected by the ozone fluxes variations created by the treatments. Flux based models could better estimate yield losses due to ozone in Mediterranean environments in which other stresses could be contemporary present; therefore, the new European directives might replace the actual thresholds based

  7. Natural variation in stomatal response to closing stimuli among Arabidopsis thaliana accessions after exposure to low VPD as a tool to recognize the mechanism of disturbed stomatal functioning.

    Science.gov (United States)

    Aliniaeifard, Sasan; van Meeteren, Uulke

    2014-12-01

    Stomatal responses to closing stimuli are disturbed after long-term exposure of plants to low vapour pressure deficit (VPD). The mechanism behind this disturbance is not fully understood. Genetic variation between naturally occurring ecotypes can be helpful to elucidate the mechanism controlling stomatal movements in different environments. We characterized the stomatal responses of 41 natural accessions of Arabidopsis thaliana to closing stimuli (ABA and desiccation) after they had been exposed for 4 days to moderate VPD (1.17 kPa) or low VPD (0.23 kPa). A fast screening system was used to test stomatal response to ABA using chlorophyll fluorescence imaging under low O2 concentrations of leaf discs floating on ABA solutions. In all accessions stomatal conductance (gs) was increased after prior exposure to low VPD. After exposure to low VPD, stomata of 39 out of 41 of the accessions showed a diminished ABA closing response; only stomata of low VPD-exposed Map-42 and C24 were as responsive to ABA as moderate VPD-exposed plants. In response to desiccation, most of the accessions showed a normal stomata closing response following low VPD exposure. Only low VPD-exposed Cvi-0 and Rrs-7 showed significantly less stomatal closure compared with moderate VPD-exposed plants. Using principle component analysis (PCA), accessions could be categorized to very sensitive, moderately sensitive, and less sensitive to closing stimuli. In conclusion, we present evidence for different stomatal responses to closing stimuli after long-term exposure to low VPD across Arabidopsis accessions. The variation can be a useful tool for finding the mechanism of stomatal malfunctioning. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  8. Ferns are less dependent on passive dilution by cell expansion to coordinate leaf vein and stomatal spacing than angiosperms.

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    Madeline R Carins Murphy

    Full Text Available Producing leaves with closely spaced veins is a key innovation linked to high rates of photosynthesis in angiosperms. A close geometric link between veins and stomata in angiosperms ensures that investment in enhanced venous water transport provides the strongest net carbon return to the plant. This link is underpinned by "passive dilution" via expansion of surrounding cells. However, it is not known whether this 'passive dilution' mechanism is present in plant lineages other than angiosperms and is another key feature of the angiosperms' evolutionary success. Consequently, we sought to determine whether the 'passive dilution' mechanism is; (i exclusive to the angiosperms, (ii a conserved mechanism that evolved in the common ancestor of ferns and angiosperms, or (iii has evolved continuously over time. To do this we first we assessed the plasticity of vein and stomatal density and epidermal cell size in ferns in response to light environment. We then compared the relationships between these traits found among ferns with modelled relationships that assume vein and stomatal density respond passively to epidermal cell expansion, and with those previously observed in angiosperms. Vein density, stomatal density and epidermal cell size were linked in ferns with remarkably similar relationships to those observed in angiosperms, except that fern leaves had fewer veins per stomata. However, plasticity was limited in ferns and stomatal spacing was dependent on active stomatal differentiation as well as passive cell expansion. Thus, ferns (like angiosperms appear to coordinate vein and stomatal density with epidermal cell expansion to some extent to maintain a constant ratio between veins and stomata in the leaf. The different general relationships between vein density and stomatal density in ferns and angiosperms suggests the groups have different optimum balances between the production of vein tissue dedicated to water supply and stomatal tissue for gas

  9. Simultaneous requirement of carbon dioxide and abscisic acid for stomatal closing in Xanthium strumarium L.

    Science.gov (United States)

    Raschke, K

    1975-01-01

    Open stomata of detached leaves of Xanthium strumarium L. closed only when carbon dioxide and abscisic acid (ABA) were presented simultaneously. Three parameters of stomatal closing were determined after additions of ABA to the irrigation water of detached leaves, while the leaves were exposed to various CO2 concentrations ([CO2]s) in the air; a) the delay between addition of ABA and a reduction of stomatal conductance by 5%, b) the velocity of stomatal closing, and c) the new conductance. Changes in all three parameters showed that stomatal responses to ABA were enhanced by CO2; this effect followed saturation kinetics. Half saturation occurred at an estimated [CO2] in the stomatal pore of 200 μl l(-1). With respect to ABA, stomata responded in normal air with half their maximal amplitude at [ABA]s between 10(-6) and 10(-5) M(+-)-ABA. The amounts of ABA taken up by the leaves during the delay increased with a power strumarium.Based on earlier findings and on the results of this investigation it is suggested that stomata close if the cytoplasm of the guard cells contains much malate and H(+). The acid content in turn is determined by the relative rates of production of malic acid (from endogenous as well as exogenous CO2) and its removal (by transport of the anion into the vacuole and exchange of the H(+) for K(+) with the environment of the guard cells). The simultaneous requirement of CO2 and ABA for stomatal closure leads to the inference that ABA inhibits the expulsion of H(+) from guard cells.

  10. Induction of mutations in citrus for the development of resistance to Xanthomonas citri (Hasse) Dowson

    International Nuclear Information System (INIS)

    Zubrzycki, H.M.; Diamante de Zubrzycki, A.

    1982-01-01

    With the aim of obtaining resistance to Xanthomonas citri in citrus, mutagenic treatment was carried out with X-rays and gamma rays on buds and seedlings. As a prerequisite, attempts were made to determine some physiological and structural differences in leaves in order to evaluate and analyse the reaction to the bacterium in qualitative and quantitative terms. Citrus were found to present 3-4 annual sproutings, each having a different intensity. Grapefruit showed a greater initial increase and final length than orange, but lemon growth was greater than all the others. According to their growth, leaves clustered in three groups. Those in the middle part of the sprout showed the greatest daily increase, followed in decreasing order by those of the base and those of the apex. In orange cultivars with different degrees of reaction to Xanthomonas citri a direct association between daily growth of leaves and susceptibility was found. In fully developed leaves the number of stomata per surface unit presented an inverse ratio with susceptibility. It was observed that in a given genotype the stomata frequency per surface unit was higher in young leaves than in developed ones. Also a direct association between the leaf area and the number of stomata per leaf was found. Natural field infections were measured in leaves of developed plants. Infection in each of the 3-4 annual sproutings depends on environmental factors during the growth period and the predisposition period of the leaves. The available variation for reaction to Xanthomonas citri was higher in oranges than in grapefruit. The abscission of each leaf depends on its degree of infection, but the cultivars classed as more resistant are those requiring a smaller affected area to provoke the leaf abscission. However, abscission of a leaf is independent of the fate of the neighbouring ones. The existence of a continuous grading of infection damage within the orange cultivars suggests a genetic component for resistance

  11. Chemical and morphological characteristics of key tree species of the Carpathian Mountains

    International Nuclear Information System (INIS)

    Mankovska, Blanka; Godzik, Barbara; Badea, Ovidiu; Shparyk, Yuri; Moravcik, Pavel

    2004-01-01

    Concentrations of Al, B, Ca, Cu, Fe, K, Mg, Mn, N, Na, P, S and Zn in the foliage of white fir (Abies alba), Norway spruce (Picea abies) and common beech (Fagus sylvatica) from 25 sites of the Carpathian Mts. forests (Czech Republic, Poland, Romania, Slovakia and Ukraine) are discussed in a context of their limit values. S/N ratio was different from optimum in 90% of localities when compared with the European limit values. Likewise we found increase of Fe and Cu concentrations compared with their background levels in 100% of locations. Mn concentrations were increased in 76% of localities. Mn mobilization values indicate the disturbance of physiological balance leading to the change of the ratio with Fe. SEM-investigation of foliage waxes from 25 sites in the Carpathian Mts. showed, that there is a statistically significant difference in mean wax quality. Epistomatal waxes were damaged as indicated by increased development of net and amorphous waxes. The most damaged stomata in spruce needles were from Yablunitsa, Synevir and Brenna; in fir needles from Stoliky, and in beech leaves from Mala Fatra, Morske Oko and Beregomet. Spruce needles in the Carpathian Mts. had more damaged stomata than fir needles and beech leaves. Spruce seems to be the most sensitive tree species to environmental stresses including air pollution in forests of the Carpathian Mountains. Foliage surfaces of three forest tree species contained Al, Si, Ca, Fe, Mg, K, Cl, Mn, Na, Ni and Ti in all studied localities. Presence of nutrition elements (Ca, Fe, Mg, K and Mn) on foliage surface hinders opening and closing stomata and it is not physiologically usable for tree species. - Chemical composition of foliage and structure of epicuticular waxes indicated phytotoxic effects of air pollution in many forest sites of the Carpathian Mountains

  12. A banana NAC transcription factor (MusaSNAC1) impart drought tolerance by modulating stomatal closure and H2O2 content.

    Science.gov (United States)

    Negi, Sanjana; Tak, Himanshu; Ganapathi, T R

    2018-03-01

    MusaSNAC1 function in H 2 O 2 mediated stomatal closure and promote drought tolerance by directly binding to CGT[A/G] motif in regulatory region of multiple stress-related genes. Drought is a abiotic stress-condition, causing reduced plant growth and diminished crop yield. Guard cells of the stomata control photosynthesis and transpiration by regulating CO 2 exchange and water loss, thus affecting growth and crop yield. Roles of NAC (NAM, ATAF1/2 and CUC2) protein in regulation of stress-conditions has been well documented however, their control over stomatal aperture is largely unknown. In this study we report a banana NAC protein, MusaSNAC1 which induced stomatal closure by elevating H 2 O 2 content in guard cells during drought stress. Overexpression of MusaSNAC1 in banana resulted in higher number of stomata closure causing reduced water loss and thus elevated drought-tolerance. During drought, expression of GUS (β-glucuronidase) under P MusaSNAC1 was remarkably elevated in guard cells of stomata which correlated with its function as a transcription factor regulating stomatal aperture closing. MusaSNAC1 is a transcriptional activator belonging to SNAC subgroup and its 5'-upstream region contain multiple Dof1 elements as well as stress-associated cis-elements. Moreover, MusaSNAC1 also regulate multiple stress-related genes by binding to core site of NAC-proteins CGT[A/G] in their 5'-upstream region. Results indicated an interesting mechanism of drought tolerance through stomatal closure by H 2 O 2 generation in guard cells, regulated by a NAC-protein in banana.

  13. Micromorphology of the floral nectary of red horse chestnut (Aesculus ×carnea Hayne

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    Elżbieta Weryszko-Chmielewska

    2014-04-01

    Full Text Available In Europe Aesculus ×carnea Hayne is planted in cities as an avenue tree. Compared to A. hippocastanum L., it is more drought resistant, but less resistant to low temperatures. A. ×carnea is a lower tree than A. hippocastanum and develops a smaller corolla. It produces dark green, shiny and crinkled leaves. Its flowers have different colours, from bright pink to carmine red. The nectary glands secrete nectar abundantly. Due to the long corolla tube, nectar is difficult to reach for bees. The aim of this study was to investigate the topography and micromorphology of the nectaries of A. ×carnea using scanning electron microscopy. The study shows that the nectary gland of red horse chestnut forms an incomplete ring around the base of the staminal filaments, surrounding only four stamens out of the seven that occur in the flower. Three stamens are outside the nectary. In its widest place, the nectary diameter reaches 2.7 mm. Three expanded portions of the gland can bee seen in the marginal part of the nectary, adjoining the petals. The part of the nectary adjacent to the filaments forms a convex protrusion with a wavy appearance (shape, which results from the vicinity of the filaments. Nectar is secreted through numerous stomata located beneath the convex part of the nectary. The stoma length is 21.7 μm, while the width 23.3 μm. In the material examined, most stomata had open pores. Secretion was observed in many places. The stomata were surrounded by 6-7 guard cells; this allows them to be classified as the cyclocytic type. The cells of the stomatal complex were raised above the surface of the other epidermal cells. The walls of the guard cells and of the adjacent epidermal cells were covered by a cuticle with irregular striation.

  14. Agronomical and Botanical Characteristics of Cuminum setifolium (Boiss. Kos.-Pol. a Plant with Potentially Medicinal Applications

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    Abbas SAFARNEJAD

    2011-03-01

    Full Text Available Medicinal plants are the most important source of medicine. Cuminum setifolium ( Boiss. Kos.-Pol. with common name of white cumin, a member of the Apiaceae family, growing wild on mountains was investigated as a species having capability for cultivation and crop breeding. Generally, there is not information about Cuminum setifolium species. The aim of this study was to found plant identification and distribution in Iran, phenology, best treatment for seeds germination, farm cultivation and anatomical description. Cuminum setifolium plant is a annual herb which is distributed in Iran, Turkmenistan, Afghanistan, Pakistan, Tien-Shan and central Asia. In our studied region, the plant is generally grown on calcareous marl soils with climatic conditions of desert cold, semi-arid to arid having hot summer and cold winter. The effects of different treatment on seed germination showed significant highest germination percentage (54.4%, germination rate (6.4% were obtained from seeds that had exposed for 3 weeks at 4�C after omit of seeds hairs. The experiment of cultivation showed the best time for sowing in Mashhad was autumn and growing time was from middle of March until end of June and ripening seeds were end of June at 2005. Microscopic observation of the root structure showed lacking secondary structures and having epidermis tissue with only a row of cells along with relatively thick cuticle and for stem and leaf structure with stomata without any hairs. Parenchyma cells contained 2-3 rows of irregular oblong cells. Stomata type of epidermis was diacytic and distance between stomata was measured 5 ?m in average.

  15. Micromorphology of glandular structures in Echium vulgare L. flowers

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    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available The micromorphology of selected elements of Echium vulgare L. flowers was investigated, with special attention to the structure of the nectaries and the stigma of the pistil as well as types of trichomes occurring on the surface of the calyx. The nectary had the shape of an uneven disc located around the lower region of the four-parted ovary of the pistil. The glandular cells formed a tier with a height of 330 μm and a radial width of 144 μm. Nectar was secreted onto the nectary surface through anomocytic stomata located at the level of other epidermal cells. Most of the stomata were open, with a different dimension of the pore. Their largest number was observed at the base of the nectary, and 462 stomata were noted on the whole surface of the nectary. The cuticle on the surface of the guard cells formed fine, circular striae. The subsidiary cells formed striated cuticular ornamentation, with the striae arranged radially in the direction of the stoma, whereas on the surface of other epidermal cells the striae formed an arrangement with different directions. The epidermis on the surface of the stigma formed regularly arranged papillae with a fan-shaped, expanded upper part which had corrugated outer walls, whereas the base of the cell formed a widened small column. The epidermis of the abaxial part of the calyx was covered by numerous non-glandular trichomes of different length which were made up of one or several cells. The glandular trichomes in the epidermis of the calyx grew with smaller density compared to the protective trichomes, and they were composed of a 1-2-celled stalk and a glandular head.

  16. Flowering biology and nectary structure of Melissa officinalis L.

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    Mirosława Chwil

    2012-12-01

    Full Text Available The present study on lemon balm (Melissa officinalis L. covered flowering biology, monitoring of pollinating insects and floral nectary structure. The micromorphology of epidermal cells of the nectary was investigated using scanning electron microscopy. The nectariferous tissues were observed using light microscopy based on semi-thin sections. Lemon balm flowered from the second decade of June until September. Buds opened from early morning hours until noon. Flowers lived for 24 hours, on the average. Their primary pollinator was the honey bee. The beginning of nectar secretion was found to be at the bud swell stage. The automorphic nectary forms a disc with four protrusions at the base of the nectary. Three smaller ones and one larger than the other ones were distinguished among them. No stomata were found on the lower protuberances, whereas on the highest part anomocytic stomata were present, the number of which was 15. The stomata exhibited different development stages and they were situated above other epidermal cells. In their outline, they were ellipsoidally shaped (18 × 23 µm and they had average-sized cuticular ledges. They produced a smooth cuticle and wax granules. In cross section, the nectary tissues were composed of a singlelayered epidermis and 9 - 11 layers of the nectary parenchyma. Their thickness was 198 µm. In longitudinal section, the height of the nectary was within a range of 354 - 404 µm. The epidermal cells produced thin outer cell walls. Some of them were completely filled with strongly stained cytoplasm, whereas others showed a high degree of vacuolisation. But the nectary parenchyma cells were marked by poorly stained cytoplasm, a large nucleus and vacuolisation of varying degree.

  17. Five-Year Impacts of Swiss Needle Cast on Douglas-fir in Interior Forests of Oregon, USA

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    FILIP, Gregory

    2007-01-01

    Full Text Available In 2001 and 2006, we examined 590 Douglas-firs in 59 stands age 10-23 years in the northern Cascade Mountain foothills in Oregon, USA. Mean 5-year-dbh growth was 6.1 cm and total-height growth was 3.6 m. Mean needle-retention index increased by 3.4 over 5 years, and mid-crown retention increased by 1.2 years. Mean percentages of stomata occluded by pseudothecia of Phaeocryptopus gaeumannii were 13.6% for 2000-(2-year-old needles and 1.7% for 2001-(1-year-old needles sampled in 2002, and 13.3% for 2004 (2-year-old needles sampled in 2006. Mean crown-length to sapwood-area ratio was 5.2 cm/cm2 in 2006. There were poor correlations (R2 <0.3 among all variables except for a moderate correlation between stand elevation and either 2000-stomata occluded (R2 = 0.43 or 2004-stomata occluded (R2 = 0.50, where there were fewer pseudothecia at the higher elevations. Either 5 years is not enough time to evaluate the affects of Swiss needle cast on Douglas-fir growth in the Oregon Cascades or there was no significant effect of Swiss needle cast during the latest outbreak on Douglas-fir growth. Based on our results and their interpretation, forest managers may need not alter their current practices in the northern Oregon Cascades, and managing a mix of Douglas-fir and western hemlock at lower elevations and noble fir at higher elevations will help offset any future stand-growth declines due to Swiss needle cast.

  18. Capability of Several Plant Species in Absorbing Gas Pollutant (NO2)

    International Nuclear Information System (INIS)

    Astra Dwi Patra; Nizar Nasrullah; EIsje L Sisworo

    2004-01-01

    Increasing pollutant from vehicles, especially NO 2 , could cause environmental quality degradation. NO 2 is disastrous for human health due to its capability to trigger long diseases. Due to this, it is important to reduce this pollutant, which could be done among others by plants. The objectives of this experiment was to find plants which have the highest capacity to absorb NO 2 and factors affecting this such as, stomata density, chlorophyll, leave thickness, leave specific density, light and dark condition. The plants exposure to NO 2 used 15 N - labelled NO 2 ( 15 NO 2 ). Twelve plant species were exposed to 15 NO 2 at a rate of 3 ppm in a gas chamber for 60 minutes. The environmental conditions in the chamber were controlled at 30 o C, 1000 lux light intensity, and 60% initial relative humidity. The total nitrogen of each plant part was analysed using the Kjeldahl method, while the 15 N content of these parts was done by emission spectrometer (YASCO - N 151). The results of this experiment showed that all the plants used in this experiment has the capacity in absorbing the pollutant gas at dark as well as light conditions. The evident showed that stomata density, leave thickness, and leave specific density affect the absorbing capacity of the pollutant gas. The higher the stomata density, the thinner the leaves, and the lower the leave specific density, the higher the capacity of plants to absorb NO 2 . It is recommended to use these 12 plants as an element of roadside green belt in towns. (author)

  19. Ultraestructura de bambúes del género Dendrocalamus (Poaceae: Bambusoideae cultivados en Costa Rica IV: Dendrocalamus asper, clones Taiwán y Tailandia

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    Mayra Montiel

    2006-06-01

    Full Text Available El análisis ultraestructural de los clones taiwanés y tailandés de Dendrocalamus asper, realizado al microscopio electrónico de barrido, mostró que el clon de Taiwán tiene estomas de bajo domo en la lámina foliar, mientras que el de Tailandia tiene estomas de alto domo; las acumulaciones de cera cuticular en el clon de Taiwán son de dos formas (cuatro en el de Tailandia. La distribución de los tejidos vasculares es igual en ambos, así como los tejidos que los rodean. Sería difícil identificar estos clones por la observación macroscópica o microscópica de las brácteas del culmo, pues no presentan diferencias significativas: una identificación fiable requiere considerar la ultraestructura de los estomas y las acumulaciones de cera cuticular.An ultraestructural analysis of the Taiwan and Thailand clones of Dendrocalamus asper made with the scanning electron microscope showed that the Taiwan clone had low dome stomata while the Thailand clone has high dome stomata in the leaf lamina. Cuticular wax accumulations in the Taiwan clone has two shapes, against four in the Thailand clone. Both have the same distribution of vascular and surrounding tissues. Macroscopic or microscopic observation of culm bracts are not recommended to differentiate these clones: a reliable identification requires observation of the ultrastructure of stomata and cuticular wax accumulations. Rev. Biol. Trop. 54(Suppl. 2: 65-75. Epub 2006 Dec. 01.

  20. The effect of gamma ray on growth and anatomy structure of garlic leaf (A. sativum L.)

    International Nuclear Information System (INIS)

    Sumiyarsih, S.; Aliudin

    1990-01-01

    This experiment was conducted in Experimental Garden Banaran, East Java. This experiment used Complete Randomized Design with 10 replications and 7 treatments as followed: garlic seeds were radiated by gamma Co 60, with dosage 0, 2, 4, 6, 8, 10, and 12 krad. The result of this experiment showed that radiated treatment of gamma Co 60 ray decreased growth percentage, plants became dwarf, root growth was short, and dosage 10 and 12 krad resulted in rotten root. Also radiation of gamma Co 60 decreased number of stomata and diameter of trachea became smaller

  1. Uprooting an abscisic acid paradigm: Shoots are the primary source.

    Science.gov (United States)

    McAdam, Scott A M; Manzi, Matías; Ross, John J; Brodribb, Timothy J; Gómez-Cadenas, Aurelio

    2016-06-02

    In the past, a conventional wisdom has been that abscisic acid (ABA) is a xylem-transported hormone that is synthesized in the roots, while acting in the shoot to close stomata in response to a decrease in plant water status. Now, however, evidence from two studies, which we have conducted independently, challenges this root-sourced ABA paradigm. We show that foliage-derived ABA has a major influence over root development and that leaves are the predominant location for ABA biosynthesis during drought stress.

  2. Herbicide-induced changes in 14CO2 uptake of leaves of some crop and weed species

    International Nuclear Information System (INIS)

    Santakumari, M.; Rama Das, V.S.

    1980-01-01

    The effect of diuron or atrazine on the rate of photosynthetic 14 CO 2 uptake of two each crop (Pisum Sativum and Pennisetum typhoides) and weed species (Amaranthus viridis and Cyperus rotundus) was studied. The results indicated a marked inhibition of 14 CO 2 fixation of leaves within two hours after diuron or atrazine treatment. However the resistant plants were able to exhibit a recovery of the net photosynthetic rate subsequently while the susceptible plants failed to recover. The results suggested that even with fully open stomata and available NADPH, the normal CO 2 fixation was not restored by herbicide treated leaves. (author)

  3. Relation between Ocean SST Dipoles and Downwind Continental Croplands Assessed for Early Management Using Satellite-based Photosynthesis Models

    Science.gov (United States)

    Kaneko, Daijiro

    2015-04-01

    Crop-monitoring systems with the unit of carbon-dioxide sequestration for environmental issues related to climate adaptation to global warming have been improved using satellite-based photosynthesis and meteorological conditions. Early management of crop status is desirable for grain production, stockbreeding, and bio-energy providing that the seasonal climate forecasting is sufficiently accurate. Incorrect seasonal forecasting of crop production can damage global social activities if the recognized conditions are unsatisfied. One cause of poor forecasting related to the atmospheric dynamics at the Earth surface, which reflect the energy budget through land surface, especially the oceans and atmosphere. Recognition of the relation between SST anomalies (e.g. ENSO, Atlantic Niño, Indian dipoles, and Ningaloo Niño) and crop production, as expressed precisely by photosynthesis or the sequestrated-carbon rate, is necessary to elucidate the mechanisms related to poor production. Solar radiation, surface air temperature, and water stress all directly affect grain vegetation photosynthesis. All affect stomata opening, which is related to the water balance or definition by the ratio of the Penman potential evaporation and actual transpiration. Regarding stomata, present data and reanalysis data give overestimated values of stomata opening because they are extended from wet models in forests rather than semi-arid regions commonly associated with wheat, maize, and soybean. This study applies a complementary model based on energy conservation for semi-arid zones instead of the conventional Penman-Monteith method. Partitioning of the integrated Net PSN enables precise estimation of crop yields by modifying the semi-closed stomata opening. Partitioning predicts production more accurately using the cropland distribution already classified using satellite data. Seasonal crop forecasting should include near-real-time monitoring using satellite-based process crop models to avoid

  4. Drought responses of two bambara groundnut (Vigna subterranea L. Verdc.) landraces collected from a dry and a humid area of Africa

    DEFF Research Database (Denmark)

    Jørgensen, Søren Thorndal; Liu, Fulai; Ouédraogo, M.

    2010-01-01

    during soil drying, Uniswa Red could be defined as a 'water-saver' such that it maintains leaf water status to a great extent of soil water deficit. This strategy is important for survival during intermittent drought. While S19-3 could be defined as a 'water-spender' with a late closure of stomata, hence...... a late declining of transpiration rate during soil drying allowed the landrace to maximize its water use despite giving up its leaf water relations. Such drought response together with a fast phenological development of S19-3 indicates that the landrace is capable of escaping from terminal drought while...

  5. The effect of elevated CO2 on the vegetative and generative growth of Phalaenopsis

    OpenAIRE

    Kromwijk, J.A.M.; Meinen, E.; Dueck, T.A.

    2014-01-01

    Phalaenopsis is a crassulacean acid metabolism (CAM) plant which absorbs and binds CO2 as malate during the night. During daytime the stomata close and the CO2 stored in the vacuole is released and used for photosynthesis. Because the CO2 taken up by CAM plants was assumed to be unaffected by the CO2 concentration in the air, additional CO2 for increased growth was generally not supplied in Phalaenopsis. However, a literature study indicated that elevated CO2 might have a positive effect in P...

  6. 126 - 133_Okanume

    African Journals Online (AJOL)

    USER

    cell shape and stomata index were diagonistic characters. While micro hairs ... Other useful characters for distinguishing ... various parts of West Africa and probably the oldest ..... 2. 2.4. 2.8. 3.2. 3.6. 4. -1. -0.8. -0.6. -0.4. -0.2. 0. 0.2. 0.4. 0.6. 0.8. S im ila rity c o e ffic ie n .... Ogie-Odia , E.A., D. Eseigbe, M.N. Ilechie, J. Erhabor.

  7. Influence of the 6 Bencilaminopurina on the in vitro behavior of Henequen plants obtained by embryogenesis

    Directory of Open Access Journals (Sweden)

    Gerardo González

    2002-10-01

    Full Text Available In the acclimatization phase, a group of derived plants from henequen embryos, germinated in a medium with different concentrations of 6 BAP, was evaluated. In these results it is evidenced that the content of 6 BAP in the germination medium determined the behaviour of the vitroplants. The lower concentrations provoked an significative increase in the height and width of the base from plants, superior surviver percentage and minor stomata opening. These results suggest that high concentations of 6 BAP prevents the development of the acclimatization phase in derived plants from henequen embryos. Key words: somatic embryogenesis, 6 BAP, aclimatization. Agave

  8. Histological effects of H/sub 2/O/sub 2/ on the structure of beech leaves and spruce needles

    Energy Technology Data Exchange (ETDEWEB)

    Masuch, G; Kettrup, A; Mallant, R K.A.M.; Slanina, J

    1985-01-01

    Summarizing the results, the following three conclusions can be drawn from the histological changes caused by H/sub 2/O/sub 2/: 1. From a smaller density, thickness of the leaves and decreased tissue volumes we can conclude that the photosynthetic rate is reduced. 2. Accumulation of starch granules in the chloroplasts and tannins in the vacuoles show, that the assimilate transport does not work sufficiently. 3. Increased number of stomata, and decreased number of xylem vessels point at a water stress. It is intended, to test these conclusions by further biochemical and physiological investigations.

  9. Morphologie inframicroscopique de Vitis vinifera L., son incidence sur la répartition des levures

    Directory of Open Access Journals (Sweden)

    J.-M. Belin

    1977-12-01

    Studies with the scanning electron microscope report the inframicroscopic morphology and the aspect of waxes of the various parts of the vine : stem (trunk, rod, ripening branches, herbaceous branches, young and adult leaves (blade, petiole, grapes (grape-stalk, pedicle, berries. This work allowed to determine the propitious zones for the yeasts installation: stomata and lenticels on  the various parts of the grape; along the veins and the edges of the leaves, on the « lenticels » and shakes of the bark of the old stem parts.

  10. Anatomy and morphology character of five Indonesian banana cultivars (Musa spp. of different ploidy level

    Directory of Open Access Journals (Sweden)

    ISSIREP SUMARDI

    2010-04-01

    Full Text Available Sumardi I, Wulandari M (2011 Anatomy and morphology character of five Indonesian banana cultivars (Musa spp. of different ploidy level. Biodiversitas 12: 167-175. In Indonesia there are many cultivars of banana, and some of them produce edible fruits. Beside their morphology, the character which necessary as a tool for classification is anatomical character. The aim of this research were to describe the anatomical character and morphology of fives Indonesian banana cultivars based on their level of ploidy. The cultivars were collected from Banana Germplasm Plantation, Yogyakarta District, Indonesia. The samples of roots, rhizome, and leaf were collected from five banana cultivars i.e.: Musa acuminata cv Penjalin, M.balbisiana cv Kluthuk warangan, M.acuminata cv Ambon warangan, M.paradisiaca cv Raja nangka , and M. paradisiaca cv Kluthuk susu. For anatomy observation samples were prepared using paraffin method, stained with 1% safranin in 70% ethanol. To observe the structure of stomata and epidermis surface, slide were prepared using modification of whole mount method. Slides were observed using Olympus BHB microscope completed with Olympus camera BM-10A. Stem and leaf morphology character of diploid level (AA and BB genome is different with triploid level (AAA, AAB, and ABB genome. Anatomy and morphology character of root and rhizome of banana in diploid level (AA and BB genome and triploid level (AAA, AAB, and ABB genome is quite similar. Distribution of stomata is found in leaf and pseudostem. Stomata is found in adaxial and abaxial epidermis layer. The size of guard cells in triploid cultivars was longer than that diploid cultivars. The root composse of epidermis layer, cortex and cylinder vascular of five cultivar’s root show anomalous structure. Rhizome consist of peripheric and centre zone. Anatomically, this was no differences in the rizome structur among five banana cultivars. The row of vascular bundles act as demarcation area

  11. Micromorphology of flowers and the structure of floral nectaries in Orobanche alsatica Kirschl.

    Directory of Open Access Journals (Sweden)

    Aneta Sulborska

    2014-04-01

    Full Text Available Orobanche alsatica Kirschl. is a very rare perennial plant included in the Polish Red Data Book. The hosts of this European-West Asian parasite are representatives of the family Apiaceae, primarily from the genera Peucedanum and Seseli. The species prefers alkaline substrates and sun-exposed slopes and hills. In Poland, it occurs most frequently in xerothermic grasslands and xerothermic fringe. The morphology of O. alsatica flowers, with special emphasis on the structure of the nectaries, was studied using light microscopy and scanning electron microscopy (SEM. The analysed plants originated from the Lublin Upland. The flowers of the species are characterised by the presence of a double perianth. The sepals are richly glandular, free; the outer sepals are dark red and the inner ones are yellow-green. Fused petals (5 form a bilabiate, dirty yellow corolla with dark red secretory trichomes on the abaxial surface. The stamens (4 with long, white S-shaped filaments are attached at the base to the corolla. There are glandular and non-glandular trichomes at the basal part of the filaments. Brown, oval anthers are characterised by the presence of a beak-like apex. The upper pistil is composed of an oval ovary and an arched style with a bipartite, fleshy, yellow stigma bearing numerous papillae. The O. alsatica nectary is formed by the basal part of the ovary at the corolla tube base. The secretory gland is intensively yellow and asymmetrical – on one side of the ovary it is higher and forms different height and size 4-5 protuberances, while on the other side it is very low. Nectar is secreted through modified stomata located primarily in the central part of the nectary. Stomatal cells are surrounded by 6-8 other epidermal cells and are located below these. The stomata are very regularly (linearly arranged forming a ring across the apical part of the protuberances. The stomata function asynchronously, as evidenced by the presence of both open and

  12. Particulate air pollution, with emphasis on traffic generated aerosols

    DEFF Research Database (Denmark)

    Fauser, Patrik

    constitute each about 5 wt-% of the collected suspended particulate matter in inner city air. The particle size distribution shows that 92 % of the mass of airborne particulate tire debris have aerodynamic diameters smaller than 1 µm. The mean aerodynamic diameter is about 1 µm for the bitumen particles...... % of this concentration derives from adsorbed particles on both leaf sides. The remainder is either respired through stomata or incorporated in the epicuticular wax layer. The fact that a substantial amount of the airborne tire and bitumen particles occur in the submicron range permits long range transportation...

  13. Acid precipitation and forest vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Tamm, C O; Cowling, E B

    1977-04-01

    Effects of acidic precipitation on forest vegetation may be classified as being either direct or indirect. Among the most important direct effects are damage to protective cuticular layers, interference with normal functioning of guard cells, poisoning of plant cells after diffusion of acidic substances through stomata or cuticle and interference with reproductive processes. Indirect effects include accelerated leaching of substances from foliar organs, increased susceptibility to drought and other environmental stress factors, and alteration of symbiotic associations and host-parasite interactions. The potential importance of nutrient uptake through foliage and the need to understand atmosphere-plant-soil interactions are stressed.

  14. Stomatal responses to carbon dioxide of isolated epidermis from a C/sub 3/ plant, the Argenteum mutant of Pisum sativum L. , and a crassulacean-acid-metabolism plant Kalanchoe daigremontiana Hamet et Perr

    Energy Technology Data Exchange (ETDEWEB)

    Jewer, P.C.; Neales, T.F.; Incoll, L.D.

    1985-01-01

    The response of stomata in isolated epidermis to the concentration of CO/sub 2/ in the gaseous phase was examined in a C/sub 3/ species, the Argenteum mutant of Pisum sativum, and a crassulacean-acid-metabolism (CAM) species, Kalanchoe daigremontiana. Epidermis from leaves of both species was incubated on buffer solutions in the presence of air containing various volume fractions of CO/sub 2/ (0 to 10,000 x 10/sup -6/). In both species and in the light and in darkness, the effect of CO/sub 2/ was to inhibit stomatal opening, the maximum inhibition of opening occurring in the range 0 to 360 x 10/sup -6/. The inhibition of opening per unit change in concentration was greatest between volume fractions of 0 and 240 x 10/sup -6/. There was little further closure above the volume fraction of 360 x 10/sup -6/, i.e. approximately ambient concentration of CO/sub 2/. Thus, although leaves of CAM species may experience much higher internal concentrations of CO/sub 2/ in the light than those of C/sub 3/ plants, this does not affect the sensitivity of their stomata to CO/sub 2/ concentration or the range over which they respond. Stomatal responses to CO/sub 2/ were similar in both the light and the dark, indicating that effects of CO/sub 2/ on stomata occur via mechanisms which are independent of light. The responses of stomata to CO/sub 2/ in the gaseous phase took place without the treatments changing the pH of the buffered solutions. Thus, it is unlikely that CO/sub 2/ elicited stomatal movement by changing either the pH or the HCO/sub 3//sup -//CO/sub 3//sup 2 -/ equilibria. It is suggested that the concentration of dissolved unhydrated CO/sub 2/ may be the effector of stomatal movement and that its activity is related to its reactivity with amines.

  15. Endophytic Association of Trichoderma asperellum within Theobroma cacao Suppresses Vascular Streak Dieback Incidence and Promotes Side Graft Growth.

    Science.gov (United States)

    Rosmana, Ade; Nasaruddin, Nasaruddin; Hendarto, Hendarto; Hakkar, Andi Akbar; Agriansyah, Nursalim

    2016-09-01

    Trichoderma species are able to persist on living sapwood and leaves of cacao ( Theobroma cacao ) in an endophytic relationship. In this research, we evaluated the ability of Trichodema asperellum introduced at the incision site in the bark for side grafting with the concentration of 4 g/10 mL, 4 g/100 mL, and 4 g/1,000 mL (suspended in water) in suppressing vascular streak dieback (VSD) incidence and promoting growth of side grafts in the field. The incidence of VSD in two local clones of cacao, MCC1 and M04, without application of T. asperellum was 71.2% and 70.1% at 21 wk after grafting, respectively. However, when the two clones were treated with a concentration of 4 g/10 mL T. asperellum , the incidence was 20.6% and 21.7%, respectively, compared to 29.1% and 20.9% at 4 g/100 mL and 18.2% and 15.6% at 4 g/1,000 mL. By comparing to the control, the treatment with the same concentrations of T. asperellum listed above, the total number of stomata in MCC1 decreased by 41.9%, 30.2%, and 14.0% and in M04 by 30.5%, 21.9%, and -2.5% (exception), respectively. Otherwise, the total area of stomata opening increased by 91.4%, 99.7%, and 28.6% in MCC1 and by 203.8%, 253.5%, and 35.9% in M04, respectively. Furthermore, the number of buds and branches treated with a mixture concentration on the the two clones increased by 90.7% and 21.7%, respectively. These data showed that the application of T. asperellum to cacao scions while grafting can decrease VSD incidence in side grafts and increase growth of grafts in addition to decreasing total number of stomata, increasing total area of opened stomata, and increasing number of buds and branches.

  16. Monitoring the Short-Term Response to Salt Exposure of Two Genetically Distinct Phragmites australis Clones with Different Salinity Tolerance Levels

    DEFF Research Database (Denmark)

    Achenbach, Luciana; Brix, Hans

    2014-01-01

    work was conducted at the laboratory of the Institute of Bioscience, Aarhus University, Denmark. Methods: The light-saturated photosynthetic rate (Pmax), stomata conductance (gs) and transpiration rate (E) were measured over different periods of salt exposure (15, 70 and 240 minutes) and at different...... in the 15-minute experiment. The Greeny-type also recovered after the 70-minute exposure, but not the Land-type. We conclude that the response to osmotic stress is genotype-dependent and that the salt-tolerant clone possesses very efficient signaling pathways to detect changes in the soil water potential...

  17. Transfer of gaseous iodine to Tradescantia

    International Nuclear Information System (INIS)

    Nakamura, Yuji; Ohmomo, Yoichiro.

    1984-01-01

    Transfer rates of gaseous elemental iodine and methyliodide from atmosphere to Tradescantia were investigated in relation to supposed genetic mutation due to radioactive iodine released from nuclear facilities. The estimated transfer rate of elemental iodine to the young buds of Tradescantia, which was given as the ratio of iodine uptake rate per unit weight of the plant to the concentration of the element in the air, was approximately 7 x 10 -2 cm 3 /g.sec, about 30 to 40 times higher than that of methyliodide. The contribution of direct deposition of elemental iodine was suggested to be significant, although methyliodide was mainly absorbed by respiration through stomata of the plant. (author)

  18. Tolerance of some Potato Mutants Induced with Gamma Irradiation to Drought in Vitro

    International Nuclear Information System (INIS)

    Al-Safadi, B.; Al-Ayyoubi, Z.

    2007-01-01

    An in vitro selection program was conducted in order to improve potato (Solanum tuberosum,L.) tolerance to drought. Potato mutant plants were obtained through a previously conducted mutation breeding program on three potato cultivars (Draga, Spunta, and Diamant) aimed to improve potato tolerance to salinity and resistance to late blight disease. In order to apply selection pressure, growth media (MS based) were prepared with the addition of 1%, 2%, 3% concentrations of Poly Ethylene Glycol (PEG). As a result, three mutants were selected that were tolerant to water stress (i.e. drought tolerant), two of them were derived from the cultivar Draga and one came from Spunta. Physiological growth parameters (plant length, leaf number, branch number, roots number, leaf area, stomata number, and chlorophyll concentration content) were determined on the growing plantlets. The selected mutants were distinguished based on some characteristics which being associated with in their tolerance to drought. Such as an increases in leaf number, root number, and a decrease in stomata number. However a reduction in chlorophyll content was observed as compared with the control. This is considered a negative parameter which may result in a decrease in number and size of tubers. Thus it is important to continue selection for higher chlorophyll content. Also, these mutant lines will need further selection in the field for plants with larger tubers before they can be considered as certified lines.

  19. A fast method to detect the occurrence of nonhomogeneous distribution of stomatal aperture in heterobaric plant leaves : Experiments with Arbutus unedo L. during the diurnal course.

    Science.gov (United States)

    Beyschlag, W; Pfanz, H

    1990-01-01

    Pressure infiltration of water into a leaf via the stomatal pores can be used to quickly determine whether all stomata are open, or as recently described for several mesophytic and xerophytic species, whether there is a non-homogeneous distribution of stomatal opening (stomatal patchiness) on the leaf surface. Information about this phenomenon is important since the commonly used algorithms for calculation of leaf conductance from water vapor exchange measurements imply homogeneously open stomata, which in the occurrence of stomatal patchiness will lead to erroneous results. Infiltration experiments in a growth chamber with leaves of the Mediterranean evergreen shrub Arbutus unedo, carried out under simulated Mediterranean summer day conditions, where the species typically exhibits a strong midday stomatal closure, revealed a temporary occurrence of stomatal patchiness during the phase of stomatal closure in the late morning and during the stomatal reopening in the afternoon. Leaves were, however, found to be fully (i.e. homogeneously) infiltratable in the morning and in the evening. At midday during maximum stomatal closure, leaves were almost non-infiltratable. During the day, the infiltrated amount of water was found to be linearly correlated with porometer measurements of leaf conductance of the same leaves, carried out with the attached leaves immediately before infiltration.

  20. Maximum leaf conductance driven by CO2 effects on stomatal size and density over geologic time.

    Science.gov (United States)

    Franks, Peter J; Beerling, David J

    2009-06-23

    Stomatal pores are microscopic structures on the epidermis of leaves formed by 2 specialized guard cells that control the exchange of water vapor and CO(2) between plants and the atmosphere. Stomatal size (S) and density (D) determine maximum leaf diffusive (stomatal) conductance of CO(2) (g(c(max))) to sites of assimilation. Although large variations in D observed in the fossil record have been correlated with atmospheric CO(2), the crucial significance of similarly large variations in S has been overlooked. Here, we use physical diffusion theory to explain why large changes in S necessarily accompanied the changes in D and atmospheric CO(2) over the last 400 million years. In particular, we show that high densities of small stomata are the only way to attain the highest g(cmax) values required to counter CO(2)"starvation" at low atmospheric CO(2) concentrations. This explains cycles of increasing D and decreasing S evident in the fossil history of stomata under the CO(2) impoverished atmospheres of the Permo-Carboniferous and Cenozoic glaciations. The pattern was reversed under rising atmospheric CO(2) regimes. Selection for small S was crucial for attaining high g(cmax) under falling atmospheric CO(2) and, therefore, may represent a mechanism linking CO(2) and the increasing gas-exchange capacity of land plants over geologic time.

  1. Identification of early flowering mutants from the cut chrysanthemum variety 'Jinba' and research on the physiological characteristics

    International Nuclear Information System (INIS)

    Cai Haiyan; Wen Lizhu; Zheng Chengshu; Sun Xia; Li Yingying

    2013-01-01

    In this study, the morphological characteristics the early flower mutants induced by EMS from the cut chrysanthemum variety 'Jinba' were characterized, and ISSR-PCR was used for molecular identification of mutants. The photosynthetic characteristics, stomatal and vascular bundle cross-section for the mutants were also measured. The florescence of mutants appeared about 59 days earlier than that of controls. The plant height, leaves and flower diameter were all smaller than those of controls, but they grew well. From the PCR amplification, the differences between the mutants and the control were in the present or absent of the amplified bands. The photosynthetic characteristics, such as the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr) and intercellular CO_2 concentration were all significantly lower than the controls. The number of mutant's stomata significantly reduced, and some stomatas appeared variation. The vascular bundles including primary phloem and primary xylem displayed difference in the size and shape. All these work lays a foundation for breeding the early flowering of excellent chrysanthemum and further characterization of the early flowering genes. (authors)

  2. Morphological, Micoscopical Studies and Elemental analysis of Polygonum Chinese L. and Rhoeo discolor Hance

    International Nuclear Information System (INIS)

    Moe Moe Lwin

    2008-03-01

    In the present study, two selected medicinal plants, namely Polygonum chinense L. (Mahaga-Kyansit) and Rhoeo discolor Hance. (Mi-gwin-gamon) are collected from Dawei District. In this paper, the outstanding features of selected plants, microscopical characters and elemental analysis of these leaves are also presented.In morphological studies of Mahaga-kyansit, herbs, swollen at nodes, black-coloured patches present at central portion of leaf blade, ochreate stipules. The inflorescences are terminally corymbose. The ovary trigonous-ovoid, stigma trifixed. In microscopical studies, stomata anomocytic. The cuticle is striation on both surface. In transverse section of midrib, the vascular bundles are collateral, about 8-10 numbers in basal, one was larger than the other bundles, 2numbers in middle regions and 1 bundle in apical regions. Calcium oxalate crystals (Rosette) are present in the parenchymatous cells. In the present study, the Migwin-gamon are rosette-forming succulent herbs. The leaves are crowded, upright, the upper surface green, the lower surface rich reddish-purple. The inflorescences are axillary, boat-shaped. Flowers involucres bracts. The androecium are stamens 6, often clothed wIth moniliform hairs, anthers often with and expanded or variously modified connective. The gynaecium are carpel 3,, trilocular, stigma capitate. In the microscopical studies, the leaves are isobilateral leaf. The stomata are tetracytic type. Lower epidermis cells larger than the upper one and stoma in the lower epidermis. Crystal of tetragonal system form (Prism) present in the mesophyll cells.

  3. Biochemical and Ultrastructural Changes in Sida cordifolia L. and Catharanthus roseus L. to Auto Pollution.

    Science.gov (United States)

    Verma, Vijeta; Chandra, Neelam

    2014-01-01

    Auto pollution is the by-product of our mechanized mobility, which adversely affects both plant and human life. However, plants growing in the urban locations provide a great respite to us from the brunt of auto pollution by absorbing the pollutants at their foliar surface. Foliar surface configuration and biochemical changes in plant species, namely, Sida cordifolia L. and Catharanthus roseus L. grown at roadside (polluted site 1, Talkatora; polluted site 2, Charbagh) in Lucknow city and in the garden of the university campus, which has been taken as reference site, were investigated. It was observed that air pollution caused by auto exhaust showed marked alterations in photosynthetic pigments (chlorophyll, carotenoid, and phaeophytin), and relative water content was reduced while antioxidative enzymes like catalase and peroxidase were found to be enhanced. The changes in the foliar configuration reveal marked alteration in epidermal traits, with decreased number of stomata, stomatal indices, and epidermal cells per unit area, while length and breadth of stomata and epidermal cells were found to be increased in leaves samples wich can be used as biomarkers of auto pollution.

  4. Application of Digital (Motic and Scanning electron microscope in histological study of leaf of Tecoma gaudichaudi DC (Bignoniaceae

    Directory of Open Access Journals (Sweden)

    Kedar Kalyani Abhimanyu

    2016-03-01

    Full Text Available Tecoma gaudichaudi DC (Bignoniaceae is a shrub or a small tree found in various regions of Maharashtra. The objective of the study was to develop various standardization parameters for the evaluation of leaves of this plant. Microscopy, powder characteristics and scanning electron microscopy (SEM of leaves were observed and results were recorded. Histological study of leaves shows underlined palisade cells on the upper epidermal surface, anomocytic stomata on the lower epidermis with covering (2–3 cells and glandular trichomes etc. The specific observed characteristics such as types of stomata and trichomes were predominantly observed on the lower epidermal surface of the leaf. Physicochemical analysis such as extractive value includes petroleum ether, ethanol, ethyl acetate and aqueous soluble extractive values of 3.08, 10.50, 8.5, and 13.4% w/w respectively; extracts were analysed by chemical test and showed presence of flavonoids, tannins, steroids and triterpenoids etc. Fluorescence analysis is one of the parameters that help in the analysis of chemical constituents. So these parameters are useful in the authentication of T. gaudichaudi DC and can play a vital role in authentication and standardization of botanicals.

  5. Plant, cell, and molecular mechanisms of abscisic-acid regulation of stomatal apertures. A new mechanism for the regulation of stomatal-aperture size in intact leaves: Accumulation of mesophyll-derived sucrose in the guard-cell wall of Vicia faba L.

    Energy Technology Data Exchange (ETDEWEB)

    Lu, P.; Outlaw, W.H. Jr.; Smith, B.G.; Freed, G.A.

    1996-12-31

    At various times after pulse labeling Vicia faba L. leaflets with {sup 14}CO{sub 2}, whole-leaf pieces and rinsed epidermal peels were harvested and subsequently processed for histochemical analysis. Cells dissected from whole leaf retained apoplastic contents whereas those from rinsed peels contained only cytoplastic contents. Sucrose specific radioactivity peaked in palisade cells, 111 GBq{center_dot}mol{sup {minus}1}, at 20 min. In contrast, the {sup 14}C content and sucrose specific radioactivity were very low in guard cells for 20 min, implying little CO{sub 2} incorporation; both then peaked at 40 min. The guard-cell apoplast had a high maximum sucrose specific radioactivity and a high sucrose influx rate. These and other comparisons implied the presence of (a) multiple sucrose pools in mesophyll cells, (b) a localized mesophyll-apoplast region that exchanges with phloem and stomata, and (c) mesophyll-derived sucrose in guard-cell walls sufficient to diminish stomatal opening by {approximately} 4 {micro}m. Factors expected to enhance sucrose accumulation in guard-cell walls are (a) high transpiration rate, which closes stomata, and (b) high apoplastic sucrose concentration, which is elevated when mesophyll-sucrose efflux exceeds translocation. Therefore, multiple physiological factors are integrated in the attenuation of stomatal-aperture size by this previously unrecognized mechanism.

  6. Induksi Poliploidi Phalaenopsis amabilis (L. Blume dan Phalaenopsis amboinensis J. J. Smith dengan Kolkisin dalam Kultur In Vitro

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    Eka Martha Della Rahayu

    2016-02-01

    Full Text Available ABSTRACTPhalaenopsis amabilis (L. Blume and Phalaenopsis amboinensis J.J. Smith (diploid are important in Phalaenopsis breeding. Polyploid species are needed for crossing with polyploid hybrid varities of Phalaenopsis. The objectives of this study were to obtain effective concentration of colchicine to induce polyploidy and to produce polyploid plantlets of P. amabilis and P. amboinensis. Experiment was arranged in randomized complete block design with one factor, the colchicine concentration. Protocorms of P. amabilis and P. amboinensis were immersed in half strength of Murashige-Skoog (1/2 MS liquid media added with colchicine (0; 0.5; 5; 25; 50, and 75 mg L-1 for 10 days. The results showed that higher concentration of colchicine on both species did not have significant effect on the survival of the plantlets at 24 weeks after treatment. The average number of leaves and roots of colchicine treated planlets from both species were less than the control plantlets. Immersing protocorm in colchicine at concentration of 50 mg L-1 for 10 days was effective in inducing polyploid plantlets of P. amabilis and P. amboinensis with the frequency of 33.3% and 40%, respectively. Polyploid plantlet has larger stomata size and lower stomata density than the diploid ones.Keywords: chromosome number, colchicine, polyploid, protocorm, stomatal density, stomatal size

  7. Taxonomic significance of leaf micromorphology in some selected taxa of Acanthaceae (Peninsular Malaysia)

    Science.gov (United States)

    Nurul-Aini, C. A. C.; Noraini, T.; Latiff, A.; Amirul-Aiman, A. J.; Ruzi, A. R.; Idris, S.

    2014-09-01

    Comparative leaf micromorphology study was conducted in eight taxa of Acanthaceae from Peninsular Malaysia. Eight chosen taxa were Acanthus ebracteatus Vahl, A. ilicifolius L., A. volubilis Wall, A. montanus T. Anderson, Andrographis paniculata (Burm.f.) Wall. ex Nees, Asystasia gangetica subsp. micrantha (Nees) Ensermu, Chroesthes longifolia (Wight) B. Hansen and Peristrophe roxburghiana (Schult.) Bremek. The objective of this study was to identify the leaf micromorphological characteristics that can be used in species identification and also as supportive data in classification. The procedures involved such as dehydration, critical point drying, gold coated and examination under scanning electron microscope. Findings in this study have demonstrated the similarities and variations in leaf micromorphological characteristics such as in type of epicuticular waxes, cuticular ornamentations, stomata characteristics and in the presence of trichomes. Six types of epicuticular waxes and five types of trichomes were observed. Variations in cuticular ornamentations and stomata structure can be used to differentiate species. One diagnostic character was found and proven to be very useful to identify Acanthus via the presence of simple trichomes (short-conicle like). In conclusion, the results of this study have shown that leaf micromorphological characteristics have taxonomic significance that can be useful in classifications and identification especially at species level.

  8. Micromorphological study (ultrastructure of lamina surface, seeds, ultrasculpture of pollen grains of Gladiolus L. species (Iridaceae Juss. of Ukrainian flora

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    Zhygalova Svitlana L.

    2014-12-01

    Full Text Available Micro-morphological characteristics of the four Gladiolus L. species of the Ukrainian flora (G. imbricatus L., G. italicus Mill., G. palustris Gaudin and G. tenuis M. Bieb. as regards leaves, seeds and pollens are presented with this investigation in a detailed way. An examination of the surface structure of the leaves, seeds and pollen grains of the Gladiolus species indicates that the characteristics of the ultrastructure of leaves and of pollen grains are not diagnostic for distinguishing species, but they could be important at genus level (leaves: features such as being amphistomatic, having the same quantity of immersed stomata on both surfaces and having a high stomata index, the presence and localisation of papillae, the shape of epidermal cells; pollen grains: monosulcate type with two operculums. However, the type of surface ultrastructure of the seed coat is a diagnostic feature as at genus level so for species. It can be mentioned that propose the use of features such as the shape and position of the cicatricle, the type of cuticle, the shape and boundaries of cells of testa, and the anticlinal cell walls as diagnostic features at genera level. The shape of seeds, the presence and disposition of wing, the level of the periclinal cell walls of the seed coat and types of relief are additional diagnostic features for distinguishing of Gladiolus species.

  9. Comparative study of three Marantodes pumilum varieties by microscopy, spectroscopy and chromatography

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    Nor-Ashila Aladdin

    Full Text Available Abstract Marantodes pumilum (Blume Kuntze (synonym: Labisia pumila (Blume Fern.-Vill, Primulaceae, is well known for its traditional use as a post-partum medication among women in Malaysia. Three varieties of M. pumilum, var. alata Scheff., var. pumila and var. lanceolata (Scheff. Mez. are commonly used. Nowadays, M. pumilum powder or extracts are commercially available as herbal supplements and beverages. Authentication of the variety is an important component of product quality control. Thus, the present work was aimed to compare the three varieties using microscopic, spectroscopic and chromatographic techniques. Microscopic anatomical examination and powder microscopy were performed on fresh and dried plant materials, respectively. Fingerprint profiles of the varieties were obtained using attenuated total reflectance-Fourier transform infrared spectrophotometer, high performance thin layer chromatography and high performance liquid chromatography. The microscopic examination showed presence of anisocytic stomata, scale and capitate glandular trichome in all varieties. The type of stomata and trichomes, outline structure of stem and leaf margin, petiole and midrib, organization of vascular system, areolar venation, pattern of anticlinal walls, the distribution of secretory canals and cell inclusion as well as the measurement of selected structures could be used to distinguish and identify each variety of M. pumilum. In addition, spectroscopic and chromatographic fingerprint analyses of the three varieties exhibited distinguishable profiles based on the intensity of certain peaks or bands. The findings from this study will provide systematic identification for these varieties.

  10. Comparative morphology of leaf epidermis in eight populations of Atlas Pistachio (Pistacia atlantica Desf., Anacardiaceae).

    Science.gov (United States)

    Belhadj, Safia; Derridj, Arezki; Aigouy, Thierry; Gers, Charles; Gauquelin, Thierry; Mevy, Jean-Philippe

    2007-10-01

    A comparative analysis was undertaken to conduct a micromorphological study of Pistacia atlantica leaves by comparing different populations grown under different climatic conditions. Leaf epidermis of eight wild populations was investigated under scanning electron microscope. Micromorphological characteristics (epidermis ornament, stomata type, waxes as well as trichomes) of the adaxial and abaxial leaf surfaces were examined. The epidermis ornament varied among populations and leaf surface, the abaxial leaf surface is reticulate with a striate surface. Messaad site shows a smooth uneven surface. The adaxial leaf surface is smooth but several ornamentations can be seen. The leaflet is amphistomatic; the stomata appeared to be slightly sunken. A variety of stomatal types were recorded; actinocytic and anomocytic types are the most frequent. The indumentum consisted of glandular and nonglandular trichomes. Unicellular glandular trichomes are recorded for P. atlantica leaves in this study. Their density is higher in Oued safene site, located at the highest altitude in comparison with the other populations. The wax occurred in all the sites and its pattern varied according to the populations studied, particularly between Berriane and Messaad. The morphological variability exhibited by the eight populations of P. atlantica may be interpreted as relevant to the ecological plasticity and the physiological mechanisms involved are discussed in this report.

  11. LEAF ANATOMICAL VARIATION IN RELATION TO STRESS TOLERANCE AMONG SOME WOODY SPECIES ON THE ACCRA PLAINS OF GHANA

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    DZOMEKU BELOVED MENSAH

    2012-12-01

    Full Text Available Leaf anatomical study was conducted on some woody species on the Accra Plains of Ghana. Leaf epidermal strips and transverse sections were mounted in Canada balsam and studied. The anatomical studies revealed numerous stomata on the lower epidermis of Azadirachta indica. The anatomical studies revealed the presence of thick cuticles, double-layered palisade mesophyll in most species and the presence of epidermal hairs in some species. Ficus capensis showed the presence of cystolith in the lower epidermis whereas Zanthoxylum zanthoxyloides showed the presence of mucilage gland in the upper epidermis. Epidermal cell of Chromolaena odorata are very large with undulating cell walls. The species studied had various adaptive anatomical features. The stomatal frequency of Azadirachta indica was very high. With the exception of Chromolaena odorata the stomatal frequencies of the species were relatively high. The stomatal dimensions showed that most of the species maintained constant stomatal length during the study period except Griffonia simplicifolia that increased the stomatal width during the afternoon. Unlike Morinda lucida, Griffonia simplicifolia and Chromolaena odorata, that showed reduction in the breadth of stomata, the other species maintained constant stomatal width.

  12. Disruption of stomatal lineage signaling or transcriptional regulators has differential effects on mesophyll development, but maintains coordination of gas exchange.

    Science.gov (United States)

    Dow, Graham J; Berry, Joseph A; Bergmann, Dominique C

    2017-10-01

    Stomata are simultaneously tasked with permitting the uptake of carbon dioxide for photosynthesis while limiting water loss from the plant. This process is mainly regulated by guard cell control of the stomatal aperture, but recent advancements have highlighted the importance of several genes that control stomatal development. Using targeted genetic manipulations of the stomatal lineage and a combination of gas exchange and microscopy techniques, we show that changes in stomatal development of the epidermal layer lead to coupled changes in the underlying mesophyll tissues. This coordinated response tends to match leaf photosynthetic potential (V cmax ) with gas-exchange capacity (g smax ), and hence the uptake of carbon dioxide for water lost. We found that different genetic regulators systematically altered tissue coordination in separate ways: the transcription factor SPEECHLESS (SPCH) primarily affected leaf size and thickness, whereas peptides in the EPIDERMAL PATTERNING FACTOR (EPF) family altered cell density in the mesophyll. It was also determined that interlayer coordination required the cell-surface receptor TOO MANY MOUTHS (TMM). These results demonstrate that stomata-specific regulators can alter mesophyll properties, which provides insight into how molecular pathways can organize leaf tissues to coordinate gas exchange and suggests new strategies for improving plant water-use efficiency. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  13. Compound stress response in stomatal closure: a mathematical model of ABA and ethylene interaction in guard cells

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    Beguerisse-Dıaz Mariano

    2012-11-01

    Full Text Available Abstract Background Stomata are tiny pores in plant leaves that regulate gas and water exchange between the plant and its environment. Abscisic acid and ethylene are two well-known elicitors of stomatal closure when acting independently. However, when stomata are presented with a combination of both signals, they fail to close. Results Toshed light on this unexplained behaviour, we have collected time course measurements of stomatal aperture and hydrogen peroxide production in Arabidopsis thaliana guard cells treated with abscisic acid, ethylene, and a combination of both. Our experiments show that stomatal closure is linked to sustained high levels of hydrogen peroxide in guard cells. When treated with a combined dose of abscisic acid and ethylene, guard cells exhibit increased antioxidant activity that reduces hydrogen peroxide levels and precludes closure. We construct a simplified model of stomatal closure derived from known biochemical pathways that captures the experimentally observed behaviour. Conclusions Our experiments and modelling results suggest a distinct role for two antioxidant mechanisms during stomatal closure: a slower, delayed response activated by a single stimulus (abscisic acid ‘or’ ethylene and another more rapid ‘and’ mechanism that is only activated when both stimuli are present. Our model indicates that the presence of this rapid ‘and’ mechanism in the antioxidant response is key to explain the lack of closure under a combined stimulus.

  14. Leaf responses to drought stress in Mediterranean accessions of Solanum lycopersicum: anatomical adaptations in relation to gas exchange parameters.

    Science.gov (United States)

    Galmés, Jeroni; Ochogavía, Joan Manuel; Gago, Jorge; Roldán, Emilio José; Cifre, Josep; Conesa, Miquel Àngel

    2013-05-01

    In a previous study, important acclimation to water stress was observed in the Ramellet tomato cultivar (TR) from the Balearic Islands, related to an increase in the water-use efficiency through modifications in both stomatal (g(s)) and mesophyll conductances (g(m)). In the present work, the comparison of physiological and morphological traits between TR accessions grown with and without water stress confirmed that variability in the photosynthetic capacity was mostly explained by differences in the diffusion of CO2 through stomata and leaf mesophyll. Maximization of gm under both treatments was mainly achieved through adjustments in the mesophyll thickness and porosity and the surface area of chloroplasts exposed to intercellular airspace (S(c)). In addition, the lower g(m) /S(c) ratio for a given porosity in drought-acclimated plants suggests that the decrease in gm was due to an increased cell wall thickness. Stomatal conductance was also affected by drought-associated changes in the morphological properties of stomata, in an accession and treatment-dependent manner. The results confirm the presence of advantageous physiological traits in the response to drought stress in Mediterranean accessions of tomato, and relate them to particular changes in the leaf anatomical properties, suggesting specific adaptive processes operating at the leaf anatomical level. © 2012 Blackwell Publishing Ltd.

  15. Effect of cycocel on photosynthetic activity and essential oil of fennel (Foeniculum vulgare Mill. under drought stress

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    Fatemeh Nouri

    2014-12-01

    Full Text Available Drought stress is one of the most important and most common environmental stresses that limit plant growth. Photosynthesis is the main determinant of plant growth and its retention ability under environmental stress condition is important for preservation of growth stability. To study the effect of spraying CCC on photosynthesis activity and essential oil content on 'Foeniculum vulgare', an experiment was done in split plot design based on complete block with four replications in research field of University of Zanjan in 2011. Levels of drought stress included, control, soft stress (when 30% of available water was out of soil, severe stress (when 90% of available water was out of soil, and three concentration of CCC 0, 1500 and 3000 mg/L. The results showed that between rates foliar application on physiologic characteristics as photosynthesis rate, transpiration severity, RWC and TΔ intercellular (Ci, stomata conductivity, mesophyll conductivity and essential oil content was significant. By spraying 3000 mg/L CCC, balanced the plant position against drought stress and could reduce negative effect. Foliar application of CCC caused significant increase in photosynthesis rate, mesophyll conductivity and significant decrease stomata conductivity, transpiration severity under drought stress and could increase essential oil content under soft stress. In this study, foliar application of CCC to content 3000 mg/L had the highest effect on this characters.

  16. A molecular basis behind heterophylly in an amphibious plant, Ranunculus trichophyllus.

    Science.gov (United States)

    Kim, Juhyun; Joo, Youngsung; Kyung, Jinseul; Jeon, Myeongjune; Park, Jong Yoon; Lee, Ho Gyun; Chung, Doo Soo; Lee, Eunju; Lee, Ilha

    2018-02-01

    Ranunculus trichophyllus is an amphibious plant that produces thin and cylindrical leaves if grown under water but thick and broad leaves if grown on land. We found that such heterophylly is widely controlled by two plant hormones, abscisic acid (ABA) and ethylene, which control terrestrial and aquatic leaf development respectively. Aquatic leaves produced higher levels of ethylene but lower levels of ABA than terrestrial leaves. In aquatic leaves, their distinct traits with narrow shape, lack of stomata, and reduced vessel development were caused by EIN3-mediated overactivation of abaxial genes, RtKANADIs, and accompanying with reductions of STOMAGEN and VASCULAR-RELATED NAC-DOMAIN7 (VDN7). In contrast, in terrestrial leaves, ABI3-mediated activation of the adaxial genes, RtHD-ZIPIIIs, and STOMAGEN and VDN7 established leaf polarity, and stomata and vessel developments. Heterophylly of R.trichophyllus could be also induced by external cues such as cold and hypoxia, which is accompanied with the changes in the expression of leaf polarity genes similar to aquatic response. A closely-related land plant R. sceleratus did not show such heterophyllic responses, suggesting that the changes in the ABA/ethylene signaling and leaf polarity are one of key evolutionary steps for aquatic adaptation.

  17. Induced polyploidization in Brassica campestris L. (Brassicaceae).

    Science.gov (United States)

    Kumar, G; Dwivedi, K

    2014-01-01

    Present experimental design has been made up to obtain crop with higher ploidy level via synthetic polyploidization. Since ploidy manipulation is generally associated with the obtainment of some increased enviable traits of the crop and also provides them greater adaptability to unfavorable or harsh circumstances as compared to its diploids counterparts. Thus, herein present research autotetraploids of Brassica campestris L. have been lucratively achieved by the application of colchicine. Two methods of treatment were utilized i.e. seed treatment and seedling treatment. No polyploidy could be obtained through seed treatment while seedling treatment responded well towards polyploidy. However, the status of autotetraploidy has been confirmed by cytomorphological investigations of treated plants as against its diploids counterparts. For the purpose, morphological parameters such as increased stomata size, pollen diameter, flower size, reproductive organs whereas reduction in plant height, leaf length, leaf breadth, stomata frequency, number of flowers/inflorescence etc. were appraised. Further, cytological observations were made that had clearly revealed the doubling of genome in the autotetraploids as compared to diploids. Meanwhile, pollen fertility and size of pollen grains were evaluated as well.

  18. Distribution and mixing of a liquid bolus in pleural space.

    Science.gov (United States)

    Bodega, Francesca; Tresoldi, Claudio; Porta, Cristina; Zocchi, Luciano; Agostoni, Emilio

    2006-02-28

    Distribution and mixing time of boluses with labeled albumin in pleural space of anesthetized, supine rabbits were determined by sampling pleural liquid at different times in various intercostal spaces (ics), and in cranial and caudal mediastinum. During sampling, lung and chest wall were kept apposed by lung inflation. This was not necessary in costo-phrenic sinus. Here, 10 min after injection, lung inflation increased concentration of labeled albumin by 50%. Lung inflation probably displaces some pleural liquid cranio-caudally, increasing labeled albumin concentration caudally to injection point (6th ics), and decreasing it cranially. Boluses of 0.1-1 ml did not preferentially reach mediastinal regions, as maintained by others. Time for an approximate mixing was approximately 1 h for 0.1 ml, and approximately 30 min for 1 ml. This relatively long mixing time does not substantially affect determination of contribution of lymphatic drainage through stomata to overall removal of labeled albumin from 0.3 ml hydrothoraces lasting 3 h [Bodega, F., Agostoni, E., 2004. Contribution of lymphatic drainage through stomata to albumin removal from pleural space. Respir. Physiol. Neurobiol. 142, 251-263].

  19. Exploding a myth: the capsule dehiscence mechanism and the function of pseudostomata in Sphagnum.

    Science.gov (United States)

    Duckett, Jeffrey G; Pressel, Silvia; P'ng, Ken M Y; Renzaglia, Karen S

    2009-01-01

    The nineteenth century air-gun explanation for explosive spore discharge in Sphagnum has never been tested experimentally. Similarly, the function of the numerous stomata ubiquitous in the capsule walls has never been investigated. Both intact and pricked Sphagnum capsules, that were allowed to dry out, all dehisced over an 8-12 h period during which time the stomatal guard cells gradually collapsed and their potassium content, measured by X-ray microanalysis in a cryoscanning electron microscope, gradually increased. By contrast, guard cell potassium fell in water-stressed Arabidopsis. The pricking experiments demonstrate that the air-gun notion for explosive spore discharge in Sphagnum is inaccurate; differential shrinkage of the capsule walls causes popping off the rigid operculum. The absence of evidence for a potassium-regulating mechanism in the stomatal guard cells and their gradual collapse before spore discharge indicates that their sole role is facilitation of sporophyte desiccation that ultimately leads to capsule dehiscence. Our novel functional data on Sphagnum, when considered in relation to bryophyte phylogeny, suggest the possibility that stomata first appeared in land plants as structures that facilitated sporophyte drying out before spore discharge and only subsequently acquired their role in the regulation of gaseous exchange.

  20. Chromosomal and morphological studies of diploid and polyploid cytotypes of Stevia rebaudiana (Bertoni Bertoni (Eupatorieae, Asteraceae

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    Vanessa M. de Oliveira

    2004-01-01

    Full Text Available In this study, we examined the chromosome number and some morphological features of strains of Stevia rebaudiana. The chromosomes were analyzed during mitosis and diakinesis, and the tetrad normality and pollen viability were also assessed. In addition, stomata and pollen were measured and some plant features were studied morphometrically. All of the strains had 2n = 22, except for two, which had 2n = 33 and 2n = 44. Pairing at diakinesis was n = 11II for all of the diploid strains, whereas the triploid and tetraploid strains had n = 11III and n = 11IV, respectively. Triploid and tetraploid plants had a lower tetrad normality rate than the diploids. All of the strains had inviable pollen. Thus, the higher the ploidy number, the greater the size of the pollen and the stomata, and the lower their number per unit area. The triploid strain produced the shortest plants and the lowest number of inflorescences, whereas the tetraploid strain had the largest leaves. Analysis of variance revealed highly significant differences among the strains, with a positive correlation between the level of ploidy and all of the morphological features examined.

  1. Lenticels as indicators of atmospheric smoke pollution

    Energy Technology Data Exchange (ETDEWEB)

    Pesek, F.

    1960-01-01

    The invasion of smoke pollution gets from the atmosphere into the plants only by lenticels and stomata. The most toxic smoke constituents penetrating into the stele are SO/sub 2/, H/sub 2/SiF/sub 6/, H/sub 3/AsO/sub 4/, HCl and C/sub 6/H/sub 5/OH. Lenticels are bark stomata filled with merenchym tissue, which hinders the entrance of mechanical smoke particles into the interior tissues of the stele. In autumn, the lenticels are packed by cork slabs formed by the cork cambium. In spring, this cork slab is broken by a new mechanical tissue. Sambucus nigra L. has a merenchym sensitive to the presence of smoke pollution, and the lenticels may serve, therefore, as indicators of smoke pollution in the atmosphere. The intensity of damage caused by smoke constituents penetrating into the plants through lenticels depends upon a series of exterior and interior factors. They are the number of lenticels per area unit of bark surface in the whole circumference, the pH of the biocomplex near the lenticel in the interior tissues of stele, and the concentration of smoke pollution in the atmosphere. The most effective way of preventing smoke damage is to install pollution control equipment in the industrial works.

  2. Determination and analysis of uptake of gaseous hydrogen peroxide by red spruce seedlings, determined by CSTR-type chamber experiments

    International Nuclear Information System (INIS)

    Claiborn, C.S.; Aneja, V.P.; Carbonell, R.G.

    1991-01-01

    In order to better understand the pathways for damage, the fate of gaseous hydrogen peroxide in red spruce needles was examined. The uptake of gaseous hydrogen peroxide by red spruce trees was determined from controlled exposure chamber experiments in which the chamber behaved as a Continuous Stirred Tank Reactor (CSTR). The results from these experiments were analyzed using a detailed transport model developed from fundamental principles, in order to determine the fate of hydrogen peroxide in the needles and characterize the exposure. The chamber was specially designed to accommodate highly reactive gases. All inner surfaces were Teflon-coated to minimize wall losses. Fluxes of hydrogen peroxide, carbon dioxide, and water vapor were determined. Both daytime and nighttime conditions were examined. Although other investigators have reported that the flux of other, less water-soluble pollutants to red spruce decreases at night when the stomata closes, the hydrogen peroxide flux did not exhibit this behavior. The results of these studies suggest that, at the concentrations observed in the atmosphere, hydrogen peroxide does not reach the inner, mesophyll tissues, but is lost in water condensing in the cuticular wax residing in the stomatal antechamber, above the stomata. The implications of the condensation in the stomatal antechamber and subsequent reactions occurring in this water for forest damage are discussed

  3. Polyploid response of Artemisia annua L. to colchicine treatment

    Science.gov (United States)

    Yunus, A.; Parjanto; Samanhudi; Hikam, M. P.; Widyastuti, Y.

    2018-03-01

    Artemisia (Artemisia annua) is a a medicinal herb originated from Asia, its contains Artemisinin for malaria (caused by Plasmodium falciparum) treatment. Artemisinin content in A. annua are relatively low, ranging from 0.01% -0.5%. In order to increase the Artemisinin content, polyploid induction could be one effort to be done. For that, this experiment aims to examine the effect of colchicine on morphological characteristics and the induction of polyploidization in Artemisia plants. Polyploid induction on Artemisia annua L. seeds was performed by soaking the Artemisia seeds in colchicine (0%, 0,05%, 0,1% and 0,2%; concentration based) for 2 hours. The experimental design was Completely Randomized Design, one factor, 4 colchicine treatments and in each treatment 7 replicate. The results showed that polyploid occur in plants treated with 0.05% colchicine concentration and its morphological characteristic are 89.4 cm height, 30 branches, 15.9 CCI chlorophyll content, 0.78 cm stem diameter, and chromosome number 2n = 27. In the stomata density of polyploid plants (treated by 0.05% colchicine) was 130 number/mm2 with stomata diameter of 22.8 μm.

  4. Foliar spray of sodium antagonistic essential mineral elements- a technique to induce salt tolerance in plants growing under saline environment (abstract)

    International Nuclear Information System (INIS)

    Ahmad, R.; Jabeen, R.

    2005-01-01

    Plants growing at saline substrate practice deficiencies in absorption of some essential mineral elements through roots due to presence of excessive sodium in rhizosphere. Sodium being antagonistic to other cations does not let them enter in roots and hence apart from its own toxicity in metabolism, the plants suffer with deficiencies of some mineral elements, which are necessary for growth. Potassium being essential mineral element is much effected due to this antagonistic behavior of sodium ion. Lagenaria siceraria (var. Loki) being a broad leaf vegetable was selected for these experiments. Plant growing at saline substrate was sprayed with specially prepared spray materials containing different dilutions of potassium nitrate. The anatomy of leaf with special reference to that of stomata was also studied to ensure absorption of required minerals. Growth of plants in terms of leaf area is being monitored at present. Some preliminary experiments show betterment in production of fruits in plants undergoing foliar spray. This hypothesis has opened a new chapter demanding series of experiments dealing with recipe of spray materials, mechanism of minerals uptake through stomata, participation of absorbed minerals in metabolic activities around palisade tissue probably by activating potassium dependent enzyme system which otherwise is blocked by replaced sodium, translocation of these minerals from leaves through petiole in rest of plants and overall effect of such spray on vegetative as well as reproductive growth in plants under saline environment. Some of this work is in progress. (author)

  5. Stomatal Blue Light Response Is Present in Early Vascular Plants.

    Science.gov (United States)

    Doi, Michio; Kitagawa, Yuki; Shimazaki, Ken-ichiro

    2015-10-01

    Light is a major environmental factor required for stomatal opening. Blue light (BL) induces stomatal opening in higher plants as a signal under the photosynthetic active radiation. The stomatal BL response is not present in the fern species of Polypodiopsida. The acquisition of a stomatal BL response might provide competitive advantages in both the uptake of CO2 and prevention of water loss with the ability to rapidly open and close stomata. We surveyed the stomatal opening in response to strong red light (RL) and weak BL under the RL with gas exchange technique in a diverse selection of plant species from euphyllophytes, including spermatophytes and monilophytes, to lycophytes. We showed the presence of RL-induced stomatal opening in most of these species and found that the BL responses operated in all euphyllophytes except Polypodiopsida. We also confirmed that the stomatal opening in lycophytes, the early vascular plants, is driven by plasma membrane proton-translocating adenosine triphosphatase and K(+) accumulation in guard cells, which is the same mechanism operating in stomata of angiosperms. These results suggest that the early vascular plants respond to both RL and BL and actively regulate stomatal aperture. We also found three plant species that absolutely require BL for both stomatal opening and photosynthetic CO2 fixation, including a gymnosperm, C. revoluta, and the ferns Equisetum hyemale and Psilotum nudum. © 2015 American Society of Plant Biologists. All Rights Reserved.

  6. Morphological and anatomical relationships in Alpine-Dinaric populations of the genus Iris L., Pallidae series (A. Kern. Trinajstić (Iridaceae

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    Bożena Mitić

    2014-01-01

    Full Text Available The relationships within the Alpine-Dinaric and cultivated populations of the genus Iris, Pallidae series, have been analysed. Seven morphological characteristics (stem length, length of the largest leaf, greatest width of the largest leaf, length of the smallest leaf, greatest width of the smallest leaf, the number of leaves and the number of flowers and seven leaf anatomical (length and width of stomata, length and width of epidermal cells, number of stomata and epidermal cells per mm'- and length of styloids have been used for this purpose. Relationships between populations were analysed by methods of multivariate statistics (Cluster, PCA and MST analyses. The results of Cluster and PCA analyses showed that, owing to leaf anatomical features, five main groups of the populations could be distinguished within the Pallidae series. Four of them belong to the species L. pallida, L. cengialti, L. illyrica and I. pseudopallida. The MST analyses showed that the fifth group contained mixed populations of I. illyrica and I. pseudopallida. The results point at the lack of taxonomic usefulness of the leaf anatomical features analysed and indicate that they caused successive geographical differentiation of the populations of the Pallidae series.

  7. Variability of morphological needle traits of Scots pine (Pinus sylvestris L. among populations from mountain and lowland regions of Poland

    Directory of Open Access Journals (Sweden)

    Łabiszak Bartosz

    2017-06-01

    Full Text Available The main goal of this work was to examine interpopulational needle traits variability of Scots pine (Pinus sylvestris L. from four mountain, one foothill and three lowland, natural populations located in Poland. This choice of locations was motivated by the presumed different origins of mountainous populations and the necessity to demonstrate how closely they are related to lowland populations. Variation in the studied populations was determined using seven morphological traits of needles: 1 - needle length, 2 - number of stomatal rows on the flat side of a needle, 3 - number of stomata per 2 mm of needle length on the flat side, 4 - number of stomatal rows on the convex side of a needle, 5 - number of stomata per 2 mm of needle length on the convex side, 6 - number of serrations per 2 mm of the needle length on the left side and 7 - number of serrations per 2 mm of the needle length on the right side. Biometric data were analysed statistically, and it was found that (i needle traits differentiate studied populations; (ii the postulated division of the population into two groups is reflected in the obtained results; and (iii a particularly strong relationship was found between two relict pine populations from the Pieniny (Sokolica, Kazalnica, Czertezik and Tatra Mts. (Wielke Koryciska, which may be the result of the common origins and history of these two populations

  8. Floral nectar production and carbohydrate composition and the structure of receptacular nectaries in the invasive plant Bunias orientalis L. (Brassicaceae).

    Science.gov (United States)

    Denisow, Bożena; Masierowska, Marzena; Antoń, Sebastian

    2016-11-01

    The data relating to the nectaries and nectar secretion in invasive Brassicacean taxa are scarce. In the present paper, the nectar production and nectar carbohydrate composition as well as the morphology, anatomy and ultrastructure of the floral nectaries in Bunias orientalis were investigated. Nectary glands were examined using light, fluorescence, scanning electron and transmission electron microscopy. The quantities of nectar produced by flowers and total sugar mass in nectar were relatively low. Total nectar carbohydrate production per 10 flowers averaged 0.3 mg. Nectar contained exclusively glucose (G) and fructose (F) with overall G/F ratio greater than 1. The flowers of B. orientalis have four nectaries placed at the base of the ovary. The nectarium is intermediate between two nectary types: the lateral and median nectary type (lateral and median glands stay separated) and the annular nectary type (both nectaries are united into one). Both pairs of glands represent photosynthetic type and consist of epidermis and glandular tissue. However, they differ in their shape, size, secretory activity, dimensions of epidermal and parenchyma cells, thickness of secretory parenchyma, phloem supply, presence of modified stomata and cuticle ornamentation. The cells of nectaries contain dense cytoplasm, plastids with starch grains and numerous mitochondria. Companion cells of phloem lack cell wall ingrowths. The ultrastructure of secretory cells indicates an eccrine mechanism of secretion. Nectar is exuded throughout modified stomata.

  9. Research into microscopic structure and essential oils of endemic medicinal plant species Satureja subspicata Bartl. ex Vis. (Lamiaceae

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    Sulejman Redžić

    2008-05-01

    Full Text Available In this study we looked into the cells and histological organization of leaves (Saturejae folium as well as a phyto-chemical composition of overground parts (Saturejae herba of endemic species Satureja subspicata Bartl. ex Vis. (Lamiaceae collected during year 2003 on south slopes of mountain Velez in Herzegovina. Microscopic organization was analyzed in wet slides using light microscope. Estimation of stomata index was done according to Ph. Yug. IV. Chemical composition of overground material extracts was determined by thin layer chromatography (TLC using thymol as a reference. In our research we found the following: Leaf structure of the analyzed species Satureja subspicata points at numerous specificities in anatomical and histological sense. In histological sense, leaf is of ventral type, with differentiated upper and lower epidermis and palisade and spongy tissue in between. Stoma index assigned according to Ph. Yug. IV leads to a conclusion that it is the case of diastitic stomata, which is common feature of most species from Lamiaceae family. Comparative qualitative analysis of essential oils in species Satureja subspicata showed similarities with other species from Lamiaceae family such as Thymus L. (thymol. In fact, we found more common substances that are part of the species Satureja montana L. extract, but in different concentrations.

  10. A new mechanism for the regulation of stomatal aperture size in intact leaves: accumulation of mesophyll-derived sucrose in the guard-cell wall of Vicia faba

    International Nuclear Information System (INIS)

    Lu, P.; Outlaw, W.H. Jr.; Smith, B.G.; Freed, G.A.

    1997-01-01

    At various times after pulse-labeling broad bean (Vicia faba L.) leaflets with 14CO2, whole-leaf pieces and rinsed epidermal peels were harvested and subsequently processed for histochemical analysis. Cells dissected from whole leaf retained apoplastic contents, whereas those from rinsed peels contained only symplastic contents. Sucrose (Suc)-specific radioactivity peaked (111 GBq mol-1) in palisade cells at 20 min. In contrast, the 14C content and Suc-specific radioactivity were very low in guard cells for 20 min, implying little CO2 incorporation; both then peaked at 40 min. The guard-cell apoplast had a high maximum Suc-specific radioactivity (204 GBq mol-1) and a high Suc influx rate (0.05 pmol stoma-1 min-1). These and other comparisons implied the presence of (a) multiple Suc pools in mesophyll cells, (b) a localized mesophyll-apoplast region that exchanges with phloem and stomata, and (c) mesophyll-derived Suc in guard-cell walls sufficient to diminish stomatal opening by approximately 3 micrometers. Factors expected to enhance Suc accumulation in guard-cell walls are (a) high transpiration rate, which closes stomata, and (b) high apoplastic Suc concentration, which is elevated when mesophyll Suc efflux exceeds translocation. Therefore, multiple physiological factors are integrated in the attenuation of stomatal aperture size by this previously unrecognized mechanism

  11. The Effect of Organic Manure and Super Absorbent on Physiological and Biochemical Characteristics of Potato (Solanum tubersum, cv Marfona

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    N. Rashidi

    2015-05-01

    Full Text Available In order to investigate effect of organic manure and super absorbent on physiological and biochemical traits of potato (Solanum tubersum, cv Marfona, a split plot experiment was conducted as randomized complete block design with three replications at Research Farm, Agriculture College, University of Razi in 2010. Main factor included two levels of super absorbent A200 (0 and 70 Kg/ha, and split plot included nine levels (0, chemical fertilizer (according to soil test, granule chicken manure (1000 kg/ ha, common chicken manure (12 ton/ha, soil mix (1000 kg/ha, cow manure (20 ton/ha, vermicompost (20 ton/ha, compost (20 ton/ha and tea compost (soaking tubers and spraying at four times. Investigating physiological traits such as leaf chlorophyll index, chlorophyll florescence and stomata conductance showed that only leaf chlorophyll index was affected by superabsorbent (P < 0.01 and organic manure (P < 0.05, while stomata conductance wad significant under it’s interaction effect at (P < 0.05. Quality and biochemical traits show that phosphorous amount of tuber was significant in superabsorbent treatment in compare to control. Crude oil percentage, protein, fiber, starch, sugar, nitrogen, phosphorous and potassium content were not affected by organic manure. The highest amount of oil and fiber were obtained under compost and cow manure respectively. Sugar and nitrogen content were high under cow manure treatment. The highest amount of potassium and phosphorous content were belonging to chicken and Khakparvar manure respectively.

  12. Comparative epidermal anatomical studies in six taxa of genus Nephrolepis Swart in Nigeria

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    A. A. Fajuke

    2018-04-01

    Full Text Available Anatomical studies in six taxa of genus Nephrolepis; N. biserrata, N. cordifolia, N. exaltata (i & (ii, N. biserrata var. furcans and N. undulata were carried out with a view to identify anatomic characters of taxonomic values. Both qualitative and quantitative anatomical studies were carried out. Quantitative data were subjected to descriptive statistical analysis. Anatomical characters studied include venation patterns, trichome types, presence and absence of stomata and values of the stomatal index which are valuable in delimiting the species. The overall results showed overlaps in the quantitative anatomical attributes of the Nephrolepis taxa studied suggesting that they belong to the same genus. Qualitative anatomical attributes that separated the genus into distinct taxa are the presence of simple multicellular glandular trichomes in N. biserrata and simple multicellular non-glandular trichomes in N. exaltata (i and N. exalta (ii while N. biserrata var. furcans and N. undulata have simple unicellular non-glandular trichomes and absence of trichome in N. cordifolia. Presence of anisocytic, diacytic or anomocytic stomata were of diagnostic important in the six taxa.

  13. The structure of arabidopsis thaliana OST1 provides insights into the kinase regulation mechanism in response to osmotic stress

    KAUST Repository

    Yunta, Cristina

    2011-11-01

    SnRK [SNF1 (sucrose non-fermenting-1)-related protein kinase] 2.6 [open stomata 1 (OST1)] is well characterized at molecular and physiological levels to control stomata closure in response to water-deficit stress. OST1 is a member of a family of 10 protein kinases from Arabidopsis thaliana (SnRK2) that integrates abscisic acid (ABA)-dependent and ABA-independent signals to coordinate the cell response to osmotic stress. A subgroup of protein phosphatases type 2C binds OST1 and keeps the kinase dephosphorylated and inactive. Activation of OST1 relies on the ABA-dependent inhibition of the protein phosphatases type 2C and the subsequent self-phosphorylation of the kinase. The OST1 ABA-independent activation depends on a short sequence motif that is conserved among all the members of the SnRK2 family. However, little is known about the molecular mechanism underlying this regulation. The crystallographic structure of OST1 shows that ABA-independent regulation motif stabilizes the conformation of the kinase catalytically essential α C helix, and it provides the basis of the ABA-independent regulation mechanism for the SnRK2 family of protein kinases. © 2011 Elsevier Ltd. All rights reserved.

  14. Reevaluation of the plant “gemstones”: Calcium oxalate crystals sustain photosynthesis under drought conditions

    Science.gov (United States)

    Tooulakou, Georgia; Giannopoulos, Andreas; Nikolopoulos, Dimosthenis; Bresta, Panagiota; Dotsika, Elissavet; Orkoula, Malvina G.; Kontoyannis, Christos G.; Fasseas, Costas; Liakopoulos, Georgios; Klapa, Maria I.; Karabourniotis, George

    2016-01-01

    ABSTRACT Land plants face the perpetual dilemma of using atmospheric carbon dioxide for photosynthesis and losing water vapors, or saving water and reducing photosynthesis and thus growth. The reason behind this dilemma is that this simultaneous exchange of gases is accomplished through the same minute pores on leaf surfaces, called stomata. In a recent study we provided evidence that pigweed, an aggressive weed, attenuates this problem exploiting large crystals of calcium oxalate as dynamic carbon pools. This plant is able to photosynthesize even under drought conditions, when stomata are closed and water losses are limited, using carbon dioxide from crystal decomposition instead from the atmosphere. Abscisic acid, an alarm signal that causes stomatal closure seems to be implicated in this function and for this reason we named this path “alarm photosynthesis.” The so-far “enigmatic,” but highly conserved and widespread among plant species calcium oxalate crystals seem to play a crucial role in the survival of plants. PMID:27471886

  15. The structure of arabidopsis thaliana OST1 provides insights into the kinase regulation mechanism in response to osmotic stress

    KAUST Repository

    Yunta, Cristina; Martí nez-Ripoll, Martí n; Zhu, Jian-Kang; Albert, Armando

    2011-01-01

    SnRK [SNF1 (sucrose non-fermenting-1)-related protein kinase] 2.6 [open stomata 1 (OST1)] is well characterized at molecular and physiological levels to control stomata closure in response to water-deficit stress. OST1 is a member of a family of 10 protein kinases from Arabidopsis thaliana (SnRK2) that integrates abscisic acid (ABA)-dependent and ABA-independent signals to coordinate the cell response to osmotic stress. A subgroup of protein phosphatases type 2C binds OST1 and keeps the kinase dephosphorylated and inactive. Activation of OST1 relies on the ABA-dependent inhibition of the protein phosphatases type 2C and the subsequent self-phosphorylation of the kinase. The OST1 ABA-independent activation depends on a short sequence motif that is conserved among all the members of the SnRK2 family. However, little is known about the molecular mechanism underlying this regulation. The crystallographic structure of OST1 shows that ABA-independent regulation motif stabilizes the conformation of the kinase catalytically essential α C helix, and it provides the basis of the ABA-independent regulation mechanism for the SnRK2 family of protein kinases. © 2011 Elsevier Ltd. All rights reserved.

  16. Molecular interaction between Methylobacterium extorquens and seedlings: growth promotion, methanol consumption, and localization of the methanol emission site.

    Science.gov (United States)

    Abanda-Nkpwatt, Daniel; Müsch, Martina; Tschiersch, Jochen; Boettner, Mewes; Schwab, Wilfried

    2006-01-01

    Four Methylobacterium extorquens strains were isolated from strawberry (Fragaria x ananassa cv. Elsanta) leaves, and one strain, called ME4, was tested for its ability to promote the growth of various plant seedlings. Seedling weight and shoot length of Nicotiana tabacum, Lycopersicon esculentum, Sinapis alba, and Fragaria vesca increased significantly in the presence of the pink-pigmented facultative methylotroph (PPFM), but the germination behaviour of seeds from six other plants was not affected. The cell-free supernatant of the bacterial culture stimulated germination, suggesting the production of a growth-promoting agent by the methylotroph. Methanol emitted from N. tabacum seedlings, as determined by proton-transfer-reaction mass spectrometry (PTR-MS), ranged from 0.4 to 0.7 ppbv (parts per billion by volume), while significantly lower levels (0.005 to 0.01 ppbv) of the volatile alcohol were measured when the seedlings were co-cultivated with M. extorquens ME4, demonstrating the consumption of the gaseous methanol by the bacteria. Additionally, by using cells of the methylotrophic yeast Pichia pastoris transformed with the pPICHS/GFP vector harbouring a methanol-sensitive promoter in combination with the green fluorescence protein (GFP) reporter gene, stomata were identified as the main source of the methanol emission on tobacco cotyledons. Methylobacterium extorquens strains can nourish themselves using the methanol released by the stomata and release an agent promoting the growth of the seedlings of some crop plants.

  17. Leaf micromorphology of some Phyllanthus L. species (Phyllanthaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Solihani, N. S., E-mail: noorsolihani@gmail.com; Noraini, T., E-mail: norainitalip@gmail.com [School of Environmental and Natural Resource Sciences Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Azahana, A., E-mail: bell-azahana@yahoo.com [Department of Plant Science, Kulliyyah of Science, International Islamic University Malaysia, Kuantan Campus, Kuantan, Pahang (Malaysia); Nordahlia, A. S., E-mail: nordahlia@frim.gov.my [Forest Research Institute of Malaysia, 52109 Kepong, Selangor (Malaysia)

    2015-09-25

    Comparative leaf micromorphological study was conducted of five chosen Phyllanthus L. (Phyllanthaceae) species, namely P. acidus L., P. elegans Wall. ex Müll. Arg., P. emblica L., P. urinaria L. and P. pulcher Wall. ex Müll. Arg. The objective of this study is to identify the leaf micromorphological characteristics that can be used in species identification. The procedures involve examination under scanning electron microscope. Findings of this study have demonstrated variations in the leaf micromorphological characteristics such as in the types of waxes present on adaxial and abaxial epidermis surfaces, in the stomata and types of trichome. Common character present in all species studied are the presence of a thin film layer and buttress-like waxes on epidermal leaf surfaces. Diagnostics characters found in this study are the presence of papilla in P. elegens, amphistomatic stomata in P. urinaria and flaky waxes in P. pulcher. The result of this study has shown that leaf micromorphological characters have some taxonomic significance and can be used in identification of species in the genus Phyllanthus.

  18. Analysis of Stomatal Patterning in Selected Mutants of MAPK Pathways

    KAUST Repository

    Felemban, Abrar

    2016-05-01

    Stomata are cellular valves in plants that play an essential role in the regulation of gas exchange and are distributed in the epidermis of aerial organs. In Arabidopsis thaliana, stomatal production and development are coordinated by the mitogen-activated protein kinase (MAPK) signalling pathway, which modulates a variety of other processes, including cell proliferation, regulation of cytokinesis, programed cell death, and response to abiotic and biotic stress. The environment also plays a role in stomatal development, by influencing the frequency at which stomata develop in leaves. This thesis presents an analysis of stomatal development in Arabidopsis mutants in two MAPK pathways: MEKK1-MKK1/MKK2-MPK4, and MAP3K17/18-MKK3. Obtained results demonstrate the effect of stress conditions on stomatal development and specify the involvement of analysed MAPK in stomatal patterning. First, both analysed pathways modulate stomatal patterning in Arabidopsis cotyledons. Second, plant growth-promoting bacteria tested enhance stomatal density and affect guard cell morphology. Third, the sucrose or mannitol treatment increases defects in stomatal patterning. Finally, salt stress or high temperature can suppress stomatal defects in mutants of the MEKK1-MKK1/MKK2-MPK4 pathway.

  19. Investigations into the endogenic abcisinic acid and cytokinin content of soja bean cultures with varying salt sensitivity, as well as into the effect of exogenically applied abcisinic acid to the Cl--translocation

    International Nuclear Information System (INIS)

    Roeb, G.

    1981-05-01

    Two soja bean cultures with different Cl - sensitivity the 'Lee' and 'Jackson' were used for the investigation. Salting of the growth medium with 75 nM NaCl massively increased the obcisinic acid (ABA) concentration in the leaves, not however of the cytokinin content. The high ABA concentrations remained in the 'Jackson' sort even after a 7-day salt treatment. The moderately salt-resistant sort 'Lee' had a remarkable Cl - retention mechanism. The addition of 10 -5 and 10 -6 M ABA to the growth medium reduced the Cl - concentration in the sprout and simultaneously increased the accumulation in the root. This ABA effect failed at high salt concentration. The order of magnitude in which ABA is taken up from a normal or salted growth medium and its distribution were investigated using 14 C. Macroautoradiographic investigations show that after 35 h the whole sprout is radioactively labelled whereby a prefered accumulation is found in youngest part of the sprout. The highest Cl - values were found in the older leaves. The ABA is obviously transported to the stomata with the transpiration flow and inhibits the transpiration by its effect on the stomata. Subjecting the soja beans to a 75 mM NaCl concentration, can lead to a decrease of transpiration due to the strong salt concentration. The addition of ABA as well had an inhibiting effect on the water release of the plants without influencing the Cl - translocation. (MG) [de

  20. Regulation of Water Use in the Southernmost European Fir (Abies pinsapo Boiss.: Drought Avoidance Matters

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    Raúl Sánchez-Salguero

    2015-06-01

    Full Text Available The current scenario of global warming has resulted in considerable uncertainty regarding the capacity of forest trees to adapt to increasing drought. Detailed ecophysiological knowledge would provide a basis to forecast expected species dynamics in response to climate change. Here, we compare the water balance (stomatal conductance, xylem water potential, needle osmotic adjustment of Abies pinsapo, a relict drought-sensitive Mediterranean fir, along an altitudinal gradient. We related these variables to soil water and nutrient availability, air temperature, atmospheric water potential, and vapour pressure deficit during two consecutive years. Our results indicate that A. pinsapo closed stomata rapidly over a very narrow range of soil water availability and atmospheric dryness. This isohydric response during water stress suggests that this relict conifer relied on the plant hormone abscisic acid to maintain closed stomata during sustained drought, instead of needle desiccation to passively drive stomatal closure, needle osmotic adjustment or a plastic response of the xylem to different levels of water availability. Both the soil and foliar nutrient contents suggest that the studied populations are not limited by nutrient deficiencies, and drought was stronger in the warmer low-elevation areas.

  1. Acclimatization of the endangered Mexican epiphytic orchid, Laelia speciosa (H.B.K. Schltr

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    Martha Mireya Ortega-Loeza

    2012-02-01

    Full Text Available In vitro propagation could be an alternative for the conservation of the endemic and endangered Mexican epiphytic orchid Laelia speciosa (H.B.K. Schltr. The goal of this study was to develop a protocol that would enhance acclimatization of in vitro – derived L. speciosa plantlets – a critical stage in propagation and subsequent conservation. Observations of stomata opening during ex vitro acclimatization, and the time of in vitro culture (0, 5, 10, 15, 20, 25, 30 days in greenhouse conditions (pre-acclimatization, on the survival and development of seedlings during the ex vitro acclimatization were carried out. In addition, the effect of different levels of nutrients (100%, 75%, 50%, 25% and 0%-strength salts and sucrose (0, 10, 20, 30, 40 g l−1 in the Murashige and Skoog medium (MS on the same parameters were measured. Plantlets incubated 20 days in greenhouse conditions before ex vitro acclimatization also displayed the best growth with a survival rate of 97.5%, related with high stomata opening. Plantlets on MS containing 100%-strength salts (with 20 days of pre-acclimatization, 40 g l−1 sucrose had the highest rate (97.5–100% of survival and vigor when acclimatized. By improving micropropagation through acclimatization, the sustainable management of L. speciosa now more likely, benefitting the conservation of this endangered species.

  2. Lateral diffusion of CO2 in leaves of the crassulacean acid metabolism plant Kalanchoe daigremontiana Hamet et Perrier.

    Science.gov (United States)

    Duarte, Heitor M; Jakovljevic, Ivona; Kaiser, Friedemann; Lüttge, Ulrich

    2005-04-01

    Dynamic patchiness of photosystem II (PSII) activity in leaves of the crassulacean acid metabolism (CAM) plant Kalanchoe daigremontiana Hamet et Perrier, which was independent of stomatal control and was observed during both the day/night cycle and circadian endogenous oscillations of CAM, was previously explained by lateral CO2 diffusion and CO2 signalling in the leaves [Rascher et al. (2001) Proc Natl Acad Sci USA 98:11801-11805; Rascher and Luttge (2002) Plant Biol 4:671-681]. The aim here was to actually demonstrate the importance of lateral CO2 diffusion and its effects on localized PSII activity. Covering small sections of entire leaves with silicone grease was used for local exclusion of a contribution of atmospheric CO2 to internal CO2 via transport through stomata. A setup for combined measurement of gas exchange and chlorophyll fluorescence imaging was used for recording photosynthetic activity with a spatiotemporal resolution. When remobilization of malic acid from vacuolar storage and its decarboxylation in the CAM cycle caused increasing internal CO2 concentrations sustaining high PSII activity behind closed stomata, PSII activity was also increased in adjacent leaf sections where vacuolar malic acid accumulation was minimal as a result of preventing external CO2 supply due to leaf-surface greasing, and where therefore CO2 could only be supplied by diffusion from the neighbouring malic acid-remobilizing leaf tissue. This demonstrates lateral CO2 diffusion and its effect on local photosynthetic activity.

  3. Anatomical, morphological and palynological studies of some onosma l. (boraginaceae) taxa endemic to anatolia

    International Nuclear Information System (INIS)

    Teke, H.I.; Binzet, R.

    2017-01-01

    In this study, the morphological, anatomical and palynological characters of Onosma discedens Hausskn. ex. Bornm., O. nana DC. and O. sorgerae var. subglabriflora Teppner were investigated. All the examined species are endemic to Anatolia, Turkey. The root cortex of examined species is multilayered. The raphide crystals are observed in epidermal cells and basal hair cells on both side of epidermis in O. sorgerae var. subglabriflora. Leaves are isobilateral (=equifacial) in O. nana and O. sorgerae var. subglabriflora, whereas leaves are dorsiventral(=bifacial) in O. discedens. Stomatas are observed on both surfaces (=amfistomatic) in all examined species. Stomata index is 9.25 of upper epidermis and 10.71 of lower epidermis in O. discedens, 9.61 of upper epidermis and 10 of lower epidermis in O. nana and 9.67 of upper epidermis and 13.63 of lower epidermis in O. sorgerae var. subglabriflora. The pollen grains are heteropolar, trisyncolporatae and sphaeroidal shape. In O. discedens, sphaeroidal (P/E: 1.13 W) and subprolate in Acetolysis and in O. nana, subprolate in shape and in O. sorgerae var. subglabriflora. Amb is three angular in all examined Onosma species. Sculpture is scabrate-rugulate in all species. Nutlet ornamentation is rugose. (author)

  4. Contrasting responses of leaf stomatal characteristics to climate change: a considerable challenge to predict carbon and water cycles.

    Science.gov (United States)

    Yan, Weiming; Zhong, Yangquanwei; Shangguan, Zhouping

    2017-09-01

    Stomata control the cycling of water and carbon between plants and the atmosphere; however, no consistent conclusions have been drawn regarding the response of stomatal frequency to climate change. Here, we conducted a meta-analysis of 1854 globally obtained data series to determine the response of stomatal frequency to climate change, which including four plant life forms (over 900 species), at altitudes ranging from 0 to 4500 m and over a time span of more than one hundred thousand years. Stomatal frequency decreased with increasing CO 2 concentration and increased with elevated temperature and drought stress; it was also dependent on the species and experimental conditions. The response of stomatal frequency to climate change showed a trade-off between stomatal control strategies and environmental factors, such as the CO 2 concentration, temperature, and soil water availability. Moreover, threshold effects of elevated CO 2 and temperature on stomatal frequency were detected, indicating that the response of stomatal density to increasing CO 2 concentration will decrease over the next few years. The results also suggested that the stomatal index may be more reliable than stomatal density for determination of the historic CO 2 concentration. Our findings indicate that the contrasting responses of stomata to climate change bring a considerable challenge in predicting future water and carbon cycles. © 2017 John Wiley & Sons Ltd.

  5. IN VITRO INOCULATION OF ASPARAGUS OFFICINALIS TISSUE CULTURE SHOOTS WITH FUSARIUM PROLIFERA TUM

    Directory of Open Access Journals (Sweden)

    A.K.MoHD OMAR

    1999-01-01

    Full Text Available Artificially inoculated asparagus tissue culture plantlets with a virulent fungus, Fusarium proliferatum showed signs of infection as early as 4 days after inoculat ion. Macroscopic observations revealed presence of early symptoms such as necrotic lesions at the affected area and light microscopic examinations clearly revealed the post-penetration events that took place including the destruction of surrounding cells. However, little is known of the hyphal activity or advancement on the host's surface at the initial stage after inoculation. Scanning electron microscopic examination clearly revealed the hyphal advancement on the surface and the mode of entrance into the host tissues beneath. Four days after inoculation, the fungi proceeded to spread out from the inoculation point onto the host surface which eventually developed into a sparse network of both aerial and non-aerial hyphae. Non-aerial hyphae form a network of mycelium that adheres to the surface and it's movement appeared to be oriented towards the stomata. Hyphal penetration occurs more often through the stomata, natural openings or wounds. In some cases, the hyphae crossed over the stomatal opening w ithout entering the host tissues. At places where the cuticle layer is absent or not well developed the hyphae successfully grew in between the epidermal cells into the tissues beneath.

  6. Organ-specific effects of brassinosteroids on stomatal production coordinate with the action of Too Many Mouths.

    Science.gov (United States)

    Wang, Ming; Yang, Kezhen; Le, Jie

    2015-03-01

    In Arabidopsis, stomatal development initiates after protodermal cells acquire stomatal lineage cell fate. Stomata or their precursors communicate with their neighbor epidermal cells to ensure the "one cell spacing" rule. The signals from EPF/EPFL peptide ligands received by Too Many Mouths (TMM) and ERECTA-family receptors are supposed to be transduced by YODA MAPK cascade. A basic helix-loop-helix transcription factor SPEECHLESS (SPCH) is another key regulator of stomatal cell fate determination and asymmetric entry divisions, and SPCH activity is regulated by YODA MAPK cascade. Brassinosteroid (BR) signaling, one of the most well characterized signal transduction pathways in plants, contributes to the control of stomatal production. But opposite organ-specific effects of BR on stomatal production were reported. Here we confirm that stomatal production in hypocotyls is controlled by BR levels. YODA and CYCD4 are not essential for BR stomata-promoting function. Furthermore, we found that BR could confer tmm hypocotyls clustered stomatal phenotype, indicating that the BR organ-specific effects on stomatal production might coordinate with the TMM organ-specific actions. © 2014 Institute of Botany, Chinese Academy of Sciences.

  7. Characteristics of blooming, floral nectaries and nectar of Malus sargentii Rehd.

    Directory of Open Access Journals (Sweden)

    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available In the years 2007-2008, the flowering biology of Malus sargentii, an ornamental apple tree native to Japan, was studied in the conditions of Lublin (Poland. The daily rate of flower opening, flowering duration and flower visitation by insects were determined. The amount of nectar produced per flower and sugar content in the nectar were investigated. The size of nectaries and the micromorphology of their surface were examined using light and scanning electron microscopy. It was found that the greatest amount of flowers opened between 11.00 and 13.00. During this time, the largest number of insects was observed in the flowers. Bees (90% were predominant among the insects, with a much smaller number of bumblebees (6% and butterflies (4%. The flower life span was 5 days. Over this period, the flower produced, on the average, 0.71 mg of nectar with an average sugar content of 32%. The nectaries of Malus sargentii are orange-yellow coloured and they represent the hypanthial type. Due to the protrusion of the nectariferous tissue, they are classified as automorphic nectaries. The surface of the epidermal cells of the nectary was distinguished by distinct cuticle folds. A small number of stomata were located only in the basal part of the nectary. At the beginning of flowering, all stomata were closed, but secretion traces were observed near well-developed outer cuticular ledges.

  8. Tolerance of some potato mutants induced with gamma irradiation to drought in vitro

    International Nuclear Information System (INIS)

    Al-Safadi, B.; Ayyoubi, Z.

    2006-04-01

    An in vitro selection program was conducted in order to improve potato (Solanum tuberosum) tolerance to drought. Potato mutant plants were obtained through a previously conducted mutation breeding program on three potato cultivars (Draga, Spunta, and Diamant) aimed at improving potato tolerance to salinity and resistance to late blight disease. In order to apply selection pressure, growth media (MS based) were prepared with the addition of 1%, 2%, 3% concentrations of Poly Ethylene Glycol (PEG). As a result, three mutants were selected that were tolerant to water stress (i.e. drought tolerant) two of which came from the cultivar Draga and one from Spunta. Physiological growth parameters (plant length, leaf number, branch number, roots number, leaf area, stomata number, and chlorophyll concentration content) were taken on the growing plantlets. The selected mutants were distinguished with some characteristics which can help in their tolerance to drought. Some of these characteristics were an increase in leaf number, root number, and a decrease in stomata number. However a reduction in chlorophyll content was observed as compared with the control. These mutant lines will need further selection in the field for plants with larger tubers before they can be considered as certified lines. (author)

  9. Padrão estomático de Capsicum ssp. resistentes e suscetíveis a Oidiopsis haplophylli Stomatal patterns of Capsicum genotypes resistant or susceptible to Oidiopsis haplophylli

    Directory of Open Access Journals (Sweden)

    Milton Luiz Paz Lima

    2010-03-01

    Full Text Available Visando relacionar a reação de Capsicum spp. resistentes e suscetíveis à Oidiopsis haplophylli com o padrão dos respectivos complexos estomáticos, foram analisados em dois ensaios, 5 e 15 genótipos de Capsicum spp. em delineamento inteiramente casualizado. Avaliou-se a abertura do ostíolo, a morfometria do estômato (comprimento, largura e área, o número de estômatos.mm-2 e a freqüência de estômatos (unidades de estômatos por células da epiderme nas superfícies adaxial e abaxial da epiderme foliar de plantas cultivadas em casa-de-vegetação. A variável abertura ostiolar não explicou a reação dos genótipos ao oídio, nem na face adaxial (R²=0,16 nem na abaxial (R²=0,13. Entretanto, o número de estômatos.mm-2 explicou a reação ao oídio em 84 % (face adaxial ou 74 % (face abaxial. Para a freqüência de estômatos, o modelo ajustou-se melhor na face adaxial (R² = 0,76, do que na face abaxial (R²=0,48. Maiores números e freqüências de estômatos em ambas as faces foliares ocorreram em pimentão 'Magali' (altamente suscetível, com valores significativamente maiores do que em 'HV-12' (altamente resistente. Sugere-se que a suscetibilidade de genótipos de Capsicum a O. haplophylli está parcialmente relacionada a mecanismos de defesa estruturais pré-formados, como o número e freqüência de estômatos, os quais se relacionam com o número de sítios de infecção. Por outro lado, para alguns genótipos, esta relação não foi significativa, indicando que outros mecanismos de resistência também estejam envolvidos.This work reports the reaction of Capsicum genotypes to the powdery mildew pathogen with variables of the stomatal complex, from samples of five to 15 Capsicum genotypes in a complete randomized experiments. Ostiolum size, stomatal morphometry (length, width and surface area, the number of stomata.mm-2, and the frequency of stomata (stomatal units per unit of epidermal cells were evaluated on both leaf

  10. Observações citológicas em citrus: V. poliploidia em relação à densidade e ao tamanho dos estomas em Citrus e outros gêneros das Aurantioideae.

    Directory of Open Access Journals (Sweden)

    C. A. Krug

    1944-01-01

    dêste caráter também se manifesta dentro de cada uma da maioria das espécies e grupos di- e tetraplóides. A-pesar disso, entretanto, chegou-se à conclusão de que a determinação da área dos estornas poderá ser útil mesmo no caso em que se queira separar triplóides de tetraplóides, da mesma progênie, conhecendo-se a área dos estornas das respectivas formas diplóides em idênticas condições de meio.In the present article two aspects dealing with the relations of polyploidy and stcmata characters in Citrus and related genera are dealt with. First the data of Hirano (5 concerning stomata density in numerous forms of the sub-family Aurantioidex are analysed in relation to their chromosomal constitution. It was thought that the- great variability of stomata number per unit area, could possibly be explained by differences in chromosome numbers. Chromosome counts of numerous plants utilized by Hirano at the Citrus Exp. Sta., Riverside, California, were made and all available bibliographical informations concerning the cytological constitution of those species and genera were gathered, whose chromosomes could not be counted at Riverside ; it was concluded that all types studied by Hirano, have 18 somatic chromosomes except for two varieties of Citrus aurantifolia, Swingle, which are triploid. This was the only instance in which differences in chromosome numbers where primarily responsable for the differences in stomata density. In the rest of the material the variability of this character must bo due to differences in genetic constitution. In the succeding chapters the results of a detailed analysis of stomata area and its variability in diploid, triploid and tetraploid Citrus forms are presented; this was done in order to find a simple method of identifying these, polyploids without making aciual chromosome counts. A total of 36 individuals of 5 different species were examined. Listing the average stomata areas, starting with the largest and finishing with

  11. A scanning electron microscopy study of the invasion of leaflets of a bloat-safe and a bloat-causing legume by rumen microorganisms.

    Science.gov (United States)

    Fay, J P; Cheng, K J; Hanna, M R; Howarth, R E; Costerton, J W

    1981-04-01

    A newly developed technique using ruthenium red to detect foci of bacterial digestion in mounts of whole leaflets that had been incubated with rumen bacteria was used to compare the digestion of alfalfa, a bloat-causing legume, and sainfoin, a bloat-safe legume. When whole leaflets were suspended in an artificial rumen medium and inoculated with rumen bacteria, massive bacterial adhesion and proliferation were noted at the stomata of alfalfa leaflets after 6 h of incubation, whereas only a few isolated bacteria adhered near the stomata of sainfoin leaflets After 22 h of incubation, the epidermal layers of alfalfa leaflets had peeled away in many areas, revealing an extensive bacterial invasion of the underlying mesophyll tissue in which large bacterial microcolonies had formed in intercellular spaces, and in intracellular spaces in several areas where plant cell walls had broken down. After 22 h of incubation, the surface of sainfoin leaflets resembled that of alfalfa leaflets at 6 h, with bacterial microcolonies adhering to the area surrounding the stomata, but without sloughing of the epidermis. Uninoculated control leaflets of both species showed no surface alteration but part of their normal bacterial flora had proliferated to form microcolonies on the surface after 22 h incubation. Dry matter loss due to leaching or bacterial digestion when whole leaflets of legumes were suspended in an artificial rumen medium, alone or with rumen bacteria, was significantly higher in the bloat-causing group. Values of leaching and of bacterial digestion were positively correlated. We conclude that reported differences in plant anatomy, and in cell wall chemistry, produce distinct rates or organic nutrient release from legume leaflets, and that these same differences produce an equally distinct susceptibility of leaflets to bacterial invasion, plant cell rupture, and the consequent release of intracellular plant components. The rate of release of organic nutrients from legume

  12. Bioaccumulation of cadmium by spring barley (Hordeum vulgare L. and its effect on selected physiological and morphological parameters

    Directory of Open Access Journals (Sweden)

    Miriama Kopernická

    2016-01-01

    Full Text Available Heavy metals and other toxic elements in the environment, mainly located in soil and groundwater, have a significant effect on plant and its productivity that has a huge attention in recent years. Accumulation of heavy metals in soil cause toxicity to plants, and contaminate the food chain. The industrial areas, as well as developing countries have been contaminated with high concentration of heavy metals. Main sources of contamination are mining and other industrial processes, as well as military and or lanfills, sludge dumps or waste disposal sites. The heavy metals are very dangerous to environment and pose serious danger to public health by entering throught the food chain or into drinking water. Phytoextraction is one way how to remove the contaminants from soil by plants. Phytoextraction of heavy metals is a technology that has been studied for several years. It is more ecological and cheaper way how to clean our environment.Several plant species are known becauce they hyperaccumulate a high contents of metals from the soil. The accumulators are mainly herbaceous species, crops and nowadays angiosperm trees with a high growth such as poplars or willows. We have focused on the determination of some morphological (lenght and weight of roots and biomass and physiological (contents of dry mass and number of lief stomata characteristics and the determination of the bioaccumulation factor and the translocation factor of cadmium by spring barley (Hordeum vulgare L.. Imprints of leaves were evaluated using an optical microscope Axiostar Plus, Carl Zeiss, lens CP Achromat 40x/0.65, eyepiece PI 10x / 18, Canon Utilities Software Zoom Browser EX 4.6 and hardware Acer Travel Mate 4600, Canon Power Shot A95. The density of stomata was evaluated on an area of 1 mm2. Samples of the dried plants (leaves and roots were mineralized by acid digestion using microwave digestion device MARS X - press 5. The end of determination to obtain the cadmium content was

  13. Modeling the water use efficiency of soybean and maize plants under environmental stresses: application of a synthetic model of photosynthesis-transpiration based on stomatal behavior.

    Science.gov (United States)

    Yu, Gui-Rui; Wang, Qiu-Feng; Zhuang, Jie

    2004-03-01

    Understanding the variability of plant WUE and its control mechanism can promote the comprehension to the coupling relationship of water and carbon cycle in terrestrial ecosystem, which is the foundation for developing water-carbon coupling cycle model. In this paper, we made clear the differences of net assimilation rate, transpiration rate, and WUE between the two species by comparing the experiment data of soybean (Glycine max Merr.) and maize (Zea mays L.) plants under water and soil nutrient stresses. WUE of maize was about two and a half times more than that of soybean in the same weather conditions. Enhancement of water stresses led to the marked decrease of Am and Em of two species, but water stresses of some degree could improve WUE, and this effect was more obvious for soybean. WUE of the two species changed with psiL in a second-order curve relation, and the WUE at high fertilization was higher than that at low fertilization, this effect was especially obvious for maize. Moreover, according to the synthetic model of photosynthesis-transpiration based on stomatal behavior (SMPTSB) presented by Yu et al. (2001), the WUE model and its applicability were discussed with the data measured in this experiment. The WUE estimated by means of the model accorded well with the measured values. However, this model underestimated the WUE for maize slightly, thus further improvement on the original model was made in this study. Finally, by discussing some physiological factors controlling Am and WUE, we made clear the physiological explanation for differences of the relative contributions of stomata- and mesophyll processes to control of Am and WUE, and the applicability of WUE model between the two species. Because the requirement to stomatal conductance by unit change of net assimilation rate is different, the responses of opening-closing activity of stomata to environmental stresses are different between the two species. To obtain the same level of net assimilation

  14. The FOUR LIPS and MYB88 transcription factor genes are widely expressed in Arabidopsis thaliana during development.

    Science.gov (United States)

    Lei, Qin; Lee, EunKyoung; Keerthisinghe, Sandra; Lai, Lien; Li, Meng; Lucas, Jessica R; Wen, Xiaohong; Ren, Xiaolin; Sack, Fred D

    2015-09-01

    The FOUR LIPS (FLP) and MYB88 transcription factors, which are closely related in structure and function, control the development of stomata, as well as entry into megasporogenesis in Arabidopsis thaliana. However, other locations where these transcription factors are expressed are poorly described. Documenting additional locations where these genes are expressed might define new functions for these genes. Expression patterns were examined throughout vegetative and reproductive development. The expression from two transcriptional-reporter fusions were visualized with either β-glucuronidase (GUS) or green fluorescence protein (GFP). Both flp and myb88 genes were expressed in many, previously unreported locations, consistent with the possibility of additional functions for FLP and MYB88. Moreover, expression domains especially of FLP display sharp cutoffs or boundaries. In addition to stomatal and reproductive development, FLP and MYB88, which are R2R3 MYB transcription factor genes, are expressed in many locations in cells, tissues, and organs. © 2015 Botanical Society of America.

  15. Impact of elevated CO2 concentration on dynamics of leaf photosynthesis in Fagus sylvatica is modulated by sky conditions.

    Science.gov (United States)

    Urban, Otmar; Klem, Karel; Holišová, Petra; Šigut, Ladislav; Šprtová, Mirka; Teslová-Navrátilová, Petra; Zitová, Martina; Špunda, Vladimír; Marek, Michal V; Grace, John

    2014-02-01

    It has been suggested that atmospheric CO2 concentration and frequency of cloud cover will increase in future. It remains unclear, however, how elevated CO2 influences photosynthesis under complex clear versus cloudy sky conditions. Accordingly, diurnal changes in photosynthetic responses among beech trees grown at ambient (AC) and doubled (EC) CO2 concentrations were studied under contrasting sky conditions. EC stimulated the daily sum of fixed CO2 and light use efficiency under clear sky. Meanwhile, both these parameters were reduced under cloudy sky as compared with AC treatment. Reduction in photosynthesis rate under cloudy sky was particularly associated with EC-stimulated, xanthophyll-dependent thermal dissipation of absorbed light energy. Under clear sky, a pronounced afternoon depression of CO2 assimilation rate was found in sun-adapted leaves under EC compared with AC conditions. This was caused in particular by stomata closure mediated by vapour pressure deficit. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Volatilization of iodine from vegetation

    International Nuclear Information System (INIS)

    Amiro, B.D.; Johnston, F.L.

    1989-01-01

    Gaseous emissions of iodine were measured from bean plant foliage. A gamma-emitting iodine tracer, Na 125 I, was taken up by the plants from a hydroponic growth medium and released to a cuvette atmosphere. The dynamics of the flux were studied using a flow-through gamma detector. The relationship between leaf radioactive tracer activity and growth-medium activity was linear, as was the relationship between the iodine flux and both leaf and growth-medium activity. Iodine flux and leaf conductance to water responded similarly to changes in light levels, suggesting that the stomata may partially control the flux. The flux was inhibited by aeration of the hydroponic growth media, and we postulate that methylation causes the iodine flux. Iodine emissions from living vegetation probably contribute < 0.1% to the stable iodine concentration in the atmosphere above terrestrial areas. However, this pathway may be a direct route for radioactive iodine transport from contaminated soils to the atmosphere. (author)

  17. Uncertainty in the response of transpiration to CO2 and implications for climate change

    International Nuclear Information System (INIS)

    Mengis, N; Keller, D P; Oschlies, A; Eby, M

    2015-01-01

    While terrestrial precipitation is a societally highly relevant climate variable, there is little consensus among climate models about its projected 21st century changes. An important source of precipitable water over land is plant transpiration. Plants control transpiration by opening and closing their stomata. The sensitivity of this process to increasing CO 2 concentrations is uncertain. To assess the impact of this uncertainty on future climate, we perform experiments with an intermediate complexity Earth System Climate Model (UVic ESCM) for a range of model-imposed transpiration-sensitivities to CO 2 . Changing the sensitivity of transpiration to CO 2 causes simulated terrestrial precipitation to change by −10% to +27% by 2100 under a high emission scenario. This study emphasises the importance of an improved assessment of the dynamics of environmental impact on vegetation to better predict future changes of the terrestrial hydrological and carbon cycles. (letter)

  18. Pharmacognostical Standardization of Upodika- Basella alba L.: An Important Ayurvedic Antidiabetic Plant

    Directory of Open Access Journals (Sweden)

    T R Shantha

    2016-01-01

    Full Text Available Objective: To establish the pharmacognostic standards for the correct identification and standardization of an important Antidiabetic plant described in Ayurveda. Materials and Methods: Standardization was carried out on the leaf and stem of Basella alba L. with the help of the macro-morphological, microscopic, physicochemical and qualitative phytochemical studies. Results: Several specific characters were identified viz. clustered calcium oxalate crystals in the cortex region, absence of trichomes, succulent, thick, mucilaginous, fibrous stem. Rubiaceous type of stomata on both sides of the leaf. Quantitative microscopy along with physicochemical and qualitative phytochemical analysis were also established. Conclusion: The pharmacognostic standards could serve as the reference for the proper identification of the Basella alba L. which is an important anti-diabetic plant described in Ayurveda.

  19. [Leaf micrografic anatomy of the Neotropical palm Bactris gasipaes (Arecaceae)].

    Science.gov (United States)

    Chaimsohn, Francisco Paulo; Montiel, Mayra; Villalobos, Enrique; Mora Urpi, Jorge

    2008-06-01

    The economic importance of the palm Bactris gasipaes is growing in the Neotropoical region. We collected leaflets from plants under a chemical fertilization regime and a population of 5000 plants per hectare, in Costa Rica. The variety, Diamantes 10, has an ascendency fom the upper Amazon basin. We used Harries hematoxiline, eocine and standard light microscopy techniques. The presence of raphids and buliform cells was confirmed for the abaxial surface of the leaflets and for the hypodermic tissue on both sides. The absence of the Krantz anatomy was confirmed in consistence with former observations about the C3 photosynthesis in other species of Palmaceae. The average stomatal density on the abaxial surface was 96.87 +/- 16.31 stomata.mm(-2) and 14.20 +/- 4.05 in the adaxial surface.

  20. Speciation of Hg in lichens

    International Nuclear Information System (INIS)

    Jereb, Vesna; Horvat, Milena

    2002-01-01

    Lichens have long been regarded as a suitable tool for monitoring the relative levels of atmospheric pollutants. Lichens have neither roots, a waxy cuticle nor stomata: hence, for mineral nutrition they are largely dependent on wet and dry deposition from the atmosphere. Moreover, lichens are perennial and can accumulate elements over long periods of time. Therefore, concentrations of elements in lichens represent the average levels of elements in the atmosphere for a long period of time. The epiphytic lichen Hypogymnia physodes is a good bioindicator of air pollution with total mercury (THg). In addition, it contains small amounts of methylmercury (MeHg + ). The first aim of our work was to test analytical techniques for determination of MeHg in lichens taken from different locations in Idrija and reference locations

  1. Physiological traits contributing to carbon storage variation in Monastery bamboo and Pai Liang in northeastern Thailand

    Directory of Open Access Journals (Sweden)

    Nisa Leksungnoen

    2017-04-01

    Full Text Available This study aims at comparing the carbon storage ability of Monastery bamboo (Thyrsostachys siamensis Gamble and Pai Liang (Dendrocalamus membranaceus × Thyrsostachys siamensis in terms of the different physiological responses to the microclimate. The stomatal conductance, leaf-to-air vapor pressure deficit (LAVPD, chlorophyll content, and water use efficiency (WUE were measured. Pai Liang had a greater dry biomass per culm than Monastery bamboo, resulting in more carbon storage. Monastery bamboo kept opening its stomata even when LAVPD increased, resulting in the loss of more water and a lower WUE leading to a lower rate of growth and carbon storage. Pai Liang contained higher amount of carbon and nitrogen in the leaf tissue, indicating a better WUE. With regards to the climate change, Pai Liang is recommended owing to a greater carbon fixation and more rapid growth rate compared to the Monastery bamboo.

  2. Responses of evergreen and deciduous Quercus species to enhanced ozone levels

    International Nuclear Information System (INIS)

    Calatayud, Vicent; Cervero, Julia; Calvo, Esperanza; Garcia-Breijo, Francisco-Jose; Reig-Arminana, Jose; Sanz, Maria Jose

    2011-01-01

    Plants of one evergreen oak (Quercus ilex) and three deciduous oaks (Q. faginea, with small leaves; Q. pyrenaica and Q. robur, with large leaves) were exposed both to filtered air and to enhanced ozone levels in Open-Top Chambers. Q. faginea and Q. pyrenaica were studied for the first time. Based on visible injury, gas exchange, chlorophyll content and biomass responses, Q. pyrenaica was the most sensitive species, and Q. ilex was the most tolerant, followed by Q. faginea. Functional leaf traits of the species were related to differences in sensitivity, while accumulated ozone flux via stomata (POD 1.6 ) partly contributed to the observed differences. For risk assessment of Mediterranean vegetation, the diversity of responses detected in this study should be taken into account, applying appropriate critical levels. - Ozone tolerance overlapped with leaf traits in four Quercus species.

  3. Responses of evergreen and deciduous Quercus species to enhanced ozone levels

    Energy Technology Data Exchange (ETDEWEB)

    Calatayud, Vicent, E-mail: calatayud_viclor@gva.e [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Cervero, Julia; Calvo, Esperanza [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Garcia-Breijo, Francisco-Jose [Laboratorio de Anatomia e Histologia Vegetal ' Julio Iranzo' , Jardin Botanico, Universitat de Valencia, c/Quart 80, 46008 Valencia (Spain); Departamento de Ecosistemas Agroforestales, Escuela Tecnica Superior del Medio Rural y Enologia, Universidad Politecnica de Valencia, Avda. Blasco Ibanez 21, 46010 Valencia (Spain); Reig-Arminana, Jose [Departamento de Ecosistemas Agroforestales, Escuela Tecnica Superior del Medio Rural y Enologia, Universidad Politecnica de Valencia, Avda. Blasco Ibanez 21, 46010 Valencia (Spain); Sanz, Maria Jose [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain)

    2011-01-15

    Plants of one evergreen oak (Quercus ilex) and three deciduous oaks (Q. faginea, with small leaves; Q. pyrenaica and Q. robur, with large leaves) were exposed both to filtered air and to enhanced ozone levels in Open-Top Chambers. Q. faginea and Q. pyrenaica were studied for the first time. Based on visible injury, gas exchange, chlorophyll content and biomass responses, Q. pyrenaica was the most sensitive species, and Q. ilex was the most tolerant, followed by Q. faginea. Functional leaf traits of the species were related to differences in sensitivity, while accumulated ozone flux via stomata (POD{sub 1.6}) partly contributed to the observed differences. For risk assessment of Mediterranean vegetation, the diversity of responses detected in this study should be taken into account, applying appropriate critical levels. - Ozone tolerance overlapped with leaf traits in four Quercus species.

  4. Microscopic Evaluation of Leaves of Memecylon umbellatum Burm

    Directory of Open Access Journals (Sweden)

    Suresh G. Killedar

    2014-01-01

    Full Text Available Objective. Aim of present work is to perform the microscopic evaluation and physicochemical analysis and to explore the morphology parameters of Memecylon umbellatum Burm leaves. Methods. Fresh, dried and desiccated powdered leaf samples were studied for their morphology, microscopy, organoleptic characters, and an assortment of other WHO recommended methods for standardisation. Results. The microscopy revealed the dorsiventral nature of the leaf. Midrib showed presence of nonlignified phloem, lignified xylem with well-defined xylem fibers, vessels, and parenchyma. Presence of Phloecentric vascular bundles surrounded by endodermis and crystal sheath. Well-defined patches of collenchyma were observed above and below the vascular bundles in the midrib area. Trichomes are mostly absent and stomata (anomocytic were observed on both epidermal surfaces. Conclusions. It can be concluded that the microscopic analysis and pharmacognostic parameters can serve as tool for developing standards for proper authentication, quality, and purity of Memecylon umbellatum Burm leaves.

  5. Variability of anatomical-physiological traits in black locust clones - Robinia pseudoacacia L

    Directory of Open Access Journals (Sweden)

    Orlović Saša S.

    2004-01-01

    Full Text Available Variability within R. pseudoacacia species represents an important factor in selection of fast-growing genotypes. Therefore, it is important to identify superior individuals according to their anatomical and physiological traits. This paper presents the results of a study of genotype variability of the main leaf anatomical (frequency, length and width of stomata, leaflet thickness among veins, leaflet thickness on the main vein, mesophyll thickness, length and width of vascular bundle of main vein and physiological (leaf area, photosynthetic pigments content and content of N P, K, Ca, Na parameters among five clones of Robinia pseudoacacia L. Significant interclonal variations were observed in the investigated parameters. Clone R-56 had the highest N, P, and K concentrations, the largest mesophyll volume and the highest pigment concentration. We concluded that the clone R-56, although without a remarkable leaf area, possesses the ability for high photosynthetic production. The results are going to be used in further work on selection.

  6. Cytomorphological studies in X-ray induced glandless haploids in Gossypium hirsutum L. (cotton)

    Energy Technology Data Exchange (ETDEWEB)

    Mehetre, S.S.; Thombre, M.V. (Mahatma Phule Krishi Vidyapeeth, Rahuri (India))

    1981-08-01

    Six haploid plants were obtained in M/sub 2/ generation of the 25 kr. X-ray irradiated Gossypium hirsutum L. cotton variety H.G. 108. The cytomorphological studies on these plants indicated highly irregular meiosis, giving on an average six bivalents, the range being 0-9. Unequal separation of chromosomes and chromatids at anaphase-1 and II respectively led to formation of abnormal tetrads and pollens with high size variations leading to high pollen sterility. These plants were characterized by miniature stature, shorter stem and internodes, smaller leaves, flowers and stomata with fewer chloroplasts, male and female sterility and halving of chromosomes. The reduction in morphological characters was nearly in the proportion of 1:2 as compared to their diploid counterparts. 31 refs.; 5 tables; 12 figures.

  7. Silica Deposition on the Leaves of Mir- and Earth-Grown Super Dwarf Wheat

    Science.gov (United States)

    Campbell, William F.; Bubenheim, David L.; Salisbury, Frank B.; Bingham, Gail E.; McManus, William R.; Biesinger, H. D.; Strickland, D. T.; Levinskikh, Maragarita; Sytchev, Vladimir N.; Podolsky, Igor

    2000-01-01

    Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) microanalysis were used to investigate the nature of crystals deposited on leaves of Mir- and Earth-grown Super Dwarf wheat (Triticum aestivum L.) plants. Leaves from these plants exhibited dense and uniformly distributed crystals on leaf abaxial surfaces when viewed by SEM. Young leaves showed that crystals initially accumulated around the stomata on the adaxial surface, but became more dense and uniformly distributed as the leaves aged. EDX microanalyses of the Balkanine (a nutrient charged clinoptilolite zeolite) medium in which the wheat plants were grown showed an elemental pattern similar to that observed on the wheat leaves. The absence of N and P in the Balkanine suggests that they were completely utilized by the plants. Only Si and O were evident in the drying agent, Sorb-it-Silica (trademark), and perhaps could have accounted for some of the Si observed on the plant tissue.

  8. Underwater photosynthesis and respiration in leaves of submerged wetland plants: gas films improve CO2 and O2 exchange

    DEFF Research Database (Denmark)

    Colmer, Timothy David; Pedersen, Ole

    2007-01-01

    (N) was enhanced up to sixfold. Gas films on submerged leaves enable continued gas exchange via stomata and thus bypassing of cuticle resistance, enhancing exchange of O(2) and CO(2) with the surrounding water, and therefore underwater P(N) and respiration.......Many wetland plants have gas films on submerged leaf surfaces. We tested the hypotheses that leaf gas films enhance CO(2) uptake for net photosynthesis (P(N)) during light periods, and enhance O(2) uptake for respiration during dark periods. Leaves of four wetland species that form gas films......, and two species that do not, were used. Gas films were also experimentally removed by brushing with 0.05% (v/v) Triton X. Net O(2) production in light, or O(2) consumption in darkness, was measured at various CO(2) and O(2) concentrations. When gas films were removed, O(2) uptake in darkness was already...

  9. Survival strategies of plants during water stress

    International Nuclear Information System (INIS)

    Scheuermann, R.; Stuhlfauth, T.; Sueltemeyer, D.; Fock, H.

    1989-01-01

    Fluorescence and gas exchange of bean, maize, sunflower and wooly foxglove were simultaneously measured at 250 μmol quanta/m 2 /s. Under severe water stresses conditions about 40% of the photochemical energy was converted to heat at PS II. This is interpreted as a protective mechanism against photoinhibitory damage when net CO 2 uptake is reduced by about 70%. After 14 CO 2 gas exchange, only in bean was a homogeneous distribution of radioactivity over the leaf observed. In all other plants we found a patchy distribution of regions with either an intensive or a reduced gas exchange. We conclude that CO 2 -recycling (photorespiration and reassimilation) behind closed stomata also contributed to energy dissipation under severe stress conditions

  10. MAPK cascades in guard cell signal transduction

    Directory of Open Access Journals (Sweden)

    Yuree eLee

    2016-02-01

    Full Text Available Guard cells form stomata on the epidermis and continuously respond to endogenous and environmental stimuli to fine-tune the gas exchange and transpirational water loss, processes which involve mitogen-activated protein kinase (MAPK cascades. MAPKs form three-tiered kinase cascades with MAPK kinases and MAPK kinase kinases, by which signals are transduced to the target proteins. MAPK cascade genes are highly conserved in all eukaryotes, and they play crucial roles in myriad developmental and physiological processes. MAPK cascades function during biotic and abiotic stress responses by linking extracellular signals received by receptors to cytosolic events and gene expression. In this review, we highlight recent findings and insights into MAPK-mediated guard cell signaling, including the specificity of MAPK cascades and the remaining questions.

  11. SALINITY AND ITS EFFECTS ON THE PHYSIOLOGICAL RESPONSE OF BEAN (PHASEOLUS VULGARIS L.

    Directory of Open Access Journals (Sweden)

    Miroslava Kaymakanova

    2009-06-01

    Full Text Available The effect of salt stress оn the physiological reaction in young bean plants was studied. The plants were grown in pots as hydroponic cultures in half-strength Hoagland nutrient solution under controlled conditions in a climatic room. The plants were treated for 7 days with NaCl and Na2SO4 (concentration 100 mM, starting at the appearance of the fi rst trifoliate leaf unfolded. The salts were added to the nutrient solution. It was established that the equimolar concentrations of both salt types caused stress in the young bean plants, which found expression in the suppression of growth, photosynthesis activity and caused changes in stomata status (conductivity, number and size. The transpiration and the cell water potential in salt-treated plants were reduced. The MDA level in root and shoot, and the proline content was increased.

  12. Detoxification and repair process of ozone injury: From O3 uptake to gene expression adjustment

    International Nuclear Information System (INIS)

    Castagna, A.; Ranieri, A.

    2009-01-01

    Plants react to O 3 threat by setting up a variety of defensive strategies involving the co-ordinated modulation of stress perception, signalling and metabolic responses. Although stomata largely controls O 3 uptake, differences in O 3 tolerance cannot always be ascribed to changes in stomatal conductance but cell protective and repair processes should be taken into account. O 3 -driven ROS production in the apoplast induces a secondary, active, self-propagating generation of ROS, whose levels must be finely tuned, by many enzymatic and non-enzymatic antioxidant systems, to induce gene activation without determining uncontrolled cell death. Additional signalling molecules, as ethylene, jasmonic and salicylic acid are also crucial to determine the spreading and the containment of leaf lesions. The main recent results obtained on O 3 sensing, signal transduction, ROS formation and detoxification mechanisms are here discussed. - A dissection of the complex network of interacting mechanisms which determine the cell fate under ozone stress.

  13. [Histo-anatomical researches of two subspecies of Lavandula angustifolia Mill].

    Science.gov (United States)

    Robu, Silvia; Galeş, Ramona; Toma, C; Stănescu, Ursula

    2011-01-01

    The structure of the inflorescences of two subspecies of Lavandula angustifolia sL. angustifolia ssp. angustifolia and. L. angustifolia ssp. pyrenaica (D.C.) Guineaţ was studied to determine the range of variation in certain histo-anatomical characters. The flower and leaf structure has been analysed on cross and superficial section using the usual techniques and methods applied in plant histo-anatomical research. In cross-section, inflorescence axis has a squared-shape contour, with four proeminent ribs. On the epiderme of inflorescence axis there are present stomata, trichoms and secretory hairs. The trichoms are pluricelullar and T-branched. The secretory hairs have a short pedicel and a uni-or bicellular head. The study revealed that there are only quantitative differences, referring to the degree of sclerification and lignification of mechanical elements and the size of the vascular bundles.

  14. Binding of Human GII.4 Norovirus Virus-Like Particles to Carbohydrates of Romaine Lettuce Leaf Cell Wall Materials

    Science.gov (United States)

    Esseili, Malak A.

    2012-01-01

    Norovirus (NoV) genogroup II genotype 4 (GII.4) strains are the dominant cause of the majority of food-borne outbreaks, including those that involve leafy greens, such as lettuce. Since human NoVs use carbohydrates of histo-blood group antigens as receptors/coreceptors, we examined the role of carbohydrates in the attachment of NoV to lettuce leaves by using virus-like particles (VLPs) of a human NoV/GII.4 strain. Immunofluorescence analysis showed that the VLPs attached to the leaf surface, especially to cut edges, stomata, and along minor veins. Binding was quantified using enzyme-linked immunosorbent assay (ELISA) performed on cell wall materials (CWM) from innermost younger leaves and outermost lamina of older leaves. The binding to CWM of older leaves was significantly (P lettuce CWM by utilizing multiple carbohydrate moieties. This binding may enhance virus persistence on the leaf surface and prevent effective decontamination. PMID:22138991

  15. Drought stress had a predominant effect over heat stress on three tomato cultivars subjected to combined

    DEFF Research Database (Denmark)

    Zhou, Rong; Yu, Xiaqing; Ottosen, Carl-Otto

    2017-01-01

    and relative water content of all cultivars significantly decreased under drought and combined stress as compared to control. The net photosynthesis and starch content were significantly lower under drought and combined stress than control in the three cultivars. Stomata and pore length of the three cultivars......BACKGROUND: Abiotic stresses due to environmental factors could adversely affect the growth and development of crops. Among the abiotic stresses, drought and heat stress are two critical threats to crop growth and sustainable agriculture worldwide. Considering global climate change, incidence...... of combined drought and heat stress is likely to increase. The aim of this study was to shed light on plant growth performance and leaf physiology of three tomatoes cultivars ('Arvento', 'LA1994' and 'LA2093') under control, drought, heat and combined stress. RESULTS: Shoot fresh and dry weight, leaf area...

  16. Drivers of Holocene treeline and timberline changes in the Retezat Mountains (South Carpathians, Romania

    Directory of Open Access Journals (Sweden)

    Ildiko VINCZE

    2014-11-01

    Full Text Available Four high-altitude lake sediment sequences (Lake Brazi, 1740 m .as.l., Lake Gales 1990 m a.s.l., Lake Bucura, 2040 m a.s.l. and Lake Lia, 1910 m a.s.l. were analyzed using multi-proxy methods (pollen, stomata, plant macrofossil and micro- and macrocharcoal in order to study responses of treeline and alpine/subalpine vegetation to climate change and human impact during the last 15000 years. Observing and reconstructing the changes of the position and structure of the treeline can provide valuable information on biotic and other factors such as human activities. Sediment cores were taken from two lakes on the northern slope (Lake Brazi and Lake Gales and two lakes from the southern slope (Lake Lia and Lake Bucura in the Retezat Mountains, South Carpathians (Romania.

  17. Comparative Leaf Anatomy of Gaiadendron punctatum and Tripodanthus belmirensis (Loranthaceae

    Directory of Open Access Journals (Sweden)

    Isabel Carmona Gallego

    2018-01-01

    Full Text Available Leaf anatomy of Gaiadendron punctatum and Tripodanthus belmirensis species is described with the aim of exploring possible characters that allow a precise identification of these two genera, characterized by tree or shrub habit, belonging to Loranthaceae family. Samples were processed and stained with routine techniques for observation on optical microscope. Both species showed similarities, such as one-layered epidermis and rubiaceous type stomata. However, a different anatomic composition was observed in aspects such as: mesophyll, position and shape of epidermic cells and presence of suber accumulations in G. punctatum, or numerous idioblasts in T. belmirensis. A dichotomous key was constructed for species determination based on anatomical leaf characters, between the species of genus Tripodanthus and G. punctatum. Furthermore, the use of anatomical characters in determination and support of distinguishable taxonomical entities inside Loranthaceae is also briefly discussed.

  18. KARAKTER FENOTIP KEDELAI (Glycine max (L. Merr. HASIL POLIPLOIDISASI DENGAN KOLKISIN

    Directory of Open Access Journals (Sweden)

    Irma Nofitahesti

    2016-12-01

    Full Text Available Abstract - Soybean (Glycine max (L. Merr is one of the most important food commodity to fulfill the protein necessity in Indonesia. Although Indonesia has many prime soybean seeds, it cannot fulfill the whole need of soybean and always rely on soybean import. This problem can be solved by increasing the quality and productivity of prime soybean seed by polyploidization with colchicine. This research aimed to study ploidy level and phenotype characters of Anjasmoro soybean which was induced by colchicine. The phenotype characters in this research were stomata size, plant height, total pod in one plant, total seed in one plant, weight of 100 seeds, flowering time, and ripening time of soybean. The ploidy level was analyzed with flow cytometry methode. The data was analyzed with one way ANOVA and Duncan test in SPSS 22 program. The result of this research showed that Anjasmoro soybean did not successfully induced by colchicine using concentration 0.01%, 0.02%, 0.025%, 0.05%, 0.075%, 0.1%, 0.15%, 0.2%, and 0.25% with duration of treatment 6, 8, 10, 12, 16, 18, and 24 hours. The treatment with colchicine concentration 0.01% and 0.02% with duration of treatment 10 hours effected the increasing of stomata size, the plant height, and the weight of 100 seeds.Key words : Soybean, polyploidization, colchicine, phenotypeAbstrak - Kedelai (Glycine max (L. Merr merupakan salah satu komoditas pangan penting sebagai sumber protein nabati yang kebutuhannya selalu mengalami peningkatan di Indonesia. Meskipun saat ini Indonesia memiliki banyak varietas kedelai unggul, namun Indonesia masih belum mampu mencukupi kebutuhan kedelai nasional sehingga terus bergantung pada impor kedelai. Permasalahan ini dapat diatasi dengan meningkatkan kualitas dan produktivitas varietas kedelai unggul yang sudah ada melalui teknik poliploidisasi dengan kolkisin. Penelitian ini bertujuan untuk mengetahui derajat ploidi dan karakter fenotip pada kedelai Anjasmoro yang diinduksi dengan

  19. Stomatal acclimation to vapour pressure deficit doubles transpiration of small tree seedlings with warming

    DEFF Research Database (Denmark)

    Marchin, Renée M.; Broadhead, Alice A.; Bostic, Laura E.

    2016-01-01

    chamber VPD. Warming increased mean water use of Carya by 140% and Quercus by 150%, but had no significant effect on water use of Acer. Increased water use of ring-porous species was attributed to (1) higher air T and (2) stomatal acclimation to VPD resulting in higher gs and more sensitive stomata......Future climate change is expected to increase temperature (T) and atmospheric vapour pressure deficit (VPD) in many regions, but the effect of persistent warming on plant stomatal behaviour is highly uncertain. We investigated the effect of experimental warming of 1.9-5.1 °C and increased VPD of 0.......5-1.3 kPa on transpiration and stomatal conductance (gs ) of tree seedlings in the temperate forest understory (Duke Forest, North Carolina, USA). We observed peaked responses of transpiration to VPD in all seedlings, and the optimum VPD for transpiration (Dopt ) shifted proportionally with increasing...

  20. Macroscopy and Microscopy Study of Scopraia dulcis L.

    Directory of Open Access Journals (Sweden)

    Djoko Santosa

    2018-04-01

    Full Text Available A morphological diversity analysis of Scoparia dulcis by macroscopy and microscopy has been conducted. The aim of this research is to determine the morphological and anatomical character of S. dulcis which grow in Opak watershed, Special Region of Yogyakarta. Samples were taken from Sleman (Cangkringan, Ngemplak Kalasan, and Prambanan and Bantul (Imogiri and Pundong region. Selection of sampling location is based on altitude difference. The samples are the third leaf order from the tip of the stem. They were measured in length and width. Microscopy analysis was performed by observing the number of glandular trichomes, palisade cells in the epidermis and stomata in the upper and lower epidermis. The data obtained were analyzed using principal component analysis (PCA. The results show that based on morphological and anatomical assessment, there were found 3 clusters of S. dulcis, i.e. Cangkringan-Ngemplak-Prambanan, Kalasan, and Imogiri-Pundong cluster.

  1. Carbon Dioxide Physiological Forcing Dominates Projected Eastern Amazonian Drying

    Science.gov (United States)

    Richardson, T. B.; Forster, P. M.; Andrews, T.; Boucher, O.; Faluvegi, G.; Fläschner, D.; Kasoar, M.; Kirkevâg, A.; Lamarque, J.-F.; Myhre, G.; Olivié, D.; Samset, B. H.; Shawki, D.; Shindell, D.; Takemura, T.; Voulgarakis, A.

    2018-03-01

    Future projections of east Amazonian precipitation indicate drying, but they are uncertain and poorly understood. In this study we analyze the Amazonian precipitation response to individual atmospheric forcings using a number of global climate models. Black carbon is found to drive reduced precipitation over the Amazon due to temperature-driven circulation changes, but the magnitude is uncertain. CO2 drives reductions in precipitation concentrated in the east, mainly due to a robustly negative, but highly variable in magnitude, fast response. We find that the physiological effect of CO2 on plant stomata is the dominant driver of the fast response due to reduced latent heating and also contributes to the large model spread. Using a simple model, we show that CO2 physiological effects dominate future multimodel mean precipitation projections over the Amazon. However, in individual models temperature-driven changes can be large, but due to little agreement, they largely cancel out in the model mean.

  2. Stomatal Responses to Light and Drought Stress in Variegated Leaves of Hedera helix1

    Science.gov (United States)

    Aphalo, Pedro J.; Sánchez, Rodolfo A.

    1986-01-01

    Direct and indirect mechanisms underlying the light response of stomata were studied in variegated leaves of the juvenile phase of Hedera helix L. Dose response curves of leaf conductance were measured with blue and red light in leaves kept in normal or in an inverted position. In the green portions of the leaves, the sensitivity to blue light was nearly 100 times higher than that to red light. No response to red light was observed in the white portions of the leaves up to 90 micromoles per square meter per second. Red light indirectly affected leaf conductance while blue light had a direct effect. Leaf conductance was found to be more sensitive to drought stress and showed a more persistent aftereffect in the white portions of the leaves. A differential effect of drought stress on the responses to blue and red light was also observed. PMID:16664900

  3. Use of sap flow measurements to validate stomatal functions for mature beech (Fagus sylvatica) in view of ozone uptake calculations

    International Nuclear Information System (INIS)

    Braun, Sabine; Schindler, Christian; Leuzinger, Sebastian

    2010-01-01

    For a quantitative estimate of the ozone effect on vegetation reliable models for ozone uptake through the stomata are needed. Because of the analogy of ozone uptake and transpiration it is possible to utilize measurements of water loss such as sap flow for quantification of ozone uptake. This technique was applied in three beech (Fagus sylvatica) stands in Switzerland. A canopy conductance was calculated from sap flow velocity and normalized to values between 0 and 1. It represents mainly stomatal conductance as the boundary layer resistance in forests is usually small. Based on this relative conductance, stomatal functions to describe the dependence on light, temperature, vapour pressure deficit and soil moisture were derived using multivariate nonlinear regression. These functions were validated by comparison with conductance values directly estimated from sap flow. The results corroborate the current flux parameterization for beech used in the DO 3 SE model. - A method was developed to derive stomatal functions and ozone uptake calculation from sap flow.

  4. Ozone impacts on cotton: towards an integrated mechanism

    International Nuclear Information System (INIS)

    Grantz, D.A.

    2003-01-01

    Vegetation removes tropospheric ozone (O 3 ) mainly through uptake by stomata. O 3 reduces growth, photosynthesis, and carbohydrate allocation. Effects on mesophyll photosynthesis, may reducing carbohydrate source strength and, indirectly, carbohydrate translocation. Alternatively direct translocation, itself, could explain all of these observations. O 3 -reduced root proliferation inhibits exploitation of soil resources and interferes with underground carbon sequestration. Simulations with cotton suggest O 3 -disrupted root development could indirectly reduce shoot photosynthesis. Strong evidence for O 3 impacts on both carbon assimilation and carbon translocation exists, but data determining the primacy of direct or indirect O 3 effects on either or both processes remain inconclusive. Pholoem loading may be particularly sensitive to O 3 . Further research on metabolic feedback control of carbon assimilation and phloem loading activity as affected by O 3 exposure is required. - Ozone impacts on Pima cotton are reviewed to evaluate the possibility that a direct effect on carbohydrate translocation could mediate the suite of symptoms observed

  5. Separating active and passive influences on stomatal control of transpiration.

    Science.gov (United States)

    McAdam, Scott A M; Brodribb, Timothy J

    2014-04-01

    Motivated by studies suggesting that the stomata of ferns and lycophytes do not conform to the standard active abscisic acid (ABA) -mediated stomatal control model, we examined stomatal behavior in a conifer species (Metasequoia glyptostroboides) that is phylogenetically midway between the fern and angiosperm clades. Similar to ferns, daytime stomatal closure in response to moderate water stress seemed to be a passive hydraulic process in M. glyptostroboides immediately alleviated by rehydrating excised shoots. Only after prolonged exposure to more extreme water stress did active ABA-mediated stomatal closure become important, because foliar ABA production was triggered after leaf turgor loss. The influence of foliar ABA on stomatal conductance and stomatal aperture was highly predictable and additive with the passive hydraulic influence. M. glyptostroboides thus occupies a stomatal behavior type intermediate between the passively controlled ferns and the characteristic ABA-dependent stomatal closure described in angiosperm herbs. These results highlight the importance of considering phylogeny as a major determinant of stomatal behavior.

  6. Stochastic gene expression in Arabidopsis thaliana.

    Science.gov (United States)

    Araújo, Ilka Schultheiß; Pietsch, Jessica Magdalena; Keizer, Emma Mathilde; Greese, Bettina; Balkunde, Rachappa; Fleck, Christian; Hülskamp, Martin

    2017-12-14

    Although plant development is highly reproducible, some stochasticity exists. This developmental stochasticity may be caused by noisy gene expression. Here we analyze the fluctuation of protein expression in Arabidopsis thaliana. Using the photoconvertible KikGR marker, we show that the protein expressions of individual cells fluctuate over time. A dual reporter system was used to study extrinsic and intrinsic noise of marker gene expression. We report that extrinsic noise is higher than intrinsic noise and that extrinsic noise in stomata is clearly lower in comparison to several other tissues/cell types. Finally, we show that cells are coupled with respect to stochastic protein expression in young leaves, hypocotyls and roots but not in mature leaves. Our data indicate that stochasticity of gene expression can vary between tissues/cell types and that it can be coupled in a non-cell-autonomous manner.

  7. Anatomical characteristics of Turkish steno-endemic Origanum leptocladum Boiss. (Lamiaceae

    Directory of Open Access Journals (Sweden)

    Süleyman Doğu

    2013-04-01

    Full Text Available Origanum leptocladum Boiss. is an endemic East Mediterranean element, naturally growing only in Ermenek district of Karaman province in Turkey. The aim of this study is to determine anatomical features of the species. The study materials were collected from Karaman-Ermenek in 2009 and then preserved in 70 % alcohol. O. leptocladum generally exhibits the anatomical feaures of the family Lamiaceae. Hovewer, herbaceaus stem is weakly-rectangle shaped or tends to be circular, the collenchymatic tissue at the corner of the stem and scleranchymatic pericycle around the vascular tissue are weakly-developed. The most striking anatomical feature is that leaf lamina is dorsiventral in the region near to midvein, but equifacial out of the midvein. According to the results, while the stomata are of mesomorphic type on the leaf surfaces, O. leptocladum has xeromorphic characters such as palisade richness in mesophyll, the occurrence of rich scleranchymatic tissue in midvein and cuticle thickness on leaf surface.

  8. Micromorphology and ultrastructure of the floral nectaries of Viola odorata L. (Violaceae

    Directory of Open Access Journals (Sweden)

    Natalia Wiśniewska

    2015-05-01

    Full Text Available In Viola odorata two inferior anthers have connective appendages (nectaries projecting into the corolla spur. Nectaries are approx. 4 mm long, elongate, with the top of the nectary bending to the lateral wall of the spur. In the top part and in the abaxial surface of middle part of the nectary all cells have papillae. Nectar is secreted through the modified stomata distributed mainly in the top of nectary The nectary consists of single-layered epidermis, nectary parenchyma and subnectary parenchyma. Features of the nectary parenchyma cells, like dense cytoplasm containing numerous mitochondria and large nuclei, are connected with high metabolic cell activity. The vascularization includes both phloem and xylem. A slight amount of starch in the nectary cells, the profusion of plasmodesmata connecting secretory cells and the presence of vascular bundles suggest that sugars secreted in the nectar were delivered by the phloem sap.

  9. Extrafloral nectaries of annatto ( Bixa orellana L.: anatomy, nectar composition and activity during organ development

    Directory of Open Access Journals (Sweden)

    Rafaela Marques de Miranda

    Full Text Available ABSTRACT This study aimed to anatomically characterize the extrafloral nectaries (EFNs of annatto (Bixa orellana and determine the composition of its nectar in order to better understand their structure and function during organ development. Standard light and scanning electron microscopy techniques were used for anatomical analysis, and test-strips and a refractometer for determining nectar composition. Both receptacle and stem EFNs were found to possess similar anatomy and nectar composition, and to secrete from early to advanced developmental stages of the organs to which they are associated. EFNs consisting of uniseriate epidermis, nectariferous parenchyma and subnectariferous parenchyma were found located where vascular tissue is immersed. Some layers of nectariferous parenchyma exhibited sclerification and cells with phenolic compounds or calcium oxalate druses were present. Nectar exuded by stomata was acidic, diluted and found to contain sugar. The anatomical and histochemical features of annatto EFNs ensure their integrity and nectar secretion function during the development of buds, flowers and fruits.

  10. MORPHOLOGICAL ANALYSIS OF THE LEAVES OF Anacardium occidentale L.

    Directory of Open Access Journals (Sweden)

    Glenda Quaresma Ramos

    2016-03-01

    Full Text Available In morphological studies are analyzed various parameters, ranging from macro scale through the micro scale to the nanometer scale, which contribute to the study of taxonomy, pharmacognosy, ecology, among others. Among the structures found in plants, the leaves are most organs analyzed. This study aimed to analyze morphological features of the leaves of the cashew tree, which is a plant of great commercial importance in Brazil. In this work we observed sinuous epidermal cells in the adaxial and abaxial, characterize their stomata in paracytic surrounded subsidiaries cells. On the abaxial surface the presence of glandular trichomes was observed; and cross-sectional analysis showed a single-layered epidermis with compact mesophyll and several layers of parenchyma cells. Keywords: leaf anatomy; cashew tree; optical microscopy.

  11. [Morphology, anatomy and floral biology of Cabralea canjerana (Vell.) Mart. (Meliaceae)].

    Science.gov (United States)

    Moscheta, Ismar S; de Souza, Luiz A; Mourão, Káthia S; da Rosa, Sônia M

    2002-01-01

    Cabralea canjerana (Vell.) Mart. is a tree that occurs frequently in secondary forests of Maringá, Paraná, Brazil and presents a valuable wood. Its flowering time occurs from August to October and the anthesis occurs during the night. Its flowers are visited by Lepidoptera-Noctuidae. The flowers are unisexual and solitary or arranged in panicles. The perianth presents a papillose epidermis with striate cuticle and a parenchymatic mesophyll. Ten stamens constitute the androecium and are arranged in a staminal tube with anthers. The anthers present epidermis, endothecium, two median layers and secretory tapetum with binucleate cells. The semi-inferior ovary presents anatropous, bitegmic and crassinucleate ovules. The nectaries are located in the base of the ovary and staminal tube and they present papillose epidermis with stomata and secretory parenchyma with a conspicuous phloematic tissue.

  12. Anatomy and Micromorphology of Inula helenium subsp. orgyalis and I. ensifolia (Asteraceae from Turkey

    Directory of Open Access Journals (Sweden)

    Tulay AYTAS AKCIN

    2017-03-01

    Full Text Available Inula helenium L. subsp. orgyalis (Boiss. Grierson and Inula ensifolia L. were investigated anatomically and micromorphologically. The secretory cavities in the leaves and stem of both investigated taxa were located in the neighbourhood of the vascular bundles and in the rhizomes in the secondary cortex. The leaf mesophylls of investigated Inula taxa were homogeneous. Stomata were anomocytic in two species. The distribution and density of the eglandular and glandular trichomes provide information of taxonomical significance. Moreover, the cypselas of I. helenium L. subsp. orgyalis were homomorphic, whereas in I. ensifolia cypselas were heteromorphic. Additionally, the number of ribs, the shape of carpopodium and stylopodium were diagnostic taxonomic characters between the two taxa.

  13. Features of morpho-anatomic structure of vegetative organs of Sedum antiquum Omelcz et Zaverucha (Crassulaceae DC.

    Directory of Open Access Journals (Sweden)

    Valentyna Berezkina

    2015-05-01

    Full Text Available The study results of biological features and morpho-anatomical structure of vegetative organs of Sedum antiquum Omelcz et Zaverucha (Crassulaceae DC. are given. S. antiquum is Eastern Carpathian-Opillia rare endemic species. It is listed in the Red Book of Ukraine and in the European Red List of Animals and Plants and is endangered in world scale. As a result of study of morpho-anatomic structure of leaves and stems of S. antiquum the anisocytic type of stomata and presence of cuticle have been determined. It was ascertained that structure of leaves is adapted to the accumulation of significant water reserves and its further gradual use. Ecological and phytocenotic conditions of growth are studied too. S. antiquum has been determined here as petrophyte, calcephyl, and succulent ephemer. This rare species need protection and control of population state in all natural habitats.

  14. Air pollution and tree growth

    Energy Technology Data Exchange (ETDEWEB)

    Scurfield, G

    1960-01-01

    The problem of air pollution is reviewed with emphasis on its origin and its effects on trees and shrubs. These effects are described from two points of view: the effects of general air pollution, and also the effects of specific pollutants. The considerable mixing, dilution and interaction that pollutants undergo in the air often renders it exceedingly difficult to assign pollution damage to any specific chemical or physical entity. Moreover, it is often impossible to assign responsibility for damage to any particular source. The constituents of general air pollution may be subdivided into those potentially incapable, and those potentially capable, of entering the plant either through the leaf stomata or indirectly by way of the soil. Specific pollutants cause damage directly, as well as indirectly from the chemical reactions that occur in the polluted atmosphere. Sulfur dioxide is discussed in detail in relation to tree and shrub damage, with numerous examples of plant injuries.

  15. Estabilidade da sílica biogênica extraída de capim Jaraguá (Hyparrhenia rufa em solução de NaOH Stability of biogenic silica extract of Jaraguá grass (Hyparrhenia rufa in NaOH solution

    Directory of Open Access Journals (Sweden)

    Liovando M. Costa

    2010-01-01

    Full Text Available Biogenic silica is used to describe compounds of hydrated silica (SiO2.nH2O, with specific shapes and sizes, deposited in plants. The chemical composition of biogenic silica and its stability in Jaraguá grass was studied in increasing concentration of NaOH. The analytical results demonstrated high concentration of Si, Al, Fe, Mg, P and low of Cu, Cd and Zn in the phytoliths composition. The silica bodies stability in NaOH solution with increasing concentration was different among the shapes and sizes. Silicified stomata and silicified plant tissues were dissolved along with the dumbbells because they are the less stable forms of biogenic silica.

  16. The effect of temperature on photosynthetic induction under fluctuating light in Chrysanthemum morifolium

    DEFF Research Database (Denmark)

    Öztürk, Isik; Ottosen, Carl-Otto; Ritz, Christian

    2013-01-01

    for photosynthetic induction. Gas exchange measurements were used to investigate the rate of induction and the opening of stomata. It was determined that induction equilibrium for C. morifolium at varying temperatures under dynamic light conditions was reached within 15 to 45 minutes except at saturating light...... intensity. For the same photon irradiance, the momentary state of induction equilibrated was higher approximately at 30° C and it decreased as temperature increased. The interaction effect of irradiance and temperature on induction equilibrium was not significant. The rate of photosynthetic induction...... and the time that it reached its 90% value (t90) was influenced by irradiance significantly. The light history of a leaf had a significant effect on t90, which indicated that an equilibrium state of induction will not always be reached within the same time. The effect of temperature on photosynthetic induction...

  17. Nanoparticle synthesis and delivery by an aerosol route for watermelon plant foliar uptake

    Science.gov (United States)

    Wang, Wei-Ning; Tarafdar, Jagadish C.; Biswas, Pratim

    2013-01-01

    An aerosol process was developed for synthesis and delivery of nanoparticles for living watermelon plant foliar uptake. This is an efficient technique capable of generating nanoparticles with controllable particle sizes and number concentrations. Aerosolized nanoparticles were easily applied to leaf surfaces and enter the stomata via gas uptake, avoiding direct interaction with soil systems, eliminating potential ecological risks. The uptake and transport of nanoparticles inside the watermelon plants were investigated systematically by various techniques, such as elemental analysis by inductively coupled plasma mass spectrometry and plant anatomy by transmission electron microscopy. The results revealed that certain fractions of nanoparticles ( d p watermelon plants. The particle size and number concentration played an important role in nanoparticle translocation inside the plants. In addition, the nanoparticle application method, working environment, and leaf structure are also important factors to be considered for successful plant foliar uptake.

  18. CO2 sensing and CO2 regulation of stomatal conductance: advances and open questions

    Science.gov (United States)

    Engineer, Cawas; Hashimoto-Sugimoto, Mimi; Negi, Juntaro; Israelsson-Nordstrom, Maria; Azoulay-Shemer, Tamar; Rappel, Wouter-Jan; Iba, Koh; Schroeder, Julian

    2015-01-01

    Guard cells form epidermal stomatal gas exchange valves in plants and regulate the aperture of stomatal pores in response to changes in the carbon dioxide (CO2) concentration in leaves. Moreover, the development of stomata is repressed by elevated CO2 in diverse plant species. Evidence suggests that plants can sense CO2 concentration changes via guard cells and via mesophyll tissues in mediating stomatal movements. We review new discoveries and open questions on mechanisms mediating CO2-regulated stomatal movements and CO2 modulation of stomatal development, which together function in CO2-regulation of stomatal conductance and gas exchange in plants. Research in this area is timely in light of the necessity of selecting and developing crop cultivars which perform better in a shifting climate. PMID:26482956

  19. Stomatal design principles in synthetic and real leaves

    DEFF Research Database (Denmark)

    Zwieniecki, Maciej A.; Haaning, Katrine S; Boyce, C. Kevin

    2016-01-01

    Stomata are portals in plant leaves that control gas exchange for photosynthesis, a process fundamental to life on Earth. Gas fluxes and plant productivity depend on external factors such as light, water and CO2 availability and on the geometrical properties of the stoma pores. The link between...... for major trends in stomatal patterning are not well understood. Here, we use a combination of biomimetic experiments and theory to rationalize the observed changes in stoma geometry. We show that the observed correlations between stoma size and density are consistent with the hypothesis that plants favour...... efficient use of space and maximum control of dynamic gas conductivity, and that the capacity for gas exchange in plants has remained constant over at least the last 325 Myr. Our analysis provides a new measure to gauge the relative performance of species based on their stomatal characteristics....

  20. Leaf and stem morphoanatomy of Petiveria alliacea.

    Science.gov (United States)

    Duarte, M R; Lopes, J F

    2005-12-01

    Petiveria alliacea is a perennial herb native to the Amazonian region and used in traditional medicine for different purposes, such as diuretic, antispasmodic and anti-inflammatory. The morphoanatomical characterization of the leaf and stem was carried out, in order to contribute to the medicinal plant identification. The plant material was fixed, freehand sectioned and stained either with toluidine blue or astra blue and basic fuchsine. Microchemical tests were also applied. The leaf is simple, alternate and elliptic. The blade exhibits paracytic stomata on the abaxial side, non-glandular trichomes and dorsiventral mesophyll. The midrib is biconvex and the petiole is plain-convex, both traversed by collateral vascular bundles adjoined with sclerenchymatic caps. The stem, in incipient secondary growth, presents epidermis, angular collenchyma, starch sheath and collateral vascular organization. Several prisms of calcium oxalate are seen in the leaf and stem.

  1. Assay of Plasma Membrane H+-ATPase in Plant Tissues under Abiotic Stresses.

    Science.gov (United States)

    Janicka, Małgorzata; Wdowikowska, Anna; Kłobus, Grażyna

    2018-01-01

    Plasma membrane (PM) H + -ATPase, which generates the proton gradient across the outer membrane of plant cells, plays a fundamental role in the regulation of many physiological processes fundamental for growth and development of plants. It is involved in the uptake of nutrients from external solutions, their loading into phloem and long-distance transport, stomata aperture and gas exchange, pH homeostasis in cytosol, cell wall loosening, and cell expansion. The crucial role of the enzyme in resistance of plants to abiotic and biotic stress factors has also been well documented. Such great diversity of physiological functions linked to the activity of one enzyme requires a suitable and complex regulation of H + -ATPase. This regulation comprises the transcriptional as well as post-transcriptional levels. Herein, we describe the techniques that can be useful for the analysis of the plasma membrane proton pump modifications at genetic and protein levels under environmental factors.

  2. Leaf Epidermis of the Rheophyte Dyckia brevifolia Baker (Bromeliaceae

    Directory of Open Access Journals (Sweden)

    Ghislaine Maria Lobo

    2013-01-01

    Full Text Available Some species of Dyckia Schult. f., including Dyckia brevifolia Baker, are rheophytes that live in the fast-moving water currents of streams and rivers which are subject to frequent flooding, but also period of low water. This study aimed to analyze the leaf epidermis of D. brevifolia in the context of epidermal adaptation to this aquatic plant’s rheophytic habitat. The epidermis is uniseriate, and the cuticle is thickened. The inner periclinal and anticlinal walls of the epidermal cells are thickened and lignified. Stomata are tetracytic, located in the depressions in relation to the surrounding epidermal cells, and covered by peltate trichomes. While the epidermal characteristics of D. brevifolia are similar to those of Bromeliaceae species, this species has made particular adaptations of leaf epidermis in response to its rheophytic environment.

  3. Chloroplastic and stomatal aspects of ozone-induced reduction of net photosynthesis in plants

    Energy Technology Data Exchange (ETDEWEB)

    Torsethaugen, Gro

    1998-09-01

    The present thesis relates to ozone-induced reduction of photosynthesis in plants. As a photochemical oxidant O{sub 3} is formed by the interaction of hydrocarbons, nitrogen oxides and oxygen in sunlight. Ozone (O{sub 3}) is the most phytotoxic of all the air pollutants and is known to reduce plant growth and net photosynthesis, cause stomatal closure, induce visible injury, accelerate senescence and induce or inhibit transcription of a variety of genes with a corresponding increase/decrease in protein products. The underlying cellular mechanisms for many of these changes are unknown. Following fields are investigated: Ozone-induced reduction of net photosynthesis; ozone and the photosynthetic apparatus in the chloroplasts; ozone and stomata; ozone effects on plant membranes; protection against ozone injury in plants. 249 refs., 22 figs., 4 tabs.

  4. Effects of extreme heat and drought on trees: what do we know and what do we need to know?

    Science.gov (United States)

    Teskey, R. O.

    2017-12-01

    It is almost certain that trees will experience heat waves and droughts during their lifetime. In response, they have acquired many adaptations to survive these periods of intense stress. For example, recently we have investigated the surprising role that stomata play in maintaining leaf function at very high temperatures by opening widely to cool the leaf even when photosynthesis is zero. This process and its trade-offs, as well as many other physiological and morphological responses to high temperatures, will be discussed. The current state of knowledge of the mechanisms trees use to cope with extreme drought, including leaf shedding, hydraulic architecture, carbohydrate storage, and changes in wood anatomy will be discussed. Examples of how the interactions between drought and heat affect trees also will be provided. Finally, an assessment of knowledge gaps and recommendations for future research will be provided.

  5. Modelling drug flux through microporated skin.

    Science.gov (United States)

    Rzhevskiy, Alexey S; Guy, Richard H; Anissimov, Yuri G

    2016-11-10

    A simple mathematical equation has been developed to predict drug flux through microporated skin. The theoretical model is based on an approach applied previously to water evaporation through leaf stomata. Pore density, pore radius and drug molecular weight are key model parameters. The predictions of the model were compared with results derived from a simple, intuitive method using porated area alone to estimate the flux enhancement. It is shown that the new approach predicts significantly higher fluxes than the intuitive analysis, with transport being proportional to the total pore perimeter rather than area as intuitively anticipated. Predicted fluxes were in good general agreement with experimental data on drug delivery from the literature, and were quantitatively closer to the measured values than those derived from the intuitive, area-based approach. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Morpho-anatomical investigations on Momordica charantia L. (Cucurbitaceae

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    İlham Eröz Poyraz

    2016-05-01

    Full Text Available Momordica charantia L. (Cucurbitaceae used for some medicinal purposes like antidiabetic, anticancer, antiviral and treat to gastritis was investigated. Morphological studies were supported by morphometric measurements and drawings of male and female flowers, fruit and seeds of the species. In anatomical studies, cross sections of stem and leaf, upper and lower surface sections of leaves were evaluated. It was detected that the stem with typical anatomical properties of a climbing dicotyl plant. The leaves were amphistotamic and with lots of cyctoliths on the lower surface of leaves. Stomata are anomocytic and situated much more at the lower surface of leaves. Morpho-anatomical investigations on Momordica charantia L. (Cucurbitaceae*

  7. Diverse roles of ERECTA family genes in plant development.

    Science.gov (United States)

    Shpak, Elena D

    2013-12-01

    Multiple receptor-like kinases (RLKs) enable intercellular communication that coordinates growth and development of plant tissues. ERECTA family receptors (ERfs) are an ancient family of leucine-rich repeat RLKs that in Arabidopsis consists of three genes: ERECTA, ERL1, and ERL2. ERfs sense secreted cysteine-rich peptides from the EPF/EPFL family and transmit the signal through a MAP kinase cascade. This review discusses the functions of ERfs in stomata development, in regulation of longitudinal growth of aboveground organs, during reproductive development, and in the shoot apical meristem. In addition the role of ERECTA in plant responses to biotic and abiotic factors is examined. Elena D. Shpak (Corresponding author). © 2013 Institute of Botany, Chinese Academy of Sciences.

  8. [Plant signaling peptides. Cysteine-rich peptides].

    Science.gov (United States)

    Ostrowski, Maciej; Kowalczyk, Stanisław

    2015-01-01

    Recent bioinformatic and genetic analyses of several model plant genomes have revealed the existence of a highly abundant group of signaling peptides that are defined as cysteine-rich peptides (CRPs). CRPs are usually in size between 50 and 90 amino acid residues, they are positively charged, and they contain 4-16 cysteine residues that are important for the correct conformational folding. Despite the structural differences among CRP classes, members from each class have striking similarities in their molecular properties and function. The present review presents the recent progress in research on signaling peptides from several families including: EPF/EPFL, SP11/SCR, PrsS, RALF, LURE, and some other peptides belonging to CRP group. There is convincing evidence indicating multiple roles for these CRPs as signaling molecules during the plant life cycle, ranging from stomata development and patterning, self-incompatibility, pollen tube growth and guidance, reproductive processes, and nodule formation.

  9. The significance of radiative coupling between vegetation and the atmosphere

    International Nuclear Information System (INIS)

    Martin, P.

    1989-01-01

    In a recent theoretical study, Jarvis and McNaughton derived an expression for the elasticity of evaporation with respect to canopy conductance to analyze the coupling between vegetation and the atmosphere. They concluded that one cannot expect a fractional change in stomatal resistance to cause a proportional change in leaf or canopy transpiration, especially for vegetation with low aerodynamic roughness. However, a potentially important stomatal feedback was left out. As stomata close, transpiration decreases, while the temperature of sunlit leaves and the associated outgoing long-wave radiation from the leaf increase. The net result is a change both in transpiration and leaf net radiation. This paper examines the assumptions made in Jarvis and McNaughton's analysis, presents an alternative derivation for the elasticity of evaporation to conductance, and discusses its theoretical and practical implications

  10. Alternative perspective on the control of transpiration by radiation.

    Science.gov (United States)

    Mott, Keith A; Peak, David

    2011-12-06

    Stomatal responses to light are important determinants for plant water use efficiency and for general circulation models, but a mechanistic understanding of these responses remains elusive. A recent study [Pieruschka R, Huber G, Berry JA (2010) Proc Natl Acad Sci USA 107:13372-13377] concluded that stomata respond to total absorbed radiation rather than red and blue light as previously thought. We tested this idea by reexamining stomatal responses to red and blue light and to IR radiation. We show that responses to red and blue light are not consistent with a response to total absorbed radiation and that apparent stomatal responses to IR radiation are explainable as experimental artifacts. In addition, our data and analysis provide a method for accurately determining the internal temperature of a leaf.

  11. Nectar secretion in the flowers of comfrey (Symphytum officinale L. and nectar chemistry

    Directory of Open Access Journals (Sweden)

    Małgorzata Stpiczyńska

    2013-12-01

    Full Text Available Nectar secretion and nectar chemistry in the flowers of comfrey (Symphytum officinale L. were examined in the four stages of anthesis: large buds, before pollen exposure: II - freshy opened flowers with the beginning of anther dehiscence: III- completely opened flowers in the maximum of pollen exposure: lV- flowers at the final stage of anthesis, without pollen in the anthers. Individual flower stays fresh 2,5-3 days, on average. Disc-shaped nectaries of S.officinale are located at the base of the four-lobbed ovary. Nectar is released through the modified stomata. Start of nectar secretion was noted at the bud stage. Nectar volume, mass of nectar and sugars differed in the examined stages of anthesis and the biggest values were noted at the final stages. Dominant sugar in nectar was sucrose with smaller amounts of fructose and glucose. The presence of amino acids was also recorded.

  12. Stomatal uptake and stomatal deposition of ozone in isoprene and monoterpene emitting plants.

    Science.gov (United States)

    Fares, S; Loreto, F; Kleist, E; Wildt, J

    2008-01-01

    Volatile isoprenoids were reported to protect plants against ozone. To understand whether this could be the result of a direct scavenging of ozone by these molecules, the stomatal and non-stomatal uptake of ozone was estimated in plants emitting isoprene or monoterpenes. Ozone uptake by holm oak (Quercus ilex, a monoterpene emitter) and black poplar (Populus nigra, an isoprene emitter) was studied in whole plant enclosures (continuously stirred tank reactors, CSTR). The ozone uptake by plants was estimated measuring ozone concentration at the inlet and outlet of the reactors, after correcting for the uptake of the enclosure materials. Destruction of ozone at the cuticle or at the plant stems was found to be negligible compared to the ozone uptake through the stomata. For both plant species, a relationship between stomatal conductance and ozone uptake was found. For the poplar, the measured ozone losses were explained by the uptake of ozone through the stomata only, and ozone destruction by gas phase reactions with isoprene was negligible. For the oak, gas phase reactions of ozone with the monoterpenes emitted by the plants contributed significantly to ozone destruction. This was confirmed by two different experiments showing a) that in cases of high stomatal conductance but under low CO(2) concentration, a reduction of monoterpene emission was still associated with reduced O(3) uptake; and b) that ozone losses due to the gas phase reactions only can be measured when using the exhaust from a plant chamber to determine the gas phase reactivity in an empty reaction chamber. Monoterpenes can therefore relevantly scavenge ozone at leaf level contributing to protection against ozone.

  13. Effect of Mahanarva fimbriolata (Hemiptera: Cercopidae) Attack on Photosynthetic Parameters of Sugarcane Genotypes of Contrasting Susceptibility.

    Science.gov (United States)

    Soares, Bruno Oliveira; Chaves, Vinicius de Vicente; Tomaz, Adriano Cirino; Kuki, Kacilda Naomi; Peternelli, Luiz Alexandre; Barbosa, Márcio Henrique Pereira

    2017-12-05

    The aim of this study was to compare the effect of spittlebug Mahanarva fimbriolata Stål (Hemiptera: Cercopidae) on photosynthetic parameters of both a susceptible (SP81-3250) and a resistant (H.Kawandang) sugarcane genotype. In the first assay, the susceptibility level of genotypes to spittlebug was confirmed by comparing damage score and chlorophyll content of the plants. In the second assay, the effect of spittlebug nymphs on photosynthetic characteristics was assessed using the following parameters: Net photosynthetic rate (A), carboxylation efficiency (A/Ci), stomata conductance (gS), transpiration (E), electron transport rate (ETR), maximum quantum yield of Photosystem 2 (PSII) (FV/FM), effective quantum yield (Y(II)), photochemical quenching (Y(NPQ)), and nonphotochemical quenching (Y(NO)). Spittlebug nymphs affected the photosynthetic process of the susceptible genotype SP81-3250 by decreasing the Chl content, ETR, FV/FM, and Y(II). However, this genotype was able to maintain A probably due to its ability to maintain stomata aperture, increase the carboxylation efficiency of Rubisco, and dissipate excess energy through the xanthophyll cycle, as Y(NPQ) increased under the spittlebug attack. On the other hand, the spittlebug did not affect Chl content and FV/FM of the H.Kawandang genotype. Furthermore, H.Kawandang increased A to compensate for the sink demand by the spittlebug by increasing stomatal aperture and carboxylation efficiency and increasing efficiency of the photochemical apparatus in converting light energy into chemical products. We can conclude that the feeding habits of spittlebug nymphs have different impacts on photosynthesis of susceptible and resistant sugarcane genotypes. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Differences in the response sensitivity of stomatal index to atmospheric CO2 among four genera of Cupressaceae conifers.

    Science.gov (United States)

    Haworth, Matthew; Heath, James; McElwain, Jennifer C

    2010-03-01

    The inverse relationship between stomatal density (SD: number of stomata per mm(2) leaf area) and atmospheric concentration of CO2 ([CO2]) permits the use of plants as proxies of palaeo-atmospheric CO2. Many stomatal reconstructions of palaeo-[CO2] are based upon multiple fossil species. However, it is unclear how plants respond to [CO2] across genus, family or ecotype in terms of SD or stomatal index (SI: ratio of stomata to epidermal cells). This study analysed the stomatal numbers of conifers from the ancient family Cupressaceae, in order to examine the nature of the SI-[CO2] relationship, and potential implications for stomatal reconstructions of palaeo-[CO2]. Methods Stomatal frequency measurements were taken from historical herbarium specimens of Athrotaxis cupressoides, Tetraclinis articulata and four Callitris species, and live A. cupressoides grown under CO2-enrichment (370, 470, 570 and 670 p.p.m. CO2). T. articulata, C. columnaris and C. rhomboidea displayed significant reductions in SI with rising [CO2]; by contrast, A. cupressoides, C. preissii and C. oblonga show no response in SI. However, A. cupressoides does reduce SI to increases in [CO2] above current ambient (approx. 380 p.p.m. CO2). This dataset suggests that a shared consistent SI-[CO2] relationship is not apparent across the genus Callitris. Conclusions The present findings suggest that it is not possible to generalize how conifer species respond to fluctuations in [CO2] based upon taxonomic relatedness or habitat. This apparent lack of a consistent response, in conjunction with high variability in SI, indicates that reconstructions of absolute palaeo-[CO2] based at the genus level, or upon multiple species for discrete intervals of time are not as reliable as those based on a single or multiple temporally overlapping species.

  15. Immunolocalization of IAA and ABA in roots and needles of radiata pine (Pinus radiata) during drought and rewatering.

    Science.gov (United States)

    De Diego, N; Rodríguez, J L; Dodd, I C; Pérez-Alfocea, F; Moncaleán, P; Lacuesta, M

    2013-05-01

    Anatomical, physiological and phytohormonal changes involved in drought tolerance were examined in different Pinus radiata D. Don breeds subjected to soil drying and rewatering. Breeds with the smallest stomatal chamber size had the lowest transpiration rate and the highest intrinsic water-use efficiency. Xylem cell size was positively correlated with leaf hydraulic conductance and needle indole-3-acetic acid (IAA) concentrations, whereas transpiration rate was negatively correlated with needle abscisic acid (ABA) levels. Since these two phytohormones seem important in regulating the P. radiata drought response, they were simultaneously immunolocalized in roots and needles of the most tolerant breed (P. radiata var. radiata × var. cedrosensis) during two sequential drought cycles and after rewatering. During drought, IAA was unequally distributed into the pointed area of the needle cross-section and mainly located in mesophyll and vascular tissue cells of needles, possibly inducing needle epinasty, whereas ABA was principally located in guard cells, presumably to elicit stomata closure. In the roots, at the end of the first drought cycle, while strong IAA accumulation was observed in the cortex, ABA levels decreased probably due to translocation to the leaves. Rewatering modified the distribution of both IAA and ABA in the needles, causing an accumulation principally in vascular tissue, with residual concentrations in mesophyll, likely favouring the acclimatization of the plants for further drought cycles. Contrarily, in the roots IAA and ABA were located in the exodermis, a natural barrier that regulates the phytohormone translocation to other plant tissues and hormone losses to the soil solution after rewatering. These results confirm that immunolocalization is an efficient tool to understand the translocation of IAA and ABA in plants subjected to different water stress situations, and clarify their role in regulating physiological responses such as stomata

  16. Quantitative Evaluation of Stomatal Cytoskeletal Patterns during the Activation of Immune Signaling in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Masaki Shimono

    Full Text Available Historically viewed as primarily functioning in the regulation of gas and water vapor exchange, it is now evident that stomata serve an important role in plant immunity. Indeed, in addition to classically defined functions related to cell architecture and movement, the actin cytoskeleton has emerged as a central component of the plant immune system, underpinning not only processes related to cell shape and movement, but also receptor activation and signaling. Using high resolution quantitative imaging techniques, the temporal and spatial changes in the actin microfilament array during diurnal cycling of stomatal guard cells has revealed a highly orchestrated transition from random arrays to ordered bundled filaments. While recent studies have demonstrated that plant stomata close in response to pathogen infection, an evaluation of stimulus-induced changes in actin cytoskeletal dynamics during immune activation in the guard cell, as well as the relationship of these changes to the function of the actin cytoskeleton and stomatal aperture, remains undefined. In the current study, we employed quantitative cell imaging and hierarchical clustering analyses to define the response of the guard cell actin cytoskeleton to pathogen infection and the elicitation of immune signaling. Using this approach, we demonstrate that stomatal-localized actin filaments respond rapidly, and specifically, to both bacterial phytopathogens and purified pathogen elicitors. Notably, we demonstrate that higher order temporal and spatial changes in the filament array show distinct patterns of organization during immune activation, and that changes in the naïve diurnal oscillations of guard cell actin filaments are perturbed by pathogens, and that these changes parallel pathogen-induced stomatal gating. The data presented herein demonstrate the application of a highly tractable and quantifiable method to assign transitions in actin filament organization to the activation of

  17. Strobilurin fungicides induce changes in photosynthetic gas exchange that do not improve water use efficiency of plants grown under conditions of water stress.

    Science.gov (United States)

    Nason, Mark A; Farrar, John; Bartlett, David

    2007-12-01

    The effects of five strobilurin (beta-methoxyacrylate) fungicides and one triazole fungicide on the physiological parameters of well-watered or water-stressed wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and soya (Glycine max Merr.) plants were compared. Water use efficiency (WUE) (the ratio of rate of transpiration, E, to net rate of photosynthesis, A(n)) of well-watered wheat plants was improved slightly by strobilurin fungicides, but was reduced in water-stressed plants, so there is limited scope for using strobilurins to improve the water status of crops grown under conditions of drought. The different strobilurin fungicides had similar effects on plant physiology but differed in persistence and potency. When applied to whole plants using a spray gun, they reduced the conductance of water through the epidermis (stomatal and cuticular transpiration), g(sw), of leaves. Concomitantly, leaves of treated plants had a lower rate of transpiration, E, a lower intercellular carbon dioxide concentration, c(i), and a lower net rate of photosynthesis, A(n), compared with leaves of control plants or plants treated with the triazole. The mechanism for the photosynthetic effects is not known, but it is hypothesised that they are caused either by strobilurin fungicides acting directly on ATP production in guard cell mitochondria or by stomata responding to strobilurin-induced changes in mesophyll photosynthesis. The latter may be important since, for leaves of soya plants, the chlorophyll fluorescence parameter F(v)/F(m) (an indication of the potential quantum efficiency of PSII photochemistry) was reduced by strobilurin fungicides. It is likely that the response of stomata to strobilurin fungicides is complex, and further research is required to elucidate the different biochemical pathways involved. Copyright (c) 2007 Society of Chemical Industry.

  18. EVALUATION OF GAS EXCHANGES IN DIFFERENT Prunus SPP. ROOTSTOCKS UNDER DROUGHT AND FLOODING STRESS

    Directory of Open Access Journals (Sweden)

    ELSA KUHN KLUMB

    2017-10-01

    Full Text Available ABSTRACT The state of Rio Grande do Sul is the largest peach productor in Brazil; however, it still possesses poor yield values when compared with other states. One of the problems associated with this is the occurrence of soils with drainage problems, mainly in Pelotas region, which depending on the year period, may undergo water deficit or flooding situations in the great majority of the years, which harm the crop development and yield. Among the harmful effects caused by these stresses stand out, the decrease in the net assimilation rate, closure of stomata, reduction of the cell activities, production of reactive oxygen species, membrane and protein destabilization. Thus, the aim of this study was to investigate in what magnitude of the gaseous exchange parameters of Prunus spp. rootstocks are influenced under drought and flood stress. In the experiment, gas exchange parameters net photosynthetic rate (A stomata conductance (gs, intercellular carbon (Ci and transpiration (E] were evaluated in three Prunus spp. rootstocks (peach tree ‘Capdeboscq’ and plum trees ‘Julior’ and ‘Marianna 2624’ under three water conditions (control, water deficit and soil flooding for seven days. The three rootstocks proved more susceptible to flooding than to water deficit, only varying in response time, which is intrinsic to each genotype, and that there is a genetic variability for the tolerance to the studied stresses. The variation on physiological response to the water deficit stress was later in both evaluated genotypes. However, in general, ‘Julior’ presented greater tolerance to both stresses when compared to the other rootstocks evaluated. Such information is useful to help in the choice of rootstocks for plant production, in the orchard management and for plant breeding programs, aiming at the selection of new genotypes with increased tolerance to these water stresses.

  19. Cerato-platanin induces resistance in Arabidopsis leaves through stomatal perception, overexpression of salicylic acid- and ethylene-signalling genes and camalexin biosynthesis.

    Science.gov (United States)

    Baccelli, Ivan; Lombardi, Lara; Luti, Simone; Bernardi, Rodolfo; Picciarelli, Piero; Scala, Aniello; Pazzagli, Luigia

    2014-01-01

    Microbe-associated molecular patterns (MAMPs) lead to the activation of the first line of plant defence. Few fungal molecules are universally qualified as MAMPs, and proteins belonging to the cerato-platanin protein (CPP) family seem to possess these features. Cerato-platanin (CP) is the name-giving protein of the CPP family and is produced by Ceratocystis platani, the causal agent of the canker stain disease of plane trees (Platanus spp.). On plane tree leaves, the biological activity of CP has been widely studied. Once applied on the leaf surface, CP acts as an elicitor of defence responses. The molecular mechanism by which CP elicits leaves is still unknown, and the protective effect of CP against virulent pathogens has not been clearly demonstrated. In the present study, we tried to address these questions in the model plant Arabidopsis thaliana. Our results suggest that stomata rapidly sense CP since they responded to the treatment with ROS signalling and stomatal closure, and that CP triggers salicylic acid (SA)- and ethylene (ET)-signalling pathways, but not the jasmonic acid (JA)-signalling pathway, as revealed by the expression pattern of 20 marker genes. Among these, EDS1, PAD4, NPR1, GRX480, WRKY70, ACS6, ERF1a/b, COI1, MYC2, PDF1.2a and the pathogenesis-related (PR) genes 1-5. CP rapidly induced MAPK phosphorylation and induced the biosynthesis of camalexin within 12 hours following treatment. The induction of localised resistance was shown by a reduced susceptibility of the leaves to the infection with Botrytis cinerea and Pseudomonas syringae pv. tomato. These results contribute to elucidate the key steps of the signalling process underlying the resistance induction in plants by CP and point out the central role played by the stomata in this process.

  20. Cerato-platanin induces resistance in Arabidopsis leaves through stomatal perception, overexpression of salicylic acid- and ethylene-signalling genes and camalexin biosynthesis.

    Directory of Open Access Journals (Sweden)

    Ivan Baccelli

    Full Text Available Microbe-associated molecular patterns (MAMPs lead to the activation of the first line of plant defence. Few fungal molecules are universally qualified as MAMPs, and proteins belonging to the cerato-platanin protein (CPP family seem to possess these features. Cerato-platanin (CP is the name-giving protein of the CPP family and is produced by Ceratocystis platani, the causal agent of the canker stain disease of plane trees (Platanus spp.. On plane tree leaves, the biological activity of CP has been widely studied. Once applied on the leaf surface, CP acts as an elicitor of defence responses. The molecular mechanism by which CP elicits leaves is still unknown, and the protective effect of CP against virulent pathogens has not been clearly demonstrated. In the present study, we tried to address these questions in the model plant Arabidopsis thaliana. Our results suggest that stomata rapidly sense CP since they responded to the treatment with ROS signalling and stomatal closure, and that CP triggers salicylic acid (SA- and ethylene (ET-signalling pathways, but not the jasmonic acid (JA-signalling pathway, as revealed by the expression pattern of 20 marker genes. Among these, EDS1, PAD4, NPR1, GRX480, WRKY70, ACS6, ERF1a/b, COI1, MYC2, PDF1.2a and the pathogenesis-related (PR genes 1-5. CP rapidly induced MAPK phosphorylation and induced the biosynthesis of camalexin within 12 hours following treatment. The induction of localised resistance was shown by a reduced susceptibility of the leaves to the infection with Botrytis cinerea and Pseudomonas syringae pv. tomato. These results contribute to elucidate the key steps of the signalling process underlying the resistance induction in plants by CP and point out the central role played by the stomata in this process.

  1. Is There a Relation between the Microscopic Leaf Morphology and the Association of Salmonella and Escherichia coli O157:H7 with Iceberg Lettuce Leaves?

    Science.gov (United States)

    VAN der Linden, Inge; Eriksson, Markus; Uyttendaele, Mieke; Devlieghere, Frank

    2016-10-01

    To prevent contamination of fresh produce with enteric pathogens, more insight into mechanisms that may influence the association of these pathogens with fresh produce is needed. In this study, Escherichia coli O157:H7 and Salmonella were chosen as model pathogens, and fresh cut iceberg lettuce was chosen as a model fresh produce type. The morphological structure of iceberg lettuce leaves (stomatal density and length of cell margins per leaf area) was quantified by means of leaf peels and light microscopy of leaves at different stages of development (outer, middle, and inner leaves of the crop) on both leaf sides (abaxial and adxial) and in three leaf regions (top, center, and bottom). The morphology of the top region of the leaves was distinctly different from that of the center and base, with a significantly higher stomatal density (up to five times more stomata), different cell shape, and longer cell margins (two to three times longer). Morphological differences between the same regions of the leaves at different stages of development were smaller or nonsignificant. An attachment assay with two attenuated E. coli O157:H7 strains (84-24h11-GFP and BRMSID 188 GFP) and two Salmonella strains (serovars Thompson and Typhimurium) was performed on different regions of the middle leaves. Our results confirmed earlier reports that these pathogens have a higher affinity for the base of the lettuce leaf than the top. Differences of up to 2.12 log CFU/g were seen ( E. coli O157:H7 86-24h11-GFP). Intermediate attachment occurred in the central region. The higher incidence of preferential bacterial attachment sites such as stomata and cell margins or grooves could not explain the differences observed in the association of the tested pathogens with different regions of iceberg lettuce leaves.

  2. Effect of vegetation on the energy balance and evapotranspiration in tallgrass prairie: a paired study with eddy covariance systems

    Science.gov (United States)

    Sun, X.; Zou, C.; Wilcox, B. P.; Stebler, E.

    2017-12-01

    Whole-year measurement with eddy covariance system was carried out over two adjoining plots with contrasting vegetation coverage in tallgrass prairie, one was treated with herbicide and mowing while the other one kept as undisturbed control. The magnitude and phase difference between soil heat storage and ground heat flux were explicitly examined for its relative weights and energy balance. Surface turbulent flux (sensible heat and latent heat) accounted for about 85% of available energy at both sites, implying that vegetation coverage didn't significantly influence the closure scenario of energy imbalance. The seasonal and daily pattern of energy partitioning were dramatically different between the contrasting sites during growing season. The treated site received slightly lower net radiation due to high albedo, had higher sensible heat, and reduced latent heat due to reduction on transpiration. Annual evapotranspiration (ET) in treated site was only accounts for about 73% of annual ET in control. Meanwhile, lower surface conductance and decoupling factor showed that vegetation removal would increase the sensibility of ET to vapor pressure deficit and soil drought. ET dynamics is controlled by leaf area and net radiation when soil moisture is high, while soil drought caused stomata closure and subdued ET during drought. Stomata closure and transpiration reduction caused decline in ET, surface conductance, and decoupling factor. Soil moisture storage served as an important reservoir to meet peak ET demand during growing season. In summary, ET was the dominant component of water balance in tallgrass prairie, and any land management alterring the albedo, soil mositure storage, or canopy phenology (e.g., NDVI) could significantly affect energy and water budgets in .

  3. Role of exogenous folic acid in alleviation of morphological and anatomical inhibition on salinity-induced stress in barley

    Directory of Open Access Journals (Sweden)

    Semra Kilic

    2016-12-01

    Full Text Available Soil salinity is a serious threat to agricultural ecological environment and agriculture sustainability. Ever increasing salinity negatively affects processes such as plant growth and development, ultimately causing diminished economic yield and quality of production, and it might cause a worldwide famine in the future. Thus, helping plants adapt to saline soils and increasing their yield and quality is a must. Our study focused on the enhancing role of exogenously applied folic acid (FA in mitigation of toxicity caused by salt (NaCl. Barley seeds were pre-treated with 50 µM FA for 24 h and then exposed to salt. Morphological and anatomical changes in seed germination and seedling growth stages were compared between different treatments of salt in laboratory conditions. Adverse effects of salt in both germination and seedling growth stages depended on the concentration of salt treatment (0.0, 0.25, 0.275, 0.30, 0.325 and 0.35 M. It was shown that the application of FA effectively alleviated the salt-induced inhibition, and reduced the negative effects of salt on germination (germination index and vigour index, seedling growth (radicle and coleoptile lengths, fresh weight and leaf (stomata and epidermis number, stomatal index, stomata sizes of adaxial and abaxial surfaces parameters. Moreover, FA elevated all examined parameters of barley also under non-stress conditions. Especially, germination and vigour indices were significantly higher than the control. Our results suggest that exogenous FA is involved in the resistance of barley to salt-stress.

  4. Formation of Calcium Carbonate Deposition in the Cotyledons during he Germination of Justicia procumbens L. (Acanthaceae Seeds

    Directory of Open Access Journals (Sweden)

    Miao-Ling Lin

    2004-12-01

    Full Text Available During seed germination of Justicia procumbens, the formation of lithocysts, trichomes and diacytic stomata in the epidermis of cotyledons was following a specific distribution pattern. During the first 1-3 days, many young stomata and trichome initial cells were formed sporadically in the adaxial and abaxial epidermis, but no lithocyst was found. Three to five days after seed sawing, two cotyledons were exposed to light and then opened. In the meantime, some lithocysts were recognized on both adaxial and abaxial epidermises. The lithocysts on the adaxial epidermis occurred in the radially arranged cells located between the central area and the margin. However on the abaxial epidermis, they were found only in the marginal cell layer and their axes were along the margin of cotyledons. The total number of lithocysts in a cotyledon at this stage was 32.2 ± 4.3 and the cystolith inside the lithocyst was spindle in shape and 48.2 ± 21.1 μm in length. Three weeks after seed sowing, the cotyledons were mature and the total number of lithocysts in a cotyledon was 112.2 ± 10.1 and the cystolith in the lithocyst was enlarged to be 119.8 ± 27.8 μm in length. The cystolith was extracellularly formed in the cell wall of lithocyst. Its surface was with many protuberances and surrounded by a cystolith sheath connecting to cytoplasmic strands. The core of cystolith was surrounded by concentrically stratified fibrils and the calcium carbonate was concentrically accumulated. The waved stratified fibrils were also deposited in the protuberances. The EDX spectra showed that the main mineral elemental compositions of cystoliths were Ca and P. Ca was deposited more in the central part of cystolith than in the marginal area.

  5. Cell size, genome size and the dominance of Angiosperms

    Science.gov (United States)

    Simonin, K. A.; Roddy, A. B.

    2016-12-01

    Angiosperms are capable of maintaining the highest rates of photosynthetic gas exchange of all land plants. High rates of photosynthesis depends mechanistically both on efficiently transporting water to the sites of evaporation in the leaf and on regulating the loss of that water to the atmosphere as CO2 diffuses into the leaf. Angiosperm leaves are unique in their ability to sustain high fluxes of liquid and vapor phase water transport due to high vein densities and numerous, small stomata. Despite the ubiquity of studies characterizing the anatomical and physiological adaptations that enable angiosperms to maintain high rates of photosynthesis, the underlying mechanism explaining why they have been able to develop such high leaf vein densities, and such small and abundant stomata, is still incomplete. Here we ask whether the scaling of genome size and cell size places a fundamental constraint on the photosynthetic metabolism of land plants, and whether genome downsizing among the angiosperms directly contributed to their greater potential and realized primary productivity relative to the other major groups of terrestrial plants. Using previously published data we show that a single relationship can predict guard cell size from genome size across the major groups of terrestrial land plants (e.g. angiosperms, conifers, cycads and ferns). Similarly, a strong positive correlation exists between genome size and both stomatal density and vein density that together ultimately constrains maximum potential (gs, max) and operational stomatal conductance (gs, op). Further the difference in the slopes describing the covariation between genome size and both gs, max and gs, op suggests that genome downsizing brings gs, op closer to gs, max. Taken together the data presented here suggests that the smaller genomes of angiosperms allow their final cell sizes to vary more widely and respond more directly to environmental conditions and in doing so bring operational photosynthetic

  6. The Arabidopsis lectin receptor kinase LecRK-V.5 represses stomatal immunity induced by Pseudomonas syringae pv. tomato DC3000.

    Directory of Open Access Journals (Sweden)

    Marie Desclos-Theveniau

    2012-02-01

    Full Text Available Stomata play an important role in plant innate immunity by limiting pathogen entry into leaves but molecular mechanisms regulating stomatal closure upon pathogen perception are not well understood. Here we show that the Arabidopsis thaliana L-type lectin receptor kinase-V.5 (LecRK-V.5 negatively regulates stomatal immunity. Loss of LecRK-V.5 function increased resistance to surface inoculation with virulent bacteria Pseudomonas syringae pv tomato DC3000. Levels of resistance were not affected after infiltration-inoculation, suggesting that LecRK-V.5 functions at an early defense stage. By contrast, lines overexpressing LecRK-V.5 were more susceptible to Pst DC3000. Enhanced resistance in lecrk-V.5 mutants was correlated with constitutive stomatal closure, while increased susceptibility phenotypes in overexpression lines were associated with early stomatal reopening. Lines overexpressing LecRK-V.5 also demonstrated a defective stomatal closure after pathogen-associated molecular pattern (PAMP treatments. LecRK-V.5 is rapidly expressed in stomatal guard cells after bacterial inoculation or treatment with the bacterial PAMP flagellin. In addition, lecrk-V.5 mutants guard cells exhibited constitutive accumulation of reactive oxygen species (ROS and inhibition of ROS production opened stomata of lecrk-V.5. LecRK-V.5 is also shown to interfere with abscisic acid-mediated stomatal closure signaling upstream of ROS production. These results provide genetic evidences that LecRK-V.5 negatively regulates stomatal immunity upstream of ROS biosynthesis. Our data reveal that plants have evolved mechanisms to reverse bacteria-mediated stomatal closure to prevent long-term effect on CO(2 uptake and photosynthesis.

  7. Use of plant woody species electrical potential for irrigation scheduling.

    Science.gov (United States)

    Ríos-Rojas, Liliana; Morales-Moraga, David; Alcalde, José A; Gurovich, Luis A

    2015-01-01

    The electrical response of plants to environmental stimuli can be measured and quantitatively related to the intensity of several stimulating sources, like temperature, solar radiation, soil water content, evapotranspiration rates, sap flow and dendrometric cycles. These relations can be used to assess the influence of different environmental situations on soil water availability to plants, defined as a steady state condition between leaf transpirative flow and soil water flow to plant roots. A restricted soil water flow due to soil dryness can trigger water stress in plants, if the atmospheric evaporative demand is high, causing partial stomata closure as a physiological response to avoid plant dehydration; water stressed and unstressed plants manifest a differential electrical response. Real time plant electrical response measurements can anticipate actions that prevent the plant reaching actual stress conditions, optimizing stomata gas exchange and photosynthetic rates. An electrophysiological sensor developed in this work, allows remote real-time recording information on plant electrical potential (EP) in the field, which is highly related to EP measurements obtained with a laboratory Keithley voltmeter sensor used in an highly controlled experimental setup. Our electrophysiological sensor is a wireless, autonomous devise, which transmits EP information via Internet to a data server. Using both types of sensors (EP electrodes with a Keithley voltmeter and the electrophysiological sensor), we measured in real time the electrical responses of Persea americana and Prunus domestica plants, to induced water deficits. The differential response for 2 scenarios: irrigation and water restriction is identified by a progressive change in slope on the daily maximal and minimal electric signal values in stressed plants, and a zero-slope for similar signals for well-watered plants. Results show a correspondence between measured signals obtained by our electrophysiological

  8. Solar-induced chlorophyll fluorescence tracks the trend of canopy stomatal conductance and transpiration at diurnal and seasonal scales

    Science.gov (United States)

    Zhang, Y.; Shan, N.; Ju, W.; Chen, J.

    2017-12-01

    Transpiration is the process of plant water loss through the stomata on the leaf surface and plays a key role in the energy and water balance of the land surface. Plant stomata function as a control interface for regulating photosynthetic uptake of CO2 and transpiration, strongly linked to plant productivity. Stomatal conductance is fundamental to larger-scale regional prediction of carbon-water cycles and their feedbacks to climate. The widely used Ball-Berry model coupled photosynthesis to a semi-empirical model of stomatal conductance. However large uncertainties remain in simulation of carbon assimilation rate in ecosystem and regional scales. The strong correlations of solar-induced fluorescence (SIF) and GPP have been demonstrated and provides an important opportunity to accurately monitor photosynthetic activity and water exchange. In this presentation, we compared both canopy-observed SIF and satellite-derived SIF with tower-based canopy stomatal conductance from hourly to 8-day scales in forest and cropland ecosystem. Using the model of stomatal conductance based on SIF, the transpiration was estimated at hourly and daily scales and compared with flux tower measurements. The results showed that the seasonal pattern of canopy stomatal conductance agreed better with SIF compared to NDVI and their relationship was higher during sunny days for forest ecosystem. Canopy stomatal conductance correlated with both tower-observed SIF and SIF from the Global Ozone Monitoring Experiment-2. Estimation of transpiration from SIF performed well in both forest and cropland ecosystem. This remotely sensed approaches from SIF for modelling stomatal conductance opens a new era to analysis and simulation of coupled carbon and water cycles under climate change.

  9. Intestinal Ostomy.

    Science.gov (United States)

    Ambe, Peter C; Kurz, Nadja Rebecca; Nitschke, Claudia; Odeh, Siad F; Möslein, Gabriela; Zirngibl, Hubert

    2018-03-16

    About 100 000 ostomy carriers are estimated to live in Germany today. The creation of an ostomy represents a major life event that can be associated with impaired quality of life. Optimal ostomy creation and proper ostomy care are crucially important determinants of the success of treatment and of the patients' quality of life. This article is based on pertinent publications retrieved by a selective search in PubMed, GoogleScholar, and Scopus, and on the authors' experience. Intestinal stomata can be created using either the small or the large bowel. More than 75% of all stomata are placed as part of the treatment of colorectal cancer. The incidence of stoma-related complications is reported to be 10-70%. Skin irritation, erosion, and ulceration are the most common early complications, with a combined incidence of 25-34%, while stoma prolapse is the most common late complication, with an incidence of 8-75%. Most early complications can be managed conservatively, while most late complications require surgical revision. In 19% of cases, an ostomy that was initially planned to be temporary becomes permanent. Inappropriate stoma location and inadequate ostomy care are the most common causes of early complications. Both surgical and patient-related factors influence late complications. Every step from the planning of a stoma to its postoperative care should be discussed with the patient in detail. Preoperative marking is essential for an optimal stoma site. Optimal patient management with the involvement of an ostomy nurse increases ostomy acceptance, reduces ostomy-related complications, and improves the quality of life of ostomy carriers.

  10. Differences in the deposition of radionuclides to leafy vegetables

    International Nuclear Information System (INIS)

    Tschiersch, J.; Shinonaga, T.; Heuberger, H.; Bunzl, K.; Pliml, A.; Dietl, F.; Keusch, M.

    2003-01-01

    To quantify the variability in deposition to several species, the dry deposition of gaseous elemental radio-iodine and particulate radio-caesium on mature leafy vegetables was studied inside a deposition chamber by comparative experiments. The simultaneous exposition of endive, head lettuce, red oak leaf lettuce, curly kale, white cabbage and spinach was performed under homogeneous and controlled conditions ( 131 vertical stroke 2 -portion, particle median, stomata opening, air humidity and temperature). Significant differences were observed for the 131 vertical stroke deposition on spring vegetables: the deposition on spinach was roughly 3times that on leaf lettuce, 4times that on endive and 9times that on head lettuce. For 134 Cs, there was no significant difference between spinach and leaf lettuce, about twice the amount was deposited on both species as on endive and 3times as on head lettuce. All summer vegetables showed differences in deposition. For Iodine, the deposition on spinach was roughly 3times (6times) that on curly kale and 35times (100times) that on white cabbage in the 2 experiments. For Caesium, the deposition to curly kale was highest, about twice that on spinach and 35times (80times) that on white cabbage. The deposition was always the lowest on the closed heads of white cabbage and head lettuce. The many open stomata of spinach increased the efficiency of gaseous deposition. In addition, rough and crimpy leafs increased the particle deposition efficiency. The estimation of the deposition velocity showed that dry deposition was in average about 8times higher for 131 vertical stroke than for 134 Cs. The influence of the particle size on the deposition velocity was small in the considered size range. Washing could reduce the contamination by about 10% for 131 vertical stroke and 45% for 134 Cs. (orig.) [de

  11. H2S AND NO SIGNALING INTERACTIONS IN THALE CRESS (ARABIDOPSIS THALIANA L. AND PEPPER (CAPSICUM ANNUUM L. LEAVES

    Directory of Open Access Journals (Sweden)

    Miroslav Lisjak

    2012-06-01

    Full Text Available This research comprehends a set of experiments with several thale cress (Arabidopsis thaliana L. and pepper (Capsicum annuum L. genotypes in controlled conditions using growth chambers, with the aim of determining the physiological role of hydrogen sulfide (H2S in plants, as well as its potential effect as a signaling compound, particularly in potential interaction with nitric oxide (NO signaling pathways. Special emphasis was focused on stomatal mechanisms and signaling in their opening and closing. Moreover, the effect of treatment of pepper plants with H2S was investigated in salt stress conditions. It was established that the applied H2S donors, NaHS and GYY4137, inhibit stomata closing in both plant species through the reduction of NO accumulation in stomata, which was proven to occur in SNP or ABA treatment. The effects of NO and H2S were opposite those in pepper plants response to salt stress as well, with increased antioxidative activity in leaf obtained after H2S treatments, and with NaHS in particular. In addition, GYY4137 could be considered as a convenient H2S donor for research into H2S functions in plants. The results point out the interactions of H2S and NO in plant cell signaling in both normal and salt stress conditions. Further research of this type should uncover H2S functions in plant metabolism more precisely, especially considering the potential practical value of this knowledge for plant stress resistance improvement and their productivity enhancement.

  12. Changes in the physiological activity of soybean (Glycine max L. Merr. under the influence of exogenous growth regulators

    Directory of Open Access Journals (Sweden)

    Anna Nowak

    2015-07-01

    Full Text Available In a two-year pot experiment (2008–2009 conducted at the Vegetation Hall, West Pomeranian University of Technology in Szczecin, we investigated the influence of exogenous growth regulators, i.e. indole-3-butyric acid (IBA and 6-benzylaminopurine (BAP and their mixture, on the activity of gas exchange and selected physiological features of soybeans (Glycine max L. Merr.. The experimental factors included the following Polish soybean cultivars: ‘Aldana’, ‘Progres’ and ‘Jutro’. During plant growth, CO2 assimilation (A, transpiration rate (E, stomatal conductance (gs, and substomatal CO2 concentration (ci were determined. Two soybean cultivars, i.e. ‘Jutro’ and ‘Progres’, showed a significant increase in the intensity of assimilation and transpiration after using all kinds of growth regulators as compared with the control plants. It was found that the ‘Jutro’ cultivar, after using a mixture of growth regulators (IBA + BAP, was characterized by the significantly highest CO2 assimilation (A and transpiration (E as well as the highest stomatal conductance (gs. The ‘Aldana’ cultivar, on the other hand, responded by a significant reduction in the transpiration rate, stomatal conductance and subsomatal CO2 concentration. The spraying of the plants with exogenous growth regulators had a significant influence on the increase in the number of stomata and stomatal pore length, mostly on the lower epidermis of the lamina. It was also found that plants from the ‘Jutro’ and ‘Aldana’ cultivars sprayed with IBA and IBA + BAP were characterized by the highest yield, as compared with the control plants. In the case of the ‘Jutro’ cultivar, after using the growth regulators, a positive correlation was observed between the assimilation and transpiration rates and the length of stomata, which in consequence produced increased yields.

  13. Species-Specific Morphological and Physiological Responses of Four Korean Native Trees Species under Elevated CO2 Concentration using Open Top Chamber

    Science.gov (United States)

    Song, W.; Byeon, S.; Lee, H.; Lee, M.; Lim, H.; Kim, H. S.

    2017-12-01

    For the last three years, studies on the morphological and physiological characteristics were carried out for four tree species (Pinus densiflora, Quercus acutissima, Sorbus alnifolia and Fraxinus rhynchophylla) which are representative native species of Korea. We used a control site and three open top chambers (con, chamber 1, 2, and 3) which were exposed to ambient and two elevated CO2 concentration ([CO2]); the concentration were the ambient (400ppm) for control and chamber 1 and 1.4 times (560ppm) and 1.8 times (720 ppm) of the atmosphere for chamber 2 and 3, respectively. Leaf mass per area (LMA), stomatal size, density and area were examined to investigate the morphological changes of the trees. Among four species, F. rhynchophylla increased their LMA with increase of CO2 concentration. In addition, F. rhynchophylla showed the decrease of stomatal density significantly (p-value=0.02), while there was no difference in stoma size. These findings resulted in 25.5% and 38.7% decrease of stomata area per unit leaf area calculated by multiplying the size and density of the stomata. On the other hand, all 4 tree species were significantly increased in height and diameter growth with the elevated CO2. However, in the case of Q. acutissima, the increase in height growth was prominent. For physiological characteristics, the maximum photosynthetic rate was faster in the chambers exposed to high [CO2] than that in the control. However the rate of carboxylation and the electron transfer rate showed no particular tendency. The measurement of hydraulic conductivity (Ks, kg/m/s/Mpa) for Crataegus pinnatifida, increased as the [CO2] in the atmosphere increased, and the 50% Loss Conductance (Mpa) tended to increase slightly with the [CO2]. The correlation analysis between hydraulic conductivity and vulnerability to cavitation showed a strong negative correlation (P <0.05), which was unlike the general tendency.

  14. The ultrastructure of epidermal surface of stem and branch internods and spores of horsetails of subgenus Equisetum (Equisetum L., Equisetaceae

    Directory of Open Access Journals (Sweden)

    D. S. Feoktistov

    2016-03-01

    Full Text Available Ultrastructure of epidermal surface of stems and branches internodes of 5 species and 3 interspecific hybrids were studied using scanning electron microscopy, as well as spore surface of 5 species of horsetail subgenus Equisetum (Equisetum, Equisetaceae: E. arvense L., E. fluviatile L., E. palustre L., E. pratense Ehrh., E. sylvaticum L., E. × mildeanum Rothm. (E. pratense × E. sylvaticum, E. × sergijevskianum C. N. Page et Gureeva (E. pratense × E. palustre, E. × lofotense Lubienski (E. arvense × E. sylvaticum. Sculptural elements from silica differ in shape, size and location on the ridges and furrows of stem and branches internodes. There are: the thin longitudinal some­times anastomosing thread-like structures (ribs, cylindrical, rounded on the tip, or conical mamillae, tubercles and spines. The thin longitudinal ribs, tubercles and spines are situated on the ridges of stem and branches; separate mamillae and groups of fused mamillae occupy the furrows. The fine surface sculpturing consists of hemispherical, globose or slightly elongate pilulae covering mamillae, surface in furrows, and especially stomata. Equisetum palustre has specific club-shaped rods arranged into regular ranks along either side of the stomatal slit. A detailed description of silica sculpture, shape, disposition and ornamentation of stomata area are presented for all studied species and hybrids. Such features as the presence, shape and arrangement of sculpture elements, ornamentation, shape and arrangement of sto­mata can be used in the taxonomy and phylogenetics of horsetails. Spores of the members of subgenus Equisetum are spherical in shape. They have not specific ornamentation, their features may not be used in systematics of horsetails.

  15. Biofertilization with Azospirillum brasilense improves in vitro culture of Handroanthus ochraceus, a forestry, ornamental and medicinal plant.

    Science.gov (United States)

    Llorente, Berta E; Alasia, María A; Larraburu, Ezequiel E

    2016-01-25

    Biofertilization with plant growth-promoting rhizobacteria is a potential alternative to plant productivity. Here, in vitro propagation of Handroanthus ochraceus (yellow lapacho), a forest crop with high economic and environmental value, was developed using the Azospirillum brasilense strains Cd and Az39 during rhizogenesis. Epicotiles of in vitro plantlets were multiplied in Woody Plant Medium (WPM). For rooting, elongated shoots were transferred to auxin-free Murashige-Skoog medium with Gamborg's vitamins and WPM, both at half salt concentration (½MSG and ½WPM), and inoculated with Cd or Az39 at the base of each shoot. Anatomical studies were performed using leaves cleared and stained with safranin for optical microscopy and leaves and roots metalized with gold-palladium for scanning electron microscopy (SEM). In ½WPM auxin-free medium, A. brasilense Cd inoculation produced 55% of rooting, increased root fresh and dry weight (45% and 77%, respectively), and led to lower stomata size and density with similar proportion of open and closed stomata. Both strains selectively increased the size or density of glandular trichomes in ½MSG. Moreover, bacteria were detected on the root surface by SEM. In conclusion, the difference in H. ochraceus response to A. brasilense inoculation depends on the strain and the plant culture media. Cd strain enhanced rooting in auxin-free ½WPM and produced plantlets with features similar to those expected in ex vitro plants. This work presents an innovative in vitro approach using beneficial plant-microorganism interaction as an ecologically compatible strategy in plant biotechnology. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. A morphological and cytological study of Petunia hybrida exposed to UV-B radiation

    International Nuclear Information System (INIS)

    Staxén, I.; Bornmann, J.F.

    1994-01-01

    The aim of this study was to investigate whether the cytoskeleton, and in particular the microtubular system, is affected by enhanced levels of ultraviolet-B (280–320 nm, 9 kJ m −2 day −1 biologically effective UV-B radiation) radiation in epidermal cells of Petunia x hybrida Vilm, isolated from leaves of plants grown under UV-B radiation and visible light. In addition, morphological changes during development were monitored. In a previous study microtubules were depolymerized and delays in the different stages of the cell cycle were found when protoplasts of Petunia were irradiated with UV-B radiation (Staxén et al. 1993. Protoplasma 173: 70–76). Thus it was of interest to ascertain whether the cytoskeleton would be similarly affected in an intact system. Assuming an effect of UV-B radiation on the microtubular system, we wished to determine whether this could be correlated to concomitant changes in leaf morphology. Plants of Petunia hybrida were grown in greenhouse conditions in the presence or absence of UV-B radiation. During the course of the experiment, samples were taken from young, expanding leaves and from older, fully expanded leaves and prepared for localization and analysis of microtubules from the adaxial epidermal cells. Morphology rather than the cytoskeleton was affected by UV radiation, despite the fact that the epidermal cytoskeleton would most likely be affected, since it is located in the cells which form the first intercepting layer for incident radiation. Morphological changes under UV-B radiation, as compared to those under control conditions, were reflected in earlier flowering and an increase in leaf number. Cell division was thus stimulated as was also evidenced from the increased leaf area. Our results indicate that the number of stomata differentiated on a leaf area basis was not altered although the number of stomata per epidermal cell was reduced. (author)

  17. Changes in chlorophyll fluorescence and photosynthetic activity of French bean leaves induced by gamma radiation

    International Nuclear Information System (INIS)

    Saakov, V.; Lang, M.; Schindler, C.; Stober, F.; Lichtenthaler, H.K.

    1992-01-01

    When exposed to gamma-radiation (12, 8 and 3.5 kGy), the growth of bean seedlings (Phaseolus vulgaris L.) was stopped and after some hours or days the plants began to wilt in a dose-dependent manner, starting from the leaf rim. The rate of the dark respiration (R) of leaves increased and that of net photosynthesis (P(N)) was strongly reduced. The regulation of stomata opening and closure was lost and the stomatal conductance (g(s)) of the gamma-ray exposed plants was strongly reduced. The reduced P(N) was only partly due to either the partial or almost full stomata closure. Chlorophyll (Chl) fluorescence measurements witha two-wavelength fluorometer and a PAM fluorometer showed an increasingly reduced variable fluorescence F(v), lower values of R(fd), of ground fluorescence F0, and of the fluorescence ratios F(v)/F(m) and F(v)/F(o). This indicated a damage to the photosynthetic apparatus. The increasing loss of photosynthetic pigments in the 350 krad exposed plants was also detected via an increase in the fluorescence ratio F690/F730. The performance of the light driven xanthophyll cycle (violaxanthin/zeaxanthin transformation) proceeded in the gamma-ray treated plants only at reduced rates. The gamma-ray damage of plants can best be detected by measurements of stomatal conductance, P(N) and various Chl fluorescence ratios such as R(fd), F(v)/F(o) and F(v)/F(m)

  18. Morphological, cytological and metabolic consequences of autopolyploidization in Hylocereus (Cactaceae) species.

    Science.gov (United States)

    Cohen, Hagai; Fait, Aaron; Tel-Zur, Noemi

    2013-11-04

    Genome doubling may have multi-level effects on the morphology, viability and physiology of polyploids compared to diploids. We studied the changes associated with autopolyploidization in two systems of somatic newly induced polyploids, diploid-autotetraploid and triploid-autohexaploid, belonging to the genus Hylocereus (Cactaceae). Stomata, fruits, seeds, embryos, and pollen were studied. Fruit pulp and seeds were subjected to metabolite profiling using established gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography (UPLC) Q-TOF-MS/MS (time of flight)-protocols. Autopolyploid lines produced lower numbers of tetrads, larger pollen grains with lower viability, larger stomata with lower density, and smaller fruits with lower seed numbers and decreased seed viability. The abundance of sugars was lower in the fruits and seeds of the two duplicated lines than in their donor lines, accompanied by increased contents of amino acids, tricarboxylic acid (TCA) cycle intermediates, organic acids and flavonoids. Betacyanins, the major fruit pigments in diploid and triploid donors, decreased following genome doubling. Both autopolyploid Hylocereus lines thus exhibited unfavorable changes, with the outcome being more dramatic in the autohexaploid than in the autotetraploid line. Induced autotetraploid and autohexaploid lines exhibited morphological and cytological characteristics that differed from those of their donor plants and that were accompanied by significant metabolic alterations. It is suggested that a developmental arrest occurs in the fruits of the autohexaploid line, since their pericarp shows a greater abundance of acids and of reduced sugars. We conclude that genome doubling does not necessarily confer a fitness advantage and that the extent of alterations induced by autopolyploidization depends on the genetic background of the donor genotype.

  19. Changes of Nitric Oxide and Its Relationship with H2O2 and Ca2+ in Defense Interactions between Wheat and Puccinia Triticina.

    Directory of Open Access Journals (Sweden)

    Mei Qiao

    Full Text Available In this research, the wheat cultivar 'Lovrin 10' and Puccinia triticina races 165 and 260 were used to constitute compatible and incompatible combinations to investigate the relationship between NO and H2O2 and between NO and calcium (Ca(2+ signaling in the cell defense process by pharmacological means. The specific fluorescent probe DAF-FM DA was coupled with confocal laser scanning microscopy and used to label intracellular nitric oxide (NO and monitoring the real-time NO dynamics during the processes of wheat defense response triggered by P. triticina infection. The results showed that at 4 h after inoculation, weak green fluorescence was observed in the stomatal guard cells at the P. triticina infection site in the incompatible combination, which indicates a small amount of NO production. Twelve hours after inoculation, the fluorescence of NO in- cell adjacent to the stomata gradually intensified, and the NO fluorescent area also expanded continuously; the green fluorescence primarily occurred in the cells undergoing a hypersensitive response (HR at 24-72 h after inoculation. For the compatible combination, however, a small amount of green fluorescence was observed in stomata where the pathogenic contact occurred at 4 h after inoculation, and fluorescence was not observed thereafter. Injections of the NO scavenger c-PTIO prior to inoculation postponed the onset of NO production to 48 h after inoculation and suppressed HR advancement. The injection of imidazole, a NADPH oxidase inhibitor, or EGTA, an extracellular calcium chelator, in the leaves prior to inoculation, delayed the onset of NO production in the incompatible combination and suppressed HR advancement. Combined with our previous results, it could be concluded that, Ca(2+ and hydrogen peroxide (H2O2 are involved in upstream of NO production to induce the HR cell death during P. triticina infection, and Ca(2+, NO and H2O2 are jointly involved in the signal transduction process of HR

  20. Interaction between isoprene and ozone fluxes at ecosystem level in a poplar plantation and its impact at European level

    Science.gov (United States)

    Zenone, T.; Hendriks, C.; Brilli, F.; Gioli, B.; Portillo Estrada, M.; Schaap, M.; Ceulemans, R.

    2015-12-01

    The emissions of Biogenic volatile organic compounds (BVOCs) from vegetation, mainly in form of isoprenoids, play an important role in the tropospheric ozone (O3) formation. The potential large expansion of isoprene emitter species (e.g. poplar) as biofuels feedstock might impact the ground level O3 formation. Here we report the simultaneous observations, using the eddy covariance (EC) technique, of isoprene, O3 and CO2 fluxes in a short rotation coppice (SRC) of poplar. The impact of current poplar plantations and associated isoprene emissions on ground level ozone concentrations for Europe was evaluated using a chemistry transport model (CTM) LOTOS-EUROS. The isoprene fluxes showed a well-defined seasonal and daily cycle that mirrored with the stomata O3 uptake. The isoprene emission and the stomata O3 uptake showed significant statistical relationship especially at elevated temperature. Isoprene was characterized by a remarkable peak of emissions (e.g. 38 nmol m-2s-1) occurring for few days as a consequence of the rapid variation of the air and surface temperature. During these days the photosynthetic apparatus (i.e. the CO2 fluxes) and transpiration rates did not show significant variation while we did observe a variation of the energy exchange and a reduction of the bowen ratio. The response of isoprene emissions to ambient O3 concentration follows the common form of the hormetic dose-response curve with a considerable reduction of the isoprene emissions at [O3] > 80 ppbv indicating a potential damping effect of the O3 levels on isoprene. Under the current condition the impact of SRC plantations on ozone concentrations / formation is very limited in Europe. Our findings indicate that, even with future scenarios with more SRC, or conventional poplar plantations, the impact on Ozone formation is negligible.

  1. Representation of physiological drought at ecosystem level based on model and eddy covariance measurements

    Science.gov (United States)

    Zhang, Y.; Novick, K. A.; Song, C.; Zhang, Q.; Hwang, T.

    2017-12-01

    Drought and heat waves are expected to increase both in frequency and amplitude, exhibiting a major disturbance to global carbon and water cycles under future climate change. However, how these climate anomalies translate into physiological drought, or ecosystem moisture stress are still not clear, especially under the co-limitations from soil moisture supply and atmospheric demand for water. In this study, we characterized the ecosystem-level moisture stress in a deciduous forest in the southeastern United States using the Coupled Carbon and Water (CCW) model and in-situ eddy covariance measurements. Physiologically, vapor pressure deficit (VPD) as an atmospheric water demand indicator largely controls the openness of leaf stomata, and regulates atmospheric carbon and water exchanges during periods of hydrological stress. Here, we tested three forms of VPD-related moisture scalars, i.e. exponent (K2), hyperbola (K3), and logarithm (K4) to quantify the sensitivity of light-use efficiency to VPD along different soil moisture conditions. The sensitivity indicators of K values were calibrated based on the framework of CCW using Monte Carlo simulations on the hourly scale, in which VPD and soil water content (SWC) are largely decoupled and the full carbon and water exchanging information are held. We found that three K values show similar performances in the predictions of ecosystem-level photosynthesis and transpiration after calibration. However, all K values show consistent gradient changes along SWC, indicating that this deciduous forest is less responsive to VPD as soil moisture decreases, a phenomena of isohydricity in which plants tend to close stomata to keep the leaf water potential constant and reduce the risk of hydraulic failure. Our study suggests that accounting for such isohydric information, or spectrum of moisture stress along different soil moisture conditions in models can significantly improve our ability to predict ecosystem responses to future

  2. Caracteres diagnósticos foliares en táxones ibéricos de Isoetes L. (Isoetaceae, Pteridophyta

    Directory of Open Access Journals (Sweden)

    Rolleri, Cristina H.

    2003-12-01

    Full Text Available This is a comparative study of foliar morphology of the species of Isoetes L. growing in the Iberian Península. The taxa included are /. durieui and /. histrix (terrestrial, /. setaceum, and /. velatum subsp. Velatum (amphibious, and /. brochonii, I. echinosporum, I. x hickeyi, I. lacustre, I. longissimum and /. velatum subsp. Asturicense (aquatic. Material of an undescribed amphibious tetraploid taxon related to /. velatum was also included in this study and referred as Isoetes sp. until proper description. Several Iberian collections, together with European and American specimens of some of the taxa were analyzed. Selected diagnostic characters of the microphylls are: cuticular ornamentation (striae, ridges and warts, cuticular flanges, epidermal patterns, stomata distribution and dimensions, foliar transverse sectíons outline, degree of development of the mesophyll, presence or absence, and distribution of the mechanical tissues (collenchyma, diaphragms, and presence or absence and type of intercellular pectic protuberances. All characters are stable, and do not vary with the age of the plants or the microphylls. Cuticular striae, ridges and warts, as well as stomata develop early in plantlets. Stomata present in the microphylls of two aquatic taxa (/. longissimum, I. velatum subsp. asturicense suggest that their absence is not entirely due to influence of aquatic environment. Collenchyma occurs, also, in species growing in different habitats. Restored herbarium material proved to be as useful as fresh or fixed material, an important advantage in the case of Isoetes species, many of which grow in vulnerable áreas or are known only through herbarium specimens due to destruction of their pristine habitats.Se presenta un estudio de morfología foliar comparada en los táxones del género Isoetes que crecen en la Península Ibérica: /. durieui e /. histrix (terrestres, /. setaceum, I. velatum subsp. velatum (anfibios e /. brochonii, I

  3. Combined impact of heavy metals (Pb2+ and Cd2+ and salinity on the condition of Lolium perenne long-term assimilation apparatus

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    V. P. Bessonova

    2014-12-01

    Full Text Available Contamination of soil and atmosphere by heavy metals negatively affects physiological and biochemical processes in plants. The objective of this study is to analyze the combined impact of heavy metals Pb2+ and Cd2+ on the background of salinity on the surface of assimilation and the state of stomata device and the content of plastid pigments in leaves of Lolium perenne L. Decrease in the area of plant leaves on the background of the impact of pollutants has been determined. By the degree of increase of negative impact on this index, variants of the experience can be arranged as follows: Pb2+ + Cd2+ < NaCl < Pb2+ + Cd2+ + NaCl. The investigated factors have the strongest impact on the area of assimilation surface. The reason for its significant decrease in plants of studied variants compared to the control is that both suppression of growth and reduction of leaves area occurs, along with the inhibition of their formation. The damaging effect of sodium chloride is also traced in drying of leaf tips, the latter become lighter in color and some of them get yellow. Under the action of heavy metals and salinity decrease in the leaf index for L. perenne is observed, especially in case of combined actions of toxins, and this rate varies more significantly than the other ones. Salinization of growing substrate significantly reduces the number of stomata on the underside of the leaf epidermis. On the contrary, under the influence of heavy metals their number increases, and under the action of Pb2+ + Cd2+ on the background of chloride salinity it becomes even higher compared with the variant where heavy metals only affect the plants. The length of guard cells of the stomata in the variants with metals in NaCl remains practically unchanged compared with the control, but at joint action it is reduced. The width of stomatal pore in the variants differs insignificantly. The same is applied to the length, except for variants where the plants were exposed

  4. Acclimatization and leaf anatomy of micropropagated fig plantlets Aclimatização e anatomia foliar de plântulas de figo micropropagadas

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    Chrystiane Fráguas Chirinéa

    2012-12-01

    Full Text Available The survival of micropropagated plants during and after acclimatization is a limiting process to plant establishment. There is little information on how the anatomy of vegetative organs of Ficus carica can be affected by culture conditions and acclimatization. The present research aimed to study the effects of time on culture medium and substrates during the acclimatization of fig tree plantlets produced in vitro, characterizing some leaf anatomy aspects of plantlets cultured in vitro and of fig trees produced in field. Plantlets previously multiplied in vitro were separated and transferred into Wood Plant Medium (WPM where they were kept for 0, 15, 30, 45 and 60 days. Different substrates were tested and studies on leaf anatomy were performed in order to compare among plantlets grown in vitro, plantlets under 20, 40 and 60 days of acclimatization, and field grown plants. Keeping plantlets for 30 days in WPM allowed better development in Plantmax during acclimatization. Field grown plants presented higher number of stomata, greater epicuticular wax thickness and greater leaf tissue production compared to in vitro ones. The leaf tissues of in vitro plantlets show little differentiation and have great stomata number compared with acclimatized plants, which reduce the number of stomata during the acclimatization process.A sobrevivência de plantas micropropagadas durante e após a aclimatização é um processo limitante para o estabelecimento de plantas. Poucas informações são encontradas de como a anatomia de órgãos vegetativos de Ficus carica pode ser afetada pelas condições de cultivo e aclimatização. O presente trabalho teve por objetivo estudar os efeitos do tempo em meio de cultura e substratos durante a aclimatização de plântulas de figueira produzidas in vitro e cultivadas no campo. Plântulas multiplicadas in vitro foram separadas e transferidas para meio WPM, onde foram mantidas por 0; 15; 30; 45 e 60 dias. Diferentes

  5. Environmental control of CO2-assimilation and leaf conductance in Larix decidua Mill. : I. A comparison of contrasting natural environments.

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    Benecke, U; Schulze, E -D; Matyssek, R; Havranek, W M

    1981-08-01

    CO 2 -assimilation and leaf conductance of Larix decidua Mill. were measured in the field at high (Patscherkofel, Austria) and low (Bayreuth, Germany) elevation in Europe, and outside its natural range along an altitudinal gradient in New Zealand.Phenology of leaf and stem growth showed New Zealand sites to have much longer growing seasons than in Europe, so that the timberline (1,330 m) season was almost twice as long as at the Austrian timberline (1,950 m).The maximum rates of photosynthesis, A max , were similar at all sites after completion of leaf growth, namely 3 to 3.5 μmol m -2 s -1 . Only the sun needles of the Bayreuth tree reached 3.5 to 5 μmol m -2 s -1 . Light response curves for CO 2 -assimilation changed during leaf ontogeny, the slope being less in young than in adult leaves. The temperature optimum for 90% of maximum photosynthesis was at all sites similar between ca. 12-28°C for much of the summer. Only at the cooler high altitude timberline sites were optima lower at ca. 10-16°C in developing needles during early summer.A linear correlation existed between A max and leaf conductance at A max , and this showed no difference between the sites except for sun needles at Bayreuth.Leaf conductance responded strongly to light intensity and this was concurrent with the light response of CO 2 -uptake. A short-term and a long-term effect were differentiated. With increasing age maximum rates of CO 2 -uptake and leaf conductance at A max increased, whereas short-term response during changes in light declined. The stomata became less responsive with increasing age and tended to remain open. The stomatal responses to light have a significant effect on the water use efficiency during diurnal courses. A higher water use efficiency was found for similar atmospheric conditions in spring than in autumn.Stomata responded with progressive closure to declining air humidity in a similar manner under dissimilar climates. Humidity response thus showed insensitivity

  6. Morfoanatomia foliar de microorquídeas de Ornithocephalus Hook. e Psygmorchis Dodson & Dressler Leaf anatomy of micro-orchids of Ornithocephalus Hook. and Psygmorchis Dodson & Dressler

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    Rayza Carla Lopes Della Colleta

    2008-12-01

    pseudobulbs. The epidermis is uniseriate and thin, with the exception of O. bicornis which has a relatively thick epidermis, and a thin, smooth cuticle. The species have amphistomatic leaves and the stomata are at the same level as the epidermal cells. Stomata are generally anomocytic and tetracytic in O. myrticola, P. pusilla and P. glossomystax. O. bicornis has tetracytic, anisocytic and actinocytic stomata. Guard cells have thick periclinal walls and small substomatic chambers, except in P. pusilla. With the exception of O. bicornis, species have heterogeneous mesophyll with different types of parenchyma. All vascular bundles are collateral. The species are mesophytic.

  7. Padrão sazonal do regime estomático em azinheiras (Quercus rotundifolia Lam. regadas Seasonal pattern of the stomatal regime of irrigated holm-oak (Quercus rotundifolia Lam.

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    F. Melhorado

    2007-01-01

    êntico tanto no Verão como no Inverno. Conclui-se que a diferença entre o Verão e o Inverno no padrão comportamental da espécie, ou seja, a passagem de aumento exponencial das resistências para bimodal no Inverno, onde se evidencia o “midday-closure”, se deve, provavelmente, à menor solicitação evaporativa durante o ocaso no período de Inverno. Confirmou-se a existência do “middayclosure” na espécie como uma adaptação não rígida, dependente da disponibilidade hídrica do solo.This project aims to study the possible variation in stomata regime between irrigated oak trees Quercus rotundifolia Lam. and the same trees under natural environmental conditions at the different seasons of the year. The study was carried in a montado situated in Mitra, southeast of Portugal, at 13 km from Évora. For this project two isolated trees were selected, one irrigated to keep the plant regularly water supplied and the other subjected to the typical dryness of our summer (we will call this the standard tree. The stomatal resistance was measured with a porometer (?AP4 at three daily periods (morning, noon and sunset in the hydrologic year of 2001-02. During the summer the stomata resistances of the irrigated tree were significantly different from the standard (99%; alfa = 0,01, presenting always the double of the stomatic aperture of the standard tree. This relation lasted through all daily periods of the season. In the summer the average of stomata resistances in both trees follows an exponential curve (r² = 0,99, with a maximum of resistance at the sunset. In winter, the differences in stomata resistance between the two trees are significative (at 99%; alfa = 0,01 over all daily period. And we have observed a change in the daily variation pattern of the resistances, becoming more visible a midday-closure, especially in the standard tree. The resistance curves follow a bimodal pattern (r² = 1 in both trees with the maximum at noon. In the irrigated tree, however, the

  8. A new discrete dynamic model of ABA-induced stomatal closure predicts key feedback loops.

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    Réka Albert

    2017-09-01

    Full Text Available Stomata, microscopic pores in leaf surfaces through which water loss and carbon dioxide uptake occur, are closed in response to drought by the phytohormone abscisic acid (ABA. This process is vital for drought tolerance and has been the topic of extensive experimental investigation in the last decades. Although a core signaling chain has been elucidated consisting of ABA binding to receptors, which alleviates negative regulation by protein phosphatases 2C (PP2Cs of the protein kinase OPEN STOMATA 1 (OST1 and ultimately results in activation of anion channels, osmotic water loss, and stomatal closure, over 70 additional components have been identified, yet their relationships with each other and the core components are poorly elucidated. We integrated and processed hundreds of disparate observations regarding ABA signal transduction responses underlying stomatal closure into a network of 84 nodes and 156 edges and, as a result, established those relationships, including identification of a 36-node, strongly connected (feedback-rich component as well as its in- and out-components. The network's domination by a feedback-rich component may reflect a general feature of rapid signaling events. We developed a discrete dynamic model of this network and elucidated the effects of ABA plus knockout or constitutive activity of 79 nodes on both the outcome of the system (closure and the status of all internal nodes. The model, with more than 1024 system states, is far from fully determined by the available data, yet model results agree with existing experiments in 82 cases and disagree in only 17 cases, a validation rate of 75%. Our results reveal nodes that could be engineered to impact stomatal closure in a controlled fashion and also provide over 140 novel predictions for which experimental data are currently lacking. Noting the paucity of wet-bench data regarding combinatorial effects of ABA and internal node activation, we experimentally confirmed

  9. A new discrete dynamic model of ABA-induced stomatal closure predicts key feedback loops.

    Science.gov (United States)

    Albert, Réka; Acharya, Biswa R; Jeon, Byeong Wook; Zañudo, Jorge G T; Zhu, Mengmeng; Osman, Karim; Assmann, Sarah M

    2017-09-01

    Stomata, microscopic pores in leaf surfaces through which water loss and carbon dioxide uptake occur, are closed in response to drought by the phytohormone abscisic acid (ABA). This process is vital for drought tolerance and has been the topic of extensive experimental investigation in the last decades. Although a core signaling chain has been elucidated consisting of ABA binding to receptors, which alleviates negative regulation by protein phosphatases 2C (PP2Cs) of the protein kinase OPEN STOMATA 1 (OST1) and ultimately results in activation of anion channels, osmotic water loss, and stomatal closure, over 70 additional components have been identified, yet their relationships with each other and the core components are poorly elucidated. We integrated and processed hundreds of disparate observations regarding ABA signal transduction responses underlying stomatal closure into a network of 84 nodes and 156 edges and, as a result, established those relationships, including identification of a 36-node, strongly connected (feedback-rich) component as well as its in- and out-components. The network's domination by a feedback-rich component may reflect a general feature of rapid signaling events. We developed a discrete dynamic model of this network and elucidated the effects of ABA plus knockout or constitutive activity of 79 nodes on both the outcome of the system (closure) and the status of all internal nodes. The model, with more than 1024 system states, is far from fully determined by the available data, yet model results agree with existing experiments in 82 cases and disagree in only 17 cases, a validation rate of 75%. Our results reveal nodes that could be engineered to impact stomatal closure in a controlled fashion and also provide over 140 novel predictions for which experimental data are currently lacking. Noting the paucity of wet-bench data regarding combinatorial effects of ABA and internal node activation, we experimentally confirmed several predictions

  10. Anatomía del tejido fotosintético de diez taxa de Opuntia establecidos en el secano árido mediterráneo de Chile Anatomy of the photosynthetic tissue in ten taxa of Opuntia established to the mediterranean arid zone of Chile

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    SILVA HERMAN

    2001-06-01

    Full Text Available Se evaluó el efecto de la exposición de cladodios a la radiación en la anatomía del tejido fotosintético de 10 taxa de Opuntia, (plantas con metabolismo ácido crasuláceo, CAM establecidos en al secano árido de la IV Región de Chile. A nivel del tejido epidérmico se evaluó el grosor de la cutícula, la densidad de estomas y las dimensiones de células oclusivas. En el tejido fotosintetico, se evaluo las dimensiones celulares con el objeto de estimar la superficie de paredes celulares expuestas al intercambio gaseoso por unidad de tejido fotosintético, relación conocida como Ames/A. Los resultados señalan grandes dimensiones celulares y baja densidad estomática, lo que determina un número reducido de estomas por unidad de superficie en relación a especies de otras vías metabólicas (C3 y C4. La comparación entre taxones, muestra diferencias significativas en la relación de áreas Ames/A, parámetro estrechamente relacionado a la capacidad fotosintética. Estas características anatómicas y sus modificaciones en combinación con el metabolismo CAM, contribuyen a su adaptación a condiciones de pluviometría limitadaThe anatomy of the photosynthetic tissue and the effect of cladode exposure to radiation was studied in ten taxa of Opuntia, plants with crassulacean acid metabolism (CAM, established in the dry lands of the IV Region of Chile. At the epidermic level the cuticle thickness, stomatal frequency, and dimension of guard cells were evaluated. In the photosynthetic tissue, cell dimensions were determined in order to estimate the area of cell walls exposed to gaseous exchange per unit of photosynthetic tissue (A mes/ A. The results indicate large cell dimensions and low stomata frequency which results in a reduced number of stomata per unit area in relation to species with other metabolic pathways (C3 and C4, The comparison between taxa shows significant differences in the relation of Ames/A areas, a parameter closely

  11. Scaling up stomatal conductance from leaf to canopy using a dual-leaf model for estimating crop evapotranspiration.

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    Risheng Ding

    Full Text Available The dual-source Shuttleworth-Wallace model has been widely used to estimate and partition crop evapotranspiration (λET. Canopy stomatal conductance (Gsc, an essential parameter of the model, is often calculated by scaling up leaf stomatal conductance, considering the canopy as one single leaf in a so-called "big-leaf" model. However, Gsc can be overestimated or underestimated depending on leaf area index level in the big-leaf model, due to a non-linear stomatal response to light. A dual-leaf model, scaling up Gsc from leaf to canopy, was developed in this study. The non-linear stomata-light relationship was incorporated by dividing the canopy into sunlit and shaded fractions and calculating each fraction separately according to absorbed irradiances. The model includes: (1 the absorbed irradiance, determined by separately integrating the sunlit and shaded leaves with consideration of both beam and diffuse radiation; (2 leaf area for the sunlit and shaded fractions; and (3 a leaf conductance model that accounts for the response of stomata to PAR, vapor pressure deficit and available soil water. In contrast to the significant errors of Gsc in the big-leaf model, the predicted Gsc using the dual-leaf model had a high degree of data-model agreement; the slope of the linear regression between daytime predictions and measurements was 1.01 (R2 = 0.98, with RMSE of 0.6120 mm s-1 for four clear-sky days in different growth stages. The estimates of half-hourly λET using the dual-source dual-leaf model (DSDL agreed well with measurements and the error was within 5% during two growing seasons of maize with differing hydrometeorological and management strategies. Moreover, the estimates of soil evaporation using the DSDL model closely matched actual measurements. Our results indicate that the DSDL model can produce more accurate estimation of Gsc and λET, compared to the big-leaf model, and thus is an effective alternative approach for estimating and

  12. Plasticity in stomatal size and density of potato leaves under different irrigation and phosphorus regimes.

    Science.gov (United States)

    Sun, Yanqi; Yan, Fei; Cui, Xiaoyong; Liu, Fulai

    2014-09-01

    The morphological features of stomata including their size and density could be modulated by environmental cues; however, the underlying mechanisms remain largely elusive. Here, the effect of different irrigation and phosphorus (P) regimes on stomatal size (SS) and stomatal density (SD) of potato leaves was investigated. The plants were grown in split-root pots under two P fertilization rates (viz., 0 and 100mgkg(-1) soil, denoted as P0 and P1, respectively) and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation regimes. Results showed that SS and SD were unresponsive to P but significantly affected by the irrigation treatment. FI plants had the largest SS, followed by DI, and PRD the smallest; and the reverse was the case for SD. Compared to FI and DI, PRD plants had significantly lower values of specific leaf area (SLA) and leaf carbon isotope discrimination (Δ(13)C) under P0. Midday leaf water potential (Ψleaf) and stomatal conductance (gs) was similar for DI and PRD, which was significantly lower than that of FI. Leaf contents of C, N, K, Ca and Mg were higher in PRD than in DI plants, particularly under P0. When analyzed across the three irrigation regimes, it was found that the P1 plants had significantly higher leaf contents of P and Mg, but significantly lower leaf K content compared to the P0 plants. Linear correlation analyses revealed that SS was positively correlated with Ψleaf and Δ(13)C; whereas SD was negatively correlated with Ψleaf, Δ(13)C and SLA, and positively correlated with leaf C, N and Ca contents. And gs was positively correlated with SS but negatively correlated with SD. Collectively, under low P level, the smaller and denser stomata in PRD plants may bring about a more efficient stomatal control over gas exchange, hereby potentially enhance water-use efficiency as exemplified by the lowered leaf Δ(13)C under fluctuating soil moisture conditions. Copyright © 2014 Elsevier GmbH. All rights reserved.

  13. The economics of leaf-gas exchange in a fluctuating environment and their upscaling to the canopy-level using turbulent transport theories

    Science.gov (United States)

    Katul, G. G.; Palmroth, S.; Manzoni, S.; Oren, R.

    2012-12-01

    Global climate models predict decreases in leaf stomatal conductance (gs) and transpiration due to increases in atmospheric CO2. The consequences of these reductions are increases in soil moisture availability and continental scale run-off at decadal time-scales. Thus, a theory explaining the differential sensitivity of stomata to changing atmospheric CO2 and other environmental conditions such as soil moisture at the ecosystem scale must be identified. Here, these responses are investigated using an optimality theory applied to stomatal conductance. An analytical model for gs is first proposed based on (a) Fickian mass transfer of CO2 and H2O through stomata; (b) a biochemical photosynthesis model that relates intercellular CO2 to net photosynthesis; and (c) a stomatal model based on optimization for maximizing carbon gains when water losses represent a cost. The optimization theory produced three gas exchange responses that are consistent with observations across a wide-range of species: (1) the sensitivity of gs to vapour pressure deficit (D) is similar to that obtained from a previous synthesis of more than 40 species, (2) the theory is consistent with the onset of an apparent 'feed-forward' mechanism in gs, and (3) the emergent non-linear relationship between the ratio of intercellular to atmospheric CO2 (ci/ca) and D agrees with the results available on this response. A simplified version of this leaf-scale approach recovers the linear relationship between stomatal conductance and leaf-photosynthesis employed in numerous climate models that currently use a variant on the 'Ball-Berry' or the 'Leuning' approaches provided the marginal water use efficiency increases linearly with atmospheric CO2. The model is then up-scaled to the canopy-level using novel theories about the structure of turbulence inside vegetation. This up-scaling proved to be effective in resolving the complex (and two-way) interactions between leaves and their immediate micro

  14. IDIOTIPE KOPI ARABIKA TANAMAN BELUM MENGHASILKAN PADA LINGKUNGAN DATARAN RENDAH DAN MENENGAH

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    - Alnopri

    2011-09-01

    Full Text Available Coffee is the second priority and is nationally leading commodity aimed to increase export  as well as  to improve added values of national production in order to gain high compatibility in the international level. The development of coffee plantation in Indonesia focuses on the increased proportion of arabica coffee. The technology offered is to establish the superior characteristics of robusta coffee (lowland habitats and that of arabica coffee (highland habitats into a single crop named robbica cofffee. The idiotype of arabica crops has not been studied at the low and moderate altitude of land.            The study uses a randomized block design arranged at a split-plot, where two altitude act as the main-plot (10 m and 500 m above sea level and ten genotypes of arabica coffee as the sub-plot (five genotypes of arabica and five genotypes of robbica, with three replicates and four crops for each experimental unit. The sample crops are located  at the centre of the plot (two crops for each experimental unit. Variables observed are plant height (cm, stem diameter (mm, are of a couple of leaf (cm2, weight of a couple of leaf (gram, the number of stomata, the level of leaf greeness, the content of leaf chlorophile (A and B, and nitrate reductase activity.            Result of variance analysis showed that genotypes significantly affect plant height, stem diameter, area of a couple of leaf, weight of a couple of leaf, and the number of stomata. The level of leaf greeness, and the number of chlorophile (A and B show insignificant responses genotypes. The study conclude that the idiotype of arabica coffee, i.e. that is having a combination of robusta and arabica performs better than pure arabica, the habitat of moderate altitude is more favourable than that lowland, and the cultivation of arabica at the moderate altitude requires a modification of enviroment by plantibg the shade plant from leguminosae family.

  15. Effects of dust on forest tree health in Zagros oak forests.

    Science.gov (United States)

    Moradi, A; Taheri Abkenar, K; Afshar Mohammadian, M; Shabanian, N

    2017-10-10

    Dust is one of the most devastating factors for the environment threatening all animal and plant species. In many regions, the ecological and economic impact of microdust on scarce species is critical. In the western region of Iran, the Zagros forests have been exposed to dust storms for many years. In this study, the effect of dust on oak trees, the most important trees of Zagros forests, is investigated. For this purpose, 3-year-old seedlings of three species of oak trees under natural conditions were exposed to dust during spring and summer months. Seedlings were divided into two groups; one group was assigned as dust treatment and the other as control that the control group washed regularly to remove dust. Anatomical characteristics of leaves and dust deposits on leaves during the study period were examined by scanning electron microscope (SEM). The rate of photosynthesis and gas exchange in control and treated plants was examined by IRGA, LCI. SEM images showed that stomata structure, trichome density, and epicuticular waxes of leaves are different in all three species. This difference in micromorphology of species influences the effects of dust deposited on the leaves. A comparison of leaf species images in control and dust treatment showed that in dust treatment the percentage of stomata blocked by dust in three species (per unit area) of Quercus infectoria, Q. libni, and Q. brantii were 61/6, 48/4, and 38/1%, respectively. The results of leaf gas exchange investigation indicated that stomatal occlusion by dust had a negative impact on the examined parameters of three oak species (P ≤ 0.01). Thus, gas exchange and photosynthetic rates of the treated species were significantly reduced. The results of both parts of the study showed the vulnerability of the three species to dust as Q. infectoria > Q. libni > Q. brantii. Therefore, based on these findings, dust can disrupt the physiological activities of the studied species and the continuation of the

  16. Powdery mildew of Ruta graveolens in Brazil caused by Oidiopsis haplophylli Oídio de Ruta graveolens no Brasil causado por Oidiopsis haplophylli

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    José Ricardo Liberato

    2006-03-01

    Full Text Available Oidiopsis haplophylli is described causing powdery mildew on Ruta graveolens for the first time in Brazil (Viçosa, MG. The fungus causes yellowing of infected leaves accompanied by the presence of a whitish mycelial colony abaxially. The following combination of characters typical of this species was observed on the specimens collected in Viçosa: mycelium hypophyllous, hemiendophytic (partly external and partly internal, entering the leaves through the stomata; conidiophores hypophyllous, produced from the internal mycelium emerging through the stomata, cylindrical, hyaline, smooth; conidia, isolate, dimorphic - primary conidia lanceolate, 66.5-91.5 x 11.0-20.0 mm l/w ratio 3.5-6.2, secondary conidia cylindrical with rounded ends, 57.0-81.5 x 13.5-20.0 mm, l/w ratio 3.1 - 5.3, aseptate, hyaline, smooth.Oidiopsis haplophylli é relatado causando oídio em arruda (Ruta graveolens pela primeira vez no Brasil (Viçosa, MG. O fungo causa um amarelecimento de folhas de arruda sem bordos definidos acompanhado de cobertura fúngica branca na superfície abaxial. O seguinte conjunto de características, típico desta espécie foi observado nos espécimes coletados em Viçosa: presença de micélio hemiendofítico (parcialmente interno e parcialmente externo, tênue a denso com penetração das folhas através dos estômatos; conidióforos originando do micélio interno, emergindo através dos estômatos, cilíndricos, hialinos, lisos; conídios unicelulares, hialinos, produzidos isoladamente, dimórficos - conídios primários lanceolados, 66,5-91,5 x 11,0-20,0 mm, razão c/l 3,5-6,2, conídios secondários cilíndricos com extremidades arredondadas, 57,0-81,5 x 13,5-20,0 mm, razão c/l 3,1-5,3.

  17. Using the Normalized Differential Wetness Index to Scale Leaf Area Index, Create Three-Dimensional Classification Maps, and Scale Seasonal Evapotranspiration Depletions in Canopies Along the Middle Rio Grande Riparian CorridorCorridor

    Science.gov (United States)

    McDonnell, D. E.; Cleverly, J. R.; Dahm, C. N.; Coonrod, J. A.

    2005-12-01

    Radiation per day (Rn). The best relationship results when stomatal side surface area is considered. Cladophylls have stomata on all sides while flat leaves have stomata on the abaxial side only. The correction multiplies LAI by .5 in flat leaf vegetation and 1 in T. chinensis vegetation. That means that transpiration rates are two times greater in T. chinensis sites compared with P. deltoides for the same leaf area. The resulting equations are put into a model to quantify ET for each available image and then for the entire growing season.

  18. The effect of vapour pressure deficit on stomatal conductance, sap pH and leaf-specific hydraulic conductance in Eucalyptus globulus clones grown under two watering regimes.

    Science.gov (United States)

    Hernandez, Maria Jose; Montes, Fernando; Ruiz, Federico; Lopez, Gustavo; Pita, Pilar

    2016-05-01

    Stomatal conductance has long been considered of key interest in the study of plant adaptation to water stress. The expected increase in extreme meteorological events under a climate change scenario may compromise survival in Eucalyptus globulus plantations established in south-western Spain. We investigated to what extent changes in stomatal conductance in response to high vapour pressure deficits and water shortage are mediated by hydraulic and chemical signals in greenhouse-grown E. globulus clones. Rooted cuttings were grown in pots and submitted to two watering regimes. Stomatal conductance, shoot water potential, sap pH and hydraulic conductance were measured consecutively in each plant over 4 weeks under vapour pressure deficits ranging 0·42 to 2·25 kPa. Evapotranspiration, growth in leaf area and shoot biomass were also determined. There was a significant effect of both clone and watering regime in stomatal conductance and leaf-specific hydraulic conductance, but not in sap pH. Sap pH decreased as water potential and stomatal conductance decreased under increasing vapour pressure deficit. There was no significant relationship between stomatal conductance and leaf-specific hydraulic conductance. Stomata closure precluded shoot water potential from falling below -1·8 MPa. The percentage loss of hydraulic conductance ranged from 40 to 85 %. The highest and lowest leaf-specific hydraulic conductances were measured in clones from the same half-sib families. Water shortage reduced growth and evapotranspiration, decreases in evapotranspiration ranging from 14 to 32 % in the five clones tested. Changes in sap pH seemed to be a response to changes in atmospheric conditions rather than soil water in the species. Stomata closed after a considerable amount of hydraulic conductance was lost, although intraspecific differences in leaf-specific hydraulic conductance suggest the possibility of selection for improved productivity under water-limiting conditions

  19. COS as a proxy for photosynthesis: foliage and soil contributions to ecosystem COS flux

    Science.gov (United States)

    Erkkilä, Kukka-Maaria; Kooijmans, Linda; Aalto, Juho; Chen, Huilin; Mammarella, Ivan; Maseyk, Kadmiel; Pihlatie, Mari; Seibt, Ulli; Sun, Wu; Vesala, Timo

    2017-04-01

    Traditionally the photosynthetic sink of CO2 (described by gross primary production, GPP) is defined from ecosystem scale measurements of CO2 flux taking into account respiration defined from the nighttime CO2 flux data. The problem with this method is the accurate determination of ecosystem respiration, since the respiratory processes can vary remarkably between daytime and nighttime. Carbonyl sulfide (COS) has been suggested to be a useful proxy for GPP since plants take up COS in a similar way as CO2 via their stomata. In contrast to CO2, there is no back-flux (respiration) of COS by plants and GPP can be calculated directly from COS flux measurements. However, leaf relative uptake (LRU) ratio, that is used when converting COS flux into GPP with a linear relation, has been treated as a constant and needs to be better determined for more accurate GPP estimates. This presentation shows the preliminary results of a measurement campaign organized in Hyytiälä Scots pine (Pinus sylvestris) stand in southern Finland during the growing season 2016. COS fluxes from the soil were measured with soil chambers over different vegetations. Pine and aspen branches were measured with branch chambers and ecosystem scale exchange was monitored via eddy covariance measurements. Preliminary results show night-time ecosystem uptake of COS (negative flux) that is about 15% of the daily uptake. Soil chambers show constantly negative COS fluxes, although there is no uptake of CO2 and the soil flux is about 25% of the total ecosystem flux. Pine and aspen branches seem to be sinks of COS throughout the day indicating open stomata during night-time. These findings suggest that negative ecosystem COS flux can be explained by soil and vegetation uptake during night-time. From branch chamber measurements we were able to calculate the leaf relative uptake (LRU) separately for aspen and pine. We find that LRU has an exponential correlation with photosynthetic active radiation (PAR) when PAR

  20. Aerial organ anatomy of Smilax syphilitica (Smilacaceae

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    João Marcelo Silva

    2012-09-01

    Full Text Available Smilax L. in Brazil is represented by 32 taxa and it is a taxonomically difficult genus because the plants are dioecious and show wide phenotypic variation. The analysis and use of leaf anatomy characters is recognized as a frequently successful taxonomic method to distinguish between individual taxon, when floral material is absent or minute differences in flowers and foliage exist such as in Smilax. The aim of this study was to characterize the anatomical features of the aerial organs in Smilax syphilitica collected from the Atlantic Rainforest, in Santa Teresa-ES and the Smilax aff. syphilitica from the Amazon Rainforest, in Manaus, Brazil. For this, a total of three samples of Smilax were collected per site. Sample leaves and stems were fixed with FAA 50, embedded in historesin, sectioned on a rotary microtome, stained and mounted in synthetic resin. Additionally, histochemical tests were performed and cuticle ornamentation was analyzed with standard scanning electron microscopy. S. syphilitica and S. aff. syphilitica differed in cuticle ornamentation, epidermal cell arrangement and wall thickness, stomata type and orientation, calcium oxalate crystal type, and position of stem thorns. Leaf blades of S. syphilitica from the Amazon Rainforest have a network of rounded ridges on both sides, while in S. aff. syphilitica, these ridges are parallel and the spaces between them are filled with numerous membranous platelets. Viewed from the front, the epidermal cells of S. syphilitica have sinuous walls (even more pronounced in samples from the Amazon; while in S. aff. syphilitica, these cells are also sinuous but elongated in the cross-section of the blade and arranged in parallel. Stomata of S. syphilitica are paracytic, whereas in S. aff. syphilitica, are both paracytic and anisocytic, and their polar axes are directed towards the mid-vein. Calcium oxalate crystals in S. syphilitica are prisms, whereas in S. aff. syphilitica, crystal sand. Thorns

  1. Induction of Tetraploid Male Sterile Tagetes erecta by Colchicine Treatment and Its Application for Interspecific Hybridization

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    Yanhong He

    2016-09-01

    Full Text Available Tagetes erecta is an annual multifunctional plant which can be cultivated under a broad range of climatic conditions. Polyploidization and interspecific hybridization are applied to facilitate breeding cultivars of T. erecta with improved ornamental qualities. Colchicine treatment to the germinating seeds was proved to be a useful tool for chromosome doubling of the male sterile two-type line ‘M525AB’, with the resulting frequency of polyploid seedlings ranging from 88.89% (following 0.05% w/v colchicine applied for a 3–6 h exposure period to a maximum of 100.00% (following 0.1% for 3–6 h, or 0.2% for 3 h. Morphological observation, stomatal size and density analysis, flow cytometric analysis and chromosome counting were conducted to identify the tetraploid plants. Distinctive morphological changes were observed in a notable proportion of polyploid plants. The colchicine-treated polyploid T. erecta plants showed dwarfed and more robust growth, thicker, larger and greener leaves, larger inflorescences and florets. The mutant plants identified through morphological observation all aligned as polyploid plants, thus morphological observation could be an effective method for the detection of polyploidy. The polyploid plants had significant larger stomata size over the abaxial leaf surface, whereas the density of stomata distribution was remarkably reduced. The survival rate of tetraploid cuttings (i.e. 38% was greatly reduced compared to that of diploid plants. The fertility of tetraploid plants was also decreased, as shown by cross-pollination yields. Interspecific hybridizations between colchicine-induced tetraploid plants of a male sterile T. erecta line and the naturally tetraploid fully fertile Tagetes patula species resulted in hybrid progeny. Most of these hybrids displayed the dwarfed growth stature and compact, larger-flower morphology which is the typical ideotype of herbaceous flowers. Thus, polyploidization may be employed

  2. Características morfoanatômicas da epiderme foliar de plantas variantes e não variantes somaclonais de bananeiras (Musa sp. Colla cv. Prata-anã cultivadas in vitro Morphoanatomical characteristics of the leaf epidermis of variant plants and somaclonal non-variants of banana trees (Musa sp. Colla cv. Prata-anã cultivated in vitro

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    Guilherme Araújo Lacerda

    2008-03-01

    Full Text Available A variação somaclonal corresponde ao aparecimento de plantas anormais durante o processo de multiplicação in vitro, principalmente relacionada à estatura, no caso o gigantismo. O objetivo deste trabalho foi averiguar as diferenças morfoanatômicas da epiderme foliar na tentativa de diferenciar as plantas de 'Prata-anã' em relação aos seus variantes somaclonais. A análise por microscopia eletrônica de varredura mostrou uma diferença significativa entre o diâmetro polar dos estômatos da 'Prata-anã' não variante e suas variantes, ambas em condições in vitro, observando-se que o mesmo não ocorre para as plantas in vivo. O número médio de estômatos é menor nas plantas variantes somaclonais, porém sem diferenças significativas a não ser para a planta PIII. A descamação de cera é evidente somente nas plantas variantes de ambos os materiais (in vitro e in vivo. Conclui-se que os caracteres morfoanatômicos da epiderme foliar, como densidade estomática, diâmetro estomático polar e a uniformidade da cera atuam como marcadores morfológicos para caracterizar as plantas micropropagadas de 'Prata-anã' em relação aos seus variantes somaclonais para a característica gigantismo.Somaclonal variation corresponds to the emergence of abnormal plants during the process of multiplication in vitro, mainly related to stature, in the case the gigantism. The aim of this work was to discover morphoanatomical differences of the leaf epidermis in an attempt to differentiate plants of "Prata-anã" from their somaclonal variants. Analysis by scanning electronic microscopy showed significant difference between the polar diameter of the stomata of the "Prata-anã" non-variant and its variants, both in vitro. The same does not happen for plants in vivo. The average number of stomata is lower in the somaclonal variant plants, but without significant differences except for plant PIII. Wax peeling is only evident in the variant plants of both the

  3. Induction and identification of polyploids in Cattleya intermedia Lindl. (orchidaceae by in vitro techniques Indução e identificação de poliploides em Cattleya intermedia Lindl. (orchidaceae através de técnicas in vitro

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    Paulo Artur Konzen Xavier de Mello e Silva

    2000-03-01

    Full Text Available The effect of colchicine on the protocorm-like bodies of Cattleya intermedia L. (Orchidaceae cultured in vitro was studied. Different concentrations of the drug (0.00, 0.05, 0.10 and 0.20% as well as two times of culture (4 or 8 days were tested to determine the best treatment for the induction of tetraploid plants. Of the 3 colchicine levels applied, 0.05 and 0.10% of drug treatments appeared to be effective on the production of mixoploids and tetraploids and could be further used in breeding programs. The suitability of stomatal area and stomata density as criteria for the distinction between diploids and tetraploids was also tested. The results suggested that tetraploid plants could be identified with a fair amount of certainty when the screening was based on the density of stomata.No presente trabalho, foi estudado o efeito da colchicina em corpos semelhantes a protocormos de Cattleya intermedia L. (Orchidaceae. Diferentes concentrações da droga (0,00; 0,05; 0,10 e 0,20%, bem como diferentes tempos de cultura (4 ou 8 dias foram testados para determinar o melhor tratamento para a indução de plantas tetraplóides. Dos três níveis de colchicina aplicados, os tratamentos com 0,05 e 0,10% da droga parecem ser mais efetivos na produção de mixoplóides e tetraplóides, sendo que tais tratamentos podem ser utilizados em programas de melhoramento. Como critério para distinção entre diplóides e tetraplóides, foram realizadas medidas de área de estômatos e densidade de estômatos das folhas. Os resultados sugerem que as plantas tetraplóides podem ser identificadas com elevado grau de certeza quando a seleção é realizada com base na densidade de estômatos.

  4. Below- and above-ground controls on tree water use in lowland tropical forests

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    Meinzer, F. C.; Woodruff, D.; McCulloh, K.; Domec, J.

    2012-12-01

    Even in moist tropical forests, fluctuations in soil water availability and atmospheric evaporative demand can constrain tree water use. Our research in three lowland tropical forest sites in Panama over the past two decades has identified a series of tree biophysical and functional traits related to daily and seasonal patterns of uptake, transport and loss of water. Studies combining measurements of sap flow and natural abundance of hydrogen isotopes in soil and xylem water during the dry season show considerable variation in depth of soil water uptake among co-occurring species. Trees able to exploit progressively deeper sources of soil water during the dry season, as indicated by increasingly negative xylem water hydrogen isotope ratios, were also able to maintain constant or even increased rates of water use. Injections of a stable isotope tracer (deuterated water) into tree trunks revealed a considerable range of water transit and residence times among co-occurring, similarly-sized trees. Components of tree hydraulic architecture were also strong determinants of patterns of water use. Sapwood hydraulic capacitance, the amount of water released per unit change in tissue water potential, was a strong predictor of several tree water use and water relations traits, including sap velocity, water residence time, daily maximum branch xylem tension, and the time of day at which stomata began to increasingly restrict transpiration. Among early and late successional species, hydraulic traits such as trunk-to-branch tapering of xylem vessels, branch sap flux, branch sapwood specific conductivity and whole-tree leaf area-specific hydraulic conductance scaled uniformly with branch wood density. Consistent with differences in trunk-to-branch tapering of vessels between early and late successional species, the ratio of branch to trunk sap flux was substantially greater in early successional species. Among species, stomatal conductance and transpiration per unit leaf area

  5. Optimal plant water use across temporal scales: bridging eco-hydrological theories and plant eco-physiological responses

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    Manzoni, S.; Vico, G.; Palmroth, S.; Katul, G. G.; Porporato, A. M.

    2013-12-01

    In terrestrial ecosystems, plant photosynthesis occurs at the expense of water losses through stomata, thus creating an inherent hydrologic constrain to carbon (C) gains and productivity. While such a constraint cannot be overcome, evolution has led to a number of adaptations that allow plants to thrive under highly variable and often limiting water availability. It may be hypothesized that these adaptations are optimal and allow maximum C gain for a given water availability. A corollary hypothesis is that these adaptations manifest themselves as coordination between the leaf photosynthetic machinery and the plant hydraulic system. This coordination leads to functional relations between the mean hydrologic state, plant hydraulic traits, and photosynthetic parameters that can be used as bridge across temporal scales. Here, optimality theories describing the behavior of stomata and plant morphological features in a fluctuating soil moisture environment are proposed. The overarching goal is to explain observed global patterns of plant water use and their ecological and biogeochemical consequences. The problem is initially framed as an optimal control problem of stomatal closure during drought of a given duration, where maximizing the total photosynthesis under limited and diminishing water availability is the objective function. Analytical solutions show that commonly used transpiration models (in which stomatal conductance is assumed to depend on soil moisture) are particular solutions emerging from the optimal control problem. Relations between stomatal conductance, vapor pressure deficit, and atmospheric CO2 are also obtained without any a priori assumptions under this framework. Second, the temporal scales of the model are expanded by explicitly considering the stochasticity of rainfall. In this context, the optimal control problem becomes a maximization problem for the mean photosynthetic rate. Results show that to achieve maximum C gains under these

  6. GENETIC RESOURCES OF ROOT VEGETABLES CROPS IN CENTRAL REGION OF RUSSIA

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    V. E. Yudaeva

    2017-01-01

    Full Text Available As a result of the research carried out in 2013-2016, the viability and originality of 1157 accessions of root vegetables have been preserved. 250 breeding accessions of carrot, beetroot and radish have been assessed for different economically valuable traits in open field and laboratory tests. Out of them, 65 accessions were selected out as sources of economically valuable traits. The early-maturing accessions of radish, such as ‘Korsar’, ‘Francuzsky Zavtrak’, ‘Mikhnevsky 1’, ‘18 Dney’, ‘Koroleva Margo’, ‘Polyna’, ‘Rozovo-Krasny s Belym Konchikom’, ‘Sofit’, ‘Kvarta’, ‘Saksa’, ‘Variant’ were regarded. The carrot accessions, such as ‘Scarlet’, ‘Koroleva Oseni’, ‘Dlinnaya Krasnaya’ were distinguished as sources of high yield capacity. The sources of high root yield in beetroot were varieties: ‘Valenta’, ‘Mestnaya iz Madagaskara’, Goldiers Super Black Beet, Zwaans Early Red Chief. The long shelf-life during wintertime was observed in beetroot varieties: ‘Slowiblot’, ‘Valenta’, ‘Lomarina’. The varieties: ‘Nevezhes’, ‘Neger Schwarz Halblange’, ‘Goldiers Super Black Beet’ were distinguished by high root marketability. With the use of world plant collection at VIR, the following varieties of root vegetables: ‘Dar Podmoskovya’ in carrot; ‘Osennya Princessa’ in beetroot; ‘Mikhnevskiy 1 ‘in garden radish; ‘Osenniy Krasavets’ in daikon; ‘Albina’ in root parsley; ‘Atlant’ in parsnip; Moscowskiy Krasavets in celery, and ‘Oseniya Udacha’ in wild radish were developed. It was also shown those varieties that had high yield capacity and root marketability were distinguished by small epidermal cell structure and large number of stomata per unit of leaf surface. It may be supposed that the large number of stomata per unit of leaf surface and small epidermal cell structure was the evidence of adaptive capacity of accessions taken for the study. 

  7. Leaf anatomy of Medicinal Shrubs and Trees from Gallery Forests of the Paranaense Province (Argentina: Part 1 Anatomía foliar de árboles y arbustos medicinales de las selvas en galería de la provincia Paranaense (Argentina. Parte 1

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    Ana M. Arambarri

    2006-12-01

    Full Text Available Sixty two species of shrubs and trees belonging to 28 families inhabiting gallery forests of the Paranaense biogeographic province (Argentina have been cited with medicinal properties. The aim of this study was to provide a tool to recognize these taxa from fragmented leaf samples. Fresh material and hydrated herbarium specimens fixed in FAA were surveyed. The main differential traits are: hypodermis presence (e.g. Myrceugenia glaucescens ; stomata and trichome types (e.g. ciclocytic stomata in Baccharis spp.; cystolith-like structure in trichomes in Aloysia gratissima var. gratissima ; midvein transection outlines (e.g. midvein convex and keel-shaped on the adaxial side in Allophylus edulis , mesophyll of the leaf blade (e.g. indifferentiated in Poiretia tetraphylla ; presence of idioblastic sclereids (e.g. in the petiole of Rollinia emarginata , presence and types of crystals (e.g. crystal sand in Sambucus australis ; presence of secretory structures (e.g. large secretory cavities in Malvaceae and Myrtaceae. We can conclude that the leaf features have diagnostic value to identify species. As a result, we offer a key to distinguish these 62 species and illustrations to clarify it. Ecological interpretation of leaf structures is also given.Entre los árboles y arbustos que forman las selvas en galería de la provincia biogeográfica Paranaense (Argentina, 62 especies pertenecientes a 28 familias son citadas como medicinales. El objetivo de este trabajo es proveer elementos para el reconocimiento de estos taxones a partir de hojas fragmentadas. Para el estudio se utilizó material fresco y ejemplares de herbario recuperados y fijados en FAA. Algunos de los principales caracteres de identificación son: la presencia de una hipodermis (e.g. en Myrceugenia glaucescens ; los tipos de estomas (e.g. los estomas ciclocíticos en Baccharis spp. y de tricomas (e.g. los tricomas cistolíticos en Aloysia gratissima var. gratissima ; el contorno de la vena

  8. Observações citolúgicas em Citrus: VI. Resultados preliminares do efeito da colchicina sôbre sementes em germinação

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    Osvaldo Bacchi

    1944-11-01

    Full Text Available Salientamos, em linhas gerais, as possibilidades econômicas da triplcidia em Citrus. Citamos a constatação de um tetraplóide (2n = 36 e de um pentaplóide (2n = 45, que constituem os únicos poliplóides naturais por nós observados. Apresentamos, a seguir, as observações preliminares sôbre uma experiência de tratamento de sementes com a colchicina, para a obtenção de plantas poliplóides. Nos tratamentos efetuados não notamos qualquer influência da mesma sobre a percentagem de germinação. As contagens do número de cromosômios em pontas de raízes e as medições das áreas dos estornas nas fôlhas nos revelaram os seguintes resultados : 1 Das plantas examinadas, três (C.3, C.9 e C.15 têm raízes di-tetraplóides, e apresentam, a julgar pela área dos seus estornas, epiderme tetraplóide. 2 Uma outra planta, a C.12, além de hiperdiplóide, com 2n=19 (e 20?, apresentou uma raiz de natureza quimérica, pois em uma de suas células contamos, aproximadamente, 38 cromosômios somáticos ; a despeito dessa alteração cromosômica, não verificamos, nesta planta, qualquer modificação no tamanho dos seus estomas.Attention is drawn to the economic importance of triploidy in Citrus. During his investigations, the author only found one tetraploid (2n = 36 and one pentaploid (2n = 45 as natural polyploids in Citrus. Preliminary results are then presented of an experiment to produce polyploids through the treatment of seeds with colchicine. Germination was not influenced by these treatments. Chromosome counts in root tips and the mensurement of stomata area gave the following results : 1 Three of the examined plants (C.3, C.9 and C.15 had diploid and tetraploid roots and a tetraploid epidermis, to judge from its stomata area. 2 Another plant, C.12, besides being an hyperdiploid (2n=19 and 20?, had one root which was a chimera, as in one of its cells approximated 38 chromosomes were counted; in spite of this chromosomal alteration, the

  9. Mechanistic modelling of Middle Eocene atmospheric carbon dioxide using fossil plant material

    Science.gov (United States)

    Grein, Michaela; Roth-Nebelsick, Anita; Wilde, Volker; Konrad, Wilfried; Utescher, Torsten

    2010-05-01

    Various proxies (such as pedogenic carbonates, boron isotopes or phytoplankton) and geochemical models were applied in order to reconstruct palaeoatmospheric carbon dioxide, partially providing conflicting results. Another promising proxy is the frequency of stomata (pores on the leaf surface used for gaseous exchange). In this project, fossil plant material from the Messel Pit (Hesse, Germany) is used to reconstruct atmospheric carbon dioxide concentration in the Middle Eocene by analyzing stomatal density. We applied the novel mechanistic-theoretical approach of Konrad et al. (2008) which provides a quantitative derivation of the stomatal density response (number of stomata per leaf area) to varying atmospheric carbon dioxide concentration. The model couples 1) C3-photosynthesis, 2) the process of diffusion and 3) an optimisation principle providing maximum photosynthesis (via carbon dioxide uptake) and minimum water loss (via stomatal transpiration). These three sub-models also include data of the palaeoenvironment (temperature, water availability, wind velocity, atmospheric humidity, precipitation) and anatomy of leaf and stoma (depth, length and width of stomatal porus, thickness of assimilation tissue, leaf length). In order to calculate curves of stomatal density as a function of atmospheric carbon dioxide concentration, various biochemical parameters have to be borrowed from extant representatives. The necessary palaeoclimate data are reconstructed from the whole Messel flora using Leaf Margin Analysis (LMA) and the Coexistence Approach (CA). In order to obtain a significant result, we selected three species from which a large number of well-preserved leaves is available (at least 20 leaves per species). Palaeoclimate calculations for the Middle Eocene Messel Pit indicate a warm and humid climate with mean annual temperature of approximately 22°C, up to 2540 mm mean annual precipitation and the absence of extended periods of drought. Mean relative air

  10. Reconstructing Middle Eocene Climate and Atmospheric Carbon Dioxide Concentration: Application of a mechanistic theoretical approach to fossil plants from the Messel Pit (Germany)

    Science.gov (United States)

    Grein, M.; Roth-Nebelsick, A.; Wilde, V.; Konrad, W.; Utescher, T.

    2009-12-01

    It is assumed that changes in atmospheric CO2 concentrations (from now on expressed as Ca) strongly influenced the development of global temperatures during parts of the Cenozoic. Thus, detailed knowledge of ancient Ca and its variations is of utmost importance for exploring the coupling of atmospheric CO2 and global climate change. Numerous techniques (such as carbon and boron isotopes) were applied in order to obtain Ca, with varying and sometimes even conflicting results. Stomatal density (number of stomata per leaf area) represents another promising proxy for the calculation of ancient Ca since many plants reduce the number of stomata (pores on the leaf surface used for gas exchange) under increasing Ca. As a reason it is assumed that plants try to adjust stomatal conductance in order to optimize their gas exchange (which means maximal assimilation at minimal transpiration). The common technique for calculating Ca from fossil stomatal frequency is to create empirical transfer functions of living plants derived from herbar material or greenhouse experiments. In the presented project, Ca of the Middle Eocene is calculated by applying a different approach which utilizes a mechanistic-theoretical calibration. It couples the processes of a) C3-photosynthesis, b) diffusion and c) transpiration with palaeoclimatic and leaf-anatomical data. The model also includes an optimisation principle supported by ecophysiological data. According to this optimisation principle, plants adjust their stomatal conductance in such a way that photosynthesis rates are constrained by optimal water use (transpiration). This model was applied in the present study to fossil plants from the Messel Pit near Darmstadt (Germany). In order to reconstruct Ca by using fossil plant taxa from Messel, numerous parameters which represent model input have to be estimated from measurements of living representatives. Furthermore, since climate parameters are also required by the model, quantitative

  11. Ectopically expressing MdPIP1;3, an aquaporin gene, increased fruit size and enhanced drought tolerance of transgenic tomatoes.

    Science.gov (United States)

    Wang, Lin; Li, Qing-Tian; Lei, Qiong; Feng, Chao; Zheng, Xiaodong; Zhou, Fangfang; Li, Lingzi; Liu, Xuan; Wang, Zhi; Kong, Jin

    2017-12-19

    Water deficit severely reduces apple growth and production, is detrimental to fruit quality and size. This problem is exacerbated as global warming is implicated in producing more severe drought stress. Thus water-efficiency has becomes the major target for apple breeding. A desired apple tree can absorb and transport water efficiently, which not only confers improved drought tolerance, but also guarantees fruit size for higher income returns. Aquaporins, as water channels, control water transportation across membranes and can regulate water flow by changing their amount and activity. The exploration of molecular mechanism of water efficiency and the gene wealth will pave a way for molecular breeding of drought tolerant apple tree. In the current study, we screened out a drought inducible aquaporin gene MdPIP1;3, which specifically enhanced its expression during fruit expansion in 'Fuji' apple (Malus domestica Borkh. cv. Red Fuji). It localized on plasma membranes and belonged to PIP1 subfamily. The tolerance to drought stress enhanced in transgenic tomato plants ectopically expressing MdPIP1;3, showing that the rate of losing water in isolated transgenic leaves was slower than wild type, and stomata of transgenic plants closed sensitively to respond to drought compared with wild type. Besides, length and diameter of transgenic tomato fruits increased faster than wild type, and in final, fruit sizes and fresh weights of transgenic tomatoes were bigger than wild type. Specially, in cell levels, fruit cell size from transgenic tomatoes was larger than wild type, showing that cell number per mm 2 in transgenic fruits was less than wild type. Altogether, ectopically expressing MdPIP1;3 enhanced drought tolerance of transgenic tomatoes partially via reduced water loss controlled by stomata closure in leaves. In addition, the transgenic tomato fruits are larger and heavier with larger cells via more efficient water transportation across membranes. Our research will

  12. Residual transpiration as a component of salinity stress tolerance mechanism: a case study for barley.

    Science.gov (United States)

    Hasanuzzaman, Md; Davies, Noel W; Shabala, Lana; Zhou, Meixue; Brodribb, Tim J; Shabala, Sergey

    2017-06-19

    While most water loss from leaf surfaces occurs via stomata, part of this loss also occurs through the leaf cuticle, even when the stomata are fully closed. This component, termed residual transpiration, dominates during the night and also becomes critical under stress conditions such as drought or salinity. Reducing residual transpiration might therefore be a potentially useful mechanism for improving plant performance when water availability is reduced (e.g. under saline or drought stress conditions). One way of reducing residual transpiration may be via increased accumulation of waxes on the surface of leaf. Residual transpiration and wax constituents may vary with leaf age and position as well as between genotypes. This study used barley genotypes contrasting in salinity stress tolerance to evaluate the contribution of residual transpiration to the overall salt tolerance, and also investigated what role cuticular waxes play in this process. Leaves of three different positions (old, intermediate and young) were used. Our results show that residual transpiration was higher in old leaves than the young flag leaves, correlated negatively with the osmolality, and was positively associated with the osmotic and leaf water potentials. Salt tolerant varieties transpired more water than the sensitive variety under normal growth conditions. Cuticular waxes on barley leaves were dominated by primary alcohols (84.7-86.9%) and also included aldehydes (8.90-10.1%), n-alkanes (1.31-1.77%), benzoate esters (0.44-0.52%), phytol related compounds (0.22-0.53%), fatty acid methyl esters (0.14-0.33%), β-diketones (0.07-0.23%) and alkylresorcinols (1.65-3.58%). A significant negative correlation was found between residual transpiration and total wax content, and residual transpiration correlated significantly with the amount of primary alcohols. Both leaf osmolality and the amount of total cuticular wax are involved in controlling cuticular water loss from barley leaves under well

  13. Thermal Remote Sensing with Uav-Based Workflows

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    Boesch, R.

    2017-08-01

    Climate change will have a significant influence on vegetation health and growth. Predictions of higher mean summer temperatures and prolonged summer draughts may pose a threat to agriculture areas and forest canopies. Rising canopy temperatures can be an indicator of plant stress because of the closure of stomata and a decrease in the transpiration rate. Thermal cameras are available for decades, but still often used for single image analysis, only in oblique view manner or with visual evaluations of video sequences. Therefore remote sensing using a thermal camera can be an important data source to understand transpiration processes. Photogrammetric workflows allow to process thermal images similar to RGB data. But low spatial resolution of thermal cameras, significant optical distortion and typically low contrast require an adapted workflow. Temperature distribution in forest canopies is typically completely unknown and less distinct than for urban or industrial areas, where metal constructions and surfaces yield high contrast and sharp edge information. The aim of this paper is to investigate the influence of interior camera orientation, tie point matching and ground control points on the resulting accuracy of bundle adjustment and dense cloud generation with a typically used photogrammetric workflow for UAVbased thermal imagery in natural environments.

  14. Expression of Arabidopsis hexokinase in citrus guard cells controls stomatal aperture and reduces transpiration

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    Nitsan eLugassi

    2015-12-01

    Full Text Available Hexokinase (HXK is a sugar-phosphorylating enzyme involved in sugar-sensing. It has recently been shown that HXK in guard cells mediates stomatal closure and coordinates photosynthesis with transpiration in the annual species tomato and Arabidopsis. To examine the role of HXK in the control of the stomatal movement of perennial plants, we generated citrus plants that express Arabidopsis HXK1 (AtHXK1 under KST1, a guard cell-specific promoter. The expression of KST1 in the guard cells of citrus plants has been verified using GFP as a reporter gene. The expression of AtHXK1 in the guard cells of citrus reduced stomatal conductance and transpiration with no negative effect on the rate of photosynthesis, leading to increased water-use efficiency. The effects of light intensity and humidity on stomatal behavior were examined in rooted leaves of the citrus plants. The optimal intensity of photosynthetically active radiation and lower humidity enhanced stomatal closure of AtHXK1-expressing leaves, supporting the role of sugar in the regulation of citrus stomata. These results suggest that HXK coordinates photosynthesis and transpiration and stimulates stomatal closure not only in annual species, but also in perennial species.

  15. Linking stomatal traits and expression of slow anion channel genes HvSLAH1 2 HvSLAC1 with grain yield for increasing salinity tolerance in barley

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    Xiaohui eLiu

    2014-11-01

    Full Text Available Soil salinity is an environmental and agricultural problem in many parts of the world. One of the keys to breeding barley for adaptation to salinity lies in a better understanding of the genetic control of stomatal regulation. We have employed a range of physiological and molecular techniques (stomata assay, gas exchange, phylogenetic analysis, QTL analysis, and gene expression to investigate stomatal behaviour and genotypic variation in barley cultivars and a genetic population in four experimental trials. A set of relatively efficient and reliable methods were developed for the characterisation of stomatal behaviour of large numbers of varieties and genetic lines. Furthermore, we have found a large genetic variation of gas exchange and stomatal traits in barley in response to salinity stress. Salt-tolerant CM72 showed significantly larger stomatal aperture in 200 mM NaCl treatment than that of salt-sensitive Gairdner. Stomatal traits such as aperture width/length were found to significantly correlate with grain yield in salt treatment. Phenotypic characterisation and QTL analysis of a segregating double haploid population of the CM72/Gairdner resulted in the identification of significant stomatal traits-related QTLs for salt tolerance. Moreover, expression analysis of the slow anion channel genes HvSLAH1 and HvSLAC1 demonstrated that their up-regulation is linked to high barley grain yield in the field.

  16. Ozone gradients in a spruce forest stand in relation to wind speed and time of the day

    Science.gov (United States)

    Pleijel, H.; Wallin, G.; Karlsson, P. E.; Skärby, L.

    Ozone concentrations were measured outside and inside a 60-year-old 15-20 m tall spruce forest at a wind-exposed forest edge in southwest Sweden, at 3 and 13 m height 15 m outside the forest, and at 3 and 13 m height inside the forest 45 m from the forest edge. Measurements at 3 m were made with three replicate tubes on each site, the replicates being separated by 10 m. In addition, horizontal and vertical wind speeds were measured at 8 m height outside and inside the forest. During daytime, the concentrations inside the forest were generally slightly lower. Negative ozone concentration gradients from the open field into the forest were observed at 3 m height when the wind speed was below approximately 1.5 m s -1. At very low wind speeds, mainly occurring during the night, the ozone concentrations at 3 m height were frequently higher inside the forest than outside the forest. This may be caused by a very large aerodynamic resistance to ozone deposition, due to very small air movements inside the forest under stable conditions. It is concluded that ozone uptake by the trees is likely to be very small at night, even if stomata are not entirely closed. Results from open-top chamber experiments are also discussed.

  17. ROS signaling and stomatal movement in plant responses to drought stress and pathogen attack.

    Science.gov (United States)

    Qi, Junsheng; Song, Chun-Peng; Wang, Baoshan; Zhou, Jianmin; Kangasjärvi, Jaakko; Zhu, Jian-Kang; Gong, Zhizhong

    2018-04-16

    Stomata, the pores formed by a pair of guard cells, are the main gateways for water transpiration and photosynthetic CO 2 exchange, as well as pathogen invasion in land plants. Guard cell movement is regulated by a combination of environmental factors including water status, light, CO 2 levels and pathogen attack, as well as endogenous signals such as abscisic acid and apoplastic reactive oxygen species (ROS). Under abiotic and biotic stress conditions, extracellular ROS are mainly produced by plasma membrane-localized NADPH oxidases, whereas intracellular ROS are produced in multiple organelles. These ROS form a sophisticated cellular signaling network, with the accumulation of apoplastic ROS an early hallmark of stomatal movement. Here, we review recent progress in understanding the molecular mechanisms of the ROS signaling network, primarily during drought stress and pathogen attack. We summarize the roles of apoplastic ROS in regulating stomatal movement, ABA and CO 2 signaling, and immunity responses. Finally, we discuss ROS accumulation and communication between organelles and cells. This information provides a conceptual framework for understanding how ROS signaling is integrated with various signaling pathways during plant responses to abiotic and biotic stress stimuli. This article is protected by copyright. All rights reserved.

  18. Unveiling common responses of Medicago truncatula to appropriate and inappropriate rust species

    Science.gov (United States)

    Vaz Patto, Maria Carlota; Rubiales, Diego

    2014-01-01

    Little is known about the nature of effective defense mechanisms in legumes to pathogens of remotely related plant species. Some rust species are among pathogens with broad host range causing dramatic losses in various crop plants. To understand and compare the different host and nonhost resistance (NHR) responses of legume species against rusts, we characterized the reaction of the model legume Medicago truncatula to one appropriate (Uromyces striatus) and two inappropriate (U. viciae-fabae and U. lupinicolus) rusts. We found that similar pre and post-haustorial mechanisms of resistance appear to be operative in M. truncatula against appropriate and inappropriate rust fungus. The appropriate U. striatus germinated better on M. truncatula accessions then the inappropriate U. viciae-fabae and U. lupinicolus, but once germinated, germ tubes of the three rusts had a similar level of success in finding stomata and forming an appressoria over a stoma. However, responses to different inappropriate rust species also showed some specificity, suggesting a combination of non-specific and specific responses underlying this legume NHR to rust fungi. Further genetic and expression analysis studies will contribute to the development of the necessary molecular tools to use the present information on host and NHR mechanisms to breed for broad-spectrum resistance to rust in legume species. PMID:25426128

  19. Arabidopsis thaliana MLO genes are expressed in discrete domains during reproductive development.

    Science.gov (United States)

    Davis, Thomas C; Jones, Daniel S; Dino, Arianna J; Cejda, Nicholas I; Yuan, Jing; Willoughby, Andrew C; Kessler, Sharon A

    2017-12-01

    MLOs in Plant Reproduction. The MILDEW RESISTANCE LOCUS-O (MLO) protein family, comprised of 15 members, plays roles in diverse cell-cell communication processes such as powdery mildew susceptibility, root thigmomorphogenesis, and pollen tube reception. The NORTIA (NTA, AtMLO7) gene is expressed in the synergid cells of the female gametophyte where it functions in intercellular communication with the pollen tube. Discrepancies between previously published promoter::GUS and promoter::gene-GUS constructs expression patterns led us to explore the regulation of NTA expression. Here we found via NTA pro ::gNTA-GUS truncations that sequences within the NTA gene negatively regulate its expression in the stomata and carpel walls. This led to the hypothesis that other MLO family members may also have additional regulatory sequences within the gene. MLO pro ::gMLO-GUS constructs were examined for each family member focusing specifically on flowers in order to determine whether other MLOs could play a role in reproductive cell-cell communication. Notably, several MLOs were expressed in the pollen, in the stigma, in the pollinated style, and in the synergids and central cell. These findings indicate that other MLOs in addition to NTA could play a role in reproduction. Previous studies on the MLO family showed that phylogenetically related MLOs had redundant functions in powdery mildew infection and root thigmomorphogenesis; however, MLO expression in reproductive tissues did not strictly follow phylogenetic relationships, indicating that MLOs from different evolutionary origins may have been recruited for function in sexual reproduction.

  20. In Vitro Characterization of Thermostable CAM Rubisco Activase Reveals a Rubisco Interacting Surface Loop1[OPEN

    Science.gov (United States)

    Shivhare, Devendra

    2017-01-01

    To maintain metabolic flux through the Calvin-Benson-Bassham cycle in higher plants, dead-end inhibited complexes of Rubisco must constantly be engaged and remodeled by the molecular chaperone Rubisco activase (Rca). In C3 plants, the thermolability of Rca is responsible for the deactivation of Rubisco and reduction of photosynthesis at moderately elevated temperatures. We reasoned that crassulacean acid metabolism (CAM) plants must possess thermostable Rca to support Calvin-Benson-Bassham cycle flux during the day when stomata are closed. A comparative biochemical characterization of rice (Oryza sativa) and Agave tequilana Rca isoforms demonstrated that the CAM Rca isoforms are approximately10°C more thermostable than the C3 isoforms. Agave Rca also possessed a much higher in vitro biochemical activity, even at low assay temperatures. Mixtures of rice and agave Rca form functional hetero-oligomers in vitro, but only the rice isoforms denature at nonpermissive temperatures. The high thermostability and activity of agave Rca mapped to the N-terminal 244 residues. A Glu-217-Gln amino acid substitution was found to confer high Rca activity to rice Rca. Further mutational analysis suggested that Glu-217 restricts the flexibility of the α4-β4 surface loop that interacts with Rubisco via Lys-216. CAM plants thus promise to be a source of highly functional, thermostable Rca candidates for thermal fortification of crop photosynthesis. Careful characterization of their properties will likely reveal further protein-protein interaction motifs to enrich our mechanistic model of Rca function. PMID:28546437

  1. Redox and the circadian clock in plant immunity: A balancing act.

    Science.gov (United States)

    Karapetyan, Sargis; Dong, Xinnian

    2018-05-01

    Plants' reliance on sunlight for energy makes their light-driven circadian clock a critical regulator in balancing the energy needs for vital activities such as growth and defense. Recent studies show that the circadian clock acts as a strategic planner to prime active defense responses towards the morning or daytime when conditions, such as the opening of stomata required for photosynthesis, are favorable for attackers. Execution of the defense response, on the other hand, is determined according to the cellular redox state and is regulated in part by the production of reactive oxygen and nitrogen species upon pathogen challenge. The interplay between redox and the circadian clock further gates the onset of defense response to a specific time of the day to avoid conflict with growth-related activities. In this review, we focus on discussing the roles of the circadian clock as a robust overseer and the cellular redox as a dynamic executor of plant defense. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Botanical and genetic characters of Erythrina × neillii cultivated in Egypt

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    Salma K. Gabr

    Full Text Available Abstract Erythrina × neillii Mabberley & Lorence, Fabaceae, is a sterile hybrid between E. herbacea L. and E. humeana Spreng. Nothing was traced about its genetic, macro and micromorphology. Therefore, it was deemed of interest to study its botanical characters, in addition to the DNA fingerprint to help in the identification of the plant. The anatomical characters of the old stem and its bark are characterized by the presence of cork cells, bast fibers and sclereids. Pericycle is sclerenchymatous forming crystal sheath. The epidermises of the leaf and young stem are characterized by the presence of anomocytic and paracytic stomata, non-glandular, unicellular and multicellular two armed hairs, and glandular club shaped hair. Calcium oxalate is present in the form of crystal sheath and prisms. Secretory cavities are distributed in the phloem and cortex. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE was used as one of the molecular methods to differentiate between the samples of Erythrina. The DNA of Erythrina was extracted and analyzed using seven-mer random primers. Randomly Amplified Polymorphic DNA were recognized. This characterization allows certification of the authenticity of Erythrina × neillii, in order to provide quality control for the plant.

  3. Effect of Irradiation of 60CO Gamma Rays on Growth of Garlic (Allium Sativum L) Plants Cv. Lumbu Hijau at Low Land Area

    International Nuclear Information System (INIS)

    Ismiyati Sutarto; Kumala Dewi; Arwin; Nurrohma

    2004-01-01

    Garlic originally come from the sub tropical area. In Indonesia, garlic is grown generally in high land area with an altitude between 1000 - 1600 m above sea level. Therefore, the area for growing and producing garlic is limited. Besides, genetic variation of garlic is very narrow since garlic belongs to vegetatively propagated crops. An effort for increasing genetic variation of garlic was done by exposing garlic cloves to gamma rays in order to obtain garlic mutant lines adapted to low land area. Garlic cloves were exposed to different doses of gamma rays 0 (untreated) 2, 4, 6, 8 and 10 Gy at the Centre for Research and Development of Isotope and Radiation Technology. Each dose consisted of 150 garlic cloves. Untreated and irradiated garlic cloves were grown at Bandar Buat Experimental Station (50 m above sea level), Padang, West Sumatera. The experiment was arranged in a randomized block design with three replication. The parameter observed were percentage of grown plants and survival harvested plants, plant height, leaf number, chlorophyll content, number of stomata, plant age, number of cloves per bulbs, fresh, dry weight and diameter of bulbs. The result indicated that the dose of gamma rays 6 Gy is an advantage dose for obtaining well adapted garlic mutant lines in the low land area. (author)

  4. Adaptation and detoxification mechanisms of Vetiver grass (Chrysopogon zizanioides) growing on gold mine tailings.

    Science.gov (United States)

    Melato, F A; Mokgalaka, N S; McCrindle, R I

    2016-01-01

    Vetiver grass (Chrysopogon zizanioides) was investigated for its potential use in the rehabilitation of gold mine tailings, its ability to extract and accumulate toxic metals from the tailings and its metal tolerant strategies. Vetiver grass was grown on gold mine tailings soil, in a hothouse, and monitored for sixteen weeks. The mine tailings were highly acidic and had high electrical conductivity. Vetiver grass was able to grow and adapt well on gold mine tailings. The results showed that Vetiver grass accumulated large amounts of metals in the roots and restricted their translocation to the shoots. This was confirmed by the bioconcentration factor of Zn, Cu, and Ni of >1 and the translocation factor of <1 for all the metals. This study revealed the defense mechanisms employed by Vetiver grass against metal stress that include: chelation of toxic metals by phenolics, glutathione S-tranferase, and low molecular weight thiols; sequestration and accumulation of metals within the cell wall that was revealed by the scanning electron microscopy that showed closure of stomata and thickened cell wall and was confirmed by high content of cell wall bound phenolics. Metal induced reactive oxygen species are reduced or eliminated by catalase, superoxide dismutase and peroxidase dismutase.

  5. Alteration of Leaf Anatomy of Handeuleum (Graptophyllum pictum L. Griff due to Gamma Irradiation

    Directory of Open Access Journals (Sweden)

    Arrin Rosmala

    2016-07-01

    Full Text Available The leaves of the plant handeuleum (Graptophyllum pictum L. Griff have long been used for traditional medicine in several regions in Indonesia. This study was aimed to determine the effect of gamma irradiation rate on the anatomy and phytochemical content of the leaf. The rates of gamma rays used were 0, 15, 30, 45, 60, 75, 90, and 105 Gy. Our results showed that gamma ray irradiation rate of 30 Gy produced leaves that contain anthocyanins and carotenoids, with the highest number of stomata and stomatal density compared with control plants. Stomatal index was found highest in the leaves with 45 Gy of gamma irradiation. High-rate gamma ray irradiation produced rigid, thick, and frangible leaves. A high rate of gamma irradiation, i.e. 75, 90, and 105 Gy, produces bigger palisade, sponges, and upper epidermis than the control plants, respectively. Our results showed an association between increasing rate of irradiation with alterations in the structure of leaf anatomy and phytochemical content of handeuleum.

  6. Enhanced methanol production in plants provides broad spectrum insect resistance.

    Directory of Open Access Journals (Sweden)

    Sameer Dixit

    Full Text Available Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR and spectra showed up to 16 fold higher methanol as compared to control wild type (WT plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid and Bemisia tabaci (whitefly, respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants.

  7. Quantifying ozone uptake at the canopy level of spruce, pine and larch trees at the alpine timberline: an approach based on sap flow measurement

    International Nuclear Information System (INIS)

    Wieser, G.; Matyssek, R.; Koestner, B.; Oberhuber, W.

    2003-01-01

    Sap-flow based measurements can be used to estimate ozone uptake at whole-tree and stand levels. - Micro-climatic and ambient ozone data were combined with measurements of sap flow through tree trunks in order to estimate whole-tree ozone uptake of adult Norway spruce (Picea abies), cembran pine (Pinus cembra), and European larch (Larix decidua) trees. Sap flow was monitored by means of the heat balance approach in two trees of each species during the growing season of 1998. In trees making up the stand canopy, the ozone uptake by evergreen foliages was significantly higher than by deciduous ones, when scaled to the ground area. However, if expressed per unit of whole-tree foliage area, ozone flux through the stomata into the needle mesophyll was 1.09, 1.18 and 1.40 nmol m -2 s -1 in Picea abies, Pinus cembra and Larix decidua, respectively. These fluxes are consistent with findings from measurements of needle gas exchange, published from the same species at the study site. It is concluded that the sap flow-based approach offers an inexpensive, spatially and temporally integrating way for estimating ozone uptake at the whole-tree and stand level, intrinsically covering the effect of boundary layers on ozone flux

  8. Characterization of in vitro haploid and doubled haploid Chrysanthemum morifolium plants via unfertilized ovule culture for phenotypical traits and DNA methylation pattern.

    Directory of Open Access Journals (Sweden)

    Haibin eWang

    2014-12-01

    Full Text Available Chrysanthemum is one of important ornamental species in the world. Its highly heterozygous state complicates molecular analysis, so it is of interest to derive haploid forms. A total of 2,579 non-fertilized chrysanthemum ovules pollinated by Argyranthemum frutescens were cultured in vitro to isolate haploid progeny. One single regenerant emerged from each of three of the 105 calli produced. Chromosome counts and microsatellite fingerprinting showed that only one of the regenerants was a true haploid. Nine doubled haploid derivatives were subsequently generated by colchicine treatment of 80 in vitro cultured haploid nodal segments. Morphological screening showed that the haploid plant was shorter than the doubled haploids, and developed smaller leaves, flowers and stomata. An in vitro pollen germination test showed that few of the haploid's pollen were able to germinate and those which did so were abnormal. Both the haploid and the doubled haploids produced yellow flowers, whereas those of the maternal parental cultivar were mauve. Methylation-sensitive amplification polymorphism (MSAP profiling was further used to detect alterations in cytosine methylation caused by the haploidization and/or the chromosome doubling processes. While 52.2% of the resulting amplified fragments were cytosine methylated in the maternal parent's genome, the corresponding proportions for the haploid's and doubled haploids' genomes were, respectively, 47.0% and 51.7%, demonstrating a reduction in global cytosine methylation caused by haploidization and a partial recovery following chromosome doubling.

  9. Stem and leaf anatomy of Plectranthus neochilus Schltr., Lamiaceae

    Directory of Open Access Journals (Sweden)

    Márcia do Rocio Duarte

    Full Text Available Plectranthus neochilus Schltr. is an aromatic herb named " boldo" or " boldo-gambá" and employed for treating hepatic insufficiency and dyspepsia in folk medicine. This paper has investigated its stem and leaf anatomy, in order to contribute for the medicinal plant identification. The botanical material was prepared according to standard microtechniques. The stem has quadrangular transection and, in secondary growth at the level analyzed, shows uniseriate epidermis and numerous trichomes. The glandular ones are capitate and peltate. The former has short unicellular or long multicellular stalk and uni- or bicellular head. The latter presents short stalk and eight-celled ovoid head. The non-glandular trichomes are multicellular, uniseriate and coated with granular cuticle. It is observed angular collenchyma, cambia forming phloem outward and xylem inward, and perivascular fiber caps next to the phloem. The blade has uniseriate epidermis coated with striate cuticle, diacytic stomata on both surfaces, numerous trichomes similar to the stem ones, and homogeneous mesophyll. The midrib shows one or two collateral bundles and the petiole has many of them distributed as an open arc.

  10. Impact of elevated CO2 concentration on dynamics of leaf photosynthesis in Fagus sylvatica is modulated by sky conditions

    International Nuclear Information System (INIS)

    Urban, Otmar; Klem, Karel; Holišová, Petra; Šigut, Ladislav; Šprtová, Mirka; Teslová-Navrátilová, Petra; Zitová, Martina; Špunda, Vladimír; Marek, Michal V.; Grace, John

    2014-01-01

    It has been suggested that atmospheric CO 2 concentration and frequency of cloud cover will increase in future. It remains unclear, however, how elevated CO 2 influences photosynthesis under complex clear versus cloudy sky conditions. Accordingly, diurnal changes in photosynthetic responses among beech trees grown at ambient (AC) and doubled (EC) CO 2 concentrations were studied under contrasting sky conditions. EC stimulated the daily sum of fixed CO 2 and light use efficiency under clear sky. Meanwhile, both these parameters were reduced under cloudy sky as compared with AC treatment. Reduction in photosynthesis rate under cloudy sky was particularly associated with EC-stimulated, xanthophyll-dependent thermal dissipation of absorbed light energy. Under clear sky, a pronounced afternoon depression of CO 2 assimilation rate was found in sun-adapted leaves under EC compared with AC conditions. This was caused in particular by stomata closure mediated by vapour pressure deficit. -- Highlights: • Sky conditions affect the relative impact of elevated CO 2 on photosynthesis. • Cloudy skies reduce light use efficiency and carbon gain when CO 2 is elevated. • Stimulation of photosynthesis by high CO 2 may decline with increasing cloud cover. • High CO 2 leads to marked afternoon photosynthesis depression in sun-adapted leaves. -- The stimulatory effect of elevated CO 2 concentration on photosynthetic carbon assimilation can be expected to diminish as cloud cover increases

  11. Ultraestructura del bambú Guadua macclurei (Poaceae: Bambusoideae de Costa Rica

    Directory of Open Access Journals (Sweden)

    Mayra Montiel

    2006-06-01

    Full Text Available Se evaluaron ultraestructuralmente secciones de la lámina de la hoja, vaina de la hoja y rama, de una planta adulta de Guadua macclurei. Las brácteas del culmo carecen de setas orales. En la superficie adaxial de la lámina foliar se observó un patrón celular diferente al de otras especies de este género. Además, hay tricomas tricelulares y bandas de estomas de alto domo muy ordenadas y evidentes, característica que la podría diferenciar de otras especies en el género. Esta es la primera descripción microscópica de esta especie.We studied the ultrastructure of sections of leaf lamina, leaf sheath and branches of an adult plant of Guadua macclurei. Culm sheaths lack fimbriae (oral setae. The adaxial section of the leaf lamina has a particular cellular pattern, previously unreported in this genus. The tricellular trichomes, and the evident and ordered bands of high dome stomata may be useful for taxonomic purposes. To the best of our knowledge, this is the first microscopic description of this species. Rev. Biol. Trop. 54(Suppl. 2: 35-42. Epub 2006 Dec. 01.

  12. In vitro growth and leaf anatomy of Cattleya walkeriana (Gardner, 1839 grown in natural ventilation system

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    Adriano Bortolotti da Silva

    2014-12-01

    Full Text Available Natural ventilation system facilitates gaseous exchanges in in vitro plants promoting changes in the leaf tissue, which can be evaluated through the leaf anatomy, and it allows a cultivation closer to the photoautrophic micropropagation. The objective of this work was to evaluate the effects on in vitro growth and on the leaf anatomy of Cattleya walkeriana grown in natural and conventional ventilation system with different concentrations of sucrose (0; 15; 30 and 45 L-1 combined with different cultivation systems (conventional micropropagation and natural ventilation system. The culture medium was composed of MS salts, solidified with 7 g L-1 of agar and pH adjusted to 5.8. Forty milliliters of culture medium were distributed in 250 mL flasks, autoclaved at 120 ºC for 20 minutes. The greater plant growth, as well as the greater thickness of the mesophyll was observed with the use of 20 g L-1 sucrose in natural ventilation system. Plants grown in natural ventilation system showed a thicker leaf mesophyll, which is directly related to photoautotrophic crops. The natural ventilation system induced more elliptical stomata and probably more functional formats.

  13. Physical, chemical and agricultural investigations of fly ash originating from oil-fired equipment, with special regard to the damaging effect on the environment

    Energy Technology Data Exchange (ETDEWEB)

    Veres, I; Czibulya, J; Ravasz, T; Boszormenyi, Z

    1972-01-01

    Physical and chemical investigations and green house tests performed with fly ash samples from a large-capacity, oil-fired thermal power plant, are described. The vanadium content determined by a colorimetric method, ranged from 3.82 to 4.14% and the nickel content was determined by a gravimetric method as 0.59-0.62%. The bulk of the fly ash belonged in a fraction of 0.06-0.10 mm. A spherical, soot-like fraction and a mineral fraction with silica, iron oxides, and alkali earth metals as main components were distinguished by morphological investigations. The soot fraction, composed of spheres with smooth surface with limited adhesion, represents minor environmental, including corrosion, hazards, while the mineral fraction which contains hard, abrasive particulates of very irregular shape with large specific surface may produce slight silicosis in man and animals, and plug the stomata in plants. In addition, this fraction represents low-temperature corrosion hazards due to the presence of tetravalent vanacylsulfate and free sulfuric acid. Greenhouse tests with overdosed fly ash revealed white mustard (Brassica hirta) to be most sensitive for fly ash, which thus may be used as an indicator plant. The damage is also dependent on the water supply. The fairly high resistivity of leguminous species, especially of beans may be due to the stimulating effect of vanadium and the increased heat absorption through the fly ash buildups.

  14. RNAi-mediated downregulation of poplar plasma membrane intrinsic proteins (PIPs) changes plasma membrane proteome composition and affects leaf physiology.

    Science.gov (United States)

    Bi, Zhen; Merl-Pham, Juliane; Uehlein, Norbert; Zimmer, Ina; Mühlhans, Stefanie; Aichler, Michaela; Walch, Axel Karl; Kaldenhoff, Ralf; Palme, Klaus; Schnitzler, Jörg-Peter; Block, Katja

    2015-10-14

    Plasma membrane intrinsic proteins (PIPs) are one subfamily of aquaporins that mediate the transmembrane transport of water. To reveal their function in poplar, we generated transgenic poplar plants in which the translation of PIP genes was downregulated by RNA interference investigated these plants with a comprehensive leaf plasma membrane proteome and physiome analysis. First, inhibition of PIP synthesis strongly altered the leaf plasma membrane protein composition. Strikingly, several signaling components and transporters involved in the regulation of stomatal movement were differentially regulated in transgenic poplars. Furthermore, hormonal crosstalk related to abscisic acid, auxin and brassinosteroids was altered, in addition to cell wall biosynthesis/cutinization, the organization of cellular structures and membrane trafficking. A physiological analysis confirmed the proteomic results. The leaves had wider opened stomata and higher net CO2 assimilation and transpiration rates as well as greater mesophyll conductance for CO2 (gm) and leaf hydraulic conductance (Kleaf). Based on these results, we conclude that PIP proteins not only play essential roles in whole leaf water and CO2 flux but have important roles in the regulation of stomatal movement. Copyright © 2015. Published by Elsevier B.V.

  15. Micropropagation of bioencapsulation and ultrastructural features of sainfoin (Onobrychis viciifolia) grown in vivo and in vitro.

    Science.gov (United States)

    Mohajer, Sadegh; Mat Taha, Rosna; Mohajer, Minoo; Khorasani Esmaeili, Arash

    2014-01-01

    To explore the potential of in vitro rapid regeneration, three varieties (Golpaygan-181, Orumieh-1763, and Gorgan-1601) of sainfoin (Onobrychis viciifolia Scop. syn. Onobrychis sativa L.) were evaluated. For the first time, an encapsulation protocol was established from somatic embryogenic callus in torpedo and cotyledonary stages to create artificial seeds. Callus derived from different concentrations of Kinetin (0-2.0 mg L(-1)) and Indole-3-acetic acid (0-2.0 mg L(-1)) was coated with sodium alginate and subsequently cultured either in Murashige and Skoog (MS) medium or in soil substrate. Adventitious shoots from synthetic beads developed into rooting in full and half strength MS medium supplemented with various concentrations of auxin and cytokinin. Prolonged water conservation of black and red soils (1:1) had the highest rate of survival plantlets in the acclimatization process. Diverse resistance techniques in Onobrychis viciifolia were evaluated when the plants were subjected to water deficiency. Higher frequency of epicuticular waxes was observed in in vivo leaves compared to in vitro leaves. Jagged trichomes nonsecreting glands covered by spines were only observed in the lower leaf side. Ultimately, stomata indices were 0.127 (abaxial), 0.188 (adaxial) in in vivo and 0.121 (abaxial), 0.201 (adaxial) in in vitro leaves.

  16. Abscisic Acid Signaling and Abiotic Stress Tolerance in Plants: A Review on Current Knowledge and Future Prospects

    Science.gov (United States)

    Vishwakarma, Kanchan; Upadhyay, Neha; Kumar, Nitin; Yadav, Gaurav; Singh, Jaspreet; Mishra, Rohit K.; Kumar, Vivek; Verma, Rishi; Upadhyay, R. G.; Pandey, Mayank; Sharma, Shivesh

    2017-01-01

    Abiotic stress is one of the severe stresses of environment that lowers the growth and yield of any crop even on irrigated land throughout the world. A major phytohormone abscisic acid (ABA) plays an essential part in acting toward varied range of stresses like heavy metal stress, drought, thermal or heat stress, high level of salinity, low temperature, and radiation stress. Its role is also elaborated in various developmental processes including seed germination, seed dormancy, and closure of stomata. ABA acts by modifying the expression level of gene and subsequent analysis of cis- and trans-acting regulatory elements of responsive promoters. It also interacts with the signaling molecules of processes involved in stress response and development of seeds. On the whole, the stress to a plant can be susceptible or tolerant by taking into account the coordinated activities of various stress-responsive genes. Numbers of transcription factor are involved in regulating the expression of ABA responsive genes by acting together with their respective cis-acting elements. Hence, for improvement in stress-tolerance capacity of plants, it is necessary to understand the mechanism behind it. On this ground, this article enlightens the importance and role of ABA signaling with regard to various stresses as well as regulation of ABA biosynthetic pathway along with the transcription factors for stress tolerance. PMID:28265276

  17. Stomatal Closure and SA-, JA/ET-Signaling Pathways Are Essential for Bacillus amyloliquefaciens FZB42 to Restrict Leaf Disease Caused by Phytophthora nicotianae in Nicotiana benthamiana

    Directory of Open Access Journals (Sweden)

    Liming Wu

    2018-04-01

    Full Text Available Bacillus amyloliquefaciens FZB42 is a plant growth-promoting rhizobacterium that induces resistance to a broad spectrum of pathogens. This study analyzed the mechanism by which FZB42 restricts leaf disease caused by Phytophthora nicotianae in Nicotiana benthamiana. The oomycete foliar pathogen P. nicotianae is able to reopen stomata which had been closed by the plant innate immune response to initiate penetration and infection. Here, we showed that root colonization by B. amyloliquefaciens FZB42 restricted pathogen-mediated stomatal reopening in N. benthamiana. Abscisic acid (ABA and salicylic acid (SA-regulated pathways mediated FZB42-induced stomatal closure after pathogen infection. Moreover, the defense-related genes PR-1a, LOX, and ERF1, involved in the SA and jasmonic acid (JA/ethylene (ET signaling pathways, respectively, were overexpressed, and levels of the hormones SA, JA, and ET increased in the leaves of B. amyloliquefaciens FZB42-treated wild type plants. Disruption of one of these three pathways in N. benthamiana plants increased susceptibility to the pathogen. These suggest that SA- and JA/ET-dependent signaling pathways were important in plant defenses against the pathogen. Our data thus explain a biocontrol mechanism of soil rhizobacteria in a plant.

  18. Accumulation of eicosapolyenoic acids enhances sensitivity to abscisic acid and mitigates the effects of drought in transgenic Arabidopsis thaliana.

    Science.gov (United States)

    Yuan, Xiaowei; Li, Yaxiao; Liu, Shiyang; Xia, Fei; Li, Xinzheng; Qi, Baoxiu

    2014-04-01

    IgASE1, a C₁₈ Δ(9)-specific polyunsaturated fatty acid elongase from the marine microalga Isochrysis galbana, is able to convert linoleic acid and α-linolenic acid to eicosadienoic acid and eicosatrienoic acid in Arabidopsis. Eicosadienoic acid and eicosatrienoic acid are precursors of arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid, which are synthesized via the Δ(8) desaturation biosynthetic pathways. This study shows that the IgASE1-expressing transgenic Arabidopsis exhibited altered morphology (decreased leaf area and biomass) and enhanced drought resistance compared to wild-type plants. The transgenic Arabidopsis were hypersensitive to abscisic acid (ABA) during seed germination, post-germination growth, and seedling development. They had elevated leaf ABA levels under well-watered and dehydrated conditions and their stomata were more sensitive to ABA. Exogenous application of eicosadienoic acid and eicosatrienoic acid can mimic ABA and drought responses in the wild type plants, similar to that found in the transgenic ones. The transcript levels of genes involved in the biosynthesis of ABA (NCED3, ABA1, AAO3) as well as other stress-related genes were upregulated in this transgenic line upon osmotic stress (300 mM mannitol). Taken together, these results indicate that these two eicosapolyenoic acids or their derived metabolites can mitigate the effects of drought in transgenic Arabidopsis, at least in part, through the action of ABA.

  19. Calcium specificity signaling mechanisms in abscisic acid signal transduction in Arabidopsis guard cells

    Science.gov (United States)

    Brandt, Benjamin; Munemasa, Shintaro; Wang, Cun; Nguyen, Desiree; Yong, Taiming; Yang, Paul G; Poretsky, Elly; Belknap, Thomas F; Waadt, Rainer; Alemán, Fernando; Schroeder, Julian I

    2015-01-01

    A central question is how specificity in cellular responses to the eukaryotic second messenger Ca2+ is achieved. Plant guard cells, that form stomatal pores for gas exchange, provide a powerful system for in depth investigation of Ca2+-signaling specificity in plants. In intact guard cells, abscisic acid (ABA) enhances (primes) the Ca2+-sensitivity of downstream signaling events that result in activation of S-type anion channels during stomatal closure, providing a specificity mechanism in Ca2+-signaling. However, the underlying genetic and biochemical mechanisms remain unknown. Here we show impairment of ABA signal transduction in stomata of calcium-dependent protein kinase quadruple mutant plants. Interestingly, protein phosphatase 2Cs prevent non-specific Ca2+-signaling. Moreover, we demonstrate an unexpected interdependence of the Ca2+-dependent and Ca2+-independent ABA-signaling branches and the in planta requirement of simultaneous phosphorylation at two key phosphorylation sites in SLAC1. We identify novel mechanisms ensuring specificity and robustness within stomatal Ca2+-signaling on a cellular, genetic, and biochemical level. DOI: http://dx.doi.org/10.7554/eLife.03599.001 PMID:26192964

  20. Shoot-derived abscisic acid promotes root growth.

    Science.gov (United States)

    McAdam, Scott A M; Brodribb, Timothy J; Ross, John J

    2016-03-01

    The phytohormone abscisic acid (ABA) plays a major role in regulating root growth. Most work to date has investigated the influence of root-sourced ABA on root growth during water stress. Here, we tested whether foliage-derived ABA could be transported to the roots, and whether this foliage-derived ABA had an influence on root growth under well-watered conditions. Using both application studies of deuterium-labelled ABA and reciprocal grafting between wild-type and ABA-biosynthetic mutant plants, we show that both ABA levels in the roots and root growth in representative angiosperms are controlled by ABA synthesized in the leaves rather than sourced from the roots. Foliage-derived ABA was found to promote root growth relative to shoot growth but to inhibit the development of lateral roots. Increased root auxin (IAA) levels in plants with ABA-deficient scions suggest that foliage-derived ABA inhibits root growth through the root growth-inhibitor IAA. These results highlight the physiological and morphological importance, beyond the control of stomata, of foliage-derived ABA. The use of foliar ABA as a signal for root growth has important implications for regulating root to shoot growth under normal conditions and suggests that leaf rather than root hydration is the main signal for regulating plant responses to moisture. © 2015 John Wiley & Sons Ltd.

  1. Volatilization of iodine from vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Amiro, B D; Johnston, F L [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Nuclear Research Establishment

    1989-01-01

    Gaseous emissions of iodine were measured from bean plant foliage. A gamma-emitting iodine tracer, Na {sup 125}I, was taken up by the plants from a hydroponic growth medium and released to a cuvette atmosphere. The dynamics of the flux were studied using a flow-through gamma detector. The relationship between leaf radioactive tracer activity and growth-medium activity was linear, as was the relationship between the iodine flux and both leaf and growth-medium activity. Iodine flux and leaf conductance to water responded similarly to changes in light levels, suggesting that the stomata may partially control the flux. The flux was inhibited by aeration of the hydroponic growth media, and we postulate that methylation causes the iodine flux. Iodine emissions from living vegetation probably contribute < 0.1% to the stable iodine concentration in the atmosphere above terrestrial areas. However, this pathway may be a direct route for radioactive iodine transport from contaminated soils to the atmosphere. (author).

  2. Ozone slows stomatal response to light and leaf wounding in a Mediterranean evergreen broadleaf, Arbutus unedo

    Energy Technology Data Exchange (ETDEWEB)

    Paoletti, Elena [Istituto Protezione Piante, Consiglio Nazionale delle Ricerche, Via Madonna del Piano, I-50019 Sesto Fiorentino (Italy)]. E-mail: e.paoletti@ipp.cnr.it

    2005-04-01

    The effect of a 90-d ozone exposure (charcoal-filtered air or 110 nmol mol{sup -1} O{sub 3}) on stomatal conductance (g{sub s}) was investigated in the Mediterranean evergreen broadleaf Arbutus unedo L. Ozone did not significantly reduce midday steady-state g{sub s} compared to controls. However, it slowed stomatal response to abrupt reduction of light intensity and to increasing water stress, applied by severing the leaf midrib. Ozone slowed stomatal closure, rather than aperture. Nevertheless, vein-cutting did not allow ozonated leaves to reach the pre-injury g{sub s} levels, like controls did, suggesting re-opening was still, slowly in progress. The sluggish behaviour was recorded 10 days after cessation of O{sub 3} exposure ('memory effect') and may affect stomatal control in response to sunflecks and leaf wounding. Mediterranean evergreen broadleaves are regarded as tolerant to O{sub 3} exposure. Nevertheless, measurements of steady-state g{sub s} at midday may not account for altered stomatal responses to stressors. - In response to ozone exposure, stomata were slower in closing rather than in opening.

  3. Leaf anatomy of the genus Ehrharta (Poaceae in southern Africa: the Setacea group

    Directory of Open Access Journals (Sweden)

    R. P. Ellis

    1987-10-01

    Full Text Available The leaf blade anatomy of the taxa of the Setacea group of species of the genus Ehrharta is described and illustrated. This group includes E. rupestris Nees ex Trin. subsp.  rupestris, subsp.  tricostata (Stapf Gibbs Russell and subsp.  dodii (Stapf Gibbs Russell, as well as E. setacea Nees subsp.  setacea, subsp.  scabra (Stapf Gibbs Russell, subsp.  uniflora (Burch, ex Stapf Gibbs Russell and subsp.  disticha Gibbs Russell. All these taxa share a very characteristic leaf anatomy with inrolled or infolded leaves without keels and have adaxial ribs with interlocking prickles. The chlorenchyma is dense and compact with inwardly projecting invaginations visible in all taxa except  E. setacea subsp.  setacea. In E .  setacea subsp. scabra typical arm cells are present. Abaxial costal and intercostal zones are not differentiated and stomata are absent. The long cells are hexagonal or inflated with sinuous walls. Silica bodies are single or paired and rounded in shape. Small hook-like prickles with short barbs are common. Microhairs with a short, truncated distal cell occur. This leaf anatomical structure differs considerably from that of the other species groups recognized in African  Ehrharta and the Setacea group appears to be more distinct from the other groups than they are from each other.

  4. Accumulation and in vivo tissue distribution of pollutant elements in Erica andevalensis

    International Nuclear Information System (INIS)

    Rossini Oliva, S.; Valdes, B.; Leidi, E.O.

    2009-01-01

    Erica andevalensis is an endemic shrub from an area in the southwest of Spain (Andalucia) characterized by acidic and contaminated soils. Scanning electron microscopy (SEM) of samples after conventional or cryo-fixation preparation protocols was used for morphological and anatomical studies. SEM coupled with EDX-analysis was employed to localise and quantify different elements within plant parts (leaves, stems and roots) in samples collected in the field. Morphological studies revealed that the species has typical adaptive structures to drought-stress such as rolled needle-like leaves, sunken stomata and a thick waxy cuticle on the upper epidermis. Roots were associated with fungi which formed intra and extra-cellular mycelia. The SEM studies showed that Cu was not sequestrated into the root tissues and was uniformly distributed in leaf tissues. Meanwhile, Pb was only localised within epidermal root tissues which indicates that its sequestration in an external matrix might represent a tolerance mechanism in this species. Iron was uniformly distributed throughout the leaves, while in roots it was predominantly retained on the epidermal cell walls. The exclusion and tolerance mechanisms adopted by this species to survive in mining areas indicate that it can be used successfully in the re-vegetation of contaminated areas

  5. A Morphological, anatomical and caryological study on endemic Pilosella hoppeana subsp. lydia taxa (Bornm. & Zahn Sell & West (Asteraceae

    Directory of Open Access Journals (Sweden)

    Hakan Sepet

    2017-11-01

    Full Text Available Plant samples of Endemic Pilosella hoppeana subsp. lydia (Bornm. & Zahn Sell&West (1975 the taxa were collected in 2013 from the Spil Mountain in Manisa, one of the natural spreading areas. A thick cover was observed on the leaves of the taxon rosette on the base. In the anatomical investigations, the radial transmission in the stem takes up a great deal of space in the bundles compared to the floem elements of the xylem elements. The body covers the epidermis cells of a thick capillary layer with dense fur, and the transmission bundles are generally arranged in a large, small bundle. The leaves are in the bifacial leaf type and accordingly the separation of palisade parenchyma and sponge parenchyma is clearly observed. The abaxial percentage is longer and more intense, and there are stoma cells that are arranged at regular intervals with cover and secretion feathers on both sides. Abdominal abdominal stomata is the upper case. The number of chromosomes was determined as 2x = 2n = 18 in karyological studies performed by Takson and chromosome measurements were made.

  6. Comparative Anatomical Investigations on six Endemic Tanacetum (Asteraceae) Taxa from Turkey

    International Nuclear Information System (INIS)

    Tekin, M.; Kartal, C.

    2016-01-01

    Tanacetum is one of the large genera, belonging to the Anthemideae tribe of Asteraceae family and has numerous medicinal plants and widely usage in folk medicine. In this study, anatomical features of six endemic species to Turkey viz. Tanacetum albipannosum, T. argenteum subsp. argenteum, T. cappadocicum, T. densum subsp. sivasicum, T. haussknechtii and T. heterotomum, were investigated for the first time. The specimens were collected from their natural habitats in Sivas province (Turkey). Transverse sections of root, stem, petiole and leaflet were observed under light microscope for various anatomical features. The results showed that, root included periderm in the outer. There were parenchymatous cortex, endodermis and pericycle under the periderm respectively. Primary xylem ridges were triarch in T. albipannosum, T. densum subsp. sivasicum, T. haussknechtii and T. heterotomum, pentarch in T. cappadocicum and hexarch in T. argenteum subsp. argenteum, and pith was filled with xylem elements. Stem was made up epidermis, parenchymatous cortex, endodermis, vascular bundles and parenchymatous pith from exterior to interior. T. heterotomum had a cavity formed by the disintegration of the cells in the center. The amphistomatic leaflets had a single layered epidermis with usually silvery or whitish tomentose indumentum and equifacial mesophyll. Stomata are anomocytic. There were significant difference among examined taxa in respect to contour of petiole, structure of cortex parenchyma and organization of vascular bundles. The anatomical characteristic features of petiole proved to be a useful tool for the taxonomic discrimination of the six studied taxa. (author)

  7. The biology of flowering and pollination in umbellate vegetables. Part II. Petroselinum sativum Hoffm.

    Directory of Open Access Journals (Sweden)

    Zofia Warakomska

    2013-12-01

    Full Text Available The aim of the study was to examine not only the occurrence of bloom of parsley, but also the degree of attractiveness of the flowers as well as the influence of insects on their pollination. There search was carried out during the 1978 and 1979 vegetation seasons. Observations were carried out near Lublin, on loess brown soil. The flowers of isolated plants were washed in order to determined the sugar content in nectar with a refractometer. The number of secreting stomata on the epidermis of nectary was on the average 575 per 1 mm2. The sugar weight in parsley equals 0.2 mg and the honey yield was 62.4 kg in 1978 and 160 kg in 1979 per ha. The yield of the nectar was mainly influenced by the 3rd row of urnbells. Isolation of flowers from pollinators caused a decrease of seed yield from 7% to 55% in 1978 and 21% to 38% in 1979. The presence of entomofauna on the flowers should be taken into consideration cohen the forecasting the seed yield in horticultural production of parsley.

  8. Programmed cell death in the leaves of the Arabidopsis spontaneous necrotic spots (sns-D mutant correlates with increased expression of the eukaryotic translation initiation factor eIF4B2

    Directory of Open Access Journals (Sweden)

    Gwenael M.D.J.-M. Gaussand

    2011-04-01

    Full Text Available From a pool of transgenic Arabidopsis (Arabidopsis thaliana plants harboring an activator T-DNA construct, one mutant was identified that developed spontaneous necrotic spots (sns-D on the rosette leaves under aseptic conditions. The sns-D mutation is dominant and homozygous plants are embryo lethal. The mutant produced smaller rosettes with a different number of stomata than the wild-type. DNA fragmentation in the nuclei of cells in the necrotic spots and a significant increase of caspase-3 and caspase-6 like activities in sns-D leaf extracts indicated that the sns-D mutation caused programmed cell death (PCD. The integration of the activator T-DNA caused an increase of the expression level of At1g13020, which encodes the eukaryotic translation initiation factor eIF4B2. The expression level of eIF4B2 was positively correlated with the severity of sns-D mutant phenotype. Overexpression of the eIF4B2 cDNA mimicked phenotypic traits of the sns-D mutant indicating that the sns-D mutant phenotype is indeed caused by activation tagging of eIF4B2. Thus, incorrect regulation of translation initiation may result in PCD.

  9. Sensitivity of terrestrial water and energy budgets to CO2-physiological forcing: an investigation using an offline land model

    International Nuclear Information System (INIS)

    Gopalakrishnan, Ranjith; Jayaraman, Mathangi; Ravindranath, N H; Bala, Govindsamy; Cao, Long; Nemani, Ramakrishna

    2011-01-01

    Increasing concentrations of atmospheric carbon dioxide (CO 2 ) influence climate by suppressing canopy transpiration in addition to its well-known greenhouse gas effect. The decrease in plant transpiration is due to changes in plant physiology (reduced opening of plant stomata). Here, we quantify such changes in water flux for various levels of CO 2 concentrations using the National Center for Atmospheric Research's (NCAR) Community Land Model. We find that photosynthesis saturates after 800 ppmv (parts per million, by volume) in this model. However, unlike photosynthesis, canopy transpiration continues to decline at about 5.1% per 100 ppmv increase in CO 2 levels. We also find that the associated reduction in latent heat flux is primarily compensated by increased sensible heat flux. The continued decline in canopy transpiration and subsequent increase in sensible heat flux at elevated CO 2 levels implies that incremental warming associated with the physiological effect of CO 2 will not abate at higher CO 2 concentrations, indicating important consequences for the global water and carbon cycles from anthropogenic CO 2 emissions.

  10. Climate and Vegetation Effects on Temperate Mountain Forest ...

    Science.gov (United States)

    Current forest composition may be resilient to typical climatic variability; however, climate trends, combined with projected changes in species composition, may increase tree vulnerability to water stress. A shift in forest composition toward tree species with higher water use has implications for biogenic emissions and deposition of reactive nitrogen and carbon compounds. Forest evapotranspiration (ET) can vary greatly at daily and seasonal time scales, but compared to carbon fluxes, often exhibits relatively consistent inter-annual behavior. The processes controlling ET involve the combined effects of physical and biological factors. Atmospheric conditions that promote high ET, consisting of high radiation and vapor pressure deficit (D), are often characterized by rainless periods when soil water supply to vegetation may be limiting and plant stomata may close to prevent excessive water loss. In contrast, periods of high ecosystem water availability require frequent precipitation and are characterized by low D. Thus, the combination of these contrasting conditions throughout a growing season may explain some of the consistency in ET. Additionally, vegetation composition is also an important factor in determining ET. In mixed species forests, physiological differences in water use strategies (e.g. isohydric/anisohydric species) can produce conservative water use throughout wet and dry phases of the growing season. Furthermore, transpiration by evergreen specie

  11. The Cotton WRKY Gene GhWRKY41 Positively Regulates Salt and Drought Stress Tolerance in Transgenic Nicotiana benthamiana.

    Directory of Open Access Journals (Sweden)

    Xiaoqian Chu

    Full Text Available WRKY transcription factors constitute a very large family of proteins in plants and participate in modulating plant biological processes, such as growth, development and stress responses. However, the exact roles of WRKY proteins are unclear, particularly in non-model plants. In this study, Gossypium hirsutum WRKY41 (GhWRKY41 was isolated and transformed into Nicotiana benthamiana. Our results showed that overexpression of GhWRKY41 enhanced the drought and salt stress tolerance of transgenic Nicotiana benthamiana. The transgenic plants exhibited lower malondialdehyde content and higher antioxidant enzyme activity, and the expression of antioxidant genes was upregulated in transgenic plants exposed to osmotic stress. A β-glucuronidase (GUS staining assay showed that GhWRKY41 was highly expressed in the stomata when plants were exposed to osmotic stress, and plants overexpressing GhWRKY41 exhibited enhanced stomatal closure when they were exposed to osmotic stress. Taken together, our findings demonstrate that GhWRKY41 may enhance plant tolerance to stress by functioning as a positive regulator of stoma closure and by regulating reactive oxygen species (ROS scavenging and the expression of antioxidant genes.

  12. Tolerance of plants to air pollutants. Shokubutsu no taiki osen taisei

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, N.; Saji, H. (National Institute for Environmental Studies, Tsukuba (Japan))

    1992-11-10

    Attempts have been made to improve tolerance of plants to air pollutants by changing activities in detoxifying enzymes against toxic substances attributable to air pollutants, through gene manipulation. An air pollutant, absorbed in a plant through its stomata, produces toxic substances in the cells and damages the organism. Detailed discussions were given on the following: Stoma opening action and reaction; injuries attributable to air pollutants and detoxifying metabolism systems; ethylene and toxic enzymes of secondary toxic substances in an organism; different detoxifying mechanisms and active enzymes; and activation of detoxifying enzymes using genes. Pollution tolerance in plants is governed by inherent plant natures and environmental conditions. Plants that have two opposing functions of emerging damages from toxicity and preventing them with detoxifying capability are controlled with a complex and delicate balance. Changing pollution tolerance in plants may be possible by manipulating genes, but the importance is to elucidate what the tolerating enzymes are, and obtain their genes. Genes that could be used are very few in number. Expectations are placed on the future development. 122 refs., 4 figs.

  13. Drought coping strategies in cotton: increased crop per drop.

    Science.gov (United States)

    Ullah, Abid; Sun, Heng; Yang, Xiyan; Zhang, Xianlong

    2017-03-01

    The growth and yield of many crops, including cotton, are affected by water deficit. Cotton has evolved drought specific as well as general morpho-physiological, biochemical and molecular responses to drought stress, which are discussed in this review. The key physiological responses against drought stress in cotton, including stomata closing, root development, cellular adaptations, photosynthesis, abscisic acid (ABA) and jasmonic acid (JA) production and reactive oxygen species (ROS) scavenging, have been identified by researchers. Drought stress induces the expression of stress-related transcription factors and genes, such as ROS scavenging, ABA or mitogen-activated protein kinases (MAPK) signalling genes, which activate various drought-related pathways to induce tolerance in the plant. It is crucial to elucidate and induce drought-tolerant traits via quantitative trait loci (QTL) analysis, transgenic approaches and exogenous application of substances. The current review article highlights the natural as well as engineered drought tolerance strategies in cotton. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  14. Comparative ecomorphology of the cyathial nectaries in eight European Euphorbia species.

    Science.gov (United States)

    Papp, Nóra; Csete, S; Farkas, Agnes

    2013-03-01

    The morphology and histology of the cyathial nectary were studied in 8 European leafy spurge (Euphorbia) species, revealing that certain histological traits of the glands are in close correlation to each species' habitat, underlining the importance of morphological evidences in determining relevant ecological tolerance spectra of plants.The structure of the cyathial glands was studied in longitudinal sections with light microscopy, and histological parameters were measured and statistically analyzed by appropriate softwares.The nectaries consist of a cuticle-covered epidermis, formed by palisade cells, under which the glandular tissue and parenchyma are composed of isodiametric and anisodiametric cells in all species. Thickness of cuticle, position of nectary stomata and number of rows comprising the glandular tissue vary to a great extent in plants living in xeric, humid or mesic habitats.Although all the studied anatomical features of the nectaries were expected to be in correspondence with the characteristics of habitat types, we have only found the number of glandular cell rows to be in strong correlation with the Ellenberg's ecological indicator values on soil moisture, which varied with species. The recorded anatomical differences among the studied Euphorbia taxa emphasize the ecological significance of glandular tissue in plant adaptation, which can also be relevant for systematic purposes.

  15. Hydraulic Strategies and Response to El Niño Drought in Amazon Rainforest

    Science.gov (United States)

    Ivanov, V. Y.; Oliveira, R. S.; Brum, M., Jr.; Prohaska, N.; Albert, L.; Taylor, T.; Fatichi, S.; Agee, E.; Saleska, S. R.; Oliveira Junior, R. C.; Dye, D. G.; Wiedemann, K. T.

    2016-12-01

    Variability of tree-scale carbon and water uptake strategies is increasingly recognized to be of paramount importance for understanding the limits of drought resilience of tropical rainforests. Here, we present evidence of such variations using a set of ecohydrologic data collected through the DOE "GoAmazon" project, with a specific emphasis on the response of a seasonal rainforest in eastern Amazonia to the strong 2015 El Niño drought. Data from 50 sapflow sensors are combined with high-frequency observations on stem and leaf water potential as well as precision dendrometry. The emerging behavior shows a spectrum of successfully co-existing hydraulic strategies, ranging from tight control against xylem failure to a near lack of regulation of the water flux through the stomata, implying the existence of other mechanisms to deal with extreme tissue dehydration. These strategies also exhibit coupling with tree growth patterns and dynamics of non-structural carbohydrates, with the latter type of trees allocating more carbon to growth and less to internal reserves, while the opposite is true for the former tree type. The results suggest a new approach for integrating hydraulic traits and carbon-cycle dynamics, and a strategy for mapping traits to function in the next generation of predictive models of ecosystem dynamics.

  16. Photosynthesis, photoprotection and antioxidant activity of purging nut under drought deficit and recovery

    Energy Technology Data Exchange (ETDEWEB)

    Pompelli, Marcelo F.; Santos, Mauro G.; Almeida-Cortez, Jarcilene S. [Federal University of Pernambuco, Department of Botany, Plant Physiology Laboratory, Prof. Moraes Rego Av. s/n, Cidade Universitaria 50670901, Recife, PE (Brazil); Barata-Luis, Ricardo [Superior Institute of Agronomy, Technical University of Lisbon, Lisbon (Portugal); Vitorino, Hermerson S.; Goncalves, Eduardo R.; Rolim, Eduardo V.; Ferreira, Vilma M.; Lemos, Eurico E.; Endres, Lauricio [Plant Physiology Laboratory, Federal University of Alagoas, Maceio, Alagoas (Brazil)

    2010-08-15

    Biodiesel is an alternative to petroleum diesel fuel. It is a renewable, a biodegradable, and also a non-toxic fuel. The general interest to produce biodiesel from Jatropha (Jatropha curcas L.) seeds oil has increased but its ability to grow on drought-prone areas has barely been investigated. The objective of this work was to identify some physiological processes that allow the Jatropha to produce in severe arid conditions by studying its leaf gas exchange and antioxidant systems under drought stress and recovering. It measured the activity of antioxidant enzymes involved in the scavenge of reactive oxygen species (ROS), as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutamine synthetase (GS), as well as malondialdehyde (MDA) content. It was also analyzed the chlorophyll (CHL), carotenoids, amino acids and soluble proteins contents. Net photosynthesis (A) and stomata conductance (g{sub s}) decreased associate with drought stress and dropped to zero in soil water beneath 5%. Drought induced decrease in stomatal and non-stomatal photosynthetic activity. The activities of SOD, CAT, APX and GS and MDA content in leaves were significantly higher in the water-stressed plants compared to well-watered plants and decreased when the plants were rewatered. These observations suggest that oxidative stress resulting from drought deficit in Jatropha could result in the production of antioxidative enzymes to counteract the oxidative damage, and the enzymes may contribute to its ability to survive in the adverse arid environment. (author)

  17. Stomatal development in barley as a bioassay for cell differentation: its use with X-rays and gibberellic acid

    Energy Technology Data Exchange (ETDEWEB)

    Zeiger, E; Rafalowsky, J [Chile Univ., Santiago. Departamento de Biologia y Genetica

    1976-01-01

    A bioassay for cell differentiation during stomatal development in barley (Hordeum vulgare L.) has been defined. It uses cell kinetics analysis to follow the temporal course of cell divisions in the developmental sequence. The rate of displacement of the divisions along the stomatal rows provides a measure of differentiation. Physical factors affecting differentiation may be tested with intact seedlings. The bioassay showed that X-ray irradiation inhibited the divisions leading to stomatal formation. The inhibition kinetics was similar to the one observed in root meristems. Chemical substances are tested by culturing excised shoots in a synthetic medium. Detached leaves responded to sucrose and light with increasing rates of stomatal divisions. Gibberellic acid (GA/sub 3/) was assayed for its effects on the growth of the leaf and the differentiation of stomata. GA/sub 3/ increased the overall length of the leaves without affecting the rates of cell division. The treated cells responded with increased elongation rates and a precocious initiation and completion of cell enlargement. GA/sub 3/ had no specific effect on stomatal differentiation.

  18. Aerial stem and leaf morphoanatomy of some species of Smilax

    Directory of Open Access Journals (Sweden)

    Aline R. Martins

    2013-06-01

    Full Text Available This study aimed to describe the morphoanatomy of the aerial vegetative organs of seven Smilax species, used in Brazilian folk medicine. Samples of leaves and stems were fixed with FAA 50, embedded in historesin, sectioned on a rotary microtome, stained and mounted in synthetic resin. Cuticle ornamentation was analyzed with standard scanning electron microscopy. In the frontal view, the walls of the adaxial epidermis are straight in S. brasiliensis, S. cissoides, S. goyazana and sinuous in the other species. The walls of the epidermis on the abaxial surface are straight in S. brasiliensis, S. goyazana, S. rufescens, sinuous in S. campestris, S. fluminensis, S. oblongifolia, and wavy in S. cissoides. The stomata are paracytic in S. brasiliensis, S. goyazana, S. oblongifolia, and S. rufescens, anomocytic in S. cissoides, S. campestris; anisocytic and paracytic in S. fluminensis. The midrib has three vascular bundles that are individually wrapped by lignified cells in S. brasiliensis, S. cissoides, and S. fluminensis. In the other, the three vascular bundles are surrounded by a single lignified sheath. In the stems the vascular cylinder is surrounded by a sclerenchymatous ring with the exception of Smilax fluminensis, which has a starch sheath and internal layers of thin-walled cells.

  19. Effects of a Heat Wave on Nocturnal Stomatal Conductance in Eucalyptus camaldulensis

    Directory of Open Access Journals (Sweden)

    Víctor Resco de Dios

    2018-06-01

    Full Text Available Nocturnal transpiration constitutes a significant yet poorly understood component of the global water cycle. Modeling nocturnal transpiration has been complicated by recent findings showing that stomata respond differently to environmental drivers over day- vs. night-time periods. Here, we propose that nocturnal stomatal conductance depends on antecedent daytime conditions. We tested this hypothesis across six genotypes of Eucalyptus camaldulensis Dehnh. growing under different CO2 concentrations (ambient vs. elevated and exposed to contrasting temperatures (ambient vs. heat wave for four days prior to the night of measurements, when all plants experienced ambient temperature conditions. We observed significant effects after the heat wave that led to 36% reductions in nocturnal stomatal conductance. The response was partly driven by changes in daytime stomatal behavior but additional factors may have come into play. We also observed significant differences in response to the heat wave across genotypes, likely driven by local adaptation to their climate of origin, but CO2 played no effect. Stomatal models may need to incorporate the role of antecedent effects to improve projections particularly after drastic changes in the environment such as heat waves.

  20. Mesophyll conductance in Zea mays responds transiently to CO2 availability: implications for transpiration efficiency in C4 crops.

    Science.gov (United States)

    Kolbe, Allison R; Cousins, Asaph B

    2018-03-01

    Mesophyll conductance (g m ) describes the movement of CO 2 from the intercellular air spaces below the stomata to the site of initial carboxylation in the mesophyll. In contrast with C 3 -g m , little is currently known about the intraspecific variation in C 4 -g m or its responsiveness to environmental stimuli. To address these questions, g m was measured on five maize (Zea mays) lines in response to CO 2 , employing three different estimates of g m . Each of the methods indicated a significant response of g m to CO 2 . Estimates of g m were similar between methods at ambient and higher CO 2 , but diverged significantly at low partial pressures of CO 2 . These differences are probably driven by incomplete chemical and isotopic equilibrium between CO 2 and bicarbonate under these conditions. Carbonic anhydrase and phosphoenolpyruvate carboxylase in vitro activity varied significantly despite similar values of g m and leaf anatomical traits. These results provide strong support for a CO 2 response of g m in Z. mays, and indicate that g m in maize is probably driven by anatomical constraints rather than by biochemical limitations. The CO 2 response of g m indicates a potential role for facilitated diffusion in C 4 -g m . These results also suggest that water-use efficiency could be enhanced in C 4 species by targeting g m . © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  1. Ozone exposure and stomatal sluggishness in different plant physiognomic classes

    Energy Technology Data Exchange (ETDEWEB)

    Paoletti, Elena, E-mail: e.paoletti@ipp.cnr.i [IPP-CNR, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Florence (Italy); Grulke, Nancy E. [US Forest Service, 4955 Canyon Crest Drive, Riverside, CA 92507 (United States)

    2010-08-15

    Gas exchange responses to static and variable light were tested in three species: snap bean (Phaseolus vulgaris, two cultivars), California black oak (Quercus kelloggii), and blue oak (Q. douglasii). The effects of 1-month (snap beans) and 2-month (oaks) O{sub 3} (ozone) exposure (70 ppb over 8 h per day in open-top chambers) were investigated. A delay in stomatal responses (i.e., 'sluggish' responses) to variable light was found to be both an effect of O{sub 3} exposure and a reason for increased O{sub 3} sensitivity in snap bean cultivars, as it implied higher O{sub 3} uptake during times of disequilibrium. Sluggishness increased the time to open (thus limiting CO{sub 2} uptake) and close stomata (thus increasing transpirational water loss) after abrupt changes in light level. Similar responses were shown by snap beans and oaks, suggesting that O{sub 3}-induced stomatal sluggishness is a common trait among different plant physiognomic classes. - Sluggish stomatal responses are suggested to be both an effect of O{sub 3} exposure and a reason of increased O{sub 3} sensitivity in plants.

  2. Nanoparticle synthesis and delivery by an aerosol route for watermelon plant foliar uptake

    International Nuclear Information System (INIS)

    Wang Weining; Tarafdar, Jagadish C.; Biswas, Pratim

    2013-01-01

    An aerosol process was developed for synthesis and delivery of nanoparticles for living watermelon plant foliar uptake. This is an efficient technique capable of generating nanoparticles with controllable particle sizes and number concentrations. Aerosolized nanoparticles were easily applied to leaf surfaces and enter the stomata via gas uptake, avoiding direct interaction with soil systems, eliminating potential ecological risks. The uptake and transport of nanoparticles inside the watermelon plants were investigated systematically by various techniques, such as elemental analysis by inductively coupled plasma mass spectrometry and plant anatomy by transmission electron microscopy. The results revealed that certain fractions of nanoparticles (d p < 100 nm) generated by the aerosol process could enter the leaf following the stomatal pathway, then pass through the stem, and reach the root of the watermelon plants. The particle size and number concentration played an important role in nanoparticle translocation inside the plants. In addition, the nanoparticle application method, working environment, and leaf structure are also important factors to be considered for successful plant foliar uptake.

  3. Variations in the dorso-ventral organization of leaf structure and Kranz anatomy coordinate the control of photosynthesis and associated signalling at the whole leaf level in monocotyledonous species.

    Science.gov (United States)

    Soares-Cordeiro, Ana Sofia; Driscoll, Simon P; Pellny, Till K; Olmos, Enrique; Arrabaça, Maria Celeste; Foyer, Christine H

    2009-12-01

    Photosynthesis and associated signalling are influenced by the dorso-ventral properties of leaves. The degree of adaxial/abaxial symmetry in stomatal numbers, photosynthetic regulation with respect to light orientation and the total section areas of the bundle sheath (BS) cells and the surrounding mesophyll (M) cells on the adaxial and abaxial sides of the vascular bundles were compared in two C(4)[Zea mays (maize) and Paspalum dilatatum] and one C(3)[Triticum turgidum (Durum wheat)] monocotyledonous species. The C(3) leaves had a higher degree of dorso-ventral symmetry than the C(4) leaves. Photosynthetic regulation was the same on each side of the wheat leaves, as were stomatal numbers and the section area of the BS relative to that of the M cells (BS/M section area ratio). In contrast, photosynthetic regulation in maize and P. dilatatum leaves showed a marked surface-specific response to light orientation. Compared to the adaxial sides of the C(4) monocotyledonous leaves, the abaxial surfaces had more stomata and the BS/M section area ratio was significantly higher. Differences in dorso-ventral structure, particularly in Kranz anatomy, serve not only to maximize photosynthetic capacity with respect light orientation in C(4) monocotyledonous leaves but also allow adaxial and abaxial-specific signalling from the respective M cells.

  4. Adaxial/abaxial specification in the regulation of photosynthesis and stomatal opening with respect to light orientation and growth with CO2 enrichment in the C4 species Paspalum dilatatum.

    Science.gov (United States)

    Soares, Ana Sofia; Driscoll, Simon P; Olmos, Enrique; Harbinson, Jeremy; Arrabaça, Maria Celeste; Foyer, Christine H

    2008-01-01

    Whole-plant morphology, leaf structure and composition were studied together with the effects of light orientation on the dorso-ventral regulation of photosynthesis and stomatal conductance in Paspalum dilatatum cv. Raki plants grown for 6 wk at either 350 or 700 microl l(-1) CO(2). Plant biomass was doubled as a result of growth at high CO(2) and the shoot:root ratio was decreased. Stomatal density was increased in the leaves of the high CO(2)-grown plants, which had greater numbers of smaller stomata and more epidermal cells on the abaxial surface. An asymmetric surface-specific regulation of photosynthesis and stomatal conductance was observed with respect to light orientation. This was not caused by dorso-ventral variations in leaf structure, the distribution of phosphoenolpyruvate carboxylase (PEPC) and ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) proteins or light absorptance, transmittance or reflectance. Adaxial/abaxial specification in the regulation of photosynthesis results from differential sensitivity of stomatal opening to light orientation and fixed gradients of enzyme activation across the leaf.

  5. Strategies of two tropical woody species to tolerate salt stress

    Directory of Open Access Journals (Sweden)

    Bruno Melo Lustosa

    2017-03-01

    Full Text Available This study aimed to evaluate the leaf primary metabolism in two woody species, Sterculia foetida and Bombacopsis glabra. Both species have seeds rich in oil and they are largely found in regions with irregularities in water availability. Seedlings were grown in a greenhouse from seeds. At 140 days after emergence, 50% of the plants were subjected to salt stress for 23 days, daily receiving 100 mM of NaCl solution. In both species, leaf stomata conductance and water potential decreased quickly under salt stress. The two species showed different strategies in photosynthetic pigment concentration and components of nitrogen metabolism. S. foetida kept the pigment concentration unchanged after 23 days of stress, while B. glabra increased concentration of chlorophyll a and carotenoids. S. foetida showed a high leaf concentration of K+ in stressed plants and a Na+/K+ ratio without differences when compared to control. Thus, S. foetida presented a better ionic balance, while B. glabra invested in photoprotection. Therefore, both species present potential to be planted in Brazilian Northeast, where water deficit and salt stress are challenging for annual crops.

  6. Internal coordination between hydraulics and stomatal control in leaves.

    Science.gov (United States)

    Brodribb, Tim J; Jordan, Gregory J

    2008-11-01

    The stomatal response to changing leaf-atmospheric vapour pressure gradient (D(l)) is a crucial yet enigmatic process that defines the daily course of leaf gas exchange. Changes in the hydration of epidermal cells are thought to drive this response, mediated by the transpiration rate and hydraulic conductance of the leaf. Here, we examine whether species-specific variation in the sensitivity of leaves to perturbation of D(l) is related to the efficiency of water transport in the leaf (leaf hydraulic conductivity, K(leaf)). We found good correlation between maximum liquid (K(leaf)) and gas phase conductances (g(max)) in leaves, but there was no direct correlation between normalized D(l) sensitivity and K(leaf). The impact of K(leaf) on D(l) sensitivity in our diverse sample of eight species was important only after accounting for the strong relationship between K(leaf) and g(max). Thus, the ratio of g(max)/K(leaf) was strongly correlated with stomatal sensitivity to D(l). This ratio is an index of the degree of hydraulic buffering of the stomata against changes in D(l), and species with high g(max) relative to K(leaf) were the most sensitive to D(l) perturbation. Despite the potentially high adaptive significance of this phenomenon, we found no significant phylogenetic or ecological trend in our species.

  7. Small RNA profiling reveals important roles for miRNAs in Arabidopsis response to Bacillus velezensis FZB42.

    Science.gov (United States)

    Xie, Shanshan; Jiang, Haiyang; Xu, Zhilan; Xu, Qianqian; Cheng, Beijiu

    2017-09-20

    Bacillus velezensis FZB42 (previously classified as Bacillus amyloliquefaciens FZB42) has been confirmed to successfully colonize plant roots and enhance defense response against pathogen infection. This study indicated that FZB42 inoculation enhanced Arabidopsis defense response against Pseudomonas syringae DC3000 through inducing the expression of PR1, PDF1.2 and stomata closure. To further clarify the induced defense response at miRNA level, sRNA libraries from Arabidopsis roots inoculated with FZB42 and control were constructed and sequenced. The reads of 21nt and 24nt in length were the most abundant groups in FZB42-treated library and control library, respectively. 234 known miRNAs and 16 novel miRNAs were identified. Among them, 11 known miRNAs and 4 novel miRNAs were differentially expressed after FZB42 inoculation. Moreover cis-elements (TC-rich repeats, TCA-element and CGTCA-motif) associated with plant defense were also found in the promoters of these miRNAs. Additionally, 141 mRNAs were predicted as potential targets of these differentially expressed miRNAs. GO annotations of the target genes indicated their potential roles in polyamine biosynthetic process and intracellular protein transport biological process, which may contribute to increased defense response. Our findings indicated that Bacillus velezensis FZB42 inoculation altered the expression of Arabidopsis miRNAs and their target genes, which were associated with defense response. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Lead bioaccumulation in Opuntia ficus-indica following foliar or root exposure to lead-bearing apatite.

    Science.gov (United States)

    El Hayek, Eliane; El Samrani, Antoine; Lartiges, Bruno; Kazpard, Veronique; Aigouy, Thierry

    2017-01-01

    The contamination of edible leafy vegetables by atmospheric heavy metal-bearing particles is a major issue in environmental toxicology. In this study, the uptake of lead by cladodes of Opuntia ficus-indica (Ofi), traditionally used in Mexican cuisine and in livestock fodder, is investigated after a 4-months exposure of either cladodes or roots to synthetic Pb-fluorapatite particles. Atomic Absorption Spectroscopy (AAS) for the quantitative analysis of Pb levels, Scanning Electron Microscopy coupled with Energy Dispersive X-Ray Spectroscopy (SEM-EDX) for the examination of the cladode surface and fate of particles, and Micro-X-ray fluorescence (μXRF) measurements for elemental mapping of Pb in cladodes, were used. The results evidence that foliar contamination may be a major pathway for the transfer of Pb within Ofi cladodes. The stomata, areoles, and cuticle of cladode surface, play an obvious role in the retention and the incorporation of lead-bearing apatite, thus revealing the hazard of eating contaminated cladodes. The possibility of using series of successive cladodes for biomonitoring the atmospheric pollution in arid and semi-arid regions is also rapidly discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Characterization of some biological specimens using TEM and SEM

    Science.gov (United States)

    Ghosh, Nabarun; Smith, Don W.

    2009-05-01

    The advent of novel techniques using the Transmission and Scanning Electron Microscopes improved observation on various biological specimens to characterize them. We studied some biological specimens using Transmission and Scanning Electron Microscopes. We followed negative staining technique with Phosphotungstic acid using bacterial culture of Bacillus subtilis. Negative staining is very convenient technique to view the structural morphology of different samples including bacteria, phage viruses and filaments in a cell. We could observe the bacterial cell wall and flagellum very well when trapped the negative stained biofilm from bacterial culture on a TEM grid. We cut ultra thin sections from the fixed root tips of Pisum sativum (Garden pea). Root tips were pre fixed with osmium tetroxide and post fixed with uranium acetate and placed in the BEEM capsule for block making. The ultrathin sections on the grid under TEM showed the granular chromatin in the nucleus. The protein bodies and large vacuoles with the storage materials were conspicuous. We followed fixation, critical point drying and sputter coating with gold to view the tissues with SEM after placing on stubs. SEM view of the leaf surface of a dangerous weed Tragia hispida showed the surface trichomes. These trichomes when break on touching releases poisonous content causing skin irritation. The cultured tissue from in vitro culture of Albizia lebbeck, a tree revealed the regenerative structures including leaf buds and stomata on the tissue surface. SEM and TEM allow investigating the minute details characteristic morphological features that can be used for classroom teaching.

  10. Problems in interpreting effects of air pollutants on spruce epicuticular waxes

    International Nuclear Information System (INIS)

    Bermadinger-Stabentheiner, E.

    1994-01-01

    Spruce needles are covered with rod-like crystals, which also fill the antechambers of the stomata with a dense meshwork. The scanning electron microscope (SEM) is very useful for studying epicuticular wax structure; with no intricate or laborious preparation, it is possible to obtain valuable information about the needle surface. Because the epicuticular wax layer forms a barrier between the plant and its environment, all influences that reach the surface from outside impact on this layer and, therefore, changes in epicuticular wax structure serve as diagnostic criteria for damage caused by air pollutants. This pollution influence begins as fusion of wax rods at the tips and results finally in total loss of the crystalline structure. Despite the simplicity of SEM investigations, alterations (artefacts) can occur to wax structures that may be confused with alterations caused by air pollutants (i.e., a too dense layer of twigs and needles, or careless handling with tweezers, results in mechanical damage that often influences the entire surface). Overheating occurring during transport or preparation and/or incorrect storage also produce artefacts. If the occurrence of such artefacts is taken into consideration, several contradictory interpretations of effects of air pollutants on epicuticular waxes can be explained. (orig.)

  11. The Evaluation of Science Learning Program, Technology and Society Application of Audio Bio Harmonic System with Solar Energy to Improve Crop Productivity

    Directory of Open Access Journals (Sweden)

    D. Rosana

    2017-04-01

    Full Text Available One of the greatest challenges in science learning is how to integrate a wide range of basic scientific concepts of physics, chemistry, and biology into an integrated learning material. Research-based teaching material in this area is still very poor and does not much involve students of science education in its implementation as part of the learning program science technology and society (STS. The purpose of this study is to get the result of evaluation of the teaching and learning of STS in the form of public service in Kulon Progo, Yogyakarta. The program to improve crop productivity through the application of Audio Bio Harmonic System (ABHS with solar energy have been selected for utilizing the natural animal sounds to open stomata of the leaves conducted during foliar fertilization, making it suitable for integrated science lessons. Component of evaluation model used is Stufflebeam model evaluation (CIPP. CIPP evaluation in these activities resulted in two aspects: The first aspect was improving the skills of students and farmers in using ABHS, and these two aspects, namely food crop productivity; (1 cayenne increased 76.4%, (2 increased red onions (56.3% and (3 of maize increased by 67.8%. Besides, it was also the effect of the application of ABHS on the rate of plant growth. The outcome of this study is the STS teaching materials and appropriate technology of ABHS with solar energy.

  12. Elevated air movement enhances stomatal sensitivity to abscisic acid in leaves developed at high relative air humidity

    Directory of Open Access Journals (Sweden)

    Dália R.A. Carvalho

    2015-05-01

    Full Text Available High relative air humidity (RH ≥ 85% during growth leads to stomata malfunctioning, resulting in water stress when plants are transferred to conditions of high evaporative demand. In this study, we hypothesized that an elevated air movement (MOV 24 h per day, during the whole period of leaf development would increase abscisic acid concentration ([ABA] enhancing stomatal functioning. Pot rose ‘Toril’ was grown at moderate (61% or high (92% RH combined with a negligible MOV or with a continuous MOV of 0.92 m s-1. High MOV reduced stomatal pore length and aperture in plants developed at high RH. Moreover, stomatal function improved when high MOV-treated plants were subjected to leaflet desiccation and ABA feeding. Endogenous concentration of ABA and its metabolites in the leaves was reduced by 35% in high RH, but contrary to our hypothesis this concentration was not significantly affected by high MOV. Interestingly, in detached leaflets grown at high RH, high MOV increased stomatal sensitivity to ABA since the amount of exogenous ABA required to decrease the transpiration rate was significantly reduced. This is the first study to show that high MOV increases stomatal functionality in leaves developed at high RH by reducing the stomatal pore length and aperture and enhancing stomatal sensitivity to ABA rather than increasing leaf [ABA].

  13. [Effects of CO2 fertilization on photosynthesis and growth of cut Anthurium andraeanum in solar greenhouse in winter].

    Science.gov (United States)

    Yang, Ke Bin; Meng, Fan Zhi; Guo, Xian Feng

    2017-06-18

    Aiming at the problem of the acute shortage of CO 2 in winter production of cut Anthurium andraeanum in solar greenhouse, the effect of CO 2 fertilization on photosynthetic characteristics and growth performance of A. andraeanum 'Fire' was investigated. Three treatments with different concentrations of CO 2 were designed, i.e., 700, 1000 and 1300 Μmol·mol -1 , with receiving no extra CO 2 as the control. The results showed that for the CO 2 -fertilized plants, the photosynthetic rate, intercellular CO 2 concentration and water use efficiency were significantly greater than those in the control plants after CO 2 fertilization for 60 days, and the largest increase range was observed in the 1000 Μmol·mol -1 CO 2 treatment, whereas the stomata conductance was significantly reduced compared with the control. Meanwhile, the contents of soluble sugar, starch and soluble protein in CO 2 -fertilized plants were significantly higher than those in control plants. Moreover, the quality of cut flowers with CO 2 fertilization was remarkably superior to control flowers in term of the parameters including spathe size, spathe color, peduncle length, leaf growth performance and peduncle growth rate. The most superior improvement was observed in the 1000 Μmol·mol -1 CO 2 treatment. It was therefore concluded that CO 2 fertilization of 1000 Μmol·mol -1 could effectively improve the winter production of cut A. andraeanum in solar greenhouse.

  14. The optimal atmospheric CO2 concentration for the growth of winter wheat (Triticum aestivum).

    Science.gov (United States)

    Xu, Ming

    2015-07-20

    This study examined the optimal atmospheric CO2 concentration of the CO2 fertilization effect on the growth of winter wheat with growth chambers where the CO2 concentration was controlled at 400, 600, 800, 1000, and 1200 ppm respectively. I found that initial increase in atmospheric CO2 concentration dramatically enhanced winter wheat growth through the CO2 fertilization effect. However, this CO2 fertilization effect was substantially compromised with further increase in CO2 concentration, demonstrating an optimal CO2 concentration of 889.6, 909.4, and 894.2 ppm for aboveground, belowground, and total biomass, respectively, and 967.8 ppm for leaf photosynthesis. Also, high CO2 concentrations exceeding the optima not only reduced leaf stomatal density, length and conductance, but also changed the spatial distribution pattern of stomata on leaves. In addition, high CO2 concentration also decreased the maximum carboxylation rate (Vc(max)) and the maximum electron transport rate (J(max)) of leaf photosynthesis. However, the high CO2 concentration had little effect on leaf length and plant height. The optimal CO2 fertilization effect found in this study can be used as an indicator in selecting and breeding new wheat strains in adapting to future high atmospheric CO2 concentrations and climate change. Copyright © 2015. Published by Elsevier GmbH.

  15. The photosynthetic response of tobacco plants overexpressing ice plant aquaporin McMIPB to a soil water deficit and high vapor pressure deficit.

    Science.gov (United States)

    Kawase, Miki; Hanba, Yuko T; Katsuhara, Maki

    2013-07-01

    We investigated the photosynthetic capacity and plant growth of tobacco plants overexpressing ice plant (Mesembryanthemum crystallinum L.) aquaporin McMIPB under (1) a well-watered growth condition, (2) a well-watered and temporal higher vapor pressure deficit (VPD) condition, and (3) a soil water deficit growth condition to investigate the effect of McMIPB on photosynthetic responses under moderate soil and atmospheric humidity and water deficit conditions. Transgenic plants showed a significantly higher photosynthesis rate (by 48 %), higher mesophyll conductance (by 52 %), and enhanced growth under the well-watered growth condition than those of control plants. Decreases in the photosynthesis rate and stomatal conductance from ambient to higher VPD were slightly higher in transgenic plants than those in control plants. When plants were grown under the soil water deficit condition, decreases in the photosynthesis rate and stomatal conductance were less significant in transgenic plants than those in control plants. McMIPB is likely to work as a CO2 transporter, as well as control the regulation of stomata to water deficits.

  16. Negative effects of fluoranthene on the ecophysiology of tomato plants (Lycopersicon esculentum Mill) Fluoranthene mists negatively affected tomato plants.

    Science.gov (United States)

    Oguntimehin, Ilemobayo; Eissa, Fawzy; Sakugawa, Hiroshi

    2010-02-01

    Cherry tomato plants (Lycopersicon esculentum Mill) were sprayed with fluoranthene and mixture of fluoranthene and mannitol solutions for 30d. The exposure was carried out in growth chambers in field conditions, and the air was filtered through charcoal filters to remove atmospheric contaminants. Plants were sprayed with 10microM fluoranthene as mist until they reached the fruiting stage, and the eco-physiological parameters were measured to determine the effects of the treatments. We measured CO(2) uptake and water vapour exchange, chlorophyll fluorescence, leaf pigment contents, visual symptoms and biomass allocation. Fluoranthene which was deposited as mist onto leaves negatively affected both growth and the quality of tomato plants, while other treatments did not. The photosynthetic rate measured at saturated irradiance was approximately 37% lower in fluoranthene-treated plants compared with the control group. Other variables, such as stomata conductance, the photochemical efficiency of PSII in the dark, Chl a, Chl b, and the total chlorophyll contents of the tomato leaves were significantly reduced in the fluoranthene-treated plants. Tomato plants treated with fluoranthene showed severe visible injury symptoms on the foliage during the exposure period. Mannitol (a reactive oxygen scavenger) mitigated effects of fluoranthene; thus, reactive oxygen species generated through fluoranthene may be responsible for the damaged tomato plants. It is possible for fluoranthene to decrease the aesthetic and hence the economic value of this valuable crop plant. 2009 Elsevier Ltd. All rights reserved.

  17. Salicylic Acid Alleviates the Adverse Effects of Salt Stress on Dianthus superbus (Caryophyllaceae) by Activating Photosynthesis, Protecting Morphological Structure, and Enhancing the Antioxidant System

    Science.gov (United States)

    Ma, Xiaohua; Zheng, Jian; Zhang, Xule; Hu, Qingdi; Qian, Renjuan

    2017-01-01

    Salt stress critically affects the physiological processes and morphological structure of plants, resulting in reduced plant growth. Salicylic acid (SA) is an important signal molecule that mitigates the adverse effects of salt stress on plants. Large pink Dianthus superbus L. (Caryophyllaceae) usually exhibit salt-tolerant traits under natural conditions. To further clarify the salt-tolerance level of D. superbus and the regulating mechanism of exogenous SA on the growth of D. superbus under different salt stresses, we conducted a pot experiment to examine the biomass, photosynthetic parameters, stomatal structure, chloroplast ultrastructure, reactive oxygen species (ROS) concentrations, and antioxidant activities of D. superbus young shoots under 0.3, 0.6, and 0.9% NaCl conditions, with and without 0.5 mM SA. D. superbus exhibited reduced growth rate, decreased net photosynthetic rate (Pn), increased relative electric conductivity (REC) and malondialdehyde (MDA) contents, and poorly developed stomata and chloroplasts under 0.6 and 0.9% salt stress. However, exogenously SA effectively improved the growth, photosynthesis, antioxidant enzyme activity, and stoma and chloroplast development of D. superbus. However, when the plants were grown under severe salt stress (0.9% NaCl condition), there was no significant difference in the plant growth and physiological responses between SA-treated and non-SA-treated plants. Therefore, our research suggests that exogenous SA can effectively counteract the adverse effect of moderate salt stress on D. superbus growth and development. PMID:28484476

  18. Salicylic Acid Alleviates the Adverse Effects of Salt Stress on Dianthus superbus (Caryophyllaceae by Activating Photosynthesis, Protecting Morphological Structure, and Enhancing the Antioxidant System

    Directory of Open Access Journals (Sweden)

    Xiaohua Ma

    2017-04-01

    Full Text Available Salt stress critically affects the physiological processes and morphological structure of plants, resulting in reduced plant growth. Salicylic acid (SA is an important signal molecule that mitigates the adverse effects of salt stress on plants. Large pink Dianthus superbus L. (Caryophyllaceae usually exhibit salt-tolerant traits under natural conditions. To further clarify the salt-tolerance level of D. superbus and the regulating mechanism of exogenous SA on the growth of D. superbus under different salt stresses, we conducted a pot experiment to examine the biomass, photosynthetic parameters, stomatal structure, chloroplast ultrastructure, reactive oxygen species (ROS concentrations, and antioxidant activities of D. superbus young shoots under 0.3, 0.6, and 0.9% NaCl conditions, with and without 0.5 mM SA. D. superbus exhibited reduced growth rate, decreased net photosynthetic rate (Pn, increased relative electric conductivity (REC and malondialdehyde (MDA contents, and poorly developed stomata and chloroplasts under 0.6 and 0.9% salt stress. However, exogenously SA effectively improved the growth, photosynthesis, antioxidant enzyme activity, and stoma and chloroplast development of D. superbus. However, when the plants were grown under severe salt stress (0.9% NaCl condition, there was no significant difference in the plant growth and physiological responses between SA-treated and non-SA-treated plants. Therefore, our research suggests that exogenous SA can effectively counteract the adverse effect of moderate salt stress on D. superbus growth and development.

  19. Histochemical response of `Grande naine' plants inoculated with M. fijiensis and Bacillus pumilus CCIBP-C5 cell free filtrate

    Directory of Open Access Journals (Sweden)

    Eilyn Mena

    2015-04-01

    Full Text Available In recent years, interest has won biocontrol Mycosphaerella fijiensis with the use of microorganisms or their products. Nevertheless, the knowledge of the biochemical events involved in Musa- M. fijiensis-microorganism interaction, is still limited. The objective was to determine the histochemical response of `Grande naine' (Musa AAA plants inoculated or not with the pathogen in the presence of culture filtrate of Bacillus pumilus CCIBP-C5. For this, techniques that allow visualization of callose, superoxide anion, lignin and phenolic compounds in the early days post inoculation (dpi were used. As a result, at 6 dpi callose deposition were observed within the stomata in plants where the culture filtrate was applied regardless of the presence or absence of the pathogen. Furthermore, a blue halo was observed around stomas, indicative of the presence of superoxide anion. It was not possible to detect accumulation of lignin or phenolic compounds with the technique used. It was demonstrated the accumulation of biochemical compounds related to defense response of `Grande naine' plants to pathogen infection. Furthermore, it was shown that the plant responds in early infection with the use of bacterial culture filtrates. These results demonstrate the possible mechanism of induction of defense response in plants of Musa sp. in the presence of bacterial culture filtrate. Key words: Black Sigatoka, callose, lignin, phenols, superoxide anion

  20. Early changes of the pH of the apoplast are different in leaves, stem and roots of Vicia faba L. under declining water availability.

    Science.gov (United States)

    Karuppanapandian, T; Geilfus, C-M; Mühling, K-H; Novák, O; Gloser, V

    2017-02-01

    Changes in pH of the apoplast have recently been discussed as an important factor in adjusting transpiration and water relations under conditions of drought via modulatory effect on abscisic acid (ABA) concentration. Using Vicia faba L., we investigated whether changes in the root, shoot and leaf apoplastic pH correlated with (1) a drought-induced reduction in transpiration and with (2) changes in ABA concentration. Transpiration, leaf water potential and ABA in leaves were measured and correlated with root and shoot xylem pH, determined by a pH microelectrode, and pH of leaf apoplast quantified by microscopy-based in vivo ratiometric analysis. Results revealed that a reduction in transpiration rate in the early phase of soil drying could not be linked with changes in the apoplastic pH via effects on the stomata-regulating hormone ABA. Moreover, drought-induced increase in pH of xylem or leaf apoplast was not the remote effect of an acropetal transport of alkaline sap from root, because root xylem acidified during progressive soil drying, whereas the shoot apoplast alkalized. We reason that other, yet unknown signalling mechanism was responsible for reduction of transpiration rate in the early phase of soil drying. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.