Leaf Ontogeny
Mostrando 13-24 de 26 artigos, teses e dissertações.
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13. Influence of Temperature on Nitrate Metabolism and Leaf Expansion in Soybean (Glycine max L. Merr.) Seedlings 1
The effect of various day temperatures on NADH-nitrate reductase, NADH- and NADPH-glutamate dehydrogenases, nitrate, protein and leaf area, measured at intervals during the ontogeny of the first trifoliolate soybean leaf, was determined. At 32.5 C and 25 C, nitrate concentration, nitrate reductase, and NADPH-glutamate dehydrogenase activities increased concu
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14. Distribution of Peltate Glandular Trichomes on Developing Leaves of Peppermint1
The pattern of peltate glandular trichome initiation and ontogeny on expanding peppermint (Mentha × piperita) leaves was defined by surveying the populations of peltate glands in each of seven developmental stages within sampling areas of leaf apical, mid-, and basal zones for both abaxial and adaxial surfaces. It was shown that new peltate glands continue
American Society of Plant Physiologists.
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15. Response of Leaf Ontogeny and Photosynthetic Activity to Reproductive Growth in Cotton
This study was conducted to determine if reproductive growth in cotton (Gossypium hirsutum L.) affects concurrent leaf development. Apparent photosynthesis (AP), stomatal conductance (Cs), soluble protein (SP), ribulose bisphosphate carboxylase (RuBisCO), and chlorophyll (Chl) were monitored in four main-stem cotton leaves which emerged at approximately 2 we
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16. Ammonia Flux between Oilseed Rape Plants and the Atmosphere in Response to Changes in Leaf Temperature, Light Intensity, and Air Humidity (Interactions with Leaf Conductance and Apoplastic NH4+ and H+ Concentrations).
NH3 exchange between oilseed rape (Brassica napus) plants and the atmosphere was examined at realistic ambient NH3 levels under controlled environmental conditions. Different leaf conductances to NH3 diffusion were obtained by changing leaf temperature (10 to 40[deg]C), light intensity (0 to 600 [mu]mol m-2 s-1), and air humidity (20 to 80%), respectively. N
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17. SO42- Deprivation Has an Early Effect on the Content of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase and Photosynthesis in Young Leaves of Wheat.
Wheat (Triticum aestivum cv Chinese Spring) supplied with 0.45 mM SO42- for 14 d with relative growth rates (RGR) of 0.22 to 0.24 d-1 was deprived of S for 7 to 8 d. There was no significant effect on RGR or leaf development (leaf 2 length was constant; leaf 3 expanded for 2-4 d; leaf 4 emerged and elongated throughout the experiment) during the S deprivatio
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18. Abnormal Stomatal Behavior and Hormonal Imbalance in flacca, a Wilty Mutant of Tomato: I. Root Effect and Kinetin-like Activity
The wilty tomato mutant, flacca, and the normal variety, Rheinlands Ruhm, were compared for kinetin-like activity in ontogeny. The mutant wilts easily because its stomata resist closure. This stomatal resistance decreases with age. The occurrence of a root factor which induces stomatal opening was inferred from grafting experiments. It was hypothesized that
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19. Metabolic Profiling of the Sink-to-Source Transition in Developing Leaves of Quaking Aspen1
Profiles of small polar metabolites from aspen (Populus tremuloides Michx.) leaves spanning the sink-to-source transition zone were compared. Approximately 25% of 250 to 300 routinely resolved peaks were identified, with carbohydrates, organic acids, and amino acids being most abundant. Two-thirds of identified metabolites exhibited greater than 4-fold chang
American Society of Plant Biologists.
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20. Diurnal Regulation of Leaf Blade Elongation in Rice by CO2 (Is it Related to Sucrose-Phosphate Synthase Activity?).
The relationship between leaf blade elongation rates (LER) and sucrose-phosphate synthase (SPS) activity was investigated at different times during ontogeny of rice (Oryza sativa L. cv Jarrah) grown in flooded soil at either 350 or 700 [mu]L CO2 L-1. High CO2 concentrations increased LER of expanding blades and in vivo activity (Vlimiting) SPS activity of ex
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21. Abnormal Stomatal Behavior and Hormonal Imbalance in flacca, a Wilty Mutant of Tomato: II. Auxin- and Abscisic Acid-like Activity
The wilty tomato mutant, flacca, and the control variety, Rheinlands Ruhm, were compared with regard to the endogenous activity and concentration of auxin- and abscisic acid-like substances during ontogeny. The mutant wilts fast under water deficit because of inability to close its stomata. Symptoms characteristic of excessive auxin are evident in the develo
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22. Functional Conservation of PISTILLATA Activity in a Pea Homolog Lacking the PI Motif1
Current understanding of floral development is mainly based on what we know from Arabidopsis (Arabidopsis thaliana) and Antirrhinum majus. However, we can learn more by comparing developmental mechanisms that may explain morphological differences between species. A good example comes from the analysis of genes controlling flower development in pea (Pisum sat
American Society of Plant Biologists.
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23. Photosynthesis, Rubisco Activity and Amount, and Their Regulation by Transcription in Senescing Soybean Leaves.
Senescence is a phase of leaf ontogeny marked by declining photosynthetic activity that, in soybean (Glycine max [L.] Merr.), is paralleled by a decline in chloroplast function. Soybean leaves have different patterns of decline in photosynthetic capacity and chloroplast function associated with nodal position and sink activity. The objective of this work was
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24. Isoprene Emission from Velvet Bean Leaves (Interactions among Nitrogen Availability, Growth Photon Flux Density, and Leaf Development).
Although isoprene synthesis is closely coupled to photosynthesis, both via ATP requirements and carbon substrate availability, control of isoprene emission is not always closely linked to photosynthetic processes. In this study we grew velvet bean (Mucuna sp.) under different levels of photon flux density (PFD) and nitrogen availability in an effort to under