I. Possible Involvement of Light Modulation of Enzymes in Stomatal Movement
نویسنده
چکیده
New evidence is provided regarding the direct effect of light on stomatal opening in the epidermis of the pea (Pisum sativwn L. var Little Marvel) leaf. Lght modulates the activity of a number of key enzymes involved in stomatal metabolism. When Isolated epidermal strips are illuminated, phosphoenolpyruvate carboxylase, NADP-malate dehydrogenase, and NADP-isocltrate debydrogenase are activated; and aspartate aminotransferase is inactivated. Sulfhydryl compounds, dithiothreitol and glutathione, enhance stomatal opening in epidermal strips both in lght or darkness while the sulHhydryl reagent N-ethylmaleinide hibits, inUcating the possible involvement of sulihydryl groups in stomatal movements. Further, light treatment increases measureable thiol levels in the epidermis about 3-fold. These results suggest that lght modulation of enzymes in the epidermis may play a significant role in the mechanism of stomatal
منابع مشابه
Light and stomatal metabolism : I. Possible involvement of light modulation of enzymes in stomatal movement.
New evidence is provided regarding the direct effect of light on stomatal opening in the epidermis of the pea (Pisum sativum L. var Little Marvel) leaf. Light modulates the activity of a number of key enzymes involved in stomatal metabolism. When isolated epidermal strips are illuminated, phosphoenolpyruvate carboxylase, NADP-malate dehydrogenase, and NADP-isocitrate dehydrogenase are activated...
متن کاملLight and Stomatal Metabolism : II. Effects of Sulfite and Arsenite on Stomatal Opening and Light Modulation of Enzymes in Epidermis.
The effect of sulfite and arsenite on stomatal opening and light modulation of enzymes was examined in isolated epidermal strips of Pisum sativum L. var Little Marvel leaves. Sulfite or arsenite at 10 micromolar rapidly inhibited the stomatal opening process in light. Light activation of phosphoenolpyruvate carboxylase and NADP-malate dehydrogenase was completely diminished when the epidermal s...
متن کاملPtrABF of Poncirus trifoliata functions in dehydration tolerance by reducing stomatal density and maintaining reactive oxygen species homeostasis
Abscisic acid-responsive element (ABRE)-binding factors (ABFs) play important roles in abiotic stress responses; however, the underlying mechanisms are poorly understood. In this study, it is reported that overexpression of Poncirus trifoliata PtrABF significantly enhanced dehydration tolerance. The transgenic lines displayed smaller stomatal apertures, reduced stomatal density/index, and lower...
متن کاملTubulin perturbation leads to unexpected cell wall modifications and affects stomatal behaviour in Populus
Cortical microtubules are integral to plant morphogenesis, cell wall synthesis, and stomatal behaviour, presumably by governing cellulose microfibril orientation. Genetic manipulation of tubulins often leads to abnormal plant development, making it difficult to probe additional roles of cortical microtubules in cell wall biogenesis. Here, it is shown that expressing post-translational C-termina...
متن کاملStomatal Movement in Response to Root Zone Temperature in Purple Heart (Tradescantia pallida)
The effects of root temperatures (25, 35 and 45°C) and temperature duration (30, 60 and 90 min) on net photosynthesis rate, stomatal conductance and transpiration rate in Tradescantia pallida were investigated. The experiment was conducted under controlled conditions with factorial arrangement based on a completely randomized design (CRD) and four replications. Result showed that, net photosynt...
متن کامل