Effect of drought stress on net CO2 uptake by Zea leaves

摘要: The net CO2 assimilation by leaves of maize (Zea mays L. cv. Adonis) plants subjected to slow or rapid dehydration decreased without changes in the total extractable activities phosphoenolpyruvate carboxylase (PEPC), malate dehydrogenase (MDH) and malic enzyme (ME). phosphorylation state PEPC extracted from after 2–3 h exposure light was not affected water deficit, either. Moreover, when which had been slowly dehydrated a leaf relative content about 60% were rehydrated, increased very rapidly any MDH, ME PEPC. CO2-dependent O2 evolution non-wilted measured with an oxygen electrode as concentration totally inhibited 10%. Nevertheless, high concentrations (5–10%) counteracted most inhibitory effect deficit that developed during but only little dehydration. In contrast what could be observed developing inhibition photosynthesis cis-abscisic acid alleviated concentrations. These results indicate uptake brought is mainly due stomatal closure plant while it non-stomatal processes dehydrated. photosynthetic apparatus appears resistant drought C3 plants. might result either down-regulation enzymes metabolite pool sizes restricted plasmodesmatal transport between mesophyll bundle-sheath cells.