Effects of rapidly imposed water deficit on photosynthetic parameters of three C4 grasses
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Water deficit, when rapidly imposed on three C4 grasses of the different metabolic subtypes, Paspalum dilatatum Poiret (NADP-malic enzyme), Cynodon dactylon (L.) Pers (NAD-malic enzyme) and Zoysia japonica Steudel (phosphoenolpyruvate carboxykinase), caused decreases in photosynthetic rates, in the quantum yield of PS II and photochemical quenching, and in the activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC). The results provide evidence for non-stomatal limitations of photosynthesis differing in nature between the three species.
Additional key wordschlorophyll a fluorescence drought stress NAD-malic enzyme NADP-malic enzyme phosphoenolpyruvate carboxykinase phosphoenolpyruvate carboxylase photosynthetic capacity Rubisco
rate of photosynthesis at saturating CO2 and high irradiance
photosynthetic photon flux density
leaf relative water content
PEPC maximal activity
Rubisco total activity
effective quantum yield of PS II electron transport
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