Loss of psbS expression reduces vegetative growth, reproductive output, and light-limited, but not light-saturated, photosynthesis in Arabidopsis thaliana (Brassicaceae) grown in temperate light environments.

摘要: Plants protect themselves against the deleterious effects of high light intensities by inducing a mechanism ubiquitous among plants known as energy dissipation, which safely converts excess to heat before it can lead formation free radicals. Mutants possessing deletion psbS gene, such npq4 mutant, cannot perform dissipation and thus offer an opportunity assess importance this process plant function. In temperate environment, greenhouse-grown mutants Arabidopsis thaliana had smaller rosette diameters leaf numbers. The reduction in size observed was associated with fewer floral stalks, fruits, lower whole-plant individual seed masses, germination rates. field, developed fruits. After controlled exposure stress, both PSII efficiency CO(2) assimilation were more significantly compromised at low intensities, but not intensities. Thus, protective nature manifests environments that include periods light, predispose photoinactivation, when photoinactivation decreases rate photosynthesis.