%A LI Geng,GAO Hui-Yuan,ZHAO Bin,DONG Shu-Ting,ZHANG Ji-Wang,YANG Ji-Shun, %T Effects of Drought Stress on Activity of Photosystems in Leaves of Maize at Grain Filling Stage %0 Journal Article %D 2009 %J Acta Agronomica Sinica %R 10.3724/SP.J.1006.2009.01916 %P 1916-1922 %V 35 %N 10 %U {https://zwxb.chinacrops.org/CN/abstract/article_4352.shtml} %8 2009-10-12 %X

At grain filling stage, the effects of drought stress on photosynthetic acivities of photosystem I (PS I) and photosystem II (PS II) in leaves of maize (Zhengdan 21, a cultivar with high starch content) were studied by simultaneously analyzing chlorophyll a fluorescence transient and light absorbance at 820 nm. The results, obtained from two years experiments, demonstrated that the drought stress significantly reduced photosynthesis (P<0.05) and grain yield (P<0.05) of the maize. The K and J steps at fluorescence transient were increased by drought stress, which indicated the inhibition of oxygen- evolving complex (OEC) and electron transport chain after QA in PS II. The acceptor side of PSII was damaged more severely than the donor side of PSII. Furthermore, the maximal oxidation-reduction activity of PS I (ΔI/Io) was also significantly decreased by the drought stress, which inhibited the photosynthetic electron tranport from the PS II to PS I, destructing the coordination between PS I and PS II. We suggest that the inhibition of PS I and PS II and the destruction of the coordination between PS I and PS II by the drought stress is one of the main reasons to cause the decrease in photosyntheis and grain yield of maize.