高温对水稻黄叶突变体剑叶光合特性和叶绿体超微结构的影响

摘要

以水稻黄叶突变体为材料,进行高温胁迫处理(9:30～17:30,40℃;其它时间段与自然温度相同),研究高温胁迫对其剑叶光合特性和叶绿体超微结构的影响.结果表明:高温胁迫使水稻黄叶突变体剑叶净光合速率(Pn)、PSⅡ原初光化学效率(Fv/F)、PSⅡ光量子效率(ΦPSⅡ)和非循环光合电子传递速率(ETR)显著降低,初始荧光(F0)显著增加,同时使剑叶叶绿素、可溶性蛋白质含量显著降低,细胞膜透性显著增加,叶片的叶绿体内基粒和基质片层模糊、疏松,结构紊乱.研究发现,40℃高温胁迫致使水稻黄叶突变体剑叶叶绿体超微结构破坏,引起PSⅡ反应中心的光化学效率降低,最终造成叶片光合能力减弱.%A xantha rice mutant was used as the material, which was subjected to high temperature stress treatment (9:30～17:30,40℃ ;the temperature of other time period was the same as natural) , to study the impact of photosynthetic characteristics and chloroplast ultrastructure on its flag leaves in high-temperature stress. The results showed: during the high temperature stress period, the flag leaves net photosynthetic rate(Fn),PSⅡ primary photochemical efficiency(Fv/Fm) ,PSⅡ optical quantum efficiency(φPSⅡ ),a-cyclic photosynthetic electron transfer rate (ETR), the content of chlorophyll and soluble protein decreased, but initial fluorescence(Fo ) and Membrane permeability increased. Grana lamellae structure of chloroplast in blades was rough and disordered,the membrane number of grana lamellae structure was relatively less,matrix fades. All above indicated that high temperature stress caused destruction of chloroplast ultrastructure in xantha rice mutant and decrease of blades photosynthetic capacity.