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

Response of High-temperature Stress on Photosynthetic Characteristics and Chloroplast Ultrastructure of Flag Leaves in Xantha Rice Mutant

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/Fm)、PSⅡ光量子效率(фPSⅡ)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-tempera- ture stress. The results showed.during the high temperature stress period, the flag leaves net photosyn- thetic rate（Pn）,PS Ⅱprimary photochemical efficiency（Fv/Fm）,PSⅡ optical quantum efficiency（ФPSⅡ）, a- cyclic photosynthetic electron transfer rate （ETR）, the content of chlorophyll and soluble protein de- creased,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 rela- tively 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.