论文部分内容阅读
本研究旨在通过梅雨前后自然光强明显变化的情况下对水稻叶片光氧化突变体812HS与野生型812S的PSII光化学活性、抗氧化酶活性等生理特性的比较研究,探讨812HS易受光氧化损伤现象的光合生理原因。结果表明,大田自然光照出现强光照前,812HS与812S的叶绿素含量、PSII活性、光合磷酸化活性、净光合速率、抗氧化酶活性和活性氧含量均无显著差异。自然强光照开始(梅雨结束)一段时间后,两种水稻的上述各项指标都发生了明显的变化。突变体812HS的叶绿素含量、PSII活性、非循环式光合磷酸化活性和净光合速率均明显低于812S。高光强下812HS叶片中抗氧化酶CAT和POD活性的上升幅度则小于812S,从而使其体内富集了更多的O_2~?、H_2O_2和MDA。光氧化突变体812HS对高光照强度较敏感的PSII活性和较低的CAT、POD活性可能是其发生叶片光氧化现象的生理成因。
The purpose of this study is to compare the physiological characteristics of PSII photochemical activity and antioxidant enzyme activity of photooxidative mutant 812HS and wild type 812S in rice leaves under the condition of obvious changes of natural light intensity before and after the rainy season to discuss the phenomenon of 812HS susceptible to photooxidation damage Photosynthetic physiological reasons. The results showed that there was no significant difference in chlorophyll content, PSII activity, photosynthetic phosphorylation activity, net photosynthetic rate, antioxidant enzyme activity and reactive oxygen species of 812HS and 812S before the natural light illumination. After a period of intense natural light start (end of the rainy season), the above indicators of both rice varieties have undergone significant changes. The chlorophyll content, PSII activity, non-cyclic photosynthetic phosphorylation activity and net photosynthetic rate of mutant 812HS were significantly lower than those of 812S. The activities of CAT and POD in 812HS leaves increased by less than 812S under high light intensity, which resulted in the accumulation of more O_2 ~?, H_2O_2 and MDA in the body. The photo-oxidative mutant 812HS is sensitive to high light intensity PSII activity and lower CAT, POD activity may be its physiological occurrence of leaf photooxidation phenomenon.