摘要
In the present study, we investigated the changes of photosynthesis, chlorophyll fluorescence and the content of carotenoid pigments in rice (Oryza sativa L.) seedling leaves and their responses to high light. The results showed that the rate of photosynthesis, the contents of individual and total carotenoids and the pool size of xanthophyll cycle decreased with age increasing of the leaf. When the leaves were exposed to high light for 2 h, the qN of mature leaf (5th leaf) increased more significantly than that of younger (6th leaf) and older leaves (3rd and 4th leaf). Comparing with the leaves before exposure to high light, the excitation pressure on PSⅡ (1- qP ) increased by 44%, 57%, 19% and 45% in the 3rd, 4th, 5th and 6th leaf under high light, respectively. The highest content of carotenoids and the greatest conversion of violaxanthin to zeaxanthin were found in the 5th leaf, and it was consistent with the 5th leaf exhibiting the strongest resistance to high light. Our results suggested that the ability of rice leaf to resist photoinhibition is related to the level of carotenoids and the ability of carotenoids biosynthesis.
研究了水稻 (OryzasativaL .)幼苗叶片生长过程中叶绿素荧光和类胡萝卜素各组分含量的变化以及它们对高光胁迫的响应。结果表明 :随着叶片的衰老 ,光合速率、类胡萝卜素不同组分及总的类胡萝卜素含量和叶黄素循环库下降 ;不同叶龄的叶片经高光胁迫后 ,第 5叶 (成熟叶 )qN增加的幅度比第 6叶 (幼嫩叶 )和老叶 (第 3和 4叶 )大 ;与高光胁迫前相比 ,第 3、4、5和 6叶光系统Ⅱ激发压 (1-qP)分别增加了 4 4 %、5 7%、19%和 4 5 % ;第 5叶具有高胡萝卜素含量和高紫黄质到玉米黄质的转化 ,这与其呈现较强的抗高光胁迫相一致。水稻叶片抵御光抑制的能力与类胡萝卜素水平和类胡萝卜素的生物合成能力以及叶片所处的生长时期相关。
基金
国家重点基础研究发展规划项目 (G19980 10 10 0 )~~
