摘要
研究了低温胁迫下水稻幼苗叶绿体光合电子传递功能及类囊体膜蛋白水平的变化。４℃低温结合３５μｍｏｌ／（ｍ２·ｓ）的弱光照处理，使水稻叶绿体全电子链、ＰＳⅡ和ＰＳⅠ的电子传递活性均降低，降低的幅度依次是：全电子链＞ＰＳⅡ＞ＰＳⅠ。对类囊体膜蛋白组分进行的ＳＤＳ－ＰＡＧＥ分析显示，低温使大部分类囊体膜蛋白特别是ＰＳⅡ功能蛋白的稳态水平降低，这可能是造成叶绿体光化学功能降低的主要原因。进一步对低温影响ＰＳⅡ电子传递活性的机理进行了探讨，所得结果表明，低温下ＰＳⅡ功能受抑的主要原因是其氧化侧的电子供应受阻，而与反应中心受到的伤害关系不大，尽管类囊体膜的ＳＤＳ－ＰＡＧＥ结果显示ＰＳⅡ的反应中心也受到低温的损伤。
Changes in
chloroplast electron transport activity and the levels of thylakoid membrane proteins of rice
leaves (Oryza sativa L. var. Saituo) during chilling stress were studied . The results
indicated that treating rice seedlings at 4℃ and a light condition of 35 μmol/(m 2·s) for one,
two and three days, caused marked and progressive decrease in chloroplast electron transport
activity through the whole chain(H 2O→MV), PSⅡ(H 2O→DCBQ) and PSⅠ(DCIP→MV),
respectively. The scales of decrease were whole chain >PSⅡ>PSⅠ. The SDS PAGE of
thylakoid membranes showed that the contents of most thylakoid polypeptides decreased
markedly during the stress, suggesting that the decrease of chloroplast photochemical function
may be a result of the destruction of major functional proteins involved. Furthermore, the
mechanisms that low temperature may inhibit PSⅡ (photosystem Ⅱ) activity in rice thylakoids
were investigatea. The results of determination on DCIP photoreduction activity of PSⅡ,
coupled with those from SDS PAGE of thylakoid membranes, indicated that chilling not only
damaged oxidative side of PSⅡ, but also affected its reaction center. However, it seemed that
only the damage at the oxidative side was responsible for the decrease of PSⅡ activity.
出处
《中国水稻科学》
CAS
CSCD
北大核心
1999年第2期99-103,共5页
Chinese Journal of Rice Science
基金
国家自然科学基金
关键词
低温
水稻
叶绿体
幼苗
光化学功能
类囊体膜
chilling stress
chloroplast
electron transport
Oryza sativa
photosystem Ⅰ
photosystem Ⅱ
protein composition
thylakoid membrane
