水分胁迫对小麦叶绿体光化学活性的影响

Effect of Water Stress on Photochemical Activity of Chloroplast from Wheat

小麦幼苗经-0.2 MPa PEG溶液根际胁迫处理24h后,类囊体膜叶绿素发射荧光强度F685/F735的比值上升;叶绿体PSI相对电子传递活性明显下降;同时PSI叶绿素蛋白复合体发生了显著降解。因此,推测PSI活性的降低可能与其叶绿素蛋白复合体的降解有关。水分胁迫也导致叶绿体Ca^(2+)-ATPase和Mg^(2+)-ATPase活性明显上升。

Wheat seedling was osmotic stressed in-0. 2 MPa PEG solution for 24 hours. It was observed that the ratio of chlorophyll emission fluorescence F685/F735 of thylakoid membrane rised; the relative electron transport activity of PS I in chloroplast decreased significantly; and the chlorophyll-protein complex of PS I was degraded remarkably as well. It indicated that there might be a relationship between decreasing of PS I activity and degradation of PS I chlorophyll-protein complex. At the same time, the activities of Ca2+-ATPase and Mg2+-ATPase in chloroplast increased obviously under water stress.