光和暗条件下低温对黄瓜和水稻叶绿素蛋白质复合体的影响

本试验以黄瓜和水稻幼苗为材料,研究了光照和黑暗条件下低温对植物叶绿素蛋白质复合体的影响。SDS—PAGE电泳结果表明:5℃及12h 280μmol m~(-2)S~(-1)处理2d,Chl-蛋白质复合体的降解明显大于5℃暗低温处理;低温与光照对P700-CPa_1的影响大于LHCP。叶绿素荧光测定表明;5℃及12h 280μmol m~(-2)s~(-1)的处理对PSⅡ的影响亦大于暗低温处理。由此认为:低温与光对植物叶绿体的PSⅠ和PSⅡ都有明显的影响,其机理可能与常温下高光强引起的光抑制相类似;不同的是低温下中等光强就能引起光抑制。因此,在光照低温下往往加剧植物冷害的发生。

THE EFFECT OF CHILLING STRESS ON CHLOROPHYLLPROTEIN COMPLEXES OF RICE AND CUCUMBER SEEDLINGS IN THE LIGHT AND DARK

In this work we used cucumber and rice seedlings as experimentalmaterials to study the changes of chlorophyll-protein complexes in leaves afterchilling treatment under dark and light. Result indicated that the chlorophyll-protein complexes were decreased in the seedlings exposed to 5℃ for 2 days. Theleaves treated with 5℃ and 280 μ mol m~(-2)s~(-1) was decreased more than that of theleaves under dark at same temperature. Effect of chilling and light interaction onP700--CPa_1 was great, while it was less on LHCP. PSⅡ activity was monitoredby chlorophyll fluorescence emission. It declined rapidly at 280 μmol m~(-2)s~(-1) PFD,but it decreased slowly at dark under same temperature. Therefore, we conclude that this injury mechanism was similar to photoinhibi-tion by strong light intensity, while photoinhibition induced by chilling tempera-ture could carry out even in a moderate photon irradiance. The interaction of lowtemperature and light did, however, result an increase at chilling injury.