Photosynthetic apparatus in chilling-sensitive plants
Photosynthetic apparatus in chilling-sensitive plants
复制标题
冷敏感植物的光合作用装置
作者：
B. Sochanowicz;Z. Kaniuga
采用SDS电泳法对番茄鲜叶、冷藏叶、暗藏叶和光照叶的蛋白质进行了分离。从鲜叶中提取的可溶性总蛋白被分成5个主要组分，其分子量分别为54，000、45，000、32，000、23，000和14，000。叶片的低温和黑暗储存导致主要在MW为45，000的组分中的显著降低，其随着低温和黑暗储存的叶片的光照而增加。MW为54，000和14，000的多肽（可能是核酮糖、二磷酸羧化酶的大小亚基）在这些条件下是稳定的。相比之下，在室温下在黑暗中储存番茄叶后，MW为54，000和14，000的多肽减少。叶绿体可溶性蛋白质经SDS电泳分离为分子量分别为64，000、54，000、20，000和14，000的组分。相同的馏分在相似的比例观察到在可溶性叶绿体蛋白质新鲜以及冷和黑暗存储和照明叶片。在低温、黑暗贮藏和光照处理后，叶片结构多肽没有发生明显变化。结果表明，番茄叶片在低温和黑暗贮藏后降解并在光照期间合成的主要蛋白质组分是胞质蛋白质组分，其在SDS电泳中产生约45，000 MW的多肽。叶绿体蛋白组分在此条件下是稳定的。
Proteins of fresh, cold and dark-stored and illuminated tomato leaves were fractionated by SDS electrophoresis. The total soluble proteins extracted from fresh leaves were separated into 5 main fractions with MWs of 54,000, 45,000, 32,000, 23,000 and 14,000. The cold and dark storage of the leaves causes a marked reduction mainly in the fraction with MW of 45,000 which increased with the illumination of the cold and dark-storaged leaves. The polypeptides with MWs of 54,000 and 14,000 (probably large and small subunits of ribulose, bisphosphate carboxylase) were stable under these conditions. In contrast, the polypeptides with MWs of 54,000 and 14,000 are decreased following the storage of tomato leaves in the dark at room temperature. Chloroplast soluble proteins were seperated by SDS electrophoresis into fractions with MWs of 64,000, 54,000, 20,000 and 14,000. The same fractions in similar proportions were observed in soluble-chloroplast proteins from fresh as well as coold and dark-stored and illuminated leaves. No drastic changes in structural polypeptides were observed following cold and dark-storage and illumination of the leaves. The results indicated that the main protein fraction, which degradated following cold and dark storage of tomato leaves and synthetized during illumination, is the fraction of cytoplasmic protein which in SDS electrophoresis gives polypeptides of about 45,000 MW. The fractions of chloroplast proteins were stable under such conditions.