温敏失绿突变体水稻1103s在失绿过程中全叶蛋白的变化

Alteration of Whole Leaf Protein of a Temperature sensitive Chlorophyll Deficient Rice Mutant During the Bleaching Process 

从全叶蛋白比较入手，研究了温敏失绿突变体水稻（ＯｒｙｚａｓａｔｉｖａＬ．）１１０３ｓ失绿前、后的变化，并结合该突变体在不同温度处理和遗传背景下叶片全蛋白的变化特征分析了变温诱导与失绿的关系。结果表明，诱导后１１０３ｓ的叶片上，失绿部分的组织中没有出现冷胁迫的迹象，其Ｒｕｂｉｓｃｏ的大、小亚基表现正常。一个５１ｋＤ（ＰＩ＝４．５）的特异蛋白Ｐ１在失绿部分的组织中消失，而在叶片绿色部分的组织中检测到了Ｐ１蛋白，不过量有所减少，说明在失绿叶片上突变基因的表达存在组织差异性。Ｐ１蛋白在常温下生长的１１０３ｓ叶片中为一大量蛋白，此蛋白在“８９０２ｓ”、“窄叶青８号”等品种中均可检测到；并且持续低温处理的１１０３ｓ植株和１１０３ｓ×８９０２ｓ杂交一代的叶片中Ｐ１蛋白的表达未受影响。由此推测，Ｐ１蛋白是水稻叶片中的一个与叶绿素的代谢过程密切相关的重要功能蛋白。在１１０３ｓ中，Ｐ１蛋白的变化不是温度诱导的直接后果，而是受突变所导致的温敏过程调控的下游变化。

s was a rice (Oryza sativa L.) mutant whose leaves would turn into chimerical chlorophyll deficient when treated with varied temperature (high-low-high). The alteration of whole leaf protein was studied with two dimensional electrophoresis during the bleaching process. No changes of large subunit and small subunit of Rubisco had been detected in the bleached tissues of 1103s, but a 51 kD (PI=4.5) special polypeptide P1 disappeared in the white area during the bleaching process. P1 polypeptide was also detected in those tissues which remained green on the chlorophyll deficient leaves, although its amount apparently decreased. In the tissue of low temperature treated 1103s and 1103s×8902s, the normal expression of P1 polypeptide had been detected. The data suggest that P1 is an important chlorophyll synthesis related down stream functional protein. In 1103s, it is regulated by some yet unknown temperature sensitive mechanisms.