Krishnasamy S, Mannan R M, Krishnan M, Gnanam A
Department of Plant Sciences, School of Biological Sciences, Madurai Kamaraj University, India.
J Biol Chem. 1988 Apr 15;263(11):5104-9.
The light-dependent protein synthesis occurring in chloroplasts isolated from the leaves of 7-day-old Vigna sinensis responded to heat shock with the induction of a set of four heat shock proteins (HSPs). The synthesis of these four HSPs at the elevated temperature was transcriptionally regulated, and all of them were found to be thylakoid membrane-bound. The synthesis of these chloroplast-coded HSPs was also observed in etioplasts during protein synthesis at the elevated temperatures with the exogenously added ATP. The in vivo induction of these plastid-coded HSPs was observed only in the leaves subjected to gradual increase in temperature but not in leaves subjected to rapid heat shock. Further, the in vitro synthesis of these plastid-coded HSPs was seen only in chloroplasts isolated from the control or from leaves subjected to gradual increase in temperature and not in chloroplasts isolated from leaves subjected to rapid heat shock. Taken together these observations suggest that in V. sinensis, the plastid genome contains a definite heat shock response and the in vivo expression of this response corresponds to the gradual rise in temperature normally occurring under field conditions.
从7日龄豇豆叶片分离出的叶绿体中发生的光依赖性蛋白质合成，对热激反应表现为诱导出一组四种热激蛋白（HSPs）。这四种HSPs在高温下的合成是受转录调控的，并且发现它们都与类囊体膜结合。在高温下添加外源ATP进行蛋白质合成时，在黄化质体中也观察到了这些叶绿体编码的HSPs的合成。这些质体编码的HSPs的体内诱导仅在温度逐渐升高的叶片中观察到，而在遭受快速热激的叶片中未观察到。此外，这些质体编码的HSPs的体外合成仅在从对照或温度逐渐升高的叶片中分离出的叶绿体中可见，而在从遭受快速热激的叶片中分离出的叶绿体中未见。综合这些观察结果表明，在豇豆中，质体基因组包含明确的热激反应，并且该反应的体内表达与田间条件下通常发生的温度逐渐升高相对应。
