Crop Biotech Institute & Department of Genetic Engineering, Kyung Hee University, Yongin 446-701, Republic of Korea.
J Plant Physiol. 2013 Jun 15;170(9):854-63. doi: 10.1016/j.jplph.2013.01.006. Epub 2013 Feb 7.
Heat is a primary abiotic stress that reduces crop yields. At the seedling stage, we identified heat-sensitive mutants that carried T-DNA inserted into a heat shock protein 70 gene, OsHsp70CP1. When grown under a constant high temperature (40°C), the seedling leaves developed severe chlorosis whereas plants grown at a constant 27°C showed a normal phenotype. This indicated that OsHsp70CP1 is essential for chloroplast differentiation from the proplastids under high temperatures. Transient expression analyses revealed that OsHsp70CP1 was localized to the stroma. OsHsp70CP1 was dominantly expressed in photosynthetic tissues; transcripts were greatly increased by heat stress. Some transcripts for plastid RNA metabolism were impaired in the mutant while others were not, demonstrating that a subset of nuclear-encoded proteins are substrates of OsHsp70CP1.
热是一种主要的非生物胁迫，会降低作物产量。在幼苗期，我们发现了一些对热敏感的突变体，它们的 T-DNA 插入到热休克蛋白 70 基因 OsHsp70CP1 中。当在恒定高温（40°C）下生长时，幼苗叶片出现严重的黄化，而在恒定 27°C 下生长的植株则表现出正常的表型。这表明 OsHsp70CP1 对于叶绿体在高温下从原质体分化是必需的。瞬时表达分析表明，OsHsp70CP1 定位于基质中。OsHsp70CP1 在光合作用组织中表达占优势；热胁迫会大大增加转录物的水平。在突变体中，一些与质体 RNA 代谢相关的转录本受到了影响，而另一些则没有，这表明一组核编码蛋白是 OsHsp70CP1 的底物。
