Pötter E, Beator J, Kloppstech K
Institut für Botanik, Universität Hannover, Germany.
Planta. 1996;199(2):314-20. doi: 10.1007/BF00196574.
Two cDNAs coding for putative light-stress proteins of barley (Hordeum vulgare L.) were cloned and the expression of the corresponding mRNAs analyzed in the barley leaf and compared to that of the well-studied ELIP (early-inducible protein) mRNA. During greening the mRNA for clone HL No. 2, which shows homology to two rice proteins of as yet unknown function, was transiently induced; its level rose more slowly and remained elevated for a longer time than was described for ELIP mRNAs. The mRNA corresponding to clone HL No. 13 was recognized as homologous to subunit P of pea glycine decarboxylase, a nuclear-encoded mitochondrial protein involved in photorespiration. Its mRNA level rose more slowly with cellular development than that of the mRNA for LHC II, the apoprotein of the chlorophyll-a/b-binding protein of PSII. The mRNAs of both novel proteins were induced by high light up to an irradiance of 2000 W.m-2. Their levels remained elevated under high light for up to 9 h, the longest time span examined, while after return to culture light conditions the mRNAs rapidly decayed, each with an individual time course. In green barley leaves the mRNA for clone HL No. 2 was expressed to the highest level in the most basal segment, similar to that of ELIPs, while in contrast the mRNA for subunit P of glycine decarboxylase accumulated to the highest level in the leaf apex where the fully developed cells and mitochondria reside. The latter finding strongly indicates that photorespiration is regulated by high light also at the level of mRNA transcription or mRNA accumulation. In addition, we show that perception of light stress is under the control of cellular development and differentiation.
克隆了两个编码大麦（Hordeum vulgare L.）假定光胁迫蛋白的cDNA，并分析了大麦叶片中相应mRNA的表达情况，并与研究充分的ELIP（早期诱导蛋白）mRNA的表达进行了比较。在绿化过程中，与两种功能未知的水稻蛋白具有同源性的克隆HL No. 2的mRNA被短暂诱导；其水平上升得比ELIP mRNA慢，且升高后持续时间更长。与克隆HL No. 13对应的mRNA被认为与豌豆甘氨酸脱羧酶的P亚基同源，豌豆甘氨酸脱羧酶是一种参与光呼吸的核编码线粒体蛋白。随着细胞发育，其mRNA水平的上升比PSII叶绿素a/b结合蛋白的脱辅基蛋白LHC II的mRNA慢。两种新蛋白的mRNA在高达2000 W.m-2的光照强度下都被诱导。在强光下，它们的水平在长达9小时（研究的最长时间跨度）内保持升高，而回到培养光照条件后，mRNA迅速降解，且各自具有独立的时间进程。在绿色大麦叶片中，克隆HL No. 2的mRNA在最基部的节段中表达水平最高，类似于ELIPs，而相比之下，甘氨酸脱羧酶P亚基的mRNA在叶尖（即完全发育的细胞和线粒体所在处）积累水平最高。后一发现有力地表明，光呼吸在mRNA转录或mRNA积累水平上也受到强光的调节。此外，我们表明光胁迫的感知受细胞发育和分化的控制。
