CHRD, a plant member of the evolutionarily conserved YjgF family, influences photosynthesis and chromoplastogenesis
CHRD, a plant member of the evolutionarily conserved YjgF family, influences photosynthesis and chromoplastogenesis
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DOI：
10.1007/s00425-006-0332-y
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发表时间：
2006-12-01
期刊：
影响因子：
4.3
通讯作者：
Vainstein, Alexander
中科院分区：
文献类型：
--
作者：
Leitner-Dagan, Yael;Ovadis, Marianna;Vainstein, Alexander
研究类胡萝卜素的过度积累的结构，在色素体导致的蛋白质的特性称为质体脂质相关蛋白（PAP），参与螯合的疏水化合物。在这里，我们的特点PAP CHRD，其中，基于序列同源性，属于一个高度保守的蛋白质组，YER 057 c/YjgF/UK 114，参与细菌，酵母和动物的基本和重要的细胞过程的调节。两个核基因的特点是在番茄植物：一个（LeChrDc）是组成型表达的各种组织和其他（LeChrDi）是由胁迫诱导的叶片和花组织中的发育线索上调。使用RNA干扰和反义方法，我们展示了它们参与光合作用等生物学重要过程。LeChrDilc表达受抑制的转基因番茄叶片中光合电子流的量子产率是其对照、非转基因对应物的30-50%，并且归因于较低的PSI活性。与抑制LeChrDilc的转基因花也积累了高达30%，每单位蛋白质的类胡萝卜素相比，对照植物，表明PAP和花特异性类胡萝卜素积累的质体之间的相互关系。我们认为，CHRD在被子植物生殖单位的作用可能是一个相当近期的进化发展，其原来的功能可能是保护植物在压力条件下保存质体功能。
Studies on the carotenoid-overaccumulating structures in chromoplasts have led to the characterization of proteins termed plastid lipid-associated proteins (PAPs), involved in the sequestration of hydrophobic compounds. Here we characterize the PAP CHRD, which, based on sequence homology, belongs to a highly conserved group of proteins, YER057c/YjgF/UK114, involved in the regulation of basic and vital cellular processes in bacteria, yeast and animals. Two nuclear genes were characterized in tomato plants: one (LeChrDc) is constitutively expressed in various tissues and the other (LeChrDi) is induced by stress in leaves and is upregulated by developmental cues in floral tissues. Using RNAi and antisense approaches, we show their involvement in biologically significant processes such as photosynthesis. The quanturn yield of photosynthetic electron flow in transgenic tomato leaves with suppressed LeChrDilc expression was 30-50% of their control, non-transgenic counterparts and was ascribed to lower PSI activity. Transgenic flowers with suppressed LeChrDilc also accumulated up to 30% less carotenoids per unit protein as compared to control plants, indicating an interrelationship between PAPs and floral-specific carotenoid accumulation in chromoplasts. We suggest that CHRD's role in the angiosperm reproductive unit may be a rather recent evolutionary development; its original function may have been to protect the plant under stress conditions by preserving plastid functionality.