The cyclin-dependent kinase inhibitor orysa;KRP1 plays an important role in seed development of rice
The cyclin-dependent kinase inhibitor orysa;KRP1 plays an important role in seed development of rice
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DOI：
10.1104/pp.106.087056
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发表时间：
2006-11-01
期刊：
影响因子：
7.4
通讯作者：
Frankard, Valerie
中科院分区：
文献类型：
--
作者：
Barroco, Rosa Maria;Peres, Adrian;Frankard, Valerie
kip相关蛋白（KRPs）在植物细胞周期的调控中起着重要作用。我们报告鉴定了五种假定的水稻（Oryza sativa）蛋白，它们与先前描述的植物KRPs共享特征基序。为了研究KRPs在水稻发育中的作用，我们构建了过表达Orysa的转基因植株；KRP1基因。表型分析显示，KRP1过表达降低了叶片发育过程中的细胞产量。叶片分生组织中细胞产量的减少部分被细胞大小的增加所补偿，这表明单叶植物中存在一种补偿机制，通过细胞扩增，生长速度的减少小于细胞产量的减少。此外,Orysa;KRP1过表达显著减少种子填充。通过过表达的KRP1种子切片发现，KRP的过量产生干扰了胚乳细胞的产生。完全形成的种子数量的减少伴随着胚乳细胞内复制的减少，这表明KRP1在连接胚乳发育和内循环中的作用。同时，发育中种子的时空转录检测表明，Orysa；KRP1在水稻籽粒形成过程中有丝分裂细胞周期的退出过程中起着重要作用。
Kip-related proteins (KRPs) play a major role in the regulation of the plant cell cycle. We report the identification of five putative rice (Oryza sativa) proteins that share characteristic motifs with previously described plant KRPs. To investigate the function of KRPs in rice development, we generated transgenic plants overexpressing the Orysa; KRP1 gene. Phenotypic analysis revealed that overexpressed KRP1 reduced cell production during leaf development. The reduced cell production in the leaf meristem was partly compensated by an increased cell size, demonstrating the existence of a compensatory mechanism in monocot species by which growth rate is less reduced than cell production, through cell expansion. Furthermore, Orysa; KRP1 overexpression dramatically reduced seed filling. Sectioning through the overexpressed KRP1 seeds showed that KRP overproduction disturbed the production of endosperm cells. The decrease in the number of fully formed seeds was accompanied by a drop in the endoreduplication of endosperm cells, pointing toward a role of KRP1 in connecting endocycle with endosperm development. Also, spatial and temporal transcript detection in developing seeds suggests that Orysa; KRP1 plays an important role in the exit from the mitotic cell cycle during rice grain formation.