Serine carboxypeptidase 46 Regulates Grain Filling and Seed Germination in Rice (Oryza sativa L.)
Serine carboxypeptidase 46 Regulates Grain Filling and Seed Germination in Rice (Oryza sativa L.)
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丝氨酸羧肽酶 46 调节水稻籽粒灌浆和种子萌发 (Oryza sativa L.)
DOI：
10.1371/journal.pone.0159737
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发表时间：
2016-07-22
期刊：
影响因子：
3.7
通讯作者：
Zhang, Jian
中科院分区：
文献类型：
--
作者：
Li, Zhiyong;Tang, Liqun;Zhang, Jian
丝氨酸羧肽酶（SCP）是催化蛋白质水解的最大的酶之一，它可以促进蛋白质的成熟。迄今为止，对水稻中SCP的功能知之甚少。在这项研究中，我们提出了一个全面的分析的基因结构和表达谱的59个水稻SCP。SCP 46主要在发育中的种子中表达，特别是在胚、胚乳和糊粉层中，并能被阿坝诱导表达。功能表征表明，敲低SCP 46导致更小的晶粒尺寸和增强种子萌发。此外，SCP 46种子萌发对阿坝抑制的敏感性比野生型低，表明SCP 46参与阿坝信号传导。RNA-seq和qRT-PCR分析表明，许多与籽粒灌浆和种子休眠相关的基因如SP、VP 1和AGPs在scp 46中表达下调。酵母双杂交试验也表明SCP 46与另一个ABA诱导蛋白DI 19 -1相互作用。综上所述，我们认为SCP 46可能通过参与阿坝信号转导而成为籽粒灌浆和种子萌发的主要调节因子。本研究结果为SCP在水稻中的作用提供了新的思路。
Serine carboxypeptidase (SCP) is one of the largest groups of enzymes catalyzing proteolysis for functional protein maturation. To date, little is known about the function of SCPs in rice. In this study, we present a comprehensive analysis of the gene structure and expression profile of 59 rice SCPs. SCP46 is dominantly expressed in developing seeds, particularly in embryo, endosperm and aleurone layers, and could be induced by ABA. Functional characterization revealed that knock-down of SCP46 resulted in smaller grain size and enhanced seed germination. Furthermore, scp46 seed germination became less sensitive to the ABA inhibition than the Wild-type did; suggesting SCP46 is involved in ABA signaling. As indicated by RNA-seq and qRT-PCR analysis, numerous grain filling and seed dormancy related genes, such as SP, VP1 and AGPs were down-regulated in scp46. Yeast-two-hybrid assay also showed that SCP46 interacts with another ABA-inducible protein DI19-1. Taken together, we suggested that SCP46 is a master regulator of grain filling and seed germination, possibly via participating in the ABA signaling. The results of this study shed novel light into the roles of SCPs in rice.