title: Serine carboxypeptidase 46 Regulates Grain Filling and Seed Germination in Rice (Oryza sativa L.).
abstract: 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.
authors.affiliation: State Key Lab of Rice Biology, China National Rice Research Institute, Hangzhou, 311400, P.R. China.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Lab of Rice Biology, China National Rice Research Institute, Hangzhou, 311400, P.R. China.
authors.forename: Liqun
authors.initials: L
authors.lastname: Tang
authors.affiliation: State Key Lab of Rice Biology, China National Rice Research Institute, Hangzhou, 311400, P.R. China.
authors.forename: Jiehua
authors.initials: J
authors.lastname: Qiu
authors.affiliation: State Key Lab of Rice Biology, China National Rice Research Institute, Hangzhou, 311400, P.R. China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.affiliation: State Key Lab of Rice Biology, China National Rice Research Institute, Hangzhou, 311400, P.R. China.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Lab of Rice Biology, China National Rice Research Institute, Hangzhou, 311400, P.R. China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Tong
authors.affiliation: China National Rice Research Institute, Hangzhou, 311400, P.R. China.
authors.forename: Xiangjin
authors.initials: X
authors.lastname: Wei
authors.affiliation: China National Rice Research Institute, Hangzhou, 311400, P.R. China.
authors.forename: Yuxuan
authors.initials: Y
authors.lastname: Hou
authors.affiliation: State Key Lab of Rice Biology, China National Rice Research Institute, Hangzhou, 311400, P.R. China.
authors.forename: Jian
authors.identifier: http://orcid.org/0000-0003-2804-0162
authors.initials: J
authors.lastname: Zhang
mesh_terms: D002268:Carboxypeptidases / Q000235:genetics* / Q000378:metabolism*; D016000:Cluster Analysis; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018745:Genome, Plant; D018525:Germination / Q000235:genetics; D009928:Organ Specificity / Q000235:genetics; D012275:Oryza / Q000502:physiology*; D010937:Plant Growth Regulators / Q000494:pharmacology; D012639:Seeds / Q000502:physiology*; D059467:Transcriptome; D003313:Zea mays / Q000235:genetics
chemical_list: D010937:Plant Growth Regulators; D002268:Carboxypeptidases; C022633:serine carboxypeptidase