OsSRT1 is involved in rice seed development through regulation of starch metabolism gene expression. (July 2016) - Zhang, Hua
Highlights: OsSRT1 knockdown results in a lower seed setting rate, lower starch contents, and higher chalky endosperms in rice seeds. OsSRT1 is required for histone deacetylation and repression of RSR1 and amylase genes during early seed development. OsSRT1 is required for histone deacetylation and repression of transposable elements in developing seeds. Abstract: OsSRT1 is a NAD + -dependent histone deacetylase, closely related to the human SIRT6 that plays key roles in genome stability and metabolic homeostasis. In this work, we investigated the role of OsSRT1 in rice seed development. Down-regulation of OsSRT1 induced higher expression of Rice Starch Regulator1 ( RSR1 ) and amylases genes in developing seeds, which resulted in a decrease of starch synthesis and an increase of starch degradation, leading to abnormal seed development. ChIP assay showed that OsSRT1 was required to reduce histone H3K9 acetylation on starch metabolism genes and transposons in developing seeds. In addition, OsSRT1 was detected to directly bind to starch metabolism genes such as OsAmy3B, OsAmy3E, OsBmy4, and OsBmy9 . Our results suggested that OsSRT1-mediated histone deacetylation is involved in starch accumulation and transposon repression to regulate normal seed development.