Proteomic analysis of lysine acetylation provides strong evidence for involvement of acetylated proteins in plant meiosis and tapetum function

Summary Protein lysine acetylation (KAC) is a dynamic and reversible post-translational modification, playing important biological roles in many organisms. Although KAC was shown to affect reproductive development and meiosis in yeast and animals, similar studies are largely lacking in flowering plants, especially in a proteome-scale investigation for a certain reproductive stage. Here, we reported results from a proteomic investigation to detect KAC status of the developing rice anthers near the time of meiosis (RAM), providing strong biochemical evidence for roles of many KAC-affected proteins during rice anther development and meiosis. We identified a total of 1,354 KAC sites in 676 proteins. Among these, 421 acetylated proteins with 629 KAC sites are novel, greatly enriching KAC information on flowering plants. GO enrichment analysis showed chromatin silencing, protein folding, fatty acid biosynthetic process, and response to stress were over-represented. In addition, certain potentially specific KAC motifs in RAM were detected. Importantly, 357 rice meiocyte proteins were acetylated; and four proteins genetically identified to be important for rice tapetum and pollen development were acetylated on 14 KAC sites in total. Furthermore, 47 putative secretory proteins were detected to exhibit acetylated status in RAM. Moreover, by comparing our lysine acetylome to the RAM phosphoproteome we obtained previously, we proposed correlation between KAC and phosphorylation as a potential modulatory mechanism in rice RAM. Taken together, this study provided the first global survey of KAC in plant reproductive development, making a promising starting point for further functional analysis of KAC during rice anther development and meiosis. This article is protected by copyright. All rights reserved.