Genome-wide transcript analysis of inflorescence development in wheat

Abstract

The process of inflorescence development is directly related to yield components that determine the final grain yield in most cereal crops. Here, microarray analysis was conducted for four different developmental stages of inflorescence to identify genes expressed specifically during inflorescence development. To select inflorescence-specific expressed genes, we conducted meta-analysis using 1245 Affymetrix GeneChip array sets obtained from various development stages, organs, and tissues of members of Poaceae. The early stage of inflorescence development was accompanied by a significant upregulation of a large number of cell differentiation genes, such as those associated with the cell cycle, cell division, DNA repair, and DNA synthesis. Moreover, key regulatory genes, including the MADS-box gene, KNOTTED-1-like homeobox genes, GROWTH-REGULATING FACTOR 1 gene, and the histone methyltransferase gene, were highly expressed in the early inflorescence development stage. In contrast, fewer genes were expressed in the later stage of inflorescence development, and played roles in hormone biosynthesis and meiosis-associated genes. Our work provides novel information regarding the gene regulatory network of cell division, key genes involved in the differentiation of inflorescence in wheat, and regulation mechanism of inflorescence development that are crucial stages for determining final grain number per spike and the yield potential of wheat.