Identification of cleistogamy-associated proteins in flower buds of near-isogenic lines of soybean by differential proteomic analysis

Differential proteomics analyses were performed on flower buds of chasmogamous (CH) and cleistogamous (CL) soybean to identify candidate genes that are associated with cleistogamy which is the production of permanently closed flowers. The proteins were extracted from flower buds of CH cv. Toyosuzu and CL cv. Karafuto-1, and separated by two-dimensional polyacrylamide gel electrophoresis. Of the 640 proteins detected on the gel, nine were differentially expressed in Toyosuzu and nine in Karafuto-1. Among these differentially expressed proteins, those associated with cleistogamy were identified using a pair of near-isogenic lines (NILs). β-Galactosidase and protein disulfide isomerase were expressed differentially between the NILs for cleistogamy. Furthermore, the mRNA expression pattern of protein disulfide isomerase corresponded to the protein level, whereas that of β-galactosidase was not consistent with the protein level. These results suggest that the protein disulfide isomerase and β-galactosidase may be useful markers for achieving a better understanding of the molecular-biological mechanisms of cleistogamy in soybean.