Construction of ethylene regulatory network based on the phytohormones related gene transcriptome profiling and prediction of transcription factor activities in soybean

Abstract

High floral abscission ratio in soybean (Glycine max L.) leads to serious yield loss in field culture condition. Ethylene is a phytohormone responsible for the regulation of developmental changes and floral abscission ratio in soybean. It is clear that different phytohormones affected overlapping physiological processes, and the physiological effects of phytohormone depended on specific hormone combination rather than the independent activity of each one. Little is known about how ethylene is integrated into the phytohormone metabolism and signal network. The results of phytohormone content analysis and three RNA-seq libraries after silver thiosulfate (STS), ethephon (ETH) and control treatment showed that ethylene biosynthesis and signal pathway was affected by STS treatment according to suppress the mRNA abundance of 1-aminocyclopropane-1-carboxylate (ACC) syntheses genes, while the ETH treatment induced both ethylene biosynthesis and signal pathway components in soybean. A number of genes involved in IAA, GA, CTK and ABA pathways components were activated or depressed correspondingly. The analysis of transcription factors (TFs) in differential transcriptome profiling and TFs prediction of the differentially transcription genes related to all phytohormone biosynthesis showed that TFs MYB played pivotal roles in the process of ethylene interplaying the whole phytohormones metabolism and signal network.