Transcription factor ERF1 promotes seed germination by repressing jasmonic acid (JA) signaling pathway.

Abstract

Key message: ERF1 integrates JA and ABA signaling pathway through MYC2 to promote seed germination, which regulates ROS homeostasis and cell wall expansion. Seed germination is a crucial step in the plant life cycle and an important trait related to agricultural production. Jasmonates (JAs) are one of the major plant hormones mediating many plant growth and development processes, including their inhibitory effects on seed germination. But how JA signaling pathway is regulated during germination is not well understood. ETHYLENE RESPONSE FACTOR 1 (ERF1), a key component of ethylene signaling pathway, has long been confirmed as a positive regulator of the jasmonic acid (JA) signaling pathway. In this study by integrating gene expression, phytohormone, biochemical and germination analysis, we proved that overexpression of ERF1 could inhibit JA signaling transduction through the nitrate signaling to accelerate the seed germination process. We also proved that ERF1 maintained reactive oxygen species (ROS) homeostasis through inhibiting the NADPH oxidase RBOHD expression and activity and optimized the cell wall structure at cellular level by repressing the JA signaling pathway. By inhibiting the expression of MYC2, ERF1 integrated abscisic acid (ABA) and JA signaling pathway to promote seed germination. Our research findings provide novel insights into the crosstalk between the JA and ABA signaling pathways mediated by ERF1 during seed germination.