Prof. Bai Mingyi's Group Reveal the Signal Transduction of H[ Home ]
Recently, Professor Bai Mingyi's group from the School of Life Science, Shandong University, has made an important progress in the signal transduction of hydrogen peroxide in plants. The paper entitled "Hydrogen peroxide positively regulatesbrassinosteroidsignaling through oxidation of the BRASSINAZOLE-RESISTANT1 transcription factor" was published in Nature Communications(DOI: 10.1038/s41467-018-03463-x).
Hydrogen peroxide(H2O2) is initially considered to be toxic by-products that accumulate under stress conditions and cause irreversible damage to cells. Recently, H2O2 is recognized as an important signaling molecule that regulates normal plant growth and development, as well as stress responses. However, how H2O2 is sensed and how this signal is transmitted to the cell machinery remains largely unclear. In this study, the authors showed that H2O2 induces the oxidation of the BRASSINAZOLE-RESISTANT1(BZR1) transcription factor, which functions as a master regulator of brassinosteroid(BR) signaling. Oxidative modification enhances BZR1 transcriptional activity by promoting its interaction with key regulators in the auxin- and light-signaling pathways, including AUXIN RESPONSE FACTOR6(ARF6) and PHYTOCHROME INTERACTING FACTOR4(PIF4). Genome-wide analysis shows that H2O2-dependent regulation of BZR1 activity plays a major role in modifying gene expression related to several BR-mediated biological processes. Furthermore, the authors show that the thioredoxin TRXh5 interacts with BZR1 and catalyzes its reduction. They conclude that reversible oxidation of BZR1 connects H2O2- and thioredoxin-mediated redox signaling to BR signaling to regulate plant development.