Phytochrome B enhances seed germination tolerance to high temperature by reducing S-nitrosylation of HFR1

Ying, Songbei; Yang, Wenjun; Li, Ping; Hu, Yulan; Lu, Shiyan; Zhou, Yun; Huang, Jinling; Hancock, John T.; Hu, Xiangyang

Abstract

Light and ambient high temperature (HT) have opposite effects on seed germination. Light induces seed germination through activating the photoreceptor phytochrome B (phyB), resulting in the stabilization of the transcription factor HFR1, which in turn sequesters the suppressor PIF1. HT suppresses seed germination and triggers protein S-nitrosylation. Here, we find that HT suppresses seed germination by inducing the S-nitrosylation of HFR1 at C164, resulting in its degradation, the release of PIF1, and the activation of PIF1-targeted SOMNUS (SOM) expression to alter gibberellin (GA) and abscisic acid (ABA) metabolism. Active phyB (phyBY276H) antagonizes HFR1 S-nitrosylation and degradation by increasing S-nitrosoglutathione reductase (GSNOR) activity. In line with this, substituting cysteine-164 of HFR1 with serine (HFR1C164S) abolishes the S-nitrosylation of HFR1 and decreases the HT-induced degradation of HFR1. Taken together, our study suggests that HT and phyB antagonistically modulate the S-nitrosylation level of HFR1 to coordinate seed germination, and provides the possibility to enhance seed thermotolerance through gene-editing of HFR1.

• Journal Article Type: Article
• Acceptance Date: Aug 8, 2022
• Online Publication Date: Sep 5, 2022
• Publication Date: Sep 5, 2022
• Deposit Date: Aug 12, 2022
• Publicly Available Date: Mar 6, 2023
• Journal: EMBO Reports
• Print ISSN: 1469-221X
• Electronic ISSN: 1469-3178
• Publisher: EMBO Press
• Peer Reviewed: Peer Reviewed
• Article Number: e54371
• DOI: https://doi.org/10.15252/embr.202154371
• Keywords: Arabidopsis; HFR1; High temperature; Seed germination; S-nitrosylation
• Public URL: https://uwe-repository.worktribe.com/output/9851971
• Publisher URL: https://www.embopress.org/journal/14693178