Red-light signaling pathway activates desert cyanobacteria to prepare for desiccation tolerance

• 成果类型: Article
• 署名作者: Xu, Hai-Feng; Dai, Guo-Zheng; Li, Ren-Han; Bai, Yang; Zuo, Ai-Wei; Zhao, Lei; Cui, Shu-Ren; Shang, Jin-Long; Cheng, Chao; Wang, Yu-Jie; Feng, Gui-Fang; Duanmu, Deqiang; Kaplan, Aaron; Qiu, Bao-Sheng
• 署名单位: Central China Normal University; Central China Normal University; Huazhong Agricultural University; Hubei Hongshan Laboratory; Hebrew University of Jerusalem
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10142
• DOI: 10.1073/pnas.2502034122
• 发表日期: 2025-03-25
• 关键词: nostoc-flagelliforme; dehydration; photosynthesis; SYSTEM; phototaxis; hydration; bacteria; cannot

摘要

Desiccation-tolerant cyanobacteria are able to survive frequent cycles of hydration and dehydration, which are closely linked to diurnal light oscillations. Previous studies have shown that light serves as a crucial anticipatory cue, activating desert cyanobacteria to prepare for desiccation. However, the mechanisms underlying their light-coupled desiccation tolerance remain largely unknown. Here, we demonstrate that red-light-induced photosynthetic genes are positively regulated by a LuxR family transcription factor NfSrr1. We further identified the cyanobacteriochrome NfPixJ as interacting with NfSrr1 and functioning as a red light sensor. Phenotypic analysis revealed that the red-light signaling module NfPixJ-NfSrr1 plays a key role in preparing cyanobacteria for desiccation tolerance. This module also regulates the synthesis of protective compatible solutes, suggesting that red light functions as a global regulatory signal for the broader stress response. Phylogenetic analysis indicates that the presence of this red-light signaling pathway, mediated by NfPixJ-NfSrr1 module, correlates with the ability of cyanobacteria to thrive in water-deficit habitats. Overall, our findings uncover a red-light signaling pathway that enhances desiccation tolerance as desert cyanobacteria encounter red light at dawn, before water limitation. These results provide insights into the mechanisms behind light-induced anticipatory stress tolerance in photosynthetic organisms.