The role of nitric oxide signalling in response to salt stress in Chlamydomonas reinhardtii.
Nitric oxide signal and GSNOR activity play an essential role for Chlamydomonas reinhardtii response to salt stress. The unicellular alga Chlamydomonas reinhardtii is one of the most important model organisms phylogenetically situated between higher plants and animals. In the present study, we used comparative proteomics and physiological approaches to study the mechanisms underlying the response to salt stress in C. reinhardtii. We identified 74 proteins that accumulated differentially after salt stress, including oxidative enzymes and enzymes associated with nitric oxide (NO) metabolism, cell damage, and cell autophagy processes. A set of antioxidant enzymes, as well as S-nitrosoglutathione reductase (GSNOR) activity, were induced to balance the cellular redox status during short-term salt stress. Enzymes involved in DNA repair and cell autophagy also contribute to adaptation to short-term salt stress. However, under long-term salt stress, antioxidant enzymes and GSNOR were gradually inactivated through protein S-nitrosylation, leading to oxidative damage and a reduction in cell viability. Modulating the protein S-nitrosylation levels by suppressing GSNOR activity or adding thioredoxin affected the plant's adaptation to salt stress, through altering the redox status and DNA damage and autophagy levels. Based on these data, we propose that unicellular algae use multiple strategies to adapt to salt stress, and that, during this process, GSNOR activity and protein S-nitrosylation levels play important roles.
School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
Xiaodong
X
Chen
Biotechnology Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, Fujian, China.
Dagang
D
Tian
The Germplasm Bank of Wild Species, Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, 650201, China.
Xiangxiang
X
Kong
The Germplasm Bank of Wild Species, Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, 650201, China.
Qian
Q
Chen
Plant Production Department, College of Food and Agricultural Sciences, King Saud University, P.O. Box. 2460, Riyadh, 11451, Saudi Arabia.
Abd Allah
AA
E F
Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai, China. huxiangyang@mail.kib.ac.cn.
Xiangyang
X
Hu
School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China. aiqunj302@mail.njust.edu.cn.
Aiqun
A
Jia
D000445:Aldehyde Oxidoreductases / Q000378:metabolism; D000975:Antioxidants / Q000378:metabolism; D001343:Autophagy; D016825:Chlamydomonas reinhardtii / Q000187:drug effects / Q000378:metabolism*; D004249:DNA Damage; D009569:Nitric Oxide / Q000378:metabolism*; D020543:Proteome; D017382:Reactive Oxygen Species / Q000378:metabolism; D054712:Salinity; D012965:Sodium Chloride / Q000633:toxicity*; D013312:Stress, Physiological
D000975:Antioxidants; D020543:Proteome; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D012965:Sodium Chloride; D000445:Aldehyde Oxidoreductases; C087006:formaldehyde dehydrogenase, glutathione-independent
Autophagy; Cellular redox status; Chlamydomonas; Proteomics; S-nitrosoglutathione reductase; Salt stress