title: Methylglyoxal as a novel signal molecule induces the salt tolerance of wheat by regulating the glyoxalase system, the antioxidant system, and osmolytes.
abstract: Reactive carbonyl species methylglyoxal (MG) has always been regarded as a cytotoxic metabolite, but now is emerging to function as signal molecule in plants. However, whether MG can induce salt tolerance is elusive. In this study, treatment of wheat seeds with NaCl reduced seed germination, plant height, root length, fresh weight, and dry weight, indicating the inhibitive effects of NaCl on seed germination and seedling growth. The inhibitive effects of NaCl were alleviated by applying exogenous MG, but aggravated by the MG scavenger N-acetyl-L-cysteine (NAC), suggesting that MG could induce the salt tolerance of wheat. In addition, MG increased glyoxalase I and glyoxalase II activities and decreased endogenous MG content in wheat seedlings under NaCl stress, whereas coapplication of NAC weakened glyoxalase activity and enhanced the endogenous MG level. Also, MG activated superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase activities; increased glutathione and ascorbic acid levels; and decreased superoxide radical production and H2O2and malondialdehyde contents under NaCl stress, while NAC reversed these physiological parameters. Furthermore, MG also induced the accumulation of proline, glycine betaine, and soluble sugar under NaCl stress, whereas this accumulation was weakened by NAC. This work reported for the first time that MG could induce the salt tolerance of wheat, and the acquisition of this salt tolerance was involved in the activation of the glyoxalase system and antioxidant system, as well as the accumulation of osmolytes.
authors.affiliation: School of Life Sciences, Yunnan Normal University, Kunming, 650500, People's Republic of China. zhongguang_li@163.com.|Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Kunming, 650500, People's Republic of China. zhongguang_li@163.com.|Key Laboratory of Biomass Energy and Environmental Biotechnology, Yunnan Province, Yunnan Normal University, Kunming, 650500, People's Republic of China. zhongguang_li@163.com.
authors.forename: Zhong-Guang
authors.initials: ZG
authors.lastname: Li
authors.affiliation: School of Life Sciences, Yunnan Normal University, Kunming, 650500, People's Republic of China.|Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Kunming, 650500, People's Republic of China.|Key Laboratory of Biomass Energy and Environmental Biotechnology, Yunnan Province, Yunnan Normal University, Kunming, 650500, People's Republic of China.
authors.forename: Xiang-Qiu
authors.initials: XQ
authors.lastname: Duan
authors.affiliation: School of Life Sciences, Yunnan Normal University, Kunming, 650500, People's Republic of China.|Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Kunming, 650500, People's Republic of China.|Key Laboratory of Biomass Energy and Environmental Biotechnology, Yunnan Province, Yunnan Normal University, Kunming, 650500, People's Republic of China.
authors.forename: Xiong
authors.initials: X
authors.lastname: Min
authors.affiliation: School of Life Sciences, Yunnan Normal University, Kunming, 650500, People's Republic of China.|Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Kunming, 650500, People's Republic of China.|Key Laboratory of Biomass Energy and Environmental Biotechnology, Yunnan Province, Yunnan Normal University, Kunming, 650500, People's Republic of China.
authors.forename: Zhi-Hao
authors.initials: ZH
authors.lastname: Zhou
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D011765:Pyruvaldehyde / Q000494:pharmacology*; D055049:Salt Tolerance; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D013869:Thiolester Hydrolases / Q000378:metabolism; D014908:Triticum / Q000187:drug effects* / Q000378:metabolism*; D000099301:Hydroxyacylglutathione Hydrolase
chemical_list: D000975:Antioxidants; D011765:Pyruvaldehyde; D012965:Sodium Chloride; D013869:Thiolester Hydrolases; D000099301:Hydroxyacylglutathione Hydrolase
keywords: Antioxidant system; Glyoxalase system; Methylglyoxal; Osmolyte; Salt tolerance