Nitric oxide contributes to methane-induced osmotic stress tolerance in mung bean

Abstract

BackgroundOsmotic stress is a major abiotic stress limiting crop production by affecting plant growth and development. Although previous reports discovered that methane (CH4) has a beneficial effect on osmotic stress, the corresponding downstream signal(s) is still elusive.ResultsPolyethylene glycol (PEG) treatment progressively stimulated the production of CH4 in germinating mung bean seeds. Exogenous CH4 and sodium nitroprusside (SNP) not only triggered nitric oxide (NO) production in PEG-stressed plants, but also alleviated the inhibition of seed germination. Meanwhile, amylase activity was activated, thus accelerating the formation of reducing sugar and total soluble sugar. Above responses could be impaired by NO scavenger(s), suggesting that CH4-induced stress tolerance was dependent on NO. Subsequent tests showed that CH4 could reestablish redox balance in a NO-dependent fashion. The addition of inhibitors of the nitrate reductase (NR) and NO synthase in mammalian (NOS), suggested that NR and NOS-like protein might be partially involved in CH4-alleviated seed germination inhibition. In vitro and scavenger tests showed that NO-mediated S-nitrosylation might be associated with above CH4 responses.ConclusionsTogether, these results indicated an important role of endogenous NO in CH4-enhanced plant tolerance against osmotic stress, and NO-regulated redox homeostasis and S-nitrosylation might be involved in above CH4 action.

A Novel Mechanism Underlying Multi-walled Carbon Nanotube-Triggered Tomato Lateral Root Formation: the Involvement of Nitric Oxide

“…2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO) was regarded as a scavenger of NO [51][52][53][54]. Tungstate (Tg; an inhibitor of NR [28,33,37,[55][56][57];) and N G -nitro-L-arginine methyl ester hydrochloride (NAME; an inhibitor of mammalian NOS-like enzyme [25,33,[36][37][38][39];) were also applied. In this study, the concentrations of above chemicals were determined in the pilot experiments, from which the significant responses were observed.…”

Research Progress on the Functions of Gasotransmitters in Plant Responses to Abiotic Stresses

“…Under osmotic stress, not only did the sugar content in maize root tissues increase by CH 4 (exogenously applied 0.65 mM), but the sugar and AsA metabolism in maize seedlings were also regulated by CH 4 [66]. Further research found a positive role of endogenous NO in CH 4 -enhanced plant tolerance against osmotic stress in mung beans [46]. This research also suggested that NO-regulated redox homeostasis and S-nitrosylation might take part in the above CH 4 action (Table 5).…”

“…Liao et al [45] found that marigold explants also stimulated NO production under drought stress. Exogenous CH 4 and sodium nitroprusside triggered the production of NO under osmotic stress [46]. Recently, studies have found that heavy metal aluminum stress induced NO generation in wheat [5,47] and peanut [48].…”

“…Re-establishing glutathione homeostasis, reducing lipid peroxidation [68] Alfalfa Salt reduced the activities of representative antioxidant enzymes Reducing reactive oxygen species over accumulation [65] Maize Osmotic stress decreased biomass and relative water contents Modulating sugar and AsA metabolism [66] Mung bean Osmotic stress broke the ion balance Re-establishing redox balance, alleviating seed germination inhibition [46] Zhu et al [65] found that 50% MRW reduced NaCl-induced lipid peroxidation and ROS overaccumulation in alfalfa, and ion homeostasis was re-established. In addition, MRW alleviated the NaCl-induced inhibition of seed germination and oxidative damage, partially by the upregulation of HO-1 [65].…”

“…Maintaining redox homeostasis is a vital mechanism for maintaining plant tolerance against various stressors. NO regulated the ion balance and sugar breakdown in the CH 4 signaling cascade by reducing ROS production in mung beans under osmotic stress [46]. Notably, HO-1/CO and Ca 2+ were reported as the downstream signals in CH 4 -induced cucumber adventitious root formation [121].…”