State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Engineering Research Center for Grassland Science, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
College of Grassland Science, Nanjing Agricultural University, Nanjing 210095, China.
Int J Mol Sci. 2019 Mar 19;20(6):1368. doi: 10.3390/ijms20061368.
The role of nitric oxide (NO) signaling in the cold acclimation of forage legumes was investigated in this study. subsp. (L.) Arcang. (hereafter ) is a forage legume with a higher cold tolerance than , a model legume. Cold acclimation treatment resulted in increased cold tolerance in both and , which was suppressed by pretreatment with tungstate, an inhibitor of nitrate reductase (NR), and 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO), a scavenger of NO. Likely, (), but not transcript, NR activity, and NO production were increased after cold treatment. Treatments with exogenous NO donors resulted in increased cold tolerance in both species. Superoxide dismutase (SOD), catalase (CAT), and ascorbate-peroxidase (APX) activities and , , (), and () transcript levels were induced in both species after cold treatment, which was suppressed by tungstate and 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO). Treatment with exogenous NO resulted in enhanced activities of SOD, CAT, and APX. Moreover, higher levels of transcript, NR activity, NO production, and antioxidant enzyme activities and transcripts were observed in as compared with after cold treatment. The results suggest that NR-derived NO production and upregulated antioxidant defense are involved in cold acclimation in both species, while the higher levels of NO production and its derived antioxidant enzymes are associated with the higher cold tolerance in as compared with .
本研究探讨了一氧化氮（NO）信号在饲料豆科植物冷驯化中的作用。 亚种。 （以下简称 ）是一种饲料豆科植物，比模式豆科植物 具有更高的耐寒性。冷驯化处理导致 和 均增加了耐寒性，而硝酸盐还原酶（NR）抑制剂钨酸盐和 NO 清除剂 2-苯基-4,4,5,5-四甲基咪唑啉-1-氧-3-氧化物（PTIO）预处理则抑制了这种耐寒性。很可能是 （），而不是 转录本，NR 活性和 NO 产生在冷处理后增加。外源 NO 供体处理可提高两种物种的耐寒性。超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）活性以及 、 、 （）、 和 （）转录本水平在冷处理后均在两种物种中诱导，而钨酸盐和 2-苯基-4,4,5,5-四甲基咪唑啉-1-氧-3-氧化物（PTIO）抑制了这些变化。外源 NO 处理可增强 SOD、CAT 和 APX 的活性。此外，与 相比，冷处理后 中的 转录本、NR 活性、NO 产生以及抗氧化酶活性和转录本水平更高。结果表明，NR 衍生的 NO 产生和上调的抗氧化防御参与了两种物种的冷驯化，而与 相比，NO 产生及其衍生的抗氧化酶水平更高与 较高的耐寒性有关。
