Liu Yang, Jiang Zhuoke, Ye Yuting, Wang Donghui, Jin Songheng
Jiyang College, Zhejiang A&F University, Zhuji, China.
Zhejiang Provincial Key Laboratory of Resources Protection and Innovation of Traditional Chinese Medicine, Zhejiang A&F University, Hangzhou, China.
Front Plant Sci. 2022 May 12;13:906071. doi: 10.3389/fpls.2022.906071. eCollection 2022.
Nitric oxide (NO), a bioactive molecule, is often involved in the regulation of physiological and biochemical processes in stressed plants. However, the effects of NO donors on dioecious plants remain unclear. Using a pot experiment, female and male were used to study the role of sex and NO in salt stress tolerance. In the present study, female and male seedlings pretreated with an NO donor (sodium nitroprusside, SNP) were exposed to salt stress, and then leaf relative water content (RWC), photosynthetic pigments, chlorophyll fluorescence parameters, NO and glutathione levels, oxidative damage, and antioxidant enzyme activities were investigated. Female plants had better tolerance to salinity, as they were characterized by significantly higher RWC, pigment content, and photochemical activities of photosystem II (PSII) and fewer negative effects associated with higher nitrate reductase (NR) activity and NO content. Pretreatment with an NO donor further increased the endogenous NO content and NR activity of both female and male plants compared with salt treatment. Moreover, pretreatment with an NO donor alleviated salt-induced oxidative damage of , especially in male plants, as indicated by reduced lipid peroxidation, through an enhanced antioxidant system, including proline and glutathione accumulation, and increased antioxidant enzyme activities. However, the ameliorating effect of the NO donor was not effective in the presence of the NO scavenger (Nω-nitro-L-arginine methyl ester, L-name). In conclusion, enhanced salt tolerance in plants is related to nitric oxide levels and the supply of NO donors is an interesting strategy for alleviating the negative effect of salt on . Our data provide new evidence to contribute to the current understanding of NO-induced salt stress tolerance.
一氧化氮（NO）作为一种生物活性分子，常参与受胁迫植物生理生化过程的调控。然而，NO供体对雌雄异株植物的影响尚不清楚。本研究通过盆栽试验，以雌雄异株植物为材料，研究性别和NO在耐盐性中的作用。本研究中，用NO供体（硝普钠，SNP）预处理的雌雄异株植物幼苗在盐胁迫下，研究叶片相对含水量（RWC）、光合色素、叶绿素荧光参数、NO和谷胱甘肽水平、氧化损伤及抗氧化酶活性。雌性植物对盐胁迫有更好的耐受性，其特征为叶片相对含水量、色素含量显著更高，光系统II（PSII）的光化学活性更高，且与较高的硝酸还原酶（NR）活性和NO含量相关的负面影响较少。与盐处理相比，用NO供体预处理进一步增加了雌雄异株植物的内源NO含量和NR活性。此外，NO供体预处理减轻了盐胁迫诱导的植物氧化损伤，尤其是雄性植物，表现为脂质过氧化降低，这是通过增强抗氧化系统实现的，包括脯氨酸和谷胱甘肽积累以及抗氧化酶活性增加。然而，在存在NO清除剂（Nω-硝基-L-精氨酸甲酯，L-NAME）的情况下，NO供体的改善作用无效。总之，植物耐盐性增强与一氧化氮水平有关，提供NO供体是减轻盐对植物负面影响的一个有趣策略。我们的数据为当前对NO诱导的盐胁迫耐受性的理解提供了新的证据。
