Nitric oxide metabolism and its interaction with reactive oxygen species during the adaptation of plants to abiotic stress

一氧化氮（NO）是一种有效的生物活性分子，其在植物的代谢和信号传导功能中起作用，提供灵活的代谢、调节参与植物适应胁迫的关键基因表达和酶活性。植物已经进化到使用能量保存和转化的机制，包括在应激条件下使用焦磷酸盐作为ATP的替代物，以及在含有NO的氧化还原反应中使用电子传递组分。长期的研究目标是通过维持氧化还原和能量水平以及调节植物细胞的氧化还原能力，程序性细胞死亡、自噬、种子萌发和形态发生事件。具体目标包括：1）探索植珠蛋白-NO循环，包括a）封闭和开放模式之间的差异，B）使用氧和氮的稳定同位素的循环周转率及其对氧可用性的依赖性，c）通过ATP和焦磷酸盐的维持和形成的NO产生、清除和能量状态之间的联系，以及d）NO代谢和植物次生代谢/酚类化合物合成的调节之间的联系;（2）研究线粒体电子传递在NO产生和清除中的作用及其与氧浓度的关系，包括交替氧化酶和细胞色素c氧化酶在NO周转中的作用，（3）研究低氧胁迫诱导植物球蛋白产生和维持植物NO周转的基因表达和表观遗传调控机制;（4）探讨了种子萌发过程中活性氧和氮之间的相互作用，重点是a）NO和超氧化物形成过氧亚硝酸盐，B）对氧浓度变化的依赖性，以及c）蛋白质S-亚硝基化的参与。转基因大麦（大麦）和拟南芥（拟南芥）植物将被用来研究植物球蛋白在维持低水平的NO胁迫下的作用。将使用蛋白质组学和代谢组学方法研究涉及植物珠蛋白，NO和硝酸盐/亚硝酸盐的循环操作中的闭合和开放模式之间的切换。NO，S-亚硝基谷胱甘肽和活性氧之间的串扰将研究植物珠蛋白的表达和线粒体电子传递链的组成部分。NO、活性氮和活性氧的代谢是提高农业植物对非生物/生物胁迫抗性的一个新的潜在目标。制定减轻植物中氧气供应有限的后果和调节种子萌发的战略，将提高农业植物对压力的抵抗力，并保持农作物产量，特别是在面临日益不可预测的天气事件和气候变化的情况下。

Nitric oxide (NO) is a potent bioactive molecule that plays a role in the metabolic and signaling functions of plants, providing flexible metabolism, regulation of key gene expression and enzyme activity involved in plant adaptations to stress. Plants have evolved to use mechanisms of energy conservation and transformation, including the use of pyrophosphate as a substitute for ATP in stress conditions and the use of electron transport components in redox reactions that contain NO. My long-term research goal is to establish the physiological role of NO turnover and phytoglobin function in the bioenergetics of stressed plant cells via the maintenance of redox and energy level and regulation of programmed cell death, autophagy, seed germination, and morphogenetic events. Specific objectives include: 1) exploring the phytoglobin-NO cycle, including a) differences between closed and opened modes, b) rates of cycle turnover and their dependence on oxygen availability using stable isotopes of oxygen and nitrogen, c) links between NO production, scavenging and energy status via the maintenance and formation of ATP and pyrophosphate, and d) links between NO metabolism and regulation of plant secondary metabolism/phenolics synthesis; 2) investigating the role of the mitochondrial electron transport in NO production and scavenging and associations with oxygen concentration, including the participation of alternative oxidase and cytochrome c oxidase in NO turnover; 3) studying the mechanisms of gene expression and epigenetic regulation leading to the induction of phytoglobins and the maintenance of NO turnover in plants under hypoxic stress; 4) exploring crosstalk between reactive oxygen and nitrogen species during seed germination, focusing on a) the formation of peroxynitrite from NO and superoxide, b) the dependence on changing oxygen concentrations, and c) the involvement of S-nitrosylation of proteins. Transgenic barley (Hordeum vulgare) and Arabidopsis (Arabidopsis thaliana) plants will be used to study the role of phytoglobins in maintaining low NO levels under stress. The switch between closed and open modes in operation of the cycle involving phytoglobin, NO and nitrate/nitrite will be studied using proteomic and metabolomic approaches. Crosstalk between NO, S-nitrosoglutathione and reactive oxygen species will be studied in relation to expression of phytoglobin and the components of the mitochondrial electron transport chain. The metabolism of NO and reactive nitrogen and oxygen species is a new potential target for improved resistance of agricultural plants to abiotic/biotic stress. The development of strategies for mitigating the consequences of limited oxygen availability in plants and in the regulation of seed germination will improve the resistance of agricultural plants to stress and maintain agricultural crop yields, particularly in the face of increasingly unpredictable weather events and climate change.