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，在植物的代谢和信号功能中发挥作用，提供灵活的代谢，调节植物适应逆境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机制，包括在胁迫条件下使用焦磷酸盐作为ATP的替代品，以及在含有NO的氧化还原反应中使用电子传递组分。我的长期研究目标是通过维持氧化还原和能量水平以及调节程序性细胞死亡、自噬、种子萌发和形态发生事件，在逆境植物细胞的生物能量学中建立NO转换和植物红蛋白功能的生理作用。具体目标包括：1)探索植物红蛋白-NO循环，包括a)关闭和打开模式的差异；b)循环周转速率及其对氧可用性的依赖（利用氧和氮的稳定同位素）；c)通过ATP和焦磷酸盐的维持和形成，NO的产生、清除和能量状态之间的联系；d) NO代谢与植物次生代谢/酚类物质合成调节之间的联系；2)研究线粒体电子传递在NO产生和清除中的作用以及与氧浓度的关系，包括替代氧化酶和细胞色素c氧化酶在NO周转中的参与；3)研究低氧胁迫下植物红蛋白诱导和NO转化的基因表达和表观遗传调控机制；4)探索种子萌发过程中活性氧和活性氮之间的串扰，重点关注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，c)蛋白质s -亚硝基化的参与。转基因大麦（Hordeum vulgare）和拟南芥（Arabidopsis thaliana）植物将用于研究植物红蛋白在逆境下维持低NO水平的作用。将使用蛋白质组学和代谢组学方法研究涉及植物红蛋白、NO和硝酸盐/亚硝酸盐的循环操作中关闭和打开模式之间的切换。NO、s -亚硝基谷胱甘肽和活性氧之间的串扰与植物红蛋白表达和线粒体电子传递链组分的关系将被研究。NO和活性氮、活性氧的代谢是提高农业植物抗非生物/生物胁迫能力的一个新的潜在靶点。制定减轻植物氧气供应有限和调节种子发芽后果的战略，将提高农业植物对胁迫的抵抗力，并保持农作物产量，特别是在面对日益不可预测的天气事件和气候变化时。

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.