一氧化氮在植物发育及植物–微生物互作中的作用机制研究进展

一氧化氮 (NO) 作为高活性信号分子，是调控植物生长发育的关键因子。NO可提高植物对非生物胁迫及生物胁迫的抗性，增强植物的免疫能力。最新的研究表明，NO在植物根系与微生物的互作过程中发挥着重要作用，NO能够促进植物根系与根瘤菌及丛枝菌根真菌形成共生体，从而提高植物对土壤氮磷养分的获取。NO作为信号物质调控植物对生物胁迫和非生物胁迫抗性的主要机制有:1) NO与活性氧系统互作，调节活性氧的水平，缓解氧化应激反应对植物的伤害；2) NO通过蛋白质的翻译后修饰，对植物免疫及抗逆过程进行调节；3) NO与多种植物激素互作，参与激素对植物生长发育的调节过程。而且NO可促进共生体的形成及发育相关基因表达，抑制免疫基因表达，通过NO与植物球蛋白 (phytoglobin) 的循环维持共生体的氧化还原水平及能量状态，从而促进植物–微生物共生关系。以往关于NO的研究主要集中在前3个方面，有关NO在植物–微生物互作中的作用机制的研究较少，NO参与植物–微生物互作机制的研究亟待加强。揭示NO增强植物抗逆性及其调节根系发育的机制，深入探究NO调控植物–微生物互作的机理，对于提高集约化作物生产体系中养分利用效率和作物生产力具有重要的理论与实践意义。

Advances in studies on the role of nitric oxide in plant development and plant-microbial interactions

Nitric oxide (NO), as a highly active signaling molecule, is a key factor to regulate plant growth and development. NO can improve the resistance of plants to biotic and abiotic stresses in order to enhance the immunity of plants. Recent studies have shown that NO also plays an important role in the interaction between plant roots and microbes, for example, NO can promote the symbiosis of plant roots with rhizobia or arbuscular mycorrhizal fungi, thus improving plant’s access to soil nitrogen and phosphorus. As a signal substance, NO regulates plant resistance to biotic and abiotic stresses through the following mechanisms: (1) NO interacts with the reactive oxygen species (ROS) system to regulate ROS level and alleviate oxidative stress; (2) NO regulates plant immunity and stress resistance processes through post-translational modification of proteins; (3) NO interacts with a variety of plant hormones to participate in the regulation of plant hormones on plant growth and development. Moreover, NO can promote the expression level of genes related to the formation and development of symbiosis, inhibit the expression of immune genes; and maintain the redox level and energy status of symbiosis by NO-phytoglobin cycle, thus promoting the symbiotic relationship. There is a need to deeply explore to uncover the mechanisms of NO’s involvement in plant-microbial interaction as well as its enhancement of plant stress resistance, and regulation of root development for improved nutrient utilization efficiency and crop productivity in intensive crop production systems.