对流层臭氧(O3)是一种二次污染物,由于产生过量的活性氧(ROS)而在植物中引起氧化应激。苯丙素代谢被诱导作为植物对胁迫的常见反应,并诱导关键酶活性和次生代谢产物的积累,在O3暴露后提供电阻或公差。类苯丙素,类异戊二烯,和生物碱途径是植物防御代谢物产生的主要次级代谢途径。长期暴露于O3显著加速了碳流向次级代谢途径的方向,导致资源转移,有利于次级产品的合成。此外,由于不同的细胞区室具有不同水平的ROS敏感性和代谢物集,次级抗氧化代谢产物的细胞内分隔可能在O3诱导的ROS解毒中起作用。植物对资源分配的反应通常会导致在O3胁迫下生长与防御之间的权衡。这些代谢调整有助于植物应对压力以及实现新的稳态。在这次审查中,我们讨论了在包括作物在内的植物物种中响应O3的次级代谢途径,树木,和药用植物;以及这种应激源的存在如何影响它们作为ROS清除剂和结构防御的作用。此外,我们讨论了O3如何影响植物的关键生理性状,叶面化学,和挥发性排放物,影响植物-植物竞争(化感作用),和植物-昆虫的相互作用,在强调土壤动力学的同时,通过改变根系渗出来影响土壤群落的组成,凋落物分解,和其他相关过程。
Tropospheric ozone (O3) is a secondary pollutant that causes oxidative stress in plants due to the generation of excess reactive oxygen species (ROS). Phenylpropanoid metabolism is induced as a usual response to stress in plants, and induction of key enzyme activities and accumulation of secondary metabolites occur, upon O3 exposure to provide resistance or tolerance. The phenylpropanoid, isoprenoid, and alkaloid pathways are the major secondary metabolic pathways from which plant defense metabolites emerge. Chronic exposure to O3 significantly accelerates the direction of carbon flows toward secondary metabolic pathways, resulting in a resource shift in favor of the synthesis of secondary products. Furthermore, since different cellular compartments have different levels of ROS sensitivity and metabolite sets, intracellular compartmentation of secondary antioxidative metabolites may play a role in O3-induced ROS detoxification. Plants\' responses to resource partitioning often result in a trade-off between growth and defense under O3 stress. These metabolic adjustments help the plants to cope with the stress as well as for achieving new homeostasis. In this review, we discuss secondary metabolic pathways in response to O3 in plant species including crops, trees, and medicinal plants; and how the presence of this stressor affects their role as ROS scavengers and structural defense. Furthermore, we discussed how O3 affects key physiological traits in plants, foliar chemistry, and volatile emission, which affects plant-plant competition (allelopathy), and plant-insect interactions, along with an emphasis on soil dynamics, which affect the composition of soil communities via changing root exudation, litter decomposition, and other related processes.