Department of Agriculture, Abdul Wali Khan University Mardan, Mardan 23200, Pakistan.
Department of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 41566, Republic of Korea.
Int J Mol Sci. 2024 Aug 5;25(15):8535. doi: 10.3390/ijms25158535.
Melatonin regulates vital physiological processes in animals, such as the circadian cycle, sleep, locomotion, body temperature, food intake, and sexual and immune responses. In plants, melatonin modulates seed germination, longevity, circadian cycle, photoperiodicity, flowering, leaf senescence, postharvest fruit storage, and resistance against biotic and abiotic stresses. In plants, the effect of melatonin is mediated by various regulatory elements of the redox network, including RNS and ROS. Similarly, the radical gas NO mediates various physiological processes, like seed germination, flowering, leaf senescence, and stress responses. The biosynthesis of both melatonin and NO takes place in mitochondria and chloroplasts. Hence, both melatonin and nitric oxide are key signaling molecules governing their biological pathways independently. However, there are instances when these pathways cross each other and the two molecules interact with each other, resulting in the formation of N-nitrosomelatonin or NOMela, which is a nitrosated form of melatonin, discovered recently and with promising roles in plant development. The interaction between NO and melatonin is highly complex, and, although a handful of studies reporting these interactions have been published, the exact molecular mechanisms governing them and the prospects of NOMela as a NO donor have just started to be unraveled. Here, we review NO and melatonin production as well as RNS-melatonin interaction under normal and stressful conditions. Furthermore, for the first time, we provide highly sensitive, ozone-chemiluminescence-based comparative measurements of the nitric oxide content, as well as NO-release kinetics between NOMela and the commonly used NO donors CySNO and GSNO.
褪黑素调节动物的重要生理过程，如昼夜节律、睡眠、运动、体温、食物摄入以及性和免疫反应。在植物中，褪黑素调节种子萌发、寿命、昼夜节律、光周期、开花、叶片衰老、采后果实贮藏以及对生物和非生物胁迫的抗性。在植物中，褪黑素的作用是通过氧化还原网络的各种调节元件介导的，包括 RNS 和 ROS。同样，自由基气体 NO 介导各种生理过程，如种子萌发、开花、叶片衰老和应激反应。褪黑素和 NO 的生物合成都发生在线粒体和叶绿体中。因此，褪黑素和一氧化氮都是独立调节其生物途径的关键信号分子。然而，有些情况下这些途径会相互交叉，两种分子会相互作用，形成 N-亚硝酰褪黑素或 NOMela，这是褪黑素的一种亚硝酰化形式，最近才被发现，并在植物发育中具有有前景的作用。NO 和褪黑素之间的相互作用非常复杂，尽管已经发表了一些报道这些相互作用的研究，但它们的确切分子机制以及 NOMela 作为 NO 供体的前景才刚刚开始被揭示。在这里，我们综述了在正常和胁迫条件下 NO 和褪黑素的产生以及 RNS-褪黑素的相互作用。此外，我们首次提供了基于臭氧化学发光的灵敏比较测量，用于测量 NOMela 和常用的 NO 供体 CySNO 和 GSNO 之间的一氧化氮含量以及 NO 释放动力学。
