Department of Horticulture, Faculty of Horticulture, University of Mohagheh Ardebili, Ardebil, Iran.
Department of Plant Breeding and Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran.
BMC Plant Biol. 2022 Jul 30;22(1):380. doi: 10.1186/s12870-022-03728-0.
Melatonin is a multi-functional molecule widely employed in order to mitigate abiotic stress factors, in general and salt stress in particular. Even though previous reports revealed that melatonin could exhibit roles in promoting seed germination and protecting plants during various developmental stages of several plant species under salt stress, no reports are available with respect to the regulatory acts of melatonin on the physiological and biochemical status as well as the expression levels of defense- and secondary metabolism-related related transcripts in bitter melon subjected to the salt stress.
Herewith the present study, we performed a comprehensive analysis of the physiological and ion balance, antioxidant system, as well as transcript analysis of defense-related genes (WRKY1, SOS1, PM H-ATPase, SKOR, Mc5PTase7, and SOAR1) and secondary metabolism-related gene expression (MAP30, α-MMC, polypeptide-P, and PAL) in salt-stressed bitter melon (Momordica charantia L.) plants in response to melatonin treatment. In this regard, different levels of melatonin (0, 75 and 150 µM) were applied to mitigate salinity stress (0, 50 and 100 mM NaCl) in bitter melon. Accordingly, present findings revealed that 100 mM salinity stress decreased growth and photosynthesis parameters (SPAD, /, Y(II)), RWC, and some nutrient elements (K, Ca, and P), while it increased Y(NO), Y(NPQ), proline, Na, Cl, HO, MDA, antioxidant enzyme activity, and lead to the induction of the examined genes. However, prsiming with 150 µM melatonin increased SPAD, /, Y(II)), RWC, and K, Ca, and P concentration while decreased Y(NO), Y(NPQ), Na, Cl, HO, and MDA under salt stress. In addition, the antioxidant system and gene expression levels were increased by melatonin (150 µM).
Overall, it can be postulated that the application of melatonin (150 µM) has effective roles in alleviating the adverse impacts of salinity through critical modifications in plant metabolism.
褪黑素是一种多功能分子，广泛用于减轻非生物胁迫因素，特别是盐胁迫。尽管先前的报告表明，褪黑素可以在几种植物物种的各个发育阶段的盐胁迫下促进种子萌发和保护植物，但没有关于褪黑素对苦瓜生理生化状态以及防御和次生代谢相关相关转录物表达水平的调节作用的报告。
本研究对盐胁迫下苦瓜的生理和离子平衡、抗氧化系统以及防御相关基因（WRKY1、SOS1、PM H-ATPase、SKOR、Mc5PTase7 和 SOAR1）和次生代谢相关基因表达（MAP30、α-MMC、多肽-P 和 PAL）进行了综合分析。用褪黑素处理。在这方面，不同浓度的褪黑素（0、75 和 150 µM）用于减轻苦瓜的盐胁迫（0、50 和 100 mM NaCl）。结果表明，100 mM 盐胁迫降低了生长和光合作用参数（SPAD、/、Y(II)）、RWC 和一些营养元素（K、Ca 和 P），同时增加了 Y(NO)、Y(NPQ)、脯氨酸、Na、Cl、HO、MDA、抗氧化酶活性，并诱导了所检查的基因。然而，150 µM 褪黑素预处理增加了 SPAD、/、Y(II)）、RWC 和 K、Ca 和 P 浓度，同时降低了盐胁迫下的 Y(NO)、Y(NPQ)、Na、Cl、HO 和 MDA。此外，褪黑素（150 µM）增加了抗氧化系统和基因表达水平。
总体而言，应用褪黑素（150 µM）可以通过对植物代谢的关键修饰来缓解盐胁迫的不利影响。
