Li Wei-Qing, Li Jia-Yu, Bi Shao-Jie, Jin Jia-Yue, Fan Zhong-Ling, Shang Zi-Lin, Zhang Yi-Fei, Wang Yan-Jie
College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China.
College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing 163319, China.
Plants (Basel). 2025 Jan 20;14(2):296. doi: 10.3390/plants14020296.
Melatonin (MT) is a crucial hormone that controls and positively regulates plant growth under abiotic stress, but the biochemical and physiological processes of the combination of melatonin seed initiation and exogenous spray treatments and their effects on maize germination and seedling salt tolerance are not well understood. Consequently, in this research, we utilized the maize cultivars Zhengdan 958 (ZD958) and Demeiya 1 (DMY1), which are extensively marketed in northeastern China's high-latitude cold regions, to reveal the modulating effects of melatonin on maize salinity tolerance by determining the impacts of varying concentrations of melatonin on maize seedling growth characteristics, osmoregulation, antioxidant systems, and gene expression. The findings revealed that salt stress (100 mM NaCl) significantly inhibited maize seed germination and seedling development, which resulted in significant increases in the HO and O content and decreases in the antioxidant enzyme activity and photosynthetic pigment content in maize seedlings. However, exogenous melatonin considerably reduced the development inhibition caused by salt stress in maize seedlings. Moreover, exogenous melatonin alleviated NaCl-induced membrane damage and oxidative stress, and reduced Na content and excessively large quantities of reactive oxygen species (ROS). In addition, exogenous melatonin increased antioxidant enzyme activity and the expression of the antioxidant enzyme genes , , and . This study demonstrates the potential role of combined melatonin seed initiation and foliar spray treatments in mitigating the detrimental effects of salt stress on maize growth, giving a theoretical foundation to future research on the possible advantages of exogenous regulating chemicals in attaining sustainable production in salt-alkaline soils.
褪黑素（MT）是一种关键激素，在非生物胁迫下控制并正向调节植物生长，但褪黑素浸种和外源喷施处理相结合的生化和生理过程及其对玉米萌发和幼苗耐盐性的影响尚不清楚。因此，在本研究中，我们利用在中国东北高纬度寒冷地区广泛销售的玉米品种郑单958（ZD958）和德美亚1号（DMY1），通过测定不同浓度褪黑素对玉米幼苗生长特性、渗透调节、抗氧化系统和基因表达的影响，揭示褪黑素对玉米耐盐性的调节作用。研究结果表明，盐胁迫（100 mM NaCl）显著抑制玉米种子萌发和幼苗发育，导致玉米幼苗中HO和O含量显著增加，抗氧化酶活性和光合色素含量降低。然而，外源褪黑素显著减轻了盐胁迫对玉米幼苗发育的抑制。此外，外源褪黑素减轻了NaCl诱导的膜损伤和氧化应激，降低了Na含量和过量的活性氧（ROS）。此外，外源褪黑素提高了抗氧化酶活性以及抗氧化酶基因、和的表达。本研究证明了褪黑素浸种和叶面喷施处理相结合在减轻盐胁迫对玉米生长的不利影响方面的潜在作用，为未来关于外源调节化学物质在盐碱地实现可持续生产中可能优势的研究提供了理论基础。
