Khan Jafar, Elsharkawy Eman, Fu Yujie, Jan Rahmatullah, Kim Kyung-Min
Key Laboratory of Forest Plant Ecology, Northeast Forestry University, Harbin, China.
Center for Health Research, Northern Border University, 73213, Arar, Saudi Arabia.
Sci Rep. 2025 Oct 6;15(1):34788. doi: 10.1038/s41598-025-18514-9.
This study investigates how melatonin (Mel) supplementation mitigates Lead (Pb) toxicity in rice by evaluating plant growth, physiology, and molecular responses. Pb stress markedly reduced root and shoot lengths by 63% and 33%, respectively, compared to control plants; however, Mel supplementation effectively mitigated this inhibition, enhancing root and shoot lengths by 100% and 47%, respectively, relative to Pb-stressed plants after 10 days. Furthermore, prolonged Mel application under Pb stress sustained growth improvement, increasing root and shoot lengths by 36% and 35%, respectively, compared to Pb-stressed plants. We observed a 19.5% increase in plant height with Mel treatment, along with improvements in yield-related traits such as panicle length and seed weight. Beyond morphological traits, Mel reduced Pb-induced oxidative stress by decreasing [Formula: see text], HO, and MDA levels by 36%, 26%, and 46%, respectively. Moreover, Mel modulated antioxidant enzyme activities in Pb + Mel-treated plants by decreasing ascorbate peroxidase (APX) activity and enhancing catalase (CAT) activity. Additionally, Mel regulated ion homeostasis, with K and Ca contents increasing by 74% and 89%, respectively. At molecular level, Mel reduced OsMTP1 levels by 45% and increased OsPCS1 by up to 193%. Overall, Mel significantly alleviates Pb toxicity by enhancing growth, physiological traits, and stress resilience in rice plants, highlighting its potential as a sustainable strategy for improving crop performance under heavy metal stress and offering promising directions for future agricultural research.
本研究通过评估植物生长、生理和分子反应，探究补充褪黑素（Mel）如何减轻水稻中的铅（Pb）毒性。与对照植株相比，铅胁迫显著降低了根长和地上部长度，分别降低了63%和33%；然而，补充Mel有效减轻了这种抑制作用，与铅胁迫植株相比，10天后根长和地上部长度分别增加了100%和47%。此外，在铅胁迫下长期施用Mel持续改善生长，与铅胁迫植株相比，根长和地上部长度分别增加了36%和35%。我们观察到，Mel处理使株高增加了19.5%，同时穗长和种子重量等产量相关性状也有所改善。除形态性状外，Mel通过分别降低[公式：见原文]、HO和MDA水平36%、26%和46%，减轻了铅诱导的氧化应激。此外，Mel通过降低抗坏血酸过氧化物酶（APX）活性和增强过氧化氢酶（CAT）活性，调节了铅+Mel处理植株中的抗氧化酶活性。此外，Mel调节离子稳态，钾和钙含量分别增加了74%和89%。在分子水平上，Mel使OsMTP1水平降低了45%，并使OsPCS1增加了高达193%。总体而言，Mel通过增强水稻植株的生长、生理性状和抗逆性，显著减轻了铅毒性，突出了其作为重金属胁迫下提高作物性能的可持续策略的潜力，并为未来农业研究提供了有希望的方向。
