Department of Horticulture/Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
Department of Agricultural Chemistry, Sylhet Agricultural University, Sylhet, 3100, Bangladesh.
Sci Rep. 2018 Jul 5;8(1):10182. doi: 10.1038/s41598-018-28561-0.
Despite involvement of melatonin (MT) in plant growth and stress tolerance, its role in sulfur (S) acquisition and assimilation remains unclear. Here we report that low-S conditions cause serious growth inhibition by reducing chlorophyll content, photosynthesis and biomass accumulation. S deficiency evoked oxidative stress leading to the cell structural alterations and DNA damage. In contrast, MT supplementation to the S-deprived plants resulted in a significant diminution in reactive oxygen species (ROS) accumulation, thereby mitigating S deficiency-induced damages to cellular macromolecules and ultrastructures. Moreover, MT promoted S uptake and assimilation by regulating the expression of genes encoding enzymes involved in S transport and metabolism. MT also protected cells from ROS-induced damage by regulating 2-cysteine peroxiredoxin and biosynthesis of S-compounds. These results provide strong evidence that MT can enhance plant tolerance to low-S-induced stress by improving S uptake, metabolism and redox homeostasis, and thus advocating beneficial effects of MT on increasing the sulfur utilization efficiency.
尽管褪黑素 (MT) 参与植物生长和胁迫耐受，但它在硫 (S) 吸收和同化中的作用尚不清楚。在这里，我们报告低 S 条件通过降低叶绿素含量、光合作用和生物量积累严重抑制生长。S 缺乏会引发氧化应激，导致细胞结构改变和 DNA 损伤。相比之下，向缺 S 植物中补充 MT 会显著减少活性氧 (ROS) 的积累，从而减轻 S 缺乏引起的对细胞大分子和超微结构的损伤。此外，MT 通过调节参与 S 转运和代谢的酶的基因表达来促进 S 的吸收和同化。MT 还通过调节 2-半胱氨酸过氧化物酶和 S 化合物的生物合成来保护细胞免受 ROS 诱导的损伤。这些结果有力地证明，MT 通过提高 S 的吸收、代谢和氧化还原平衡来增强植物对低 S 诱导胁迫的耐受能力，从而倡导 MT 对提高硫利用效率的有益作用。
