School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, China.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing, China.
J Pineal Res. 2024 Aug;76(5):e12995. doi: 10.1111/jpi.12995.
Melatonin (MT) has been implicated in the plant response to phosphorus (P) stress; however, the precise molecular mechanisms involved remain unclear. This study investigated whether MT controls internal P distribution and root cell wall P remobilization in rice. Rice was treated with varying MT and P levels and analyzed using biochemical and molecular techniques to study phosphorus utilization. The results demonstrated that low P levels lead to a rapid increase in endogenous MT levels in rice roots. Furthermore, the exogenous application of MT significantly improved rice tolerance to P deficiency, as evidenced by the increased biomass and reduced proportion of roots to shoots under P-deficient conditions. MT application also mitigated the decrease in P content regardless in both the roots and shoots. Mechanistically, MT accelerated the reutilization of P, particularly in the root pectin fraction, leading to increased soluble P liberation. In addition, MT enhanced the expression of OsPT8, a gene involved in root-to-shoot P translocation. Furthermore, we observed that MT induced the production of nitric oxide (NO) in P-deficient rice roots and that the mitigating effect of MT on P deficiency was compromised in the presence of the NO inhibitor, c-PTIO, implying that NO is involved in the MT-facilitated mitigation of P deficiency in rice. Overall, our findings highlight the potential of MT as a promising strategy for enhancing rice tolerance to P deficiency and improving P use efficiency in agricultural practices.
褪黑素（MT）被认为参与了植物对磷（P）胁迫的反应；然而，其中涉及的确切分子机制仍不清楚。本研究探讨了 MT 是否控制了水稻内部 P 分布和根细胞壁 P 再利用。通过使用不同的 MT 和 P 水平处理水稻，并使用生化和分子技术进行分析，以研究磷的利用。结果表明，低 P 水平会导致水稻根中内源性 MT 水平的快速增加。此外，外源性 MT 的应用显著提高了水稻对 P 缺乏的耐受性，这表现在 P 缺乏条件下生物量增加和根与茎的比例降低。MT 的应用还减轻了根和地上部分 P 含量的降低。从机制上讲，MT 加速了 P 的再利用，特别是在根果胶部分，导致可溶 P 的释放增加。此外，MT 增强了 OsPT8 的表达，OsPT8 是一个参与根到茎 P 转运的基因。此外，我们观察到 MT 在 P 缺乏的水稻根中诱导了一氧化氮（NO）的产生，而在存在 NO 抑制剂 c-PTIO 的情况下，MT 对 P 缺乏的缓解作用受到损害，这表明 NO 参与了 MT 促进水稻缓解 P 缺乏的过程。总的来说，我们的研究结果强调了 MT 作为一种有前途的策略的潜力，它可以提高水稻对 P 缺乏的耐受性，并提高农业实践中 P 的利用效率。
