College of Forestry and Grassland, Nanjing Forestry University, Nanjing 210037, China.
College of Forestry and Grassland, Nanjing Forestry University, Nanjing 210037, China; Co-Innovation Centre for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China.
Sci Total Environ. 2024 Dec 1;954:176333. doi: 10.1016/j.scitotenv.2024.176333. Epub 2024 Sep 19.
Salinization is very detrimental to photosynthetic processes and plant growth, while nanoparticles (NPs) are considered to be the emerging materials to improve plant adaptability to salt stress. Cyclocarya paliurus is being planted on saline-alkali soils to meet the growing demand for its leaves and medicinal products. However, this species exhibits low salt tolerance and little information is available on whether NPs application would mitigate the salt-induced effects. This study explored the influence of three oxide NPs and their application doses on improving salt tolerance in C. paliurus under simulated natural conditions. The results showed that these oxide NPs could modify the salt tolerance in C. paliurus seedlings, but the alleviating effects varied in the NPs types and their application doses. Under the salt stress, foliar applications of SiO-NPs with 500 mg L and MnO-NPs with 50 mg L significantly increased net photosynthetic rate and seedling height by 52.0-59.5 %, and reduced the salt injury index by 67.6-70.7 %. Transcriptomic analysis revealed that the genes related to photosynthesis pathway were well responsive to both salt stress and NPs application, while the applications of high-dose SiO- and MnO-NPs up-regulated the expression of 50 photosynthesis-related genes. Weighted gene co-expression network analysis (WGCNA) indicated there existed a close relationship between physiological parameters and gene expression patterns, and the nine key genes in mitigating salt stress in C. paliurus were identified after the NPs application. Our findings suggested that the effects of NPs on mitigating salt-induced damages depending on the NP type and applied dose. The applications of SiO-NPs and MnO-NPs with an appropriate dose hold great promise for mitigating the salt-induced photosynthetic dysfunction via regulation of related key genes, and ultimately promoting plant growth and ameliorating the salt-tolerance.
盐渍化对光合作用和植物生长非常不利，而纳米颗粒（NPs）被认为是提高植物适应盐胁迫能力的新兴材料。为了满足对其叶子和药用产品的日益增长的需求，人们正在盐碱地种植青钱柳。然而，该物种的耐盐性较低，关于纳米颗粒的应用是否会减轻盐诱导的影响的信息很少。本研究探讨了三种氧化物 NPs 及其应用剂量对改善模拟自然条件下青钱柳耐盐性的影响。结果表明，这些氧化物 NPs 可以改变青钱柳幼苗的耐盐性，但 NPs 类型和应用剂量的缓解效果不同。在盐胁迫下，叶面喷施 500mg/L 的 SiO-NPs 和 50mg/L 的 MnO-NPs 可使净光合速率和苗高分别显著提高 52.0-59.5%，盐害指数降低 67.6-70.7%。转录组分析表明，与光合作用途径相关的基因对盐胁迫和 NPs 应用都有很好的响应，而高剂量的 SiO-和 MnO-NPs 的应用上调了 50 个与光合作用相关的基因的表达。加权基因共表达网络分析（WGCNA）表明，生理参数与基因表达模式之间存在密切关系，经 NPs 处理后，鉴定出 9 个缓解青钱柳盐胁迫的关键基因。我们的研究结果表明，NPs 对缓解盐诱导损伤的影响取决于 NP 类型和应用剂量。适当剂量的 SiO-NPs 和 MnO-NPs 的应用有望通过调节相关关键基因来缓解盐诱导的光合作用功能障碍，从而促进植物生长并改善耐盐性。
