Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Jinqi Road No. 1000, Fengxian District, Shanghai 201403, China.
Int J Mol Sci. 2024 Oct 8;25(19):10799. doi: 10.3390/ijms251910799.
Salt stress can adversely affect global agricultural productivity, necessitating innovative strategies to mitigate its adverse effects on plant growth and yield. This study investigated the effects of exogenous salicylic acid (SA), grafting (G), and their combined application (GSA) on various parameters in tomato plants subjected to salt stress. The analysis focused on growth characteristics, photosynthesis, osmotic stress substances, antioxidant enzyme activity, plant hormones, ion content, and transcriptome profiles. Salt stress severely inhibits the growth of tomato seedlings. However, SA, G, and GSA improved the plant height by 22.5%, 26.5%, and 40.2%; the stem diameter by 11.0%, 26.0%, and 23.7%; the shoot fresh weight by 76.3%, 113.2%, and 247.4%; the root fresh weight by 150.9%, 238.6%, and 286.0%; the shoot dry weight by 53.5%, 65.1%, and 162.8%; the root dry weight by 150.0%, 150.0%, and 166.7%, and photosynthesis by 4.0%, 16.3%, and 32.7%, with GSA presenting the most pronounced positive effect. Regarding the osmotic stress substances, the proline content increased significantly by more than 259.2% in all treatments, with the highest levels in GSA. Under salt stress, the tomato seedlings accumulated high Na levels; the SA, G, and GSA treatments enhanced the K and Ca absorption while reducing the Na and Al levels, thereby alleviating the ion toxicity. The transcriptome analysis indicated that SA, G, and GSA influenced tomato growth under salt stress by regulating specific signaling pathways, including the phytohormone and MAPK pathways, which were characterized by increased endogenous SA and decreased ABA content. The combined application of grafting and exogenous SA could be a promising strategy for enhancing plant tolerance to salt stress, offering potential solutions for sustainable agriculture in saline environments.
盐胁迫会对全球农业生产力产生不利影响，因此需要创新策略来减轻其对植物生长和产量的不利影响。本研究探讨了外源水杨酸（SA）、嫁接（G）及其联合应用（GSA）对盐胁迫下番茄植株各项参数的影响。分析重点为生长特性、光合作用、渗透胁迫物质、抗氧化酶活性、植物激素、离子含量和转录组谱。盐胁迫严重抑制番茄幼苗生长。然而，SA、G 和 GSA 分别使株高提高了 22.5%、26.5%和 40.2%；茎直径提高了 11.0%、26.0%和 23.7%；地上部鲜重提高了 76.3%、113.2%和 247.4%；根鲜重提高了 150.9%、238.6%和 286.0%；地上部干重提高了 53.5%、65.1%和 162.8%；根干重提高了 150.0%、150.0%和 166.7%；光合作用提高了 4.0%、16.3%和 32.7%，其中 GSA 效果最显著。关于渗透胁迫物质，脯氨酸含量在所有处理中均显著增加，超过 259.2%，其中 GSA 最高。在盐胁迫下，番茄幼苗积累了大量的 Na；SA、G 和 GSA 处理提高了 K 和 Ca 的吸收，同时降低了 Na 和 Al 的水平，从而缓解了离子毒性。转录组分析表明，SA、G 和 GSA 通过调节特定的信号通路，包括植物激素和 MAPK 通路，来影响番茄在盐胁迫下的生长，其特征是内源 SA 增加，ABA 含量降低。嫁接和外源 SA 的联合应用可能是增强植物耐盐性的一种有前途的策略，为盐环境下的可持续农业提供了潜在的解决方案。
