Abstract:

Maize， an important food and feed crop， faces severe growth inhibition， yield reduction， and quality deterioration under salt stress. Jasmonic acid and its derivatives （JAs）， crucial phytohormones involved in plant defense mechanisms， have been shown through studies in model plants to play essential roles in salt stress responses. To investigate JAs-mediated salt stress adaptation mechanisms in maize， we subjected seedlings to combined treatments of 200 mmol·L^-1 NaCl and 100 μmol·L^-1 methyl jasmonate （MeJA） for six hours. Transcriptomic analysis of shoots and roots identified differentially expressed genes （DEGs） associated with both JA signaling and salt stress response. Eight overlapping DEGs from shoot-root comparisons were subsequently validated using RT-qPCR. The study revealed 362 and 803 stress-responsive DEGs in overground and subterranean tissues， respectively. Functional enrichment analyses （GO and KEGG） demonstrated these genes participate in carbohydrate metabolism/transport， defensive secondary metabolite biosynthesis， antioxidant enzyme production， along with abscisic acid and ethylene signaling pathways. These findings indicated that JA signaling activates specific genetic and metabolic networks underlying salt stress adaptation of maize， providing critical insights for further elucidating the molecular mechanisms of JA-mediated salt tolerance regulation.

Key words: salt stress, jasmonic acid （JA）, transcriptome, maize, gene expression analysis

摘要：

玉米是重要的粮饲兼用作物，盐胁迫严重影响其生长发育，导致产量和品质下降。茉莉酸及其衍生物（jasmonates, JAs）是与植物防御相关的天然植物激素，基于模式植物的研究表明，JAs在响应盐胁迫中发挥重要作用。为探究玉米中JAs介导的盐胁迫响应的具体机制，分别对100 μmol·L^-1 MeJA和200 mmol·L^-1 NaCl处理6 h玉米幼苗的地上和地下部组织进行转录组测序，交叉分析得到JA诱导且响应高盐胁迫的差异表达基因（differential expression genes, DEGs），并挑选8个DEGs通过RT-qPCR进行验证。结果发现地上和地下部组织中分别共有362和803个基因差异表达，GO和KEGG富集分析显示这些基因涉及糖的合成转运、防御性次生代谢物合成、抗氧化酶合成以及脱落酸和乙烯信号通路。研究结果提示JA信号通路诱导玉米高盐胁迫响应的潜在关键基因和代谢途径，为进一步挖掘JA信号通路调控抗盐性的具体分子机制提供了线索。

关键词: 盐胁迫, 茉莉酸, 转录组, 玉米, 基因表达分析