Zhao Changyan, Liu Yantao, Jia Xiuping, Liu Shengli, Wang Peng, Zhu Zhifeng, Wan Sumei, Duan Wei
College of Agriculture, Tarim University, Alar, Xinjiang, China.
Crop Research Institute, Xinjiang Academy of Agricultural and Reclamation Science, Shihezi, Xinjiang, China.
Front Plant Sci. 2025 Apr 16;16:1558877. doi: 10.3389/fpls.2025.1558877. eCollection 2025.
Salt stress always causes irreversible damages to the growth of seedlings in arid and semi-arid areas due to the weakest salt resistance at the seedling stage. Melatonin is a multifunctional molecule that can enhance the salt stress resistance of several crops. However, the effect of melatonin on the salt stress resistance of is still unclear.
In this study, four H. annuus germplasms with different salt resistance (YE988, S2102, Longkuiza 4, and 909S) were selected from a total of 164 germplasms from China, France, Chili, the Unit States, etc. Then, four treatments for the four germplasms were designed, including (1) CK, no salt stress + no melatonin application; (2) MT, no salt stress + melatonin application; (3) K, salt stress + no melatonin application; (4) MK, salt stress + melatonin application. After that, the key genes and metabolic pathways involved in the responses of salt resistance of H. annuus germplasms to melatonin were determined by transcriptome and metabolome analysis.
The results showed that there were 530 differentially expressed genes (37 upregulated genes and 493 down-regulated genes) in leaves in MK vs. K, and these genes were mainly involved in fatty acids, diterpenoid biosynthesis, linolenic acid metabolism, cysteine and methionine metabolism. There were 60 differentially abundant metabolites (17 up-regulated metabolites and 43 downregulated metabolites) in leaves in MK vs. K, mainly concentrating in tryptophan metabolism, biosynthesis of amino acids, biosynthesis of secondary metabolites and metabolic pathways. The integrated transcriptome and metabolome analysis results showed that melatonin regulated the b-alanine metabolism, monoterpene biosynthesis, and glutathione metabolism pathways, and increased the contents of spermine and spermidine in cells by promoting the expression of genes such as and in the b-alanine metabolic pathway. In summary, melatonin could enhance salt stress signaling by up-regulating the expression of genes related to the synthesis of spermine and spermidine in leaves, to regulate photosynthesis and reactive oxygen species metabolism, ultimately enhancing the salt resistance of . This study will advance understanding of mechanism by which melatonin enhances salt resistance of H. annuus, and provide a scientific basis for the breeding of saltresistant cultivars.
由于苗期耐盐性最弱，盐胁迫总是对干旱和半干旱地区的幼苗生长造成不可逆转的损害。褪黑素是一种多功能分子，可增强多种作物的耐盐胁迫能力。然而，褪黑素对向日葵耐盐胁迫的影响仍不清楚。
本研究从来自中国、法国、智利、美国等的164份种质中筛选出4份耐盐性不同的向日葵种质（YE988、S2102、陇葵杂4号和909S）。然后，对这4种种质设计了4种处理，包括：（1）CK，无盐胁迫+不施用褪黑素；（2）MT，无盐胁迫+施用褪黑素；（3）K，盐胁迫+不施用褪黑素；（4）MK，盐胁迫+施用褪黑素。之后，通过转录组和代谢组分析确定了向日葵种质耐盐性对褪黑素响应中涉及的关键基因和代谢途径。
结果表明，MK组与K组相比，向日葵叶片中有530个差异表达基因（37个上调基因和493个下调基因），这些基因主要参与脂肪酸、二萜生物合成、亚麻酸代谢、半胱氨酸和蛋氨酸代谢。MK组与K组相比，向日葵叶片中有60个差异丰富的代谢物（17个上调代谢物和43个下调代谢物），主要集中在色氨酸代谢、氨基酸生物合成、次生代谢物生物合成和代谢途径。转录组和代谢组综合分析结果表明，褪黑素调节β-丙氨酸代谢、单萜生物合成和谷胱甘肽代谢途径，并通过促进β-丙氨酸代谢途径中如[具体基因]等基因的表达，增加细胞中精胺和亚精胺的含量。综上所述，褪黑素可通过上调向日葵叶片中与精胺和亚精胺合成相关基因的表达来增强盐胁迫信号，调节光合作用和活性氧代谢，最终增强向日葵的耐盐性。本研究将推进对褪黑素增强向日葵耐盐性机制的理解，并为耐盐向日葵品种的选育提供科学依据。
