中植棉2号调控色氨酸代谢发挥抗黄萎病作用OA

[Objective]This study aims to investigate the molecular mechanism underlying the resistance of Zhongzhimian 2 to Verticillium wilt.[Methods]Roots and leaves of Zhongzhimian 2(disease-resistant variety)and Jimian 11(disease-susceptible variety)were collected at 48 h after inoculation with Verticillium dahliae strain Vd991,followed by freeze-drying.Non-targeted metabolomics technology was employed to analyze the differential metabolites in the roots and leaves of Zhongzhimian 2 and Jimian 11,and the differential metabolic pathways were further analyzed.[Results]Compared with Jimian 11,the abundance of tryptophan and chorismate in the roots of Zhongzhimian 2 decreased,while the abundance of 13 metabolites including salicylic acid,anthranilate,and indole increased.The abundance of 13 metabolites,including tryptophan,chorismate,and anthranilate,was upregulated in the leaves of Zhongzhimian 2,while the abundance of 10 metabolites,including salicylic acid and indole,was downregulated.These differential metabolites were primarily enriched in the biosynthesis of unsaturated fatty acids,tryptophan metabolism,the biosynthesis of phenylalanine,tyrosine,and tryptophan,and linoleic acid metabolism.Comprehensive analysis revealed that the tryptophan metabolism showed the most significant differences.Zhongzhimian 2 inhibited tryptophan synthesis by downregulating the expression levels of the tryptophan synthase genes GhTSA1 and GhTSB1,leading to the accumulation of indole and subsequently promoting salicylic acid synthesis in the roots,thereby activating root immune responses to pathogen infection and conferring resistance to Verticillium wilt.[Conclusion]This study analyzed and compared the differences in secondary metabolites between the roots and leaves of Zhongzhimian 2 and Jimian 11,elucidated the mechanism by which Zhongzhimian 2 exerts its resistance to Verticillium wilt by regulating tryptophan metabolism and provided a theoretical basis for disease-resistant breeding.