Yang Kankan, Zhou Geng, Chen Chen, Liu Xiaohong, Wei Lin, Zhu Feiying, Liang Zhihuai, Chen Huiming
Longping Branch, Graduated School of Hunan University, Changsha, China.
Hunan Academy of Agricultural Sciences, Changsha, China.
Front Plant Sci. 2024 Aug 7;15:1447860. doi: 10.3389/fpls.2024.1447860. eCollection 2024.
Fusarium wilt (FW) caused by f. sp. is a destructive soil-borne disease in cucumber (. L). However, there remains limited knowledge on the molecular mechanisms underlying FW resistance-mediated defense responses in cucumber.
In this study, metabolome and transcriptome profiling were carried out for two FW resistant (NR) and susceptible (NS), near isogenic lines (NILs) before and after inoculation. NILs have shown consistent and stable resistance in multiple resistance tests conducted in the greenhouse and in the laboratory. A widely targeted metabolomic analysis identified differentially accumulated metabolites (DAMs) with significantly greater NR accumulation in response to infection, including many phenolic acid and flavonoid compounds from the flavonoid biosynthesis pathway.
Transcriptome analysis identified differentially expressed genes (DEGs) between the NILs upon inoculation including genes for secondary metabolite biosynthesis and transcription factor genes regulating the flavonoid biosynthesis pathway. Joint analysis of the metabolomic and transcriptomic data identified DAMs and DEGs closely associated with the biosynthesis of phenolic acid and flavonoid DAMs. The association of these compounds with NR-conferred FW resistance was exemplified by assays. These assays found two phenolic acid compounds, bis (2-ethylhexyl) phthalate and diisooctyl phthalate, as well as the flavonoid compound gallocatechin 3-O-gallate to have significant inhibitory effects on growth. The antifungal effects of these three compounds represent a novel finding.
Therefore, phenolic acids and flavonoids play important roles in NR mediated FW resistance breeding in cucumber.
由尖孢镰刀菌黄瓜专化型（F. sp.）引起的枯萎病（FW）是黄瓜（C. L.）中一种具有破坏性的土传病害。然而，关于黄瓜中抗枯萎病介导的防御反应的分子机制，目前仍知之甚少。
在本研究中，对接种前后的两个抗枯萎病（NR）和感病（NS）近等基因系（NILs）进行了代谢组和转录组分析。NILs在温室和实验室进行的多次抗性试验中表现出一致且稳定的抗性。广泛靶向代谢组分析鉴定出差异积累代谢物（DAMs），在感染后NR积累显著增加，包括许多来自黄酮类生物合成途径的酚酸和黄酮类化合物。
转录组分析确定了接种后NILs之间的差异表达基因（DEGs），包括次生代谢物生物合成基因和调节黄酮类生物合成途径的转录因子基因。代谢组和转录组数据的联合分析确定了与酚酸和黄酮类DAMs生物合成密切相关的DAMs和DEGs。这些化合物与NR赋予的枯萎病抗性的关联通过体外试验得到例证。这些试验发现两种酚酸化合物，邻苯二甲酸二（2-乙基己基）酯和邻苯二甲酸二异辛酯，以及黄酮类化合物没食子儿茶素3-O-没食子酸酯对尖孢镰刀菌生长有显著抑制作用。这三种化合物的抗真菌作用是一项新发现。
因此，酚酸和黄酮类化合物在黄瓜NR介导的枯萎病抗性育种中发挥重要作用。
