藜麦茎部响应瓜笄霉侵染的代谢组分析

Metabolomics of the stems of quinoa in response to infection by Choanephora cucurbitarum

摘要:

【背景】藜麦笄霉软腐病(quinoa Choanephora rot)的病原为瓜笄霉(Choanephora cucurbitarum)，但藜麦响应其侵染后的代谢变化尚未明确。【目的】研究瓜笄霉侵染藜麦后的代谢物变化及关键代谢途径，以利于了解该病的生理生化机制。【方法】基于非靶向代谢组学研究技术，结合多元统计分析方法，分析瓜笄霉侵染藜麦茎部代谢物差异及代谢途径变化。【结果】相较于对照组，瓜笄霉侵染藜麦后，显著差异代谢物有512种(P<0.01)，其中283种为上调，229种为下调。KEGG富集分析发现藜麦茎部响应瓜笄霉侵染的主要差异代谢物共19种(P<0.05)，这些主要代谢物显著富集到花生四烯酸代谢、亚油酸代谢、α-亚麻酸代谢、黄酮和黄酮醇的生物合成共4条代谢通路。【结论】瓜笄霉侵染可导致藜麦中花生四烯酸代谢、亚油酸代谢、α-亚麻酸代谢、黄酮和黄酮醇的生物合成等代谢途径发生变化，其中α-亚麻酸代谢及其相关代谢物茉莉酸的积累、黄酮和黄酮醇的生物合成受阻，可能是藜麦响应瓜笄霉侵染的主要方式。

Abstract:

[Background] The pathogen responsible for quinoa Choanephora rot is Choanephora cucurbitarum. However, the metabolic changes of quinoa in response to the infection remain unclear. [Objective] We studied the changes of metabolites and key metabolic pathways in quinoa after infection with C. cucurbitarum, aiming to understand the physiological and biochemical mechanisms of the disease. [Methods] We employed non-targeted metabolomics and multivariate statistical analysis to investigate the changes in metabolites and metabolic pathways in quinoa stems after infection with C. cucurbitarum. [Results] Compared with the control, infection with C. cucurbitarum in quinoa resulted in 512 differential metabolites (P<0.01), including 283 upregulated metabolites and 229 downregulated metabolites. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed 19 main differential metabolites in the quinoa stems in response to infection (P<0.05). These differential metabolites were enriched in four metabolic pathways: arachidonic acid metabolism, linoleic acid metabolism, alpha-linolenic acid metabolism, and flavone and flavonol biosynthesis. [Conclusion] C. cucurbitarum infection leads to changes in arachidonic acid metabolism, linoleic acid metabolism, α-linolenic acid metabolism, and flavone and flavonol biosynthesis in quinoa. The accumulation of jasmonic acid from α-linolenic acid metabolism and the blocked biosynthesis of flavone and flavonol may be involved in the response of quinoa to C. cucurbitarum infection.