暗褐网柄牛肝菌菌核形成相关基因分析

Genes involved in sclerotium formation of Phlebopus portentosus

摘要:

【背景】暗褐网柄牛肝菌(Phlebopus portentosus)是第一个能够人工栽培的食用牛肝菌，人工栽培过程中，不同菌株会形成数量不等的菌核。【目的】探明不同菌株产核差异机制。【方法】采集多菌核(JH1)、寡菌核(JH2)菌株的成熟菌核及无菌核(JH3)菌株培养相同时间的菌丝体进行转录组测序，分析差异表达基因对菌核形成的作用和功能。【结果】KEGG富集分析显示，JH2 vs. JH1互比，苯丙氨酸、酪氨酸和色氨酸的生物合成，精氨酸和脯氨酸代谢，半胱氨酸及蛋氨酸代谢显著富集；JH3 vs. JH1互比，乙醛酸和二羧酸代谢显著富集；JH3 vs. JH2互比，谷胱甘肽、乙醛酸和二羧酸代谢显著富集。菌核形成相关基因分析显示，从JH2 vs. JH1、JH3 vs. JH1和JH3 vs. JH2的差异表达基因中分别筛选到69、118和82条与信号转导、感知刺激、防御、碳水化合物活性酶等有关的基因，其中碳水化合物活性酶基因数量最多。三个比较组共有的碳水化合物活性酶基因在JH1中的表达量高于JH2、JH3，表明JH1更能充分利用底物营养以形成更多菌核。【结论】本研究从转录组水平初步分析了暗褐网柄牛肝菌不同菌株产核差异的原因，为后续菌核与出菇及产量相关性研究提供了理论基础。

Abstract:

[Background] Phlebopus portentosus is the first edible species of Boletales that can be cultivated artificially, and the number of sclerotia varies during the artificial cultivation of different strains. [Objective] To explore the different mechanisms of sclerotium production of different strains. [Methods] The mature sclerotia of the strain with multiple sclerotia (JH1) and the strain with oligo-sclerotia (JH2) and the mycelia of the strain with no sclerotium (JH3) cultivated for the same time period were collected. Transcriptome sequencing was performed to identify the differentially expressed genes (DEGs) in sclerotium formation, and the roles of these DEGs were analyzed. [Results] The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment showed that the DEGs between JH2 and JH1 were mainly enriched in the phenylalanine, tyrosine, and tryptophan biosynthesis, arginine, proline metabolism, cysteine and methionine metabolism. The DEGs between JH3 and JH1 were mainly involved in glyoxalate and dicarboxylate metabolism, and those between JH3 and JH2 in glutathione metabolism and glyoxylate and dicarboxylate metabolism. Among the sclerotium formation-associated DEGs between JH2 and JH1, between JH3 and JH1, and between JH3 and JH2, respectively, 69, 118, and 82 genes were associated with signal transduction, sensory stimulation, defense, and carbohydrate active enzymes, and those associated with carbohydrate active enzymes had the highest abundance. The expression of carbohydrate active enzyme genes shared by the three comparison groups in JH1 was higher than that in JH2 and JH3, indicating that JH1 could make full use of the substrate to form more sclerotia. [Conclusion] The differences in sclerotium production among different strains of P. portentosus were preliminarily analyzed at the transcriptome level, which provided a theoretical basis for the subsequent research on the correlations of sclerotia with fruiting and yield.