乙烯调控灵芝酸生物合成关键基因的筛选

灵芝是我国著名的药用真菌，灵芝酸是其主要活性成分，具有多种药理活性。乙烯可以促进灵芝酸的生物合成，但其调控机理尚不明确。本实验利用非靶向代谢组研究发现Top 20差异代谢物中含有6种灵芝的活性成分(灵芝酸η、赤芝酸F、赤芝酸N、丹芝酸A、灵芝酸V1和灵芝酸δ)，其中有4种灵芝酸(灵芝酸η、赤芝酸F、赤芝酸N和灵芝酸V1)为上调积累，2种灵芝酸(灵芝酸δ和丹芝酸A)为下调积累。通过非靶向代谢组与转录组的关联分析发现基因GL23307、GL25546和GL29595同时与3种灵芝酸积累显著相关，并通过启动子顺式元件预测，发现分别编码泛素蛋白和抑肽酶基因GL25546、GL23307的启动子区域含有响应乙烯信号的顺式作用元件GCC-box，因此，推测这两个基因在乙烯调控灵芝酸生物合成中发挥重要作用。

Screening of key genes in response to ethylene for mediating ganoderic acid biosynthesis

Ganoderma lingzhi is a well-known medicinal fungus in China. Ganoderic acid is a typical active component with many bioactivities. Ethylene is reported to increase the production of ganoderic acid in G. lingzhi, however, the regulatory mechanism of ethylene remains unclear. Nontargeted metabolomics study found that there were six ganoderic acids (ganoderic acid eta, lucidenic acid F, lucidenic acid N, ganolucidic acid A, ganoderic acid V1, and ganoderic acid delta) in the Top 20 differential metabolites. Four of them (ganoderic acid eta, lucidenic acid F, lucidenic acid N, and ganoderic acid V1) were up-regulated expressed metabolites, and two (ganoderic acid delta and ganolucidic acid A) were down-regulated expressed metabolites. GL23307, GL25546 and GL29595 were significantly correlated to accumulation of three ganoderic acids. It was also found that there had cis-acting elements GCC-box to respond to ethylene signal in the promoter region of encoding peptidase inhibitor and ubiquitin genes GL25546 and GL23307. The above results indicate that these genes play the essential roles in respond to ethylene in mediating ganoderic acid biosynthesis.