Li Taiying, Kim Jin-Hyun, Jung Boknam, Ji Sungyeon, Seo Mun Won, Han You Kyoung, Lee Sung Woo, Bae Yeoung Seuk, Choi Hong-Gyu, Lee Seung-Ho, Lee Jungkwan
Department of Applied Biology, Dong-A University, Busan, Republic of Korea.
Department of Molecular Genetics, Dong-A University, Busan, Republic of Korea.
J Ginseng Res. 2020 Jan;44(1):161-167. doi: 10.1016/j.jgr.2018.11.005. Epub 2018 Nov 23.
The ascomycete fungi (Cd) and (Fs) cause ginseng root rot and significantly reduce the quality and yield of ginseng. Cd produces the secondary metabolite radicicol, which targets the molecular chaperone Hsp90. Fs is resistant to radicicol, whereas other fungal genera associated with ginseng disease are sensitive to it. Radicicol resistance mechanisms have not yet been elucidated.
Transcriptome analyses of Fs and Cd mycelia treated with or without radicicol were conducted using RNA-seq. All of the differentially expressed genes (DEGs) were functionally annotated using the transcript database. In addition, deletions of two transporter genes identified by RNA-seq were created to confirm their contributions to radicicol resistance.
Treatment with radicicol resulted in upregulation of chitin synthase and cell wall integrity genes in Fs and upregulation of nicotinamide adenine dinucleotide dehydrogenase and sugar transporter genes in Cd. Genes encoding an ATP-binding cassette transporter, an aflatoxin efflux pump, ammonium permease 1 (), and nitrilase were differentially expressed in both Fs and Cd. Among these four genes, only the ABC transporter was upregulated in both Fs and Cd. The aflatoxin efflux pump and were upregulated in Cd, but downregulated in Fs, whereas nitrilase was downregulated in both Fs and Cd.
The transcriptome analyses suggested radicicol resistance pathways, and deletions of the transporter genes indicated that they contribute to radicicol resistance.
子囊菌（Cd）和（Fs）可导致人参根腐病，显著降低人参的品质和产量。Cd产生次生代谢产物萝卜素，其作用靶点为分子伴侣Hsp90。Fs对萝卜素具有抗性，而与人参病害相关的其他真菌属对其敏感。萝卜素抗性机制尚未阐明。
使用RNA测序对经或未经萝卜素处理的Fs和Cd菌丝体进行转录组分析。所有差异表达基因（DEG）均使用转录本数据库进行功能注释。此外，对RNA测序鉴定出的两个转运蛋白基因进行缺失操作，以确认它们对萝卜素抗性的作用。
萝卜素处理导致Fs中几丁质合酶和细胞壁完整性基因上调，Cd中烟酰胺腺嘌呤二核苷酸脱氢酶和糖转运蛋白基因上调。编码ATP结合盒转运蛋白、黄曲霉毒素外排泵、铵通透酶1（）和腈水解酶的基因在Fs和Cd中均差异表达。在这四个基因中，只有ABC转运蛋白在Fs和Cd中均上调。黄曲霉毒素外排泵和在Cd中上调，但在Fs中下调，而腈水解酶在Fs和Cd中均下调。
转录组分析揭示了萝卜素抗性途径，转运蛋白基因的缺失表明它们对萝卜素抗性有作用。
