Li Xiang, Li Mengtao, Liu Xiangkai, Jiang Yilin, Zhao Dongfang, Gao Jie, Wang Zhenhui, Jiang Yun, Chen Changqing
College of Life Science, Jilin Agricultural University, Changchun 130118, China.
College of Plant Protection, Jilin Agricultural University, Changchun 130118, China.
J Fungi (Basel). 2022 Jul 26;8(8):779. doi: 10.3390/jof8080779.
(1) Background: Ilyonectria robusta can cause ginseng to suffer from rusty root rot. Secondary metabolites (SMs) produced by Bacillus methylotrophicus NJ13 can inhibit the mycelial growth of I. robusta. However, the molecular mechanism of the inhibition and response remains unclear. (2) Methods: Through an in vitro trial, the effect of B. methylotrophicus NJ13’s SMs on the hyphae and conidia of I. robusta was determined. The change in the physiological function of I. robusta was evaluated in response to NJ13’s SMs by measuring the electrical conductivity, malondialdehyde (MDA) content, and glucose content. The molecular interaction mechanism of I. robusta’s response to NJ13’s SMs was analyzed by using transcriptome sequencing. (3) Results: NJ13’s SMs exhibited antifungal activity against I. robusta: namely, the hyphae swelled and branched abnormally, and their inclusions leaked out due to changes in the cell membrane permeability and the peroxidation level; the EC50 value was 1.21% (v/v). In transcripts at 4 dpi and 7 dpi, the number of differentially expressed genes (DEGs) (|log2(fold change)| > 1, p adj ≤ 0.05) was 1960 and 354, respectively. NJ13’s SMs affected the glucose metabolism pathway, and the sugar-transporter-related genes were downregulated, which are utilized by I. robusta for energy production. The cell wall structure of I. robusta was disrupted, and chitin-synthase-related genes were downregulated. (4) Conclusions: A new dataset of functional responses of the ginseng pathogenic fungus I. robusta was obtained. The results will benefit the development of targeted biological fungicides for I. robusta and the study of the molecular mechanisms of interaction between biocontrol bacteria and phytopathogenic fungi.
(1) 背景：强壮伊氏真壳菌可导致人参患锈根腐病。甲基营养型芽孢杆菌NJ13产生的次级代谢产物（SMs）能抑制强壮伊氏真壳菌的菌丝生长。然而，抑制作用及其响应的分子机制仍不清楚。(2) 方法：通过体外试验，测定甲基营养型芽孢杆菌NJ13的SMs对强壮伊氏真壳菌菌丝和分生孢子的影响。通过测量电导率、丙二醛（MDA）含量和葡萄糖含量，评估强壮伊氏真壳菌对NJ13的SMs响应时生理功能的变化。利用转录组测序分析强壮伊氏真壳菌对NJ13的SMs响应的分子相互作用机制。(3) 结果：NJ13的SMs对强壮伊氏真壳菌表现出抗真菌活性：即菌丝异常肿胀和分支，由于细胞膜通透性和过氧化水平的变化，其内含物泄漏；半数有效浓度（EC50）值为1.21%（v/v）。在接种后4天和7天的转录本中，差异表达基因（DEGs）（|log2（倍数变化）|>1，校正P值≤0.05）的数量分别为1960个和354个。NJ13的SMs影响葡萄糖代谢途径，与糖转运蛋白相关的基因下调，而强壮伊氏真壳菌利用这些基因进行能量产生。强壮伊氏真壳菌的细胞壁结构被破坏，几丁质合酶相关基因下调。(4) 结论：获得了人参致病真菌强壮伊氏真壳菌功能响应的新数据集。这些结果将有助于开发针对强壮伊氏真壳菌的靶向生物杀菌剂，以及研究生防细菌与植物病原真菌之间相互作用的分子机制。
