Table_1_Identification of the Ilex macrocarpa anthracnose pathogen and the antifungal potential of the cell-free supernatant of Bacillus velezensis against Colletotrichum fioriniae.DOCX

IntroductionAnthracnose is a significant fungal disease that affects tree growth and development, with Colletotrichum spp. exhibiting host non-specificity and targeting various organs, making disease control challenging.
MethodsThis study aimed to identify the pathogenic species causing anthracnose in Ilex macrocarpa in Nanchong, Sichuan Province, and screen effective fungicides, particularly biological ones. The pathogen was identified as Colletotrichum fioriniae through morphological observation, pathogenicity assays, and molecular biological methods. Three biological and five chemical fungicides were evaluated for their effects on the mycelial growth and spore germination rate of the pathogen.
ResultsThe results indicated that prochloraz was the most effective chemical fungicide, while the cell-free supernatant (CFS) of Bacillus velezensis had the most significant inhibitory effect among the biological fungicides. Transcriptome analysis revealed that the CFS of B. velezensis significantly reduced the expression of genes associated with ribosomes, genetic information processing, membrane lipid metabolism, and sphingolipid biosynthesis in C. fioriniae. Additionally, the glutathione pathway’s expression of various genes, including key genes such as GST, GFA, Grx, TRR, and POD, was induced. Furthermore, the expression of 17 MFS transporters and 9 ABC transporters was increased. Autophagy-related ATGs were also affected by the B. velezensis CFS.
DiscussionThese findings suggest that the B. velezensis CFS may inhibit C. fioriniae through interference with ribosomes, genetic information processing, cell membrane metabolism, and energy metabolism. These results provide potential target genes for the B. velezensis CFS and insights into the antifungal mechanism by which B. velezensis inhibits C. fioriniae.

引言
炭疽病是一类严重危害树木生长发育的真菌病害，炭疽菌属（Colletotrichum spp.）宿主非特异性强且可侵染植物多种器官，使得该病害的防治难度极大。
方法
本研究旨在明确四川省南充市大果冬青（Ilex macrocarpa）炭疽病的病原菌种类，并筛选高效杀菌剂，尤其是生防杀菌剂。本研究通过形态学观察、致病性测定以及分子生物学方法，将病原菌鉴定为刺盘孢（Colletotrichum fioriniae）。本研究评估了3种生防杀菌剂与5种化学杀菌剂对该病原菌菌丝生长及孢子萌发率的抑制效果。
结果
研究结果显示，咪鲜胺（prochloraz）是效果最优的化学杀菌剂，而贝莱斯芽孢杆菌（Bacillus velezensis）无细胞上清液（cell-free supernatant，CFS）在生防杀菌剂中抑制效果最为显著。转录组分析结果表明，贝莱斯芽孢杆菌无细胞上清液可显著抑制刺盘孢中与核糖体、遗传信息加工、膜脂代谢及鞘脂生物合成相关的基因表达。此外，该上清液可诱导谷胱甘肽途径中多种基因的表达，包括谷胱甘肽S-转移酶（GST）、GFA、谷氧还蛋白（Grx）、硫氧还蛋白还原酶（TRR）以及过氧化物酶（POD）等关键基因。同时，17个主要促进因子超家族（MFS）转运蛋白与9个ATP结合盒式（ABC）转运蛋白的表达量均出现上调。自噬相关基因ATGs的表达亦受到贝莱斯芽孢杆菌无细胞上清液的调控。
讨论
本研究结果表明，贝莱斯芽孢杆菌无细胞上清液可通过干扰病原菌的核糖体功能、遗传信息加工、细胞膜代谢及能量代谢，从而抑制刺盘孢的生长。上述研究结果为贝莱斯芽孢杆菌无细胞上清液的应用提供了潜在靶标基因，并为阐明贝莱斯芽孢杆菌抑制刺盘孢的抗真菌机制提供了理论依据。