College of Agronomy, Jiangxi Agricultural University, Nanchang, Jiangxi, China 330045; Key Laboratory of Crop Physiology, Ecology, and Genetic Breeding of the Ministry of Education, Jiangxi Agricultural University, Nanchang, Jiangxi, China 330045.
College of Agronomy, Jiangxi Agricultural University, Nanchang, Jiangxi, China 330045.
Pestic Biochem Physiol. 2024 Sep;204:106086. doi: 10.1016/j.pestbp.2024.106086. Epub 2024 Aug 13.
Actinomycetes have emerged as significant biocontrol resources due to their rich array of bioactive natural products. While much research has historically focused on secondary metabolites isolated from their fermentation broth, there remains a dearth of reports on their volatile organic compounds (VOCs). Here, strain ML27, isolated from soil, was identified as Streptomyces albidoflavus based on morphological features, physiological, biochemical, and molecular characteristics (16S rRNA, atpD, recA, and rpoB gene sequences). VOCs from S. albidoflavus strain ML27 were effectively captured using solid-phase microextraction (SPME) and tentatively identified through gas chromatography-mass spectrometry (GC/MS). Among these compounds, 4-ethyl-1,2-dimethoxybenzene exhibited broad-spectrum antifungal activity and demonstrated efficacy in controlling citrus anthracnose, with a control efficacy of 86.67%. Furthermore, the inhibitory mechanism of 4-ethyl-1,2-dimethoxybenzene against Colletotrichum gloeosporioides was revealed. Results indicated that 4-ethyl-1,2-dimethoxybenzene induced swelling, deformity, and breakage in C. gloeosporioides mycelia, and significantly inhibited spore germination. Transcriptome analysis revealed that 4-ethyl-1,2-dimethoxybenzene inhibited the growth and development of C. gloeosporioides primarily by disrupting energy metabolism and the integrity of the cell wall and membrane. Based on these results, it is promising to develop 4-ethyl-1,2-dimethoxybenzene as a novel biopesticide for controlling citrus anthracnose.
放线菌由于其丰富的生物活性天然产物而成为重要的生物防治资源。虽然历史上许多研究都集中在从发酵液中分离出的次级代谢产物上，但关于其挥发性有机化合物 (VOCs) 的报道仍然很少。在这里，从土壤中分离出的菌株 ML27 根据形态特征、生理生化和分子特征 (16S rRNA、atpD、recA 和 rpoB 基因序列) 被鉴定为白色链霉菌。使用固相微萃取 (SPME) 有效地捕获了白色链霉菌 ML27 菌株的 VOCs，并通过气相色谱-质谱联用 (GC/MS) 进行了初步鉴定。在这些化合物中，4-乙基-1,2-二甲氧基苯表现出广谱抗真菌活性，并在控制柑橘炭疽病方面表现出功效，控制效果为 86.67%。此外，还揭示了 4-乙基-1,2-二甲氧基苯对胶孢炭疽菌的抑制机制。结果表明，4-乙基-1,2-二甲氧基苯诱导胶孢炭疽菌菌丝肿胀、变形和断裂，并显著抑制孢子萌发。转录组分析表明，4-乙基-1,2-二甲氧基苯主要通过破坏能量代谢和细胞壁及膜的完整性来抑制胶孢炭疽菌的生长和发育。基于这些结果，有望开发 4-乙基-1,2-二甲氧基苯作为防治柑橘炭疽病的新型生物农药。
