BACKGROUNDPaecilomyces is emerging as an efficient biocontrol agent owing to its rapid growth, high sporulation capacity, and ability to compete for space and nutrients with fungal pathogens. Recently, Paecilomyces maximus spores were reported to contain dipicolinic acid (DPA), which was identified as a key component involved in P. maximus spore resistance to environmental stresses. DPA was found to be synthesized by the first DPA synthase (PmDpa) reported in fungi.RESULTSHere, the role of the pmdpa gene in P. maximus colonization and biocontrol ability was analyzed by comparing the biocontrol properties of wild‐type P. maximus NJC01 and knock‐out mutant Δpmdpa. NJC01 and Δpmdpa reduced Colletotrichum brevisporum mycelial growth by 48.1% and 34.2%, respectively. Δpmdpa showed 37.8%–56.9% lower colonization ability on soybean pods compared to NJC01. The ability of NJC01 to compete for space and nutrients with C. brevisporum was higher than that of Δpmdpa. In preventive application, 1 × 108 NJC01 spores mL−1 reduced anthracnose symptoms on soybean pods by 42.2–42.5% after 10 days. However, 1 × 108 Δpmdpa spores mL−1 reduced the disease symptoms by only 27.8%. The original phenotypes were recovered when using the complemented strain, Δpmdpa/pmdpa. Interestingly, combination of 1 × 108 NJC01 spores mL−1 and 0.02 mg mL−1 DPA promoted colony formation, and increased NJC01 preventive and curative efficacies up to 49.2% and 42.5%, respectively.CONCLUSIONSpmdpa was found to play a key role in P. maximus colonization and growth, revealing the first key factor involved in Paecilomyces biocontrol properties. © 2025 Society of Chemical Industry.

中文翻译：

---

大拟青霉 Paecilomyces maximusDPA 合酶基因 pmdpa 参与大豆炭疽病的定植和生物防治功效

背景泡霉菌因其快速生长、高孢子形成能力以及与真菌病原体争夺空间和营养的能力而成为一种有效的生物防治剂。最近，据报道，大拟青霉孢子含有二篱現酸 （DPA），这被确定为参与大牡蛎孢子抵抗环境胁迫的关键成分。发现 DPA 是由真菌中报道的第一个 DPA 合酶 （PmDpa） 合成的。结果通过比较野生型 P. maximus NJC01 和敲除突变体 Δpmdpa 的生物防治特性，分析 pmdpa 基因在大松定植和生防能力中的作用。NJC01 和 Δpmdpa 分别使短炭疽菌菌丝体生长减少了 48.1% 和 34.2%。与 NJC01 相比，Δpmdpa 在大豆荚上的定植能力降低了 37.8%–56.9%。NJC01 与短孢梭菌竞争空间和养分的能力高于 Δpmdpa。在预防性应用中，1 × 108 个 NJC01 孢子 mL-1 在 10 天后将大豆荚上的炭疽病症状减少了 42.2-42.5%。然而，1 × 108 个 Δpmdpa 孢子 mL-1 仅使疾病症状减轻了 27.8%。当使用互补菌株 Δpmdpa/pmdpa 时，恢复了原始表型。有趣的是，1 × 108 个 NJC01 孢子 mL-1 和 0.02 mg mL-1 DPA 的组合促进了集落形成，并将 NJC01 的预防和治疗效果分别提高了 49.2% 和 42.5%。结论发现 Pmdpa 在 P. maximus 定植和生长中起关键作用，揭示了 Paecilomyces 生物防治特性所涉及的第一个关键因素。© 2025 化工学会.