Herbicides are the most used form of weed management worldwide but their excessive use could lead to negative impacts on human health and the environment. Biological weed management utilizing microorganisms and their metabolites presents a promising alternative. The weed-associated fungus Lasiodiplodia theobromae TBRC 15112 produces a broad spectrum of biological molecules, and shows potential as a bioherbicide. In this study, L. theobromae crude extracts from cultures caused leaf lesions in crowfoot grass (Dactyloctenium aegyptium L.) and tridax daisy (Tridax procumbens L.). The treated tridax daisy plants wilted and collapsed in three days. Using HP-20SS column chromatography, the 20, 30 and 40% acetone fractions caused leaf lesions covering 54, 30 and 34% of whole leaf areas of D. aegyptium, respectively, whereas relatively lower severities were observed for the 50–70% fractions. Eight compounds, including one new metabolite, were isolated and characterized for their structures using NMR spectroscopic data. Of these, five exhibited bioherbicidal activity, namely uracil, tyrosol, N-(4-hydroxyphenyl) acetic acid, N-(4-hydroxyphenyl) acetamide (4HPA), and the new metabolite. This metabolite, which we named lasiodiplin, is similar to alboatrin but distinct at two positions. Intriguingly, the mixture of tyrosol and 4HPA had a greater effect on weed leaves than pure compounds alone, suggesting a synergistic effect. The crude extracts also caused leaf lesions on five of six tested crops. Our study revealed that L. theobromae crude extracts have bioherbicidal activity on the narrow-leaf and broad-leaf weeds. The data could pave a way for further development of bioherbicides based on microorganisms and microbial products.

中文翻译：

---

Lasiodiplodia theobromae 次生代谢物对窄叶和阔叶杂草管理的生物除草效果


除草剂是全球最常用的杂草管理形式，但过度使用可能会对人类健康和环境产生负面影响。利用微生物及其代谢物的生物杂草管理提供了一种很有前途的替代方案。杂草相关真菌 Lasiodiplodia theobromae TBRC 15112 产生广谱生物分子，并显示出作为生物除草剂的潜力。在这项研究中，来自培养物的 L. theobromae 粗提取物在鱼尾草 （Dactyloctenium aegyptium L.） 和 tridax daisy （Tridax procumbens L.） 中引起叶片病变。处理过的 tridax 雏菊植株在三天内枯萎和塌陷。使用 HP-20SS 柱色谱法，20% 、 30% 和 40% 的丙酮馏分分别导致覆盖埃及石斛 54%、 30% 和 34% 全叶面积的叶片损伤，而观察到 50-70% 馏分的严重程度相对较低。使用 NMR 波谱数据分离了 8 种化合物，包括 1 种新代谢物，并对其结构进行了表征。其中，5 种表现出生物除草活性，即尿嘧啶、酪醇、N-（4-羟基苯基）乙酸、N-（4-羟基苯基）乙酰胺 （4HPA） 和新的代谢物。这种代谢物，我们命名为 lasiodiplin，与 alboatrin 相似，但在两个位置不同。有趣的是，酪醇和 4HPA 的混合物对杂草叶的影响比单独的纯化合物更大，这表明存在协同效应。粗提取物还导致 6 种测试作物中的 5 种出现叶片损伤。我们的研究表明，L. theobromae 粗提取物对窄叶和阔叶杂草具有生物除草活性。这些数据可能为进一步开发基于微生物和微生物产品的生物除草剂铺平道路。