Agroécologie, INRAE, Institut Agro, Université Bourgogne Franche-Comté, Dijon, France.
De Sangosse-Bonnel, CS 10005, Pont du Casse, France.
Appl Environ Microbiol. 2022 Mar 22;88(6):e0217721. doi: 10.1128/aem.02177-21. Epub 2022 Jan 26.
The use of herbicides for weed control is very common, but some of them represent a threat to human health, are environmentally detrimental, and stimulate herbicide resistance. Therefore, using microorganisms as natural herbicides appears as a promising alternative. The mycoflorae colonizing different species of symptomatic and asymptomatic weeds were compared to characterize the possible mycoherbicidal candidates associated with symptomatic weeds. A collection of 475 symptomatic and asymptomatic plants belonging to 23 weed species was established. A metabarcoding approach based on amplification of the internal transcribed spacer (ITS) region combined with high-throughput amplicon sequencing revealed the diversity of fungal communities hosted by these weeds: 542 fungal genera were identified. The variability of the composition of fungal communities revealed a dispersed distribution of taxa governed neither by geographical location nor by the botanical species, suggesting a common core displaying nonspecific interactions with host plants. Beyond this core, specific taxa were more particularly associated with symptomatic plants. Some of these, such as , , , , are known pathogens, while others such as , , and are not, at least on crops, and constitute new tracks to be followed in the search for mycoherbicidal candidates. This approach is original because the diversity of weed-colonizing fungi has rarely been studied before. Furthermore, targeting both the ITS1 and ITS2 regions to characterize the fungal communities (i) highlighted the complementarity of these two regions, (ii) revealed a great diversity of weed-colonizing fungi, and (iii) allowed for the identification of potential mycoherbicides, among which were unexpected genera.
除草剂被广泛用于杂草防治，但其中一些除草剂对人类健康构成威胁，对环境有害，并会刺激杂草产生抗药性。因此，使用微生物作为天然除草剂似乎是一种很有前途的替代方法。本研究比较了定殖于不同症状和无症状杂草的真菌菌群，以鉴定与症状杂草相关的可能具有除草活性的微生物候选物。采集了 23 种杂草的 475 种症状和无症状植物，建立了一个样本集。基于内转录间隔区（ITS）区域扩增与高通量扩增子测序相结合的宏条形码方法，揭示了这些杂草所携带的真菌群落的多样性：鉴定出 542 个真菌属。真菌群落组成的可变性表明，分类群的分布既不受地理位置也不受植物物种的影响，这表明存在一个核心，该核心显示与宿主植物的非特异性相互作用。除了这个核心之外，还有一些特定的分类群与症状植物有更密切的关联。其中一些，如 、 、 、 ，是已知的病原体，而其他一些，如 、 、 ，则不是，至少在作物上不是，它们构成了寻找具有除草活性的微生物候选物的新途径。这种方法是原创的，因为以前很少研究过定殖于杂草的真菌的多样性。此外，针对 ITS1 和 ITS2 区域来对真菌群落进行特征分析：（i）突出了这两个区域的互补性；（ii）揭示了定殖于杂草的真菌的多样性；（iii）能够鉴定出具有潜在除草活性的微生物，其中包括一些意想不到的属。
