Oulkhir Fatima Ezzahra, Allaoui Abdelmounaaim, Idbella Ayoub, Danouche Mohammed, Bargaz Adnane, Biskri Latefa, Idbella Mohamed
AgroBioSciences (AgBS) Program College of Agriculture and Environmental Sciences, Mohammed VI Polytechnic University, Lot 660, Hay Moulay Rachid, Ben Guerir, 43150, Morocco.
Mohammed VI Polytechnic University, Lot 660, Hay Moulay Rachid, 43150, Ben Guerir, Morocco.
Microb Ecol. 2025 Aug 19;88(1):89. doi: 10.1007/s00248-025-02590-5.
Fusarium culmorum is a soil-borne fungal pathogen causing root and stem rot, seedling blight, and significant yield losses in small grain cereals, including wheat. This study aimed to evaluate the antifungal potential of Bacillus subtilis ED24, an endophytic strain isolated from Ziziphus lotus (L.) roots, and its effects on wheat growth and yield under controlled conditions. In vitro assays demonstrated that B. subtilis ED24 inhibited F. culmorum mycelial growth by up to 87%, associated with the secretion of 37 distinct secondary metabolites, predominantly involved in carbon cycling. In pot experiments, B. subtilis ED24 significantly enhanced wheat germination (85%) and growth compared to infected plants treated with the chemical fungicide tebuconazole. Although nutrient analysis showed significantly higher shoot nitrogen (32.34 mg/pot) and phosphorus (2.41 mg/pot) contents in the B. subtilis ED24 treatment compared to tebuconazole (8.11 and 0.18 mg/pot, respectively), no significant differences were observed when compared to the infected control (C-). Similarly, B. subtilis ED24 led to improved thousand grain weight (40.4 g), protein content (19.98%), and ash content (1.95%) relative to tebuconazole (29.1 g, 18.31%, and 1.74%, respectively), yet these values did not differ significantly from the infected control (C-). Notably, the number of seeds per pot was significantly increased by B. subtilis ED24 compared to the infected control (C-) (113.8 seeds/pot vs. 54.2 seeds/pot). Additionally, B. subtilis ED24 modulated the wheat rhizosphere microbiome, enriching beneficial taxa such as Eurotiomycetes fungal class and the bacterial genus Paramesorhizobium. These findings suggest that the antifungal activity and growth-promoting effects of B. subtilis ED24 are likely mediated through the synthesis of unique bioactive metabolites and microbiome modulation, offering a promising sustainable alternative to chemical fungicides in wheat production.
禾谷镰刀菌是一种土壤传播的真菌病原体，可引起根腐病和茎腐病、幼苗枯萎病，并导致包括小麦在内的小粒谷物严重减产。本研究旨在评估从莲枣树根部分离出的内生菌株枯草芽孢杆菌ED24的抗真菌潜力，以及在可控条件下其对小麦生长和产量的影响。体外试验表明，枯草芽孢杆菌ED24对禾谷镰刀菌菌丝生长的抑制率高达87%，这与37种不同次生代谢产物的分泌有关，这些次生代谢产物主要参与碳循环。在盆栽试验中，与用化学杀菌剂戊唑醇处理的受感染植株相比，枯草芽孢杆菌ED24显著提高了小麦的发芽率（85%）和生长量。虽然养分分析显示，与戊唑醇处理相比（分别为8.11和0.18毫克/盆），枯草芽孢杆菌ED24处理的地上部氮（32.34毫克/盆）和磷（2.41毫克/盆）含量显著更高，但与受感染对照（C-）相比，未观察到显著差异。同样，与戊唑醇相比（分别为29.1克、18.31%和1.74%），枯草芽孢杆菌ED24使千粒重（40.4克）、蛋白质含量（19.98%）和灰分含量（1.95%）有所提高，但这些值与受感染对照（C-）没有显著差异。值得注意的是，与受感染对照（C-）相比，枯草芽孢杆菌ED24使每盆种子数显著增加（113.8粒/盆对54.2粒/盆）。此外，枯草芽孢杆菌ED24调节了小麦根际微生物群，富集了有益类群，如散囊菌纲真菌类和副中生根瘤菌属细菌。这些发现表明，枯草芽孢杆菌ED24的抗真菌活性和促生长作用可能是通过合成独特的生物活性代谢产物和调节微生物群介导的，这为小麦生产中化学杀菌剂提供了一种有前景的可持续替代方案。
