Inhibitory Effect of Trichoderma longibrachiatum on Growth of Fusarium Species and Accumulation of Fumonisins

Abstract

Fusarium spp. cause devastating crop diseases and produce carcinogenic mycotoxins suchas fumonisins, threatening global food safety and human health. In this study, Trichodermalongibrachiatum A25011, isolated from apples in Aksu, Xinjiang, exhibited significant antagonisticactivity with mycelial growth inhibition rates of 54.52% against F. verticillioides 48.62%against F. proliferatum, and 58.22% against F. oxysporum in confrontation assays. Enzymeactivity detection revealed high chitinase (583.21 U/mg protein) and moderate cellulase(43.92 U/mg protein) production, which may have the capacity to degrade fungal cellwalls. High-Performance Liquid Chromatography–Mass Spectrometry (HPLC-MS/MS)analyses enabled the quantification of fungal hormones including gibberellin A3 (GA3,2.44 mg/L), cytokinins (cis-zeatin riboside (CZR): 0.69 mg/L; trans-zeatin riboside (TZR):0.004 mg/L; kinetin: 0.006 mg/L), and auxins (indole-3-acetic acid (IAA): 0.35 mg/L;abscisic acid: 0.06 mg/L). Application of a T. longibrachiatum A25011 spore suspensionaround the roots of peanut plants enhanced growth by 13.20% (height), 5.65% (stem andleaf biomass), and 39.13% (root biomass). Notably, A25011 reduced F. proliferatum-derivedfumonisin accumulation in rice-based cultures by 93.58% (6 d) and 99.35% (10 d), suggestingbiosynthetic suppression. The results demonstrated that T. longibrachiatum strain A25011exhibited excellent biocontrol capability against Fusarium spp., proving its dual role insimultaneously suppressing fungal growth and fumonisin accumulation while promotingplant growth. T. longibrachiatum A25011 could be applied as a multifunctional biocontrolagent in sustainable agriculture in the future.