Functional characterization of key glycoside hydrolase genes in Trichoderma harzianum T-22 reveals their critical role in biocontrol against Phytophthora capsici

Article

作者: Yin, Yanjing ; Long, Youhua ; Chen, Xiang ; Li, Rongyu ; Zhu, Yuxian ; Peng, Guanxing ; Wang, Haidong ; Yang, Jiao ; Wang, Weizhen ; Yin, Xianhui

Biocontrol is becoming an increasingly prevalent pest management strategy in agricultural systems, and the biocontrol fungal strain Trichoderma harzianum T-22 has been widely used in combating different plant diseases. Phytophthora capsici, a destructive oomycete pathogen, can infect a broad range of hosts and cause huge economic losses. A previous study found that T. harzianum T-22 can effectively inhibit P. capsici, and a large number of glycoside hydrolase (GH) encoding genes were upregulated during T. harzianum-P. capsici interaction. In the current study, the GH family was characterized and the expression pattern of six interaction induced genes (ThIIGH1-6) was determined by qPCR analysis. To investigate the function of key genes for biocontrol efficacy, a robust gene knock-out strategy was established and four genes (ThIIGH1-4) encoding putatively secreted proteins were successfully knocked out. Biological characteristic assays showed that deletion of these genes did not affect basal growth or development of T. harzianum. However, the ThIIGH1 and ThIIGH3 knock-out mutants displayed significantly decreased inhibitory activity against P. capsici. Cell wall hydrolase activity assays suggested that the biocontrol impairment of the mutants is mainly caused by the reduction of cellulase activity. Moreover, ThIIGH1 and ThIIGH3 were independently overexpressed in T. harzianum, which resulted in genetic engineering strains with higher inhibitory activity against P. capsici. Our results demonstrate a direct functional link between the target genes and the mechanisms essential for biocontrol. The genetic transformation system developed for T. harzianum thereby serves as a robust platform for advancing gene function study and strain improvement.

2024-09-01·PEST MANAGEMENT SCIENCE

Dual RNA sequencing during Trichoderma harzianum–Phytophthora capsici interaction reveals multiple biological processes involved in the inhibition and highlights the cell wall as a potential target

Article

作者: Li, Wenzhi ; Wang, Haidong ; Zhang, Zhuzhu ; Wang, Weizhen ; Long, Youhua ; Yin, Xianhui

Abstract:

BACKGROUND:

Phytophthora capsici is a destructive oomycete pathogen, causing huge economic losses for agricultural production. The genus Trichoderma represents one of the most extensively researched categories of biocontrol agents, encompassing a diverse array of effective strains. The commercial biocontrol agent Trichoderma harzianum strain T‐22 exhibits pronounced biocontrol effects against many plant pathogens, but its activity against P. capsici is not known.

RESULTS:

T. harzianum T‐22 significantly inhibited the growth of P. capsici mycelia and the culture filtrate of T‐22 induced lysis of P. capsici zoospores. Electron microscopic analyses indicated that T‐22 significantly modulated the ultrastructural composition of P. capsici, with a severe impact on the cell wall integrity. Dual RNA sequencing revealed multiple biological processes involved in the inhibition during the interaction between these two microorganisms. In particular, a marked upregulation of genes was identified in T. harzianum that are implicated in cell wall degradation or disruption. Concurrently, the presence of T. harzianum appeared to potentiate the susceptibility of P. capsici to cell wall biosynthesis inhibitors such as mandipropamid and dimethomorph. Further investigations showed that mandipropamid and dimethomorph could strongly inhibit the growth and development of P. capsici but had no impact on T. harzianum even at high concentrations, demonstrating the feasibility of combining T. harzianum and these cell wall synthesis inhibitors to combat P. capsici.

CONCLUSION:

These findings provided enhanced insights into the biocontrol mechanisms against P. capsici with T. harzianum and evidenced compatibility between specific biological and chemical control strategies. © 2024 Society of Chemical Industry.

2024-06-11·LANGMUIR

Design of Carboxymethylcellulose/Poloxamer-Based Bioformulation Embedding Trichoderma afroharzianum for Agricultural Applications

Article

作者: Borzacchiello, Assunta ; Vinale, Francesco ; di Gennaro, Mario ; Della Sala, Francesca

Microbial biological control agents are believed to be a potential alternative to classical fertilizers to increase the sustainability of agriculture. In this work, the formulation of Trichoderma afroharzianum T22 (T22) spores with carboxymethyl cellulose (CMC) and Pluronic F-127 (PF-127) solutions was investigated. Rheological and microscopical analysis were performed on T22-based systems at three different CMC/PF-127 concentrations, showing that polymer aggregates tend to surround T22 spores, without viscosity, and the viscoelastic properties of the formulations were affected. Contact angle measurements showed the ability of PF-127 to increase the wettability of the systems, and the effect of the formulations on the viability of the spores was evaluated. The viability of the spores was higher over 21 days in all the formulations, compared to the control in water, at 4 and 25 °C. Finally, the effectiveness of the formulations on sweet basil was estimated by greenhouse tests. The results revealed a beneficial effect of the CMC/PF-127 mixture, but none on the formulation with T22. The data show the potential of CMC/PF-127 mixtures for the future design of microorganism-based formulations.

100 项与 Polyphemusin II 相关的药物交易

登录后查看更多信息