Evaluation of Trichoderma harzianum mutant lines in the resistance induction against white mold and growth promotion of common bean

Abstract

Genetic engineering has brought improvements of Trichoderma species for biotechnological processes such as agriculture. It has previously been reported that sm1 and aquaglyceroporin genes from Trichoderma harzianum are strongly expressed during pathogens biocontrol. We have previously shown that Sm1 plays a significant role in plant disease resistance and aquaporin (AQP) regulate physiological processes and responses related to water stress. Here, we report the evaluation of mutant lines with sm1 (deleated) and aqp (overexpressed) in Phaseoulus vulgaris growth promotion and disease resistance induction. It was investigated plants physiological and biochemical responses, plant growth promotion and biocontrol of Sclerotinia sclerotiorum, the causal agent of white mold. Treatments included Trichoderma harzianum wyld type, mutant line overexpressing aquaporin (Aqua), and deleted{Delta} Epl1mutant line. Our results demonstrated that Aqua mutant line increased leaf area in 25%, in comparison to non-treated plants. It also differed from other treatments, in comparison to plants with treatments ALL-42 and{Delta} Epl1, which increased 28% and 91%, respectively (Isso e abstract, ta confuse e extensor. Specific activity of {beta}-1.3 glucanase was higher in plants treated with T. harzianum {Delta}Epl1 mutant isolate, in leaves and roots respectively with 2.07 Umg-1 and 2.57 Umg-1. Plants inoculated or not with S. sclerotiorum presented with 2.27 Umg-1 and 2.34 Umg-1 of {beta}-1.3 glucanase on average, respectively, but enzymatic activity was higher on leaves when compared to the roots. The Aqua mutant demonstrated excellent growth promoting properties. Both mutants of T. harzianum do not induce resistance to white mold on common bean plants.