Genetic enhancement of < i > Trichoderma asperellum < /i > biocontrol potentials and carbendazim tolerance for chickpea dry root rot disease management

This study investigates the N-methyl-n-nitro-N-nitrosoguanidine (NTG) (100 mg/L) induced mutants ofTrichoderma asperellum. Six NTG (3 each from 1st& 2nd round) induced mutants were developed and evaluated their biocontrol activities and carbendazim tolerance. Among the mutant N2-3, N2-1, N1 and N2-2 gave the best antagonistic and volatile metabolite activities on inhibition of chickpeaF.oxysporum f. sp.ciceri,B.cinerea andR.bataticola mycelium under in vitro condition. Mutant N2-2 (5626.40 μg/ml) showed the highest EC50 value against carbendazim followed by N2-3 (206.36 μg/ml) and N2-1 (16.41 μg/ml); and succeeded to sporulate even at 2000 μg/ml of carbendazim. The biocontrol activity of N2-2 and N2 with half-dose of carbendazim was evaluated on chickpea dry root rot under controlled environment. Disease reduction and progress of the dry root rot was extremely l ow in T7 (N2-2 + with half-dose of carbendazim) treatment. Further, carbendazim resistant mutants demonstrated mutation intub2 gene of β-tubulin family which was suggested through the 37 and 183 residue changes in the superimposed protein structures encoded bytub2 gene in N2 and N2-2 with WT respectively. This study conclusively implies that the enhanced carbendazim tolerance in N2-2 mutant did not affect the mycoparasitism and plant growth activity ofTrichoderma. These mutants were as good as the wild-type with respect to all inherent attributes.
Source: PLoS One - Category: Biomedical Science Authors: Source Type: research