Trichoderma elicitors create a potential chemical barrier through induced systemic resistance against Colletotrichum falcatum and minimise sucrose losses in sugarcane

Abstract

Red rot disease caused by Colletotrichum falcatum leads to acute sucrose losses in sugarcane. Minimising sucrose losses through Trichoderma elicitors will fetch an eco-friendly technology to sugarcane growers. An experiment was conducted for evaluating the effects of elicitors from Trichoderma strains (STr 83, STr 108 and STr 116) against Colletotrichum falcatum for minimising sucrose losses. Following Trichoderma elicitor perception, a chemical barrier against C. falcatum was activated in sugarcane through enhanced accumulation of phenols, enhanced polyphenol oxidase, peroxidase, superoxidase dismutase, phenylalanine ammonia lyase, tyrosine ammonia lyase, chitinase and β-1,3 glucanase activities arrayed in setts at 45 days after pathogen inoculation (dpi). Phenol fluxes and enhanced activities of polyphenol oxidase, peroxidase, superoxidase dismutase, phenylalanine ammonia lyase, tyrosine ammonia lyase, chitinase and β-1,3 glucanase in foliar tissues were carried forward till 330 dpi (harvest stage). STr 83 elicitors exhibited maximum increase in phenols (106%), chitinase (540%), 1, 3 β-glucanases (160%) and activities of polyphenol oxidase (125%), peroxidase (346%), superoxide dismutase (54%), phenylalanine ammonia lyase (162%) and tyrosine ammonia lyase (206%) at 210 dpi. This chemical barrier orchestrated the diverse biochemical pathways for induced systemic resistance and minimised sucrose losses by 0.19–0.26 t ha−1 at cane harvest stage.