Abiotic Stresses Affect Trichoderma harzianum T39-Induced Resistance to Downy Mildew in Grapevine

Abstract

Enhancement of plant defense through the application of resistance inducers seems a promising alternative to chemical fungicides for controlling crop diseases but the efficacy can be affected by abiotic factors in the field. Plants respond to abiotic stresses with hormonal signals that may interfere with the mechanisms of induced systemic resistance (ISR) to pathogens. In this study, we exposed grapevines to heat, drought, or both to investigate the effects of abiotic stresses on grapevine resistance induced by Trichoderma harzianum T39 (T39) to downy mildew. Whereas the efficacy of T39-induced resistance was not affected by exposure to heat or drought, it was significantly reduced by combined abiotic stresses. Decrease of leaf water potential and upregulation of heat-stress markers confirmed that plants reacted to abiotic stresses. Basal expression of defense-related genes and their upregulation during T39-induced resistance were attenuated by abiotic stresses, in agreement with the reduced efficacy of T39. The evidence reported here suggests that exposure of crops to abiotic stress should be carefully considered to optimize the use of resistance inducers, especially in view of future global climate changes. Expression analysis of ISR marker genes could be helpful to identify when plants are responding to abiotic stresses, in order to optimize treatments with resistance inducers in field.

Trichoderma harzianumelicits induced resistance in sunflower challenged byRhizoctonia solani

“…; Roatti et al . ). However, no study has been investigated on induction of defence substances in sunflower roots by T. harzianum against seedling blight caused by R .…”

Predisposition in Plant Disease: Exploiting the Nexus in Abiotic and Biotic Stress Perception and Response

“…Delineation of stress network interactions has implications for disease management, such as in deploying chemically or biologically induced resistance (156,193). The efficacy of plant activators depends on the environmental context, and abiotic stresses are expected to influence JA and SA network dynamics during pathogen attack (24).…”

IN-VITRO ANTAGONISM EXPERIMENT OF Trichoderma spp. TO Ganoderma sp. WHICH ATTACKS SENGON TREES

“…bersifat sebagai antagonisme secara in vitro dengan terbentuknya zona penghambatan yang merupakan indikasi awal terlibatnya antibiotik dan antagonisme baik pada media PDA maupun MEA (Karthikeyan et al, 2007). Aktivitas Trichoderma untuk menghambat pertumbuhan patogen sangat dipengaruhi oleh lingkungan (Roatti et al, 2013). Persentase laju penghambatan Trichoderma spp.…”