Induced Abiotic Stress: Prospects for Powdery Mildew Resistance in Tomato Plants

Induced Abiotic Stress: Prospects for Powdery Mildew Resistance in Tomato Plants

Inducing plant immune system during its seedling stage with weak shocks of abiotic stress can be a novel approach to disease control. An experiment was conducted with tomato as a model plant to increase its resistance towards powdery mildew disease (Oidium spp. and Leveillula spp.) by inducing its innate immune system at an early seedling stage through weak shocks of drought. Plants were treated with three levels of drought stress: low, medium and high (75%, 50% and 25% field capacities respectively). Twenty five days after drought induction, plants were inoculated with low and high doses of powdery mildew conidia (104 and 106 conidia per ml respectively), and all the plants were then well watered for next 30 days. Drought treated plants showed elevated hydrogen peroxide (H2O2) level and after disease inoculation, such plants had higher Total Phenol Content (TPC) and less Area Under Disease Progression Curve (AUDPC) with higher biomass compared to the control plants; showing enhanced resistance to the powdery mildew. The immunity provided by the virtue of hydrogen peroxide and the phenolic compounds might be responsible for the development of disease resistance in the plants.