2,4-Dichlorophenoxy acetic acid, abscisic acid, and hydrogen peroxide induced resistance-related components against potato early blight (Alternaria solani, Sorauer)

Induction of acquired resistance activates defense-related genes. Current study aimed to (a) initiate potato acquired resistance to the Early Blight disease caused by Alternaria solani through treating potato plants with low and repetitive doses of 2,4-dichlorophenoxy acetic acid (2,4-D), abscisic acid (AB), and hydrogen peroxide (H2O2) and (b) test the success of the use of the chemical inducers along with the application of fungicides. Potato cultivars Nicola and Spunta were treated once per wk for 6 wk and challenged 1 wk later by in the control of A. solani. Results showed that peroxidase (POD), phenylalanine ammonia lyase (PAL), and polyphenoloxidase (PPO) enzyme activities and gene regulation were significantly increased after 1 d of infection and lasted for more than 15 d. The 2,4-D and H2O2 inducers significantly increased both enzyme activities and gene expression of PAL, PPO, and POD for more than 15 d post inoculation. PAL was the most increased at the enzyme activity and gene expression levels. Incorporation of such in-expensive treatments might reduce management costs and reduce the environmental pollution.