Priming by low abiotic stress and DL-β-Aminobutyric acid compared to Acibenzolar-S- methyl to control of Tomato Crown and Root Rot Disease

Crown and root rot disease caused by Fusarium oxysporum f.sp. radicis-lycopersici (FORL) is a destructive factor on the transplant and mature tomato (Lycopersicon esculentum Mill) plants in greenhouses of Turkey. The synergistic effect of abiotic stress (100 mM NaCl) by known chemical defense inducers Acibenzolar-S- methy (ASM) and DL-β-Aminobutyric Acid (BABA) on tomato plants was tested. The plants roots were immersed into 125, and 500 µg mL-1 BABA or plants foliages were separately sprayed by ASM (0.2 mg mL-1) or BABA (125, 500 µg mL-1) before the plants were inoculated with 106 spor / ml fungal suspension by day 1 post treatment. Interestingly, BABA and ASM treatment combination led to negative effect on plant resistance though the plants sprayed with these compounds alone showed resistance to pathogen. Furthermore, in another study conducted on only by BABA and abiotic stress (foliar spray) resulted in remarkable plant disease resistance if the plants simultaneously were detached into BABA (125µg mL-1) solution. This combination caused a positive effect on plants, which was comparable with the plants detached into the highest BABA concentration at 500µg mL-1. Disease severity on plants on which abiotic stress and BABA combination used was also lower than the control and BABA-sprayed with 500µg mL-1 plants alone by day 20 post inoculation. Therefore, synergistic effect between salt stress and BABA at lower concentrations suggests FORL resistance that could be associated with stress regulation effect of BABA.