The Selection of the best regeneration medium and evaluation of the effect of verapamil on the plant defense response in the explants inoculated with Agrobacterium tumefaciens in tomato (Solanum Lycopersicum)

To optimize tomato (Solanum Lycopersicum) plant tissue culture condition, the effect of 13 different hormonal combinations and two explants of cotyledon and hypocotyl on the regeneration rate of three Newton, Infinity and Defines cultivars were investigated. Experiments were conducted in a factorial based on a completely randomized design with three replications. The highest shoot number (11.9 shoots per explant) was obtained for Defines cultivar on MS medium containing the hormones of TDZ=0.68, NAA=0.1milligrams per liter and cotyledon explant. Plant defense responses against environmental factors are one of the inhibitor factors of explants regeneration in plant tissue culture. Calcium ion signaling is one of the primary events and, of course, the most important event in plant defense response against pathogens, Therefore, the effect of verapamil as a calcium channel blocker was investigated on the plant defense response. For this purpose, inoculation was performed using Agrobacterium tumefaciens strain LBA4404 and based on optimized tissue culture condition. The effect of verapamil in four concentrations of 0, 50, 100 and 200 milligrams per liter was investigated in a co-culture medium. Results showed that the use of verapamil in comparison with the control sample reduced the plant defense response. Also, the use of 50 milligrams per liter of verapamil increased the amount of regeneration.