Activities of Defense Enzymes in Tomato Leaves with Riboflavin and TYLCV Inoculation

Tomato cultivar '1479' were treated with riboflavin and TYLCV.The activities of peroxidase(POD),polyphenoloxidase(PPO) and phenylalanine ammonialyase(PAL) in tomato leaves were determined to study.The results showed that riboflavin can significantly lower disease index of tomato yellow leaf curl virus,and the induced resistant effect with 2 mmol/L riboflavin was the best,reached 41.91%.The activities of POD,PPO and PAL were increased significantly in tomato leaves within 96 h after spraying 2 mmol/L riboflavin.After inoculating TYLCV,the activities of defense enzymes in tomato leaves were significantly increased with riboflavin treatment and TYLCV inoculation.The above results indicated that the systematically-enhanced activities of POD,PPO and PAL by riboflavin were closely correlated to the induced resistance of tomato to TYLCV.