Nitric oxide (NO) and hydrogen peroxide (H2O2) have been shown to be important signaling molecules that participate in the regulation of several physiological processes. In particular, they have significant role in plant resistance to pathogens by contributing to induction defense genes. Here, whether NO and H2O2 participate in the resistance responses against Verticillium dahliae toxins (VD-toxins) and their effects on the expression of GST gene are studied. The results reveal that NO and H2O2 are produced as part of a complex network of signals that respond to VD-toxins and may converge to function both synergistically and independently by inducing resistant responses. GST gene is potentially involved in the resistance mechanism in the cotton suspension cells. NO induces the expression of GST gene independently of H2O2. H2O2 may be a more potent signal in the resistance responses against VD-toxins.
