Verapamil, a Calcium Channel Blocker, Induces Systemic Antiviral Resistance in Susceptible Plants
Plant viruses can cause serious crop losses. Calcium homoeostasis is involved in the movement of animal viruses. We have examined whether intracellular calcium flux can interfere with spread of virus in plants. The calcium channel blocker verapamil, applied to Nicotiana tabacum cv. Xanthi-nc plant leaves, interfered with Tobacco mosaic virus infection in treated and untreated leaves, reducing TMV lesion number by 68 and 71%, respectively. Verapamil interfered with calcium homoeostasis of leaf cells, evident by increased calcium efflux from leaf segments. This is a first effort to use calcium channel blockers as an inducer of systemic virus resistance in plants.