Authors:R. Bacsó, Y. Hafez, Z. Király and L. Király
In spite of the enormous information from research on genetics of plant disease resistance, the question still remains unresolved: what is directly inhibiting or killing pathogens and suppressing symptoms in resistant plants? This is particularly true for resistance to viral infections. Here we show that externally applied reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) or ROS-producing (O
[superoxide] and H2O2) chemical systems infiltrated into tobacco leaves 2 hours after inoculation suppress replication of Tobacco mosaicvirus (TMV) in the susceptible Samsun (nn) cultivar. This was determined by a biological and a real-time PCR method. Infiltration of leaves of the resistant Xanthi (NN) cultivar with the ROS-producing chemicals and H2O2 significantly suppressed local necrotic lesions (i.e. the hypersensitive response) after inoculation of tobacco leaves with TMV. Accordingly, an early accumulation or external application of ROS, such as O
and H2O2, in tobacco may contribute to the development of resistance to TMV infection.
Smith, H. A., Swaney, S. L., Parks, T. D., Wernsman, E. A. and Dougherty, W. G. (1994): Transgenic plantvirusresistance mediated by untranslatable sense RNAs: Expression, regulation and fate of nonessential RNAs. Plant Cell 6, 1441