Showing papers on "Systemic acquired resistance published in 1980"

Role of different stresses in inducing systemic acquired resistance to TMV and increasing cytokinin level in tobacco.

Abstract: The application of leaf spot inducing bacteria or HgCl2 to lower leaves of Xanthi-nc tobacco, or systemic virus infection by cucumber mosaic virus increased the cytokinin level and induced resistance to tobacco mosaic virus (TMV), the development of local lesions, in the upper leaves. Acquired resistance (protection) induced by different agents was manifested by suppression of the necrotic reaction in the upper leaves after inoculation by TMV, rather than by inhibition of multiplication of the virus. The hypothesis that cytokinins have a role in suppressing necrosis is supported by the fact that exogenously applied cytokinin also inhibits the necrosis caused by HgCl2. Root formation by derooted Xanthi-nc tobacco plants (which had previously been inoculated by bacteria or virus or treated by HgCl2) was strongly inhibited, which also suggests an increase in cytokinin levels in inoculated plants. Stresses caused by treatment of the lower leaves of tobacco plants with viral, bacterial, or with mercuric chloride increase cytokinin levels in the untreated leaves. At the same time, to the necrosis usually caused by TMV is controlled in these leaves.