Stimulated ethylene production in tobacco (Nicotiana tabacum L. cv. Ky 57) leaves infected systemically with cucumber mosaic virus yellow strain

Ethylene production was stimulated in the leaves of tobacco (Nicotiana tabacum L. cv. Ky 57) infected systemically with cucumber mosaic virus yellow strain (CMV-Y). This observation was made with the 9th leaf of tobacco plants which had been inoculated with CMV-Y on the 6th leaf at the middle stage of growth. A transient peak of ethylene production per fresh-weight base appeared 2 weeks after inoculation when the mosaic symptoms of green, yellow and white sectors covered about 40% of the leaf area. The increase in ethylene production was accompanied by an increase in 1-aminocyclopropane-1-carboxylate (ACC) content and activities of ACC synthase and ACC oxidase in systemically-infected leaves. Among three sectors with different colors in CMV-Y-infected mosaic leaves, ACC content was highest in the green sector, implying ethylene production took place most actively there. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.