DIFFERENTIAL ACTIVATION OF EXPRESSION OF A SUBERIZATION-ASSOCIATED ANIONIC PEROXIDASE GENE IN NEAR-ISOGENIC RESISTANT AND SUSCEPTIBLE TOMATO LINES BY ELICITORS OF VERTICILLIUM-ALBO-ATRATRUM

We tested whether the expression of the suberization-associated anionic peroxidase gene is involved in the timely appearance of the vascular suberized coating involved in the resistance of a tomato line to Verticillium albo-atrum. The mRNA for this peroxidase appeared at a higher level one day earlier in wound-healing fruits of the resistant tomato line than in a near-isogenic susceptible line. Cell cultures from the resistant line, when treated with low levels (nanograms per milliliter) of fungal elicitor, generated the peroxidase mRNA and this apparent activation of the peroxidase gene expression could be detected in minutes, whereas the cells from the susceptible line hardly responded.