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Differential repression of the Ve R-genes in tomato

Castroverde, Christian Danve M., Morais de Avila, Larissa G., Romero, Vivian Amaya, Blaya-Fernandez, Josefa, Nazar, Ross N., Robb, Jane
Plant gene 2019 v.18 pp. 100174
Verticillium wilt, chromatin, genes, intergenic DNA, loci, messenger RNA, pathogens, promoter regions, tomatoes, transcription (genetics)
Resistance to Verticillium wilt disease has been associated with the tomato Ve R-gene locus that comprises two genes, Ve1 and Ve2. Previous transcript analyses revealed that the tomato Ve genes are expressed differentially and that Ve1 induction by pathogen colonization mitigates the Ve2-induced defense/stress cascade. Using a promoter-reporter assay, we have sought to map regulatory sequence elements that may be responsible for Ve gene regulation. Systematic deletion mutations of the shared upstream intergenic region between Ve1 and Ve2 were fused to an EYFP reporter sequence and plant transformants expressing these constructs were selected. We showed that both functional Ve1 and Ve2 promoter regions have similar transcriptional activity, comparable to endogenous Ve2 transcript levels, suggesting that more distant regulatory elements or chromatin mechanism normally repress Ve1 promoter activity and/or influence encoded endogenous mRNA levels.