OLIGONUCLEOTIDES EVALUATION FOR MEASURING GENE EXPRESSION DURING TOMATO BACTERIAL WILT

Abstract

Bacterial wilt caused by Ralstonia solanacearum affects the tomato (Solanum lycopersicum) crop  in several parts of México. Knowledge of plant-bacteria interaction might provide tools to control this disease. The expression profiles of genes related with defense in tomato and pathogenicity in R. solanacearum, could allow the identification of essential genes for blocking wilt development. The RT-qPCR technique is suitable to quantify the levels of gene expression. However, it is important to evaluate the efficiency and dynamic range of oligonucleotides to be used in order to rule out the possibility that the differences observed are influenced by technical issues and not only by biological causes. With the aim of identifying oligonucleotide pairs that can perform properly under the experimental conditions used, in this study, the performance of 40 oligonucleotides pairs, both previously reported and de novo synthesized, were evaluated; 23 of these pairs are associated to 16 genes of tomato and 17 are associated to 10 genes of R. solanacearum. Results showed that those oligonucleotides with adequate performance in one laboratory, not always perform adequately under the conditions prevalent in other laboratory, which underlines the importance of reviewing sequences and evaluating each pair of oligonucleotides with the reagents and equipment with which the gene expression levels are going to be evaluated, regardless of previous reports on the performance of such oligonucleotides.