Adenine phosphoribosyl transferase (SmAPRT) is an appropriate reference gene for quantitative gene expression analysis by RT-qPCR in different tissues as well as in the response to some specific stress conditions of eggplant (Solanum melongena L.)

Abstract

Eggplant (Solanum melongena L.), an important vegetable crop because of its nutritional and medicinal values, is often attacked by insects and pathogens. Quantitative gene expression analysis by reverse transcription‒quantitative PCR (RT‒qPCR) is an effective and common approach to analyze the function of genes involving in the stress responses in eggplant. The RT‒qPCR method always included the step of normalizing the expression data of the target gene to that of a stably expressed internal reference gene to ensure the accuracy of the quantitative results. This paper presented the evaluation of the transcriptional expression of adenine phosphoribosyl transferase (SmAPRT) gene in different tissues of S. melongena (young leaf, mature leaf, stem, root, flower, and fruit) under normal conditions. Besides, the expression of SmAPRT was also measured in leaf tissues of plants damaged by mechanical wounding, plants treated with stress signal molecules induced by methyl jasmonate (MeJA) or methyl salicylate (MeSA), and untreated control plants. PCR with a SmAPRT-specific primer pair (SmAPRT-qF as forward primer and SmAPRT-qR as reverse primer) amplified a 103-bp fragment from S. melongena with the efficiency of 92.7%. This value was within the recommended range (90‒110%). The Ct values of qPCR reactions using cDNA template from the wounded plants or plants treated with MeJA or MeSA were not statistically significantly different from the Ct ones of the control plants. This SmAPRT gene was also stably expressed in all tested eggplant tissues. Therefore, SmAPRT would be used as a reference gene to normalize expression data of genes of interest in different tissues as well as in the response of S. melongena to the specific stress conditions as stated above.