Transcriptional profiles of drought-responsive genes in modulating transcription, signal transduction and biochemical pathways in tomato
Experiment description: To unravel the molecular mechanisms of drought responses in tomato, gene expression profiles between two drought-tolerant lines identified from an introgression line population of Solanum pennellii, and the recurrent parent S. lycopersicon cv. M82, a drought-sensitive cultivar, were investigated under drought stress using tomato microarrays. Around 400 drought-responsive genes were specifically expressed in the drought-tolerant lines. These specifically regulated genes are most likely caused by the two inserted chromosome fragments of S. pennellii which possibly contain drought tolerance quantitative trait loci (QTLs). Among these genes are a number of transcription factors and signaling proteins, which could be global regulators involved in tomato responses to drought stress. Genes involved in organism growth and development process were also specifically regulated by drought stress, including those controlling cell wall structure, wax biosynthesis and plant height. Moreover, key enzymes in pathways of gluconeogenesis (fructose-bisphosphate aldolase), purine and pyrimidine nucleotides biosynthesis (adenylate kinase), tryptophan degradation (aldehyde oxidase), starch degradation (beta-amylase), methionine biosynthesis (Cystathionine beta-lyase), and removal of superoxide radicals (catalase) were also specifically affected by drought stress. The results indicated that tomato plants could adapt to water deficit condition through decreasing energy dissipation, increasing ATP energy provision and reducing oxidative damages. The specifically and commonly regulated genes identified in this study could provide further information to facilitate understanding the mechanisms of drought-tolerance in tomato.
Author: Zhibiao Ye
Contact: Zhibiao Ye (firstname.lastname@example.org), Huazhong Agricultural University