Identification of Differentially Expressed Genes by cDNA-AFLP Technique in Response to Drought Stress in Triticum durum

Abstract

Drought is the single largest abiotic stress factor leading to reduced crop yields. The identification of diff erentially expressed genes and the understanding of their functions in environmentally stressful conditions are essential to improve drought tolerance. Transcriptomics is a powerful approach for the global analysis of molecular mechanisms under abiotic stress. To identify genes that are important for drought tolerance, we analyzed mRNA populations from untreated and drought-stressed leaves of Triticum durum by cDNA-amplified fragment length polymorphism (cDNA-AFLP) technique. Overall, 76 transcript-derived fragments corresponding to differentially induced transcripts were successfully sequenced. Most of the transcripts identified here, using basic local alignment search tool (BLAST) database, were genes belonging to different functional categories related to metabolism, energy, cellular biosynthesis, cell defense, signal transduction, transcription regulation, protein degradation and transport. The expression patterns of these genes were confirmed by quantitative reverse transcriptase real-time polymerase chain reaction (qRT-PCR) based on ten selected genes representing different patterns. These results could facilitate the understanding of cellular mechanisms involving groups of genes that act in coordination in response to stimuli of water deficit. The identification of novel stress-responsive genes will provide useful data that could help develop breeding strategies aimed at improving durum wheat tolerance to field stress.

Keywords

• cDNA-AFLP
• drought stress
• transcript-derived fragments
• durum wheat
• real-time PCR