Comparative Transcript Profiling and Multiplex qRT-PCR Analysis Between Salt-Tolerant and Sensitive Wheat Genotypes

Abstract

Identification of candidate genes combined with gene expression profiling carries importance to facilitate the molecular basis of salt stress response in plants. Here, cDNA-AFLP was used to compare the transcribed sequences among two bread and two durum wheat genotypes with different levels of salt tolerance. Transcript derived fragments (TDFs) screened on polyacrylamide gels and 36 salt stress induced unique fragments were detected in salt tolerant bread wheat genotype (Alpu cv.). The fragment size of these 36 TDFs was ranged between 99bp to 252bp. Full sequence information of 14 TDFs were obtained after cloning, then GeXP analyzer-based multiplex qRT-PCR assay was performed on leaf tissue derived from 12 TDFs. Targeted gene expression levels of two TDFs (TDF4-GT066302 and TDF11-GT066301) were showed clear upregulation in salt tolerant bread wheat genotype (Alpu cv.) and they were matched with hypothetical proteins. Especially, gene expression level of GT066301 was increased as 3.28 fold at 27th hours of salt stress for salt tolerant genotype. According to blastx similarity results, out of 14 sequenced fragments, two TDFs were closely matched with “cytochrome P450 monooxygenase” protein while four of them matched with Oryza “hypothetical” and “unknown” proteins. Outputs of this study might ensure comparative data for hypothetical protein gene expression and new useful alleles in response to salt stress in wheat.