Spatial and Temporal Expression of Transcripts Related to Drought Stress in Two Contrasting Genotypes of Common Bean

The genes related to drought stress tolerance are differentially expressed in plant tissues and also along the time of exposure to stress. This study aimed at profiling the relative expression of selected transcripts in roots, stems and leaves in two contrasting genotypes of common bean for tolerance to drought (BAT 477 - tolerant and IAC-Carioca 80SH - susceptible),  subjected to five temporal samplings (24h, 48h, 72h, 96h and 120h) starting from a 16% soil moisture. We used the cDNA-AFLP technique for the identification of differentially expressed transcripts in both genotypes and the RT-qPCR to perform the relative expression analyses of the transcription factor DREB2C, which has been described as involved in the response to abiotic stresses, and also six selected transcripts (Serine-threonine protein kinase, Glycosyl hydrolase family 14, Serine protease family S1C HTRA-related, S-adenosylmethionine synthetase, Legume lectin domain, Ribosomal protein S7e). Comparing the relative expression between both genotypes under drought, we categorized the transcripts according to their spatial expression (induction or repression in roots, stems and leaves) and temporal expression (initial - 24h-48h, intermediate - 72h and late - 96h-120h). The DREB2C was induced in stems with late expression. The ribosomal protein was initially induced in stems and leaves. The glycosyl hydrolase was initially and late- induced in stems, intermediately in roots and lately in leaves. The S-adenoylmethionine synthetase was initially and lately induced in roots. The legume lectin was intermediately repressed in stems. The serine-threonine kinase was late- induced in roots, while serine protease was repressed.