Transcriptional Profiles of Roots of Different Soybean Genotypes Subjected to Drought Stress

To identify differentially expressed genes in soybean grown under different drought conditions, cDNA libraries from roots of different genotypes were constructed. Genes of contrasting genotypes of soybean were found to be differentially expressed in plants exposed to drought conditions. A total of 753 no redundant clones were identified by PCR, and these were printed on microarray glass slides. Probes of total RNA were prepared from bulked roots subjected to 25 and 50 min (Bulk 1) or 75 and 100 min (Bulk 2) of drought stress. Differential expression of 145 genes, involved in metabolic pathways responsive to biotic and abiotic stresses, was observed. These genes were classified into nine functional categories, including energy, transcription factors, metabolism, stress response, protein synthesis, cell communication, cell cycle, cell transport, and unknown function. The functionality of some of these genes was confirmed by quantitative real-time PCR (qRT-PCR).