Transcriptome analysis of drought response in a domestic wheat cultivar (Triticum aestivum L. cv. Keumkang)

Drought stress is one of the most important environmental factors limiting agricultural productivity of wheat (Triticum aestivum L.), particularly under the conditions of global climate change. Although the molecular mechanisms underlying plant drought stress-responses have been recently studied in various wheat cultivars, to date, profiling of the drought response-related transcriptome of Keumkang, a domestic wheat cultivar cultivated mainly in South Korea, has not been conducted. Therefore, based on Illumina RNA sequencing (RNA-seq), we performed a comparative transcriptome analysis in seedlings of cv. Keumkang kept under drought stress up to 24 h. A total of 4700, 10,560, and 9656 up-regulated and 1128, 6363, and 8428 down-regulated transcripts, relative to control levels, were identified in the aboveground parts of wheat seedlings at 3, 6, and 24 h after drought initiation, respectively. The most representative transcripts, including those of abscisic acid (ABA) response genes, ethylene-activated signaling pathways, and water deficit, desiccation, cold, and wounding responsive genes were expressed at higher levels under drought than under normal conditions; furthermore, many drought tolerance-related genes accumulated under the same conditions. Our results contribute to expanding our understanding of the molecular events associated with drought responses and provide a deeper insight into genetic information for further studies on the adaptability of cv. Keumkang to abiotic stress.