Transcriptome analysis and transcription factors responsive to drought stress in Hibiscus cannabinus

Kenaf is an annual bast fiber crop. Drought stress influences the growth of kenaf stems and causes a marked decrease in fiber yield and quality. Research on the drought resistance of kenaf is therefore important, but limited information is available on the response mechanism of kenaf to drought stress. In this study, a transcriptome analysis of genes associated with the drought stress response in kenaf was performed. About 264,244,210 bp high-quality reads were obtained after strict quality inspection and data cleaning. Compared with the control group, 4,281 genes were differentially expressed in plants treated with drought stress for 7 d (the drought stress group). Compared with the control group, 605 genes showed differential expression in plants subjected to drought stress for 6 d and then watered for 1 d (the rewatering group). Compared with the rewatering group, 5,004 genes were differentially expressed in the drought stress group. In the comparisons between the drought stress and control groups, and between the drought stress and rewatering groups, the pathway that showed the most highly significant enrichment was plant hormone signal transduction. In the comparison between the rewatering and control groups, the pathways that showed the most highly significant enrichment were starch and sucrose metabolism. Eight transcription factors belonging to the AP2/ERF, MYB, NAC, and WRKY families (two transcription factors per family) detected in the leaf transcriptome were associated with the drought stress response. The identified transcription factors provide a basis for further investigation of the response mechanism of kenaf to drought stress.