Comparative transcriptome analysis of root hairs proliferation induced by water deficiency in maize

Root hairs functions as water channels and nutritional components transporters in plants. It has been shown to enhance nutrient uptake including phosphate, nitrogen, potassium and calcium. In the experiment, the droughtinduced root hairs were collected. By transcriptome sequence and analysis, the molecular mechanisms and differentially expressed genes related to root hairs growth and development were studied. As a result, by using the HiSeq 2500 platform, 61,872,790 clean reads with 96.23% Q20 bases and 9.28 Gb clean bases with 58.88% GC ratio were obtained for normal root. In contrast with Control group, 67,650,572 clean reads with 96.43% Q20 bases and 10.15 Gb clean bases with 58.3% GC content were obtained for drought-induced root hairs. Totally, 323 differentially expressed genes (DEGs) were identified. Among these DEGs, 109 genes were upregulated and 214 genes were downregulated in drought-induced root hairs. Moreover, metabolic pathway enrichment analysises on the 323 DEGs revealed that totally 10 metabolic pathways were distinctly regulated. In details, alanine, aspartate and alutamate metabolism, galactose metabolism and nitrogen metabolism were significantly upregulated. 7 metabolic pathways such as phenylpropanoid biosynthesis, phenylalanine metabolism, biosynthesis of secondary metabolites and flavonoid biosynthesis were significantly downregulated. Furthermore, functional genes and transcription factors were both found to be involved in drought-induced root hair proliferation. These results will help us understand better the molecular mechanism of maize root hair growth and development.