Transcriptome Characterization of Gene Profiling During Early Stage of Nitric Oxide-Induced Adventitious Rooting in Mung Bean Seedlings

Abstract

Nitric oxide (NO) functions as a signaling molecule modulating diverse developmental and physiological processes in plants. NO was recently shown to strongly induce the formation of adventitious roots in plants. A transcriptome analysis was performed using RNA-Seq and qRT-PCR technologies to obtain further insights into the gene expression profile underlying NO-induced adventitious rooting. Sodium nitroprusside (SNP), a widely used NO donor, significantly up-regulated the GO terms and pathways oxidoreductase activity, wounding response, water deprivation response, microtubule-based process, cell cycle, cell wall synthesis, photosynthesis, hydrolase activity at the root induction stage, response to stress, cell wall loosening and biogenesis, ethylene signaling at the root initiation stage. In total, 2582 and 2588 differentially expressed genes (DEGs, fold change ≥ 2) were selected in plants receiving the 6- and 24-h SNP treatments, respectively. The analysis of the most highly differentially expressed genes (RPKM ≥ 10 and fold change ≥ 2) shows that NO significantly regulated the expression of genes involved in nitrogen compound response, stress response, oxidative stress response, cell wall modification, signal transduction, protein processing, secondary metabolism, metabolic processes, and transcription factors (TFs), as well as plant hormone signaling. Notably, the expression of a large number of genes encoding peroxidase (POD) isoforms was significantly differentially regulated by SNP. Furthermore, qRT-PCR results indicated that NO significantly up-regulated the expression of several genes with known functions in pathways such as auxin signaling and stress response, as well as TF genes, at the root induction and initiation stages. The evidence obtained implies that NO up-regulated the expression of genes that are involved in the key cellular processes leading to the root formation.