Microarray analysis of nitric oxide responsive transcripts in Arabidopsis root G2/M junction cells

Nitric oxide (NO) is an inevitable signaling molecule available throughout the plants life. In addition to its effects on each step of plant growth, it possibly has a key role in cell cycle. However, limited by the current understanding of the cell cycle, gene expression profiles of the G2/M junction cells in responses to NO remain limited. Regulation on gene expression in response to NO was investigated in root G2/M junction cells by applying whole genome ATH1 microarray analysis, which included more than 24,000 genes. We analyzed the effects of NO on G2/M junction cells isolated by fluorescent activated cell sorting (FACS) employing a G2/M definite transgenic reporter construct (cycB1::GFP) in Columbia wild-type (WT) and chlorophyll a/b combining proteins associated with (cue1) mutant (with high level endogenous NO) background. By comparing the gene expression under 20 μM sodium nitroprusside (SNP) in WT background, 35 differentially expressed genes were observed. Thirty genes were up-regulated genes while five others down-regulated. Majority of genes were phytohormone-related. Their involvement in the cell cycles regulation, indicated that NO may regulate cell division through the regulation of phytohormone. By comparing the gene expression in the cue1 background, it was noticed that 110 genes are differentially expressed. Thirteen genes were up-regulated while 97 down-regulated. A majority of genes were involved in metabolic regulation and stress response indicating that NO may aggravate metabolic disorder in cue1 mutant. This research revealed the effects of NO on G2/M junction cells in Arabidopsis based on a whole genome microarray. These researchers provide essential insight into plant cell cycle and growth in response to NO.