Figure 2

The expression pattern of 51 assembled unigenes involved in nitric oxide metabolism from two libraries.

(a) The pathway of NO metabolism in planta. The heatmap of expression profiling generated from two transcriptomic libraries. Red indicates a high expression level, and green indicates a low expression level. PAB: pseudobulb with axillary bud. PIB: pseudobulb with inflorescent bud. (b–k) The relative gene expression levels of the following ten genes involved in NO metabolism were monitored in PIB and PAB at the vegetative stage (□ white square), the bolting period ( gray square) and the reproductive stage (■ black square): NOS-interacting protein (NOSIP); NOS protein inhibitor (NOSPI); NOS-associated protein (NOSAP); nitric oxide synthase-like (NOS); nitrite transporter (NiT); nitrite reductase (NiR); nitrate reductase (NaR); nitrate transporter (NaT); molybdopterin synthase catalytic subunit (MPT) and non-symbiotic hemoglobin (Hb-1). Gene expression levels in each sample were compared to those in PAB at the vegetative stage. Error bars indicate standard deviation (s.d.). Asterisks represent significant differences from PAB tissue at the vegetative stage according to two-way ANOVA (*p < 0.05; **p < 0.005; ***p < 0.0005).