Multiple roles of nitrate transport accessory protein NAR2 in plants

Figures & data

Figure 1 Root cross sections of plants transformed with OsNAR2.1 promoter-GUS genes. The expression specificity of OsNAR2.1 in the root of ten-day-old seedlings (Oryza sativa L. ssp. Japonica cv. Nipponbare) cultured with de-ionized water containing 25 mgL⁻¹ hygromycin. Transverse sections are taken from approximately 0.5 mm (A), 1.5 mm (B), 1 cm (C) and 1.5 cm (D) from the root tip.

Table 1 Literature summary of the tissue expression and regulation of some NRT2s in higher plants

Gene (Accession number)	Expression		Regulation
	Characterization	Technique
AtNRT2.1/2.2 (AF019748/AF01979)	Root cortical and epidermal cells	RT-PCR; GUS/GFP fusion	NO3^−, sucrose and light induction; NH4^+ and amino acids repression
AtNRT2.3 (AB015472)	Mainly in roots	RT-PCR	NO3^− induction in shoots
AtNRT2.4 (AB015472)			Modest NO3^− induction
AtNRT2.6 (AL353992)			-
AtNRT2.5 (AC012187)			NO3^− repression; Glucose induction
AtNRT2.7 (AL163792)	Shoots; Embryo; seeds	RT-PCR; GUS/GFP fusion	NO3^− insensity
ZmNRT2.1 (AY129953)	Root epidermis and cortex	RT-PCR; In situ hybridization	NO3^− induction; Glucose down- and sucrose upregulation
ZmNRT2.2 (AY659965)	Root endodermis, centralcylinder and lateral primordia
NpNRT2 (Y08210)	Strong in epidermis and endodermis close to the root tip, week in the epidermis and lateral root primordia in the mature part of the root	RNA gel blot; In situ hybridization	NO3^− induction
HvNRT2.1	Root	RNA gel blot	NO3^− and NO2^− induction
OsNAR2.1 (AP008208)	Strongest in root epidermis and lower in cortex and stele	RT-PCR; GUS fusion	NO3^−, light and sucrose upregulation; NH4^+ repression
OsNRT2.1 (AP008519)	Whole roots; leaves; week in hulls and anthers
OsNRT2.2 (AP008519)	Whole roots; leaves; strong in hulls and anthers
OsNRT2.3a (AP003245)	Root stele; leaves; seed scutellum
OsNRT2.3b (AP003245)
OsNRT2.4 (AP004614)	Adventitious root primordial; leaves; ends of the hull and in vascular tissue of the anther	NO3^−, light and sucrose upregulation; NH4^+ repression