Table 3.

Summary of the relative gene expression level of N and C metabolism genes in the three genotypes growing under N limitation, the number of positive or negative indicates the higher or lower level of the trait relative to the SRG-100 genotype.

	SRG-100	SRG-200	SRG-150
Adaptation to N limitation	*	**	***
LEAVES N TRANSPORTER GENES
ZmNRT1.1	+	+++++	++
ZmNRT1.2	+	++++++	++
ZmNRT2.2	+	+++	+
ZmNRT2.3	+	++	+
STEM N TRANSPORTER GENES
ZmNRT1.1	+	++++	++
ZmNRT1.2	+	+	+
ZmNRT2.2	+	+	+
ZmNRT2.3	+	+	+
ROOTS N TRANSPORTER GENES
ZmNRT1.1	+	+	+
ZmNRT1.2	+	++	−
ZmNRT2.2	+	−	−
ZmNRT2.3	+	+++	+
LEAVES GLUTAMINE SYNTHASE GENES
ZmGln1	+	+++	+
ZmGln2	+	+++	+
ZmGln4	+	+++++	+++
ZmGln5	+	++++++	++
ZmGS1.3	+	++++++++	++
ZmGS1.4	+	++	+
ROOTS GLUTAMINE SYNTHESIS GENES
ZmGln1	+	+	+
ZmGln2	+	+	+
ZmGln4	+	+	+
ZmGln5	+	+	++
ZmGS1.3	+	+	+
ZmGS1.4	+	+	+++
LEAVES NITRATE AND NITRITE REDUCTASE GENES
ZmNR1	+	+++++	++
ZmNR2	+	+++	+
ZmNAR1S	+	+++++++	+++
ZmNiR	+	++	+
ZmF-NiR	+	+	+
ROOTS NITRATE AND NITRITE REDUCTASE GENES
ZmNR1	+	+	+
ZmNR2	+	+	+
ZmNAR1S	+	+	+
ZmNiR	+	+	+
ZmF-NiR	+	+	+
Carbon metabolism genes
ZmAGPP	+	+	+
ZmSuPP	+	+	+
ZmSS	+	+	+++