Table II.

Summary of real-time RT-PCR data for selected candidate genes at control Zn concentrations

Transcript levels relative to EF1α of selected candidate genes as determined by real-time RT-PCR are given for shoot and root tissues from plants grown under control conditions. Values are mean and se of between three and five independent experiments for A. halleri and A. thaliana. The statistical significances of the differences between A. halleri and A. thaliana expression levels was assessed with a Student's t test (two sample assuming unequal variances), P values are indicated as follows: * = P < 0.05; ** = P < 0.01; *** = P < 0.001. In real-time RT-PCR experiments, genes were determined as not expressed (n.e.) when C_T values were above a threshold of 35 and reaction efficiencies with the respective cDNA were more than 5% below the mean RE for the respective primer pair; n.d. = not determined.The normalized -fold difference between A. halleri and A. thaliana from ATH1 microarray data is given for comparison (see Table I for further details). Flags denote calls as given by MAS5: P = present; M = marginal; A = absent. NAS1 and NAS4 were included for comparison with the other members of the NAS family.

Gene Name	Root							Shoot							Tissue with Higher Expression in A. halleri Compared to A. thaliana
	Real-Time RT-PCR				Microarray			Real-Time RT-PCR				Microarray
		A. halleri Transcript Level		A. thaliana Transcript Level	A. halleri/A. thaliana Transcript Ratio	A. halleri/A. thaliana Signal Ratio	A. halleri Flag	A. thaliana Flag	A. halleri Transcript Level		A. thaliana Transcript Level	A. halleri/A. thaliana Transcript Ratio	A. halleri/A. thaliana Signal Ratio	A. halleri Flag	A. thaliana Flag	Real-Time RT-PCR	Microarray
Cytoplasmic metal influx
ZIP3	498 ± 46.0	**	108 ± 46.1	4.62	1.71*	P	P	10.2 ± 2.62	*	1.29 ± 0.43	7.89	2.37	A	A	Root, shoot
ZIP4	155 ± 19.6	***	13.1 ± 1.74	11.9	24.6***	P	A	52.6 ± 7.96		92.1 ± 44.3	0.57	4.04*	P	P	Root	Root, shoot
ZIP9	654 ± 189	*	50.0 ± 4.61	13.1	36.2***	P	P, A	n.e.		n.e.	n.d.	6.32	A	A	Root	Root
ZIP10	17.9 ± 4.98	*	2.89 ± 0.71	6.18	111**	P, M	A	n.e.		n.e.	n.d.	3.24	A	A	Root	Root
IRT3	191 ± 20.5	***	40.9 ± 14.6	4.68	4.47*	P	P	85.0 ± 4.70		63.8 ± 38.9	1.33	1.70*	P	P	Root	Root
ZIP6	122 ± 27.9	*	26.3 ± 4.78	4.64	2.16*	P	P	183 ± 33.5	**	18.2 ± 5.35	10.1	7.34***	P	M, A	Root, shoot	Shoot
Root-to-shoot metal transport
HMA4	2,092 ± 401	**	327 ± 29.2	6.39	0.71	P	P	1,141 ± 332	*	37.9 ± 31.4	30.1	52.5**	P	A	Root, shoot	Shoot
FRD3	292 ± 87.8	*	18.8 ± 4.95	15.5	44.6***	P	P	46.5 ± 13.3	*	7.45 ± 3.05	6.23	37.1*	P	A	Root, shoot	Root
Other membrane transport
MTP8	10.6 ± 3.53	*	1.39 ± 0.53	7.65	15.9*	A	A	32.4 ± 7.84	*	2.86 ± 1.45	11.3	65.0**	P, A	A	Root, shoot	Shoot
PHT1;4	77.6 ± 15.9	*	18.7 ± 1.43	4.15	19.1**	P	P	108 ± 10.2	***	20.2 ± 10.3	5.33	446*	P	A	Root, shoot	Root
Nicotianamine/thiol biosynthesis pathways
NAS1	52.0 ± 10.4		49.5 ± 24.9	1.05	0.81	P	P	37.4 ± 9.27		79.3 ± 26.7	0.47	0.54	P, M	P
NAS2	437 ± 113	*	27.5 ± 14.9	15.9	48.4***	P	P	n.e.		n.e.	n.d.	3.14	P, A	A	Root	Root
NAS3	13.9 ± 2.55	**	0.20 ± 0.05	71.4	5.22**	P	A	44.7 ± 5.06	*	15.8 ± 6.43	2.82	7.89**	P	P	Root, shoot	Root, shoot
NAS4	12.3 ± 1.54		6.93 ± 2.12	1.78	13.7	P, M	A	34.5 ± 10.4	*	125 ± 34.6	0.28	0.36*	P	P
OASA2	22.7 ± 5.28		83.5 ± 27.1	0.27	3.25*	P	P	13.3 ± 2.08		64.7 ± 30.8	0.21	10.6***	P	P		Shoot
SAMS2	881 ± 140	**	158 ± 36.4	5.59	2.60*	P	P	422 ± 65.4	**	70.6 ± 24.6	5.97	8.54***	P	P	Root, shoot	Shoot
Stress protection
PDI1	362 ± 56.7	*	173 ± 42.9	2.10	3.50**	P	P	355 ± 63.3	*	91.3 ± 47.1	3.89	39.5**	P	P	Root, shoot	Shoot
PDI2	118 ± 20.4		125 ± 48.8	0.94	3.08*	P	P	129 ± 16.9		127 ± 49.3	1.01	17.5**	P	P		Shoot