Table I.

RT-PCR quantitation of MT1a and MT2a mRNA expression in excised roots, hypocotyls, cotyledons, and primary leaves from 6.5-d-old Ws seedlings

Plant Part	MT1a		MT2a
	Control	40 μm CuCl2	Control	40 μm CuCl2
	%
Root	62  ± 29	54  ± 24	75  ± 32	68  ± 22
Hypocotyl	31  ± 20	91  ± 35	27  ± 34	77  ± 26
Cotyledon	139  ± 20	142  ± 11	13  ± 27	182  ± 28
Primary leaves	20  ± 13	183  ± 47	130  ± 51	137  ± 43

mRNA expression levels were quantitated fluorometrically after size verification on agarose gels (see Methods) and are expressed as mean percentages ± sd of measured β-tubulin mRNA levels. High sd of primary leaf mRNA is the result of the difficulty in excising small (approximately 7% of total seedling fresh weight) primary leaves at this stage of development.