Table II.

In vitro enzyme activities in root extracts from NHPT and HPT seedlings of the Sh1Sus1 and the sh1sus1 genotype

Genotype and Treatment	Enzyme Activity					Protein
	SuSy	INV		HK	FK
		Neutral	Acid
	nmol h−1 tip−1					μg tip−1
Sh1Sus1
NHPT	155  ± 27	162  ± 13	1046  ± 68	34  ± 3	68  ± 14	61  ± 1
HPT	326  ± 10	86  ± 14	202  ± 19	106  ± 14	82  ± 14	64  ± 1
sh1sus1
NHPT	nda	123  ± 8	459  ± 25	23  ± 2	49  ± 2	40  ± 3
HPT	19  ± 6	67  ± 2	100  ± 6	77  ± 4	48  ± 8	38  ± 2

Groups of 30 excised root tips from NHPT or HPT seedlings were homogenized for measurement of enzyme activities as described in Methods. Data are means ± sd of three independent repetitions.

^and, Not detectable.