Table I.

Thylakoid-bound and soluble isoprene synthase activity from leaf fractionations performed within a 2-week period

Experiment	Isoprene Synthase Activity
	Thylakoid bound	Percent	Soluble	Percent	Total	Percent
	pmol isoprene min−1		pmol isoprene min−1		pmol isoprene min−1
1	1146	45	1418	55	2564	100
2	740	47	821	53	1561	100
3	1368	44	1742	56	3110	100
4	840	25	2583	75	3423	100
Average	1024	40	1641	60	2665	100
sd	287	11	735	11	817

Mature willow leaves (10 g) were fractionated into total thylakoid-bound and soluble isoprene synthase activities, as described in Methods. Each value is the average of duplicate samples.