Table 1. Quantification of products formed in situ from [³H]HHA by pea epicotyl epidermis.

Extractant (a–g′) or residue	% of supplied radioactivity ± SE
	Native epidermis	Heat-denatured epidermis
a. Acidified aqueous methanol1 (methanol/formic acid/water) (9 : 1 : 1) (MFW) in vacuo	55.2 ± 4.6	92.2 ± 1.1
b. Toluene	7.5 ± 1.6**	0.5 ± 0.3
c. Chloroform/methanol (2 : 1) (CM)	2.3 ± 0.5*	0.2 ± 0.1
d. Chloroform/methanol/water (10 : 10 : 3) (CMW)	0.9 ± 0.6	0.0 ± 0.0
e. Proteinase K (releasing putative peptide-bonded material)	0.4 ± 0.1	0.4 ± 0.2
f. Chloroform/methanol/NaOH (CMNaOH) (releasing putative ester-bonded material)	1.9 ± 0.4**	0.4 ± 0.2
g. XEG (releasing putative xyloglucan-bonded material)	0.02	0.02
g′. 2M TFA (releasing putative unspecified matrix polysaccharide-bonded material)	0.2 ± 0.2	0.0 ± 0.0
Final insoluble residue (H or H′)	0.0 ± 0.0	0.0 ± 0.0
Total	68.4	93.7

In three independent experiments, blot-dried pea epicotyl epidermis (200 mg; native or heat-denatured) was incubated with 2.81, 4.28 or 12.1 kBq [³H]HHA in 300 µl buffer (pH 5.5) at 20°C for 24 h. The radiolabelled products were then fractionated as in Figure 2. Errors are given as ± SE (n = 3 biological replicates).

* P_{native vs. denatured} < 0.05. ** P_{native vs. denatured} < 0.01.

¹Extract ‘a’ includes only the solutes in the first MFW extraction, performed in vials. The epidermis was subsequently washed more thoroughly by irrigation with MFW by a paper chromatography setup, where the chromatographically mobile radioactivity was not assayed. This explains why the total is <100%;

²No SE given (n = 1).