Table II.
Concentration of oligolignols identified in COMT-deficient or control poplars
| Product
|
Mean pmol mg−1 Dry Weight ± s.e.m.
|
Fold Change
|
||||
|---|---|---|---|---|---|---|
| Control
|
COMT
|
|||||
| WT | 35S 17B | 35S 21B | ASB 2B | ASB 10B | ||
| G(8–O–4)5H 1a | ND | ND | ND | 683 ± 70* | 666 ± 120* | 260 |
| G(8–O–4)5H 1b | ND | ND | ND | 51.4 ± 5* | 49.6 ± 7* | 19 |
| G(8–5)G′(8–O–4)5H 2 | ND | ND | ND | 68.0 ± 5* | 84.7 ± 20* | 29 |
| G(8–O–4)5H′ 3a | ND | ND | ND | 180 ± 20* | 191 ± 40* | 71 |
| G(t8–O–4)G | 69.5 ± 31 | 38.8 ± 29 | 94.3 ± 40 | 111 ± 30 | 86.8 ± 32 | |
| G(8–5)G | 105 ± 40 | 95.5 ± 28 | 98.1 ± 24 | 134 ± 40 | 111 ± 30 | |
| G(8–8)G | 53.3 ± 8 | 46.5 ± 3 | 42.2 ± 5 | 68.7 ± 8 | 77.3 ± 3 | |
| S(8–8)S | coel. | coel. | coel. | 17.8 ± 5 | 14.2 ± 7 | |
| S(8–5)G | 41.3 ± 6 | 31.2 ± 9 | 39.3 ± 5 | 12.0 ± 1 | 26.6 ± 3 | |
| G(8–5)V′ | ND | ND | ND | ND | ND | |
| G(8–5)G′ | 13.5 ± 7 | 2.52 ± 0.4 | 4.64 ± 1.2 | 50.0 ± 9* | 43.9 ± 10* | 6.8 |
| G(t8–O–4)G(t8–O–4)G | 20.4 ± 4 | 15.6 ± 7 | 23.3 ± 5 | 14.1 ± 3 | 9.22 ± 3.0 | |
| S(t8–O–4)S(8–5)G | ND | ND | ND | ND | ND | |
| G(t8–O–4)S(8–5)G | 151 ± 30 | 153 ± 30 | 152 ± 20 | 61.8 ± 9* | 57.9 ± 10* | 0.40 |
| G(e8–O–4)S(8–5)G | 35.7 ± 4 | 37.7 ± 7 | 34.9 ± 6 | 3.35 ± 0.9* | 4.06 ± 1.2* | 0.10 |
| S(t8–O–4)S(8–5)G′ | coel. | coel. | coel. | coel. | coel. | |
| SP(8–8)S | 20.3 ± 6 | 27.2 ± 5 | 24.4 ± 6 | ND* | ND* | 0.11 |
| G(t8–O–4)S(8–5)G′ | 107 ± 10 | 125 ± 20 | 96.0 ± 13 | 68.6 ± 5 | 126 ± 10 | |
| G(e8–O–4)S(8–5)G′ | 85.8 ± 7 | 92.9 ± 25 | 82.1 ± 13 | 14.8 ± 4* | 18.7 ± 8* | 0.19 |
| G(8–O–4)S(8–8)S(8–O–4)G | 66.4 ± 6 | 65.0 ± 11 | 67.5 ± 6 | 19.1 ± 2* | 26.6 ± 4* | 0.34 |
Mean concentrations, expressed as pmol mg−1 dry weight, are shown for the control poplar lines (wild-type and transgenic lines 35S 17B and 35S 21B) and poplars down-regulated for COMT (transgenic lines ASB 2B and ASB 10B). Those oligolignols for which the concentration could be determined in control (Morreel et al., 2004) and/or COMT-deficient poplar are presented. The fold change of the product abundance in COMT-deficient poplars relative to the control lines is indicated. When the peak was not detected, the relative increase was calculated using a detection limit of 2.6 pmol mg−1 dry weight. Significantly different concentrations between control and COMT-deficient poplars are marked by an asterisk. coel., Concentration not determined because of coelution of two or more compounds; ND, not detected; s.e.m., se of the mean.