Table 1.
Activity [μkat (g f.
wt)−1] |
|||||||
---|---|---|---|---|---|---|---|
Sample | Intact tissue | s.d. | Damaged tissue | s.d. | AF | Mean AF | |
LIN | B I | 0·69 | 0·16 | 2·63 | 0·39 | 4 | 8 |
B II | 0·23 | 0·03 | 3·11 | 0·70 | 14 | ||
B III | 0·23 | 0·09 | 1·66 | 0·44 | 7 | ||
C I | 0·69 | 0·13 | 4·65 | 0·57 | 7 | ||
C II | 0·29 | 0·04 | 3·85 | 0·86 | 14 | ||
C IV | 1·15 | 0·04 | 11·01 | 1·57 | 10 | ||
D I | 0·86 | 0·16 | 6·02 | 1·44 | 7 | ||
D II | 0·57 | 0·09 | 3·65 | 0·65 | 6 | ||
D V | 1·33 | 0·08 | 8·82 | 0·21 | 7 | ||
HNL | B VI | 1·84 | 0·13 | 4·33 | 0·82 | 2·4 | 4 |
B VII | 9·05 | 0·10 | 12·79 | 0·58 | 1·4 | ||
B VIII | 2·54 | 0·22 | 9·70 | 0·32 | 3·8 | ||
C IX | 6·03 | 0·78 | 9·11 | 0·64 | 1·5 | ||
C VI | 1·18 | 0·56 | 3·35 | 0·22 | 2·8 | ||
C VIII | 2·37 | 0·17 | 6·52 | 0·29 | 2·8 | ||
D IX | 1·43 | 0·41 | 7·07 | 0·81 | 4·9 | ||
D IV | 2·99 | 1·42 | 30·43 | 7·71 | 10·2 | ||
D VIII | 1·33 | 0·08 | 8·82 | 0·21 | 6·6 |
Leaf tissue damage was achieved using a dissection pin. Linamarase (LIN; or BGLU) as well as hydroxynitrile lyase (HNL) activity was determined in the soluble protein fraction of samples from damaged and intact leaf areas. The activity of both enzymes increases up to ten-fold in response to tissue damage. Values given are means ± s.d. with n = 3 per treatment (intact and damaged), leaf stage (B, C, D) and seedling (I–IX). AF: activation factor (quotient of mean enzyme activity in samples taken from damaged tissue and mean enzyme activity in samples taken from intact tissue); mean AF: mean of all activation factors; f. wt: fresh weight.