Table I.
Treatment | Leaf No. | Fresh Leaf Wt | Leaf B | AIR Ba | dRG-II-B in Total RG-IIb |
---|---|---|---|---|---|
mg | μg g−1 dry leaf | % | |||
25 μm B | Cotyledon | 660 ± 38 | 99.3 ± 5.2 | 32.9 ± 2.4 | 85 |
First leaf | 858 ± 62 | 69.5 ± 1.3 | 19.7 ± 1.7 | 82 | |
Second leaf | 546 ± 43 | 39.3 ± 2.7 | 11.0 ± 0.6 | 87 | |
Third leaf | 241 ± 44 | 32.5 ± 2.2 | 15.3 ± 1.9 | 86 | |
Fourth leaf | 26 ± 4 | 32.0 ± 5.0 | 14.7 ± 4.2 | 82 | |
0 μm B | Cotyledon | 751 ± 40 | 92.4 ± 6.1 | 41.3 ± 1.8 | 93 |
First leaf | 530 ± 50 | 21.5 ± 1.2 | 19.1 ± 4.9 | 88 | |
Second leaf | 216 ± 30 | 4.2 ± 1.6 | 3.8 ± 0.1 | 35 | |
Third leaf | 131 ± 20 | 3.0 ± 1.0 | 3.0 ± 0.1 | 10 | |
Fourth leaf | 37 ± 14 | 2.6 ± 0.3 | 2.7 ± 0.1 | 20 |
Plants were precultured for 7 d in 10 μm B. Seven days prior to harvest, one-half of the plants were transferred to B-free solution and the remaining one-half were transferred to 25 μm B. Fresh leaf wt was expressed as means ± se (n = 8). Alcohol-insoluble residue (AIR) were isolated from each leaf (details in “Materials and Methods”). B was determined in the leaf and AIR samples by inductively coupled plasma-mass spectrometry (ICP-MS). Data are means of three replicates and se are shown.
AIR B was calculated from the B content in AIR determined by ICP-MS and the yield of AIR.
The relative proportion of dRG-II-B to total RG-II was determined by size exclusion chromatography (SEC)/refractive index detector of the endo-polygalacturonase (EPG) digests of the AIR. Data are average from two individual experiments.