Table V.
Analyses of the chloroplast ultrastructure, pigment, and lipid composition in wild-type, tpt-1, adg1-1, and adg1-1/tpt-1 plants
Areas of chloroplast cross sections as well as maximum lengths and widths of 20 chloroplast images were determined from electromicrographs. The ratio of cut grana area to chloroplast area was determined for eight to 20 chloroplasts of each line. n.d., Not detectable. Plants harvested for pigment analyses were grown in growth cabinets under controlled environmental conditions in a light/dark cycle of 12 h/12 h. Numbers in parentheses represent percentage values relative to the wild type. If not stated otherwise, the data represent means ± se of three independent measurements. A statistical analysis of the data sets between the mutant lines and the wild type was conducted according to the Welch test.
| Variable | Wild Type (n = 20) | tpt-1 (n = 20) | adg1-1 (n = 20) | adg1-1/tpt-1 (n = 20) |
|---|---|---|---|---|
| Chloroplast dimensions and composition | ||||
| Chloroplast area (μm2) | 11.93 ± 0.44 | 14.29 ± 0.67a | 9.90 ± 0.47a | 8.82 ± 0.55b |
| Chloroplast length (μm) | 6.24 ± 0.21 | 5.86 ± 0.16 | 6.26 ± 0.17 | 5.77 ± 0.18 |
| Chloroplast width (μm) | 2.40 ± 0.07 | 2.93 ± 0.10b | 1.90 ± 0.05b | 1.95 ± 0.10b |
| Width/length ratio | 0.39 ± 0.02 | 0.51 ± 0.02b | 0.31 ± 0.01a | 0.34 ± 0.02 |
| Grana thylakoid area per chloroplast area (%) | 14.57 ± 1.16 (n = 8) | 17.43 ± 0.67c (n = 20) | 18.62 ± 1.06c (n = 8) | 26.37 ± 2.02b (n = 8) |
| Average no. of plastoglobules per chloroplast | 5.95 ± 0.64 | 7.40 ± 0.64 | 6.05 ± 0.28 | 12.90 ± 1.47b |
| Average no. of starch grains per chloroplast | 1.55 ± 0.23 | 1.70 ± 0.26 | n.d. | n.d. |
| Starch grain area per chloroplast (μm2) | 0.48 ± 0.08 | 0.56 ± 0.10 | n.d. | n.d. |
| Area per starch grain (μm2) | 0.33 ± 0.06 | 0.35 ± 0.05 | n.d. | n.d. |
| Pigment contents and ratios | ||||
| Total chlorophyll (μg g−1 fresh weight) | 1,461 ± 15 (100) | 1,570 ± 92 (107) | 1,167 ± 26 (78)b | 1,048 ± 12 (72)b |
| Chl a/b | 2.68 ± 0.09 (100) | 2.71 ± 0.06 (101) | 2.10 ± 0.26 (78) | 1.69 ± 0.06 (63)b |
| Carotenoids (μg g−1 fresh weight) | 47.0 ± 4.8 (100) | 50.1 ± 3.2 (107) | 37.4 ± 1.7 (79) | 39.0 ± 4.9 (83) |
| Chlorophyll/carotenoid ratio | 31.1 ± 1.2 (100) | 31.3 ± 0.6 (101) | 31.2 ± 0.2 (101) | 26.9 ± 0.2 (84) |
| Total lipids (mg g−1 fresh weight) | 5.1 ± 0.5 | 4.7 ± 0.6 | 4.8 ± 0.2 | 4.4 ± 0.3 |
| Polar lipids (mol %) | ||||
| MGDG | 49.6 ± 2.6 | 48.3 ± 2.3 | 45.9 ± 5.2 | 39.9 ± 1.6b |
| Phosphatidylglycerol | 8.4 ± 1.4 | 7.3 ± 1.2 | 7.8 ± 1.4 | 10.1 ± 2.2 |
| Digalactosyl diacylglycerol | 16.9 ± 1.1 | 18.5 ± 0.9 | 17.2 ± 0.6 | 16.4 ± 0.9 |
| Phosphatidylinositol | 1.5 ± 0.9 | 1.1 ± 0.6 | 1.6 ± 0.1 | 2.3 ± 0.3c |
| Sulfolipid | 1.2 ± 0.4 | 1.4 ± 0.6 | 1.6 ± 0.5 | 1.9 ± 0.1b |
| Phosphatidylethanolamine | 8.7 ± 0.9 | 10.1 ± 2.0 | 10.5 ± 2.0 | 10.8 ± 0.5b |
| PC | 13.8 ± 1.5 | 13.3 ± 1.3 | 15.4 ± 3.1 | 18.7 ± 3.8 |
P < 0.01.
P < 0.001.
P < 0.05.