Table 3.
Leaf Carotenoid Content and Xanthophyll Cycle Activity a
| Postillumination DES (%)
|
||||
|---|---|---|---|---|
| Lines | Carotenoid/Chlorophyll (mol·mol−1) | XC (% Total Carotenoid) | 2 Min | 23 Min |
| Wild type | ||||
| HL | 0.30 ± 0.01 | 17.9 ± 0.5 | NDb | ND |
| LL | 0.24 ± 0.01 | 15.9 ± 0.6 | 12.0 ± 3.3 | 29.6 ± 4.1 |
| CP29 | ||||
| HL | 0.27 ± 0.01 | 15.6 ± 0.9 c | ND | ND |
| LL | 0.25 ± 0.01 | 12.9 ± 0.3 d | 9.4 ± 2.4 | 30.4 ± 4.4 |
| CP26 | ||||
| HL | 0.28 ± 0.01 | 17.4 ± 0.8 | ND | ND |
| LL | 0.25 ± 0.01 | 15.1 ± 0.6 | 10.4 ± 3.1 | 33.3 ± 4.7 |
a
Carotenoids and chlorophylls extracted from leaf discs from dark-adapted or light-treated plants (grown under HL or LL) were assayed by reverse-phase HPLC. The deepoxidation state (DES) of the XC pigments zeaxanthin (Z), antheraxanthin (A), and violaxanthin (V) was calculated as (Z + 1/2 A) /(Z + A + V), for leaves exposed to 1000 μmol quanta·m−2·sec−1 in CO2-saturating conditions for either 2 or 23 min; the preillumination DES was <4% for all lines. Data are means ±se, n ≥ 4.
b
ND, not determined.
c
Significant difference of P < 0.05 from the corresponding wild-type parental line.
d
Significant difference of P < 0.01 from the corresponding wild-type parental line.