Defects in leaf carbohydrate metabolism compromise acclimation to high light and lead to a high chlorophyll fluorescence phenotype in Arabidopsis thaliana

Table 2 Carbohydrate contents of LL-grown plants (A) as well as contents of adenylates in Col-0, adg1-1, tpt-2 and adg1-1/tpt-2 grown in LL (B) or HL (C)

Plant lines	Starch	Sucrose	Glucose	Fructose
(μmol C6·g^-1 fw)
A Plants grown in LL
Col-0	4.69 ± 0.59 ^b, ^d	1.71 ± 0.18	1.69 ± 0.48 ^b, ^d	0.53 ± 0.13
adg1-1	0.24 ± 0.06 ^a	1.47 ± 0.33	2.46 ± 0.14 ^a, ^c	1.05 ± 0.07
tpt-2	3.89 ± 0.47 ^b, ^d	1.10 ± 0.14 ^d	1.04 ± 0.07 ^b, ^d	0.32 ± 0.13
adg1-1/tpt-2	0.69 ± 0.54 ^a, ^c	1.36 ± 0.38	1.86 ± 0.16 ^a, ^c	0.68 ± 0.19
Plant lines	ATP	ADP	AMP	EC
(nmol·g^-1 fw)
B Plants grown in LL
Col-0	34.0 ± 1.5	14.8 ± 1.1	1.3 ± 0.1	0.83
adg1-1	48.4 ± 13.5	21.7 ± 4.9	1.9 ± 0.6	0.82
tpt-2	30.1 ± 4.5	12.4 ± 2.0	1.1 ± 0.2	0.83
adg1-1/tpt-2	36.3 ± 0.4	16.9 ± 0.9	1.2 ± 0.1	0.82
Plant lines	ATP	ADP	AMP	EC
(nmol·g^-1 fw)
C Plants grown in HL
Col-0	159.5 ± 10.5	90.8 ± 5.4	19.9 ± 1.8 ^d	0.76
adg1-1	191.9 ± 25.4	90.8 ± 8.6	14.9 ± 2.1	0.80
tpt-2	208.4 ± 7.9	106.3 ± 6.3	17.4 ± 3.1 ^d	0.79
adg1-1/tpt-2	154.5 ± 11.1	88.0 ± 4.7	9.0 ± 1.2 ^a, ^c	0.79

Leaf samples were taken after 8 h in the light. Metabolism in the leaf samples was quenched immediately in N₂ during illumination. The data represent the mean ± SE of n = 3 (A) or n = 6 (B and C) measurements. Significant differences in the data pairs were identified by the ANOVA test and further analyzed by the Tukey-Kramer test. The letters as superscripts denote the lines to which a significant difference (P < 0.05) was found with a = Col-0, b = adg1-1, c = tpt-2 and d = adg1-1/tpt-2. The energy charge (EC) was calculated from the relationship EC = ([ATP] + 0.5·[ADP])/([ATP] + [ADP] + [AMP]).

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