Figures & data
Fig. 1. Changes in the expression levels of GGP/VTC2 in the IE-VTC2 plants after treatment with ES.
Note: Two-week-old control and IE-VTC2 plants grown on MS medium under normal conditions were sprayed with 100 μM ES containing 0.1% (v/v) Tween 20 (ES treatment) and then grown for up to 7 d. A solution containing 0.1% (v/v) Tween 20 without ES was sprayed as mock treatment. Total RNAs were prepared from the mock- and the ES-treated plants at the indicated times and subjected to quantitative RT-PCR analysis with specific primers for the GGP/VTC2 and Actin2 genes. The details of the procedures are described in “Materials and methods.” Relative expression levels were normalized to Actin2 mRNA. Data are means ± SD for independent experiments (n = 3). An asterisk indicates that the mean value was significantly different from that of the respective pre-treated plants as analyzed by Student’s t test (p < 0.05).
Fig. 2. Time-course effects of transient expression of GGP/VTC2 on intracellular AsA levels.
Note: The experimental conditions were as described in Fig. . The levels of AsA and DHA in the extracts prepared from the mock- and ES-treated plants at the indicated times were analyzed as described in “Materials and methods.” Data are means ± SD for independent experiments (n = 3–10). An asterisk indicates that the mean value was significantly different from that of the respective pre-treated plants as analyzed by Student’s t test (*p < 0.05; **p < 0.01).
Fig. 3. Effects of ES-inducible transient expression of GGP/VTC2 on GGP activity.
Note: Experimental conditions were as in Fig. . Extracts prepared from leaves of the control and IE-VTC2 plants 3 d after mock and ES treatments were used for an assay to measure GDP-d-glucose phosphorylase activity as described in “Materials and methods.” Activity was assayed by phosphate-dependent reduction of GDP-d-glucose and the production of GDP by the HPLC system. Data are means value ± SD for independent experiments (n = 3–4). An asterisk indicates that the mean value was significantly different from that of mock-treated plants as analyzed by Student’s t test (p < 0.01).
Fig. 4. Effects of transient expression of GGP/VTC2 on AsA levels under continuous light and dark conditions.
Note: Two-week-old control and IE-VTC2 plants grown on MS medium under normal conditions were sprayed with 100 μM ES containing 0.1% (v/v) Tween 20 and then grown for 5 d under continuous light or dark conditions. The levels of AsA and DHA in extracts prepared from the control and IE-VTC2 plants at the indicated times were analyzed as described in “Materials and methods.” Data are means ± SD for independent experiments (n = 3). An asterisk indicates that the mean value was significantly different from that of the control plants under the same conditions as analyzed by Student’s t test (*p < 0.05).
