Table I.

Ascorbate in tomato leaf and fruit of P35S:SlgalldhRNAi transgenic and control plants

Reduced (AsA) and total ascorbate (Tot Asc) contents of P35S:SlgalldhRNAi line 8, line 5, and control plants were measured in young developing leaves from seedlings at the indicated DAS and in developing fruits at the indicated days postanthesis (DPA). Apoplastic ascorbate content was measured in the fully expanded fourth leaf of 6-week-old plants. The reduced/total ascorbate ratio was determined for all the samples. Data represent mean ± sd of six individual plants with two repeats per plant. The superscript a (a) indicates values that were determined by the t test to be significantly different (P < 0.05) from control.

Plant Stage (DAS)0(Seed)15212842
Leafμmol g−1 FW
    AsAControl2.4 ± 0.21.5 ± 0.12.5 ± 0.32.6 ± 0.31.8 ± 0.1
Line 82.5 ± 0.31.2 ± 0.1a1.1 ± 0.1a1.3 ± 0.1a1.4 ± 0.2a
Line 52.5 ± 0.21.1 ± 0.2a1.2 ± 0.2a1.4 ± 0.1a1.3 ± 0.2a
    Tot AscControl2.5 ± 0.32.9 ± 0.24.5 ± 0.58.7 ± 0.78.5 ± 0.3
Line 82.6 ± 0.22.9 ± 0.34.9 ± 0.56.1 ± 0.48.1 ± 0.3
Line 52.6 ± 0.22.8 ± 0.35.5 ± 0.57.7 ± 0.18.1 ± 0.4
    RatioControl0.90.50.50.30.2
Line 810.40.20.20.2
Line 510.40.20.20.2
Fruit Stage (DPA)1020303842
Fruit
    AsAControl0.3 ± 0.10.4 ± 0.11.3 ± 0.11.7 ± 0.11.7 ± 0.2
Line 80.5 ± 0.1a0.9 ± 0.1a1.6 ± 0.2a1.6 ± 0.72.0 ± 0.2
Line 50.6 ± 0.1a0.7 ± 0.1a1.6 ± 0.2a1.8 ± 0.21.9 ± 0.2
    Tot AscControl1.6 ± 0.11.6 ± 0.11.6 ± 0.21.7 ± 0.12.0 ± 0.1
Line 82.0 ± 0.1a1.8 ± 0.31.7 ± 0.21.6 ± 0.72.2 ± 0.2
Line 51.8 ± 0.1a1.6 ± 0.11.6 ± 0.22.0 ± 0.22.1 ± 0.2
    RatioControl0.20.20.810.9
Line 80.20.50.90.90.9
Line 50.30.40.90.90.9
Leaf ApoplastControlLine 8Line 5
nmol g−1 FW
AsA85 ± 60111 ± 10121 ± 47
Tot Asc648 ± 49402 ± 47a370 ± 104a
Ratio0.10.30.3