Fruit-specific phenotypes of T1 generation tomatoes (cv. MicroTom) expressing both Del and Ros1 under the control of the E8 promoter. (a) Map of T-DNA region of the binary vector used for transformation. LB, left T-DNA border region; RB, right T-DNA border region; Kan r , nptII gene conferring kanamycin resistance under the control of the nos promoter; cmv3¢, terminator region of cauliflower mosaic virus. (b) Phenotypic analysis of wild-type (upper row), Del/Ros1C (middle) and Del/Ros1N (lower) tomato fruit harvested at the green (left column), breaker (middle) and red (right) ripening stages. (c) Del/Ros1N tomato plant showing fruit at different stages of ripening. (d) Whole and cross-section of ripe wild-type and Del/Ros1N tomato fruit. All scale bars, 2 cm.

Expression of Del and Ros1 causes the upregulation of genes required for anthocyanin biosynthesis and results in increased PAL activity and higher total antioxidant capacity. (a) Northern blots showing the differential expression of several anthocyanin biosynthetic genes identified by suppression subtractive hybridization. (b) Schematic representation of the anthocyanin biosynthetic pathway. Flavonoid classes relevant to this article are shown in boxes. Yellow box, flavonols; purple box, anthocyanins; PAL, phenylalanine ammonia lyase; 4CL, 4-coumarate:coenzyme A ligase; C4H, cinnamate 4-hydroxylase; C3H, 4-coumarate 3-hydroxylase; CHS, chalcone synthase; CHI, chalcone isomerase; F3H, flavanone-3-hydroxylase; F3¢H, flavonoid-3¢-hydroxylase; F3¢5¢H, flavonoid-3¢5¢-hydroxylase; FLS, flavonol synthase; DFR, dihydroflavonol reductase; ANS, anthocyanidin synthase; 3-GT, flavonoid 3-O-glucosyltransferase; RT, flavonoid 3-O-glucoside-rhamnosyltransferase AAC, anthocyanin acyltransferase; 5-GT, flavonoid-5-glucosyltransferase; GST, glutathione S-transferase; PAT, putative anthocyanin transporter. PAT and GST may be involved in transport of anthocyanins into the vacuole (purple circle). X, acyl group on the 3-glucoside moiety of the anthocyanin. (c) Analysis of specific PAL activity in ripe tomato fruit from wild-type and transgenic lines Del/Ros1C and Del/Ros1N. Histograms represent mean values ± s.d. of separate measurements (n ¼ 3). Results were confirmed in two additional independent experiments. (d) Analysis of hydrophilic and lipophilic antioxidant activity in ripe tomato fruit from wild-type and transgenic lines Del/Ros1C and Del/Ros1N. Data represent mean values ± s.d. and are derived from at least seven tomatoes per plant.