Figure 1.
Preparation for tissue-specific analysis.
A, The fruit ripening stages of cv. Micro Tom. The six stages included immature green (I), mature green (M), breaker (B), turning (T), red ripe (R), and overripe (O). B, The fruit tissues of cv. Micro Tom. The eight tissues included skin, mesocarp, endocarp, septum, locular tissue, seed, placenta. and core. These were separated by hand-sectioning.
Figure 2.
β-Xylosidase and α-arabinofuranosidase activities gradually decreased in fruit tissues during ripening.
A, β-Xylosidase activity. B, α-Arabinofuranosidase activity. Total protein in the cell wall was extracted from each fruit tissue and assayed for β-xylosidase and α-arabinofuranosidase activity. The five tissues analyzed in these assays included skin, mesocarp/endocarp, septum, locular tissue, and seed. Ripening stage: I, immature green; M, mature green; B, breaker; T, turning; R, red ripe; O, overripe. ±SD of three independent replicates.
Figure 3.
XG and GAX biosynthesis-related gene expression patterns differed among tissues.
Gene expression was analyzed by RT-PCR. A, α-1,6-xylosyltransferase involved in XG biosynthesis, SlXXT-L: SGN-U581426 (27 cycles); B, arabinosyltransferase involved in XG biosynthesis, SlXST1: Sl07g044960 (35 cycles); C, SlXST2: Sl07g049610 (30 cycles), D, β-1,4-xylosyltransferase involved in GAX biosynthesis, SlIRX9-L1: SGN-U583344 (35 cycles); E, SlIRX9-L2: SGN-U568972 (30 cycles); D, 17S rRNA, as a control (17 cycles). Expression levels were compared to rRNA in the same assay. The four tissues analyzed in these assays included skin, mesocarp/endocarp, septum, and locular tissue. Ripening stages were as follows: I, immature green; M, mature green; B, breaker; T, turning; R, red ripe; O, overripe.
Figure 4.
Changes in xylose and arabinose content differed in fruit tissues during ripening.
A, Xylose content per 1/endocarp, septum, and locular tissue. Ripening stage: I, immature green; M, mature green; B, breaker; T, turning; R, red ripe; O, overripe. ±SD of three independent replicates.
Figure 5.
Immunolocalization of XG, GAX, and XTH epitopes in tomato fruit longitudinal and cross sections.
A, Immunolocalization of XG and GAX in fruit sections. Top panels: Negative control (treated with only secondary antibodies). Middle panels: Xyloglucan immunolabeled with LM15 antibody. Bottom panels: Glucuronoarabinoxylan immunolabeled with LM11 antibody. Bars represent 1 mm. B, Immunolocalization of XG and GAX in pericarp. Top panels: Negative control. Middle panels: Immunolabeled with LM15 antibody. Bottom panels: Immunolabeled with LM11 antibody. Bars represent 0.2 mm. C, Immunolocalization of XTH in pericarp. Top panels: Negative control. Bottom panels; immunolabeled with anti-XTH antibody. Bars represent 0.2 mm. Ripening stage: M, mature green; T, turning; R, red ripe.
Figure 6.
Inner surface of the inner fruit pericarp following Toluidine Blue dye staining.
The permeability and integrity of the inner epidermal lipid membrane was tested with a Toluidine Blue O dye penetration test. The lower panels are shown at greater magnification. The test was applied to fruit at four ripening stages: MG, B, T, and R. Although the pericarp and locular tissues were stained, the inner epidermis of the pericarp was not stained in any stage. M, mature green; B, breaker; T, turning; R, red ripe.