Fractionation and partial characterization of cell walls from normal and non‐ripening mutant tomato fruit

Abstract

Cell walls extracted from cv. Rutgers, 7711 (ripening inhibited), and nor (non‐ripening) tomato (Lycopersicon eseulentum Mill.) pericarp tissue at various stages of post‐maturation development have been separated into four distinct fractions and their carbohydrate composition characterized. The amount of ionically‐associated, chelator‐soluble (CDTA, cyclohexanediaminetetraacetic acid) uronic acid in ‘Rutgers’ fruit cell walls remained constant during ripening, whereas the amount of residual pectin, which was extracted with cold alkali (Na2CO3) and was apparently covalently bound, decreased. These changes did not occur in rin and nor mutant fruit at a similar chronological age. The galactose content in pectic polysaccharide preparations extracted from tomato cell walls with CDTA and Na2,CO3, decreased by 65% during ripening. A similar but diminished decrease also occurred in rin and nor fruit. A non‐cellulosic polysaccharide(s) was present in walls which resisted extraction with Na‐acetate/CDTA, Na2CO3, and 4 M KOH. In ‘Rutgers’ fruit, the content of galactose in this polysaccharide(s) decreased 44% during ripening, whereas little or no significant change was observed in rin or nor mutant fruit.