Changes in Activity of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase and Three Peroxisomal Enzymes during Tomato Fruit Development and Ripening

Abstract

Ribulose-1,5-bisphosphate carboxylase/oxygenase, catalase, glycolate oxidase, and hydroxypyruvate reductase activities on a protein and fresh weight basis were measured over seven stages of tomato fruit development and ripening. Ribulose-1,5-bisphosphate carboxylase decreased steadily during fruit development from 23 ± 8 nmoles per minute per milligram protein at the mature green stage to 13.4 ± 2 at the table ripe stage. There was no change in partially purified preparations of the enzyme in the ratio of carboxylase to oxygenase activity, which was about 10. Catalase activity reached a maximum during the climacteric,.simultaneously with increased ethylene and CO2 formation. Glycolate oxidase activity decreased during early stages of development and was barely detectable at the climacteric. Hydroxypyruvate reductase, associated with serine formation by the glycerate pathway, increased in specific activity during early stages of tomato fruit ripening. In the fruit of the rin tomato mutant, which does not ripen normally, none of these changes in enzyme activity occurred.During the climacteric period of tomato fruit ripening, CO2 evolution and 02 consumption increase 5-to 6-fold (3,10,18 (11), increases in activity in tomato (1), pear (5, 6), and apple (7) during ripening and can be induced by ethylene to increase in activity in preclimacteric mango (20). Glycolate metabolism, similar to that in leaf peroxisomes (24), has been proposed to be associated with the climacteric respiration in tomatoes (4) and pears (5). On a Chl basis, tomato fruit have substantial ribulose-P22 carboxylase/oxygenase in the outer wall of the pericarp (4, 15), and whole fruit flx CO2 by both this enzyme and P-enolpyruvate carboxylase (8). The oxygenase function of ribulose-P2 carboxylase/oxygenase in crude extracts from tomato fruit has been reported to increase relative to carboxylase activity during ripening (4), and glycolate has been observed to accumulate in tomatoes (4) and in strawberries and cherries (13)

Changes in oxidative processes and components of the antioxidant system during tomato fruit ripening

“…Catalase activity decreased at the beginning of ripening while both CAT activity and CAT mRNA peaked at the pink stage (Tables 1, 3). There are conicting data on CAT activity during ripening in tomato with reports of both increased activity (Baker 1973;Martin et al 1979) and decreased activity (Brennan et al 1979). Increases in catalase activity during ripening have been reported in grape, pear, apple, mango and papaya Gerhardt 1938, 1942;Mattoo and Modi 1969;Brennan and Frenkel 1977;Pal and Selvaraj 1987).…”

“…Changes in protein content are common features of fruit ripening (Martin et al 1979;Pal and Selvaraj 1987;Rogiers et al 1998) and the dramatic reduction in protein content at the beginning of ripening in Ailsa Craig tomatoes ( Fig. 1) has to be taken into account when enzymatic activities are analysed in the fruit.…”

From root to fruit: RNA-Seq analysis shows that arbuscular mycorrhizal symbiosis may affect tomato fruit metabolism

“…Biochemical data showed a decrease in enzymatic activity of glycolate oxidase and hydroxypyruvate reductase from breaker to red ripe stages [27] while a time-course analysis of genome-wide gene expression [13] showed that the large majority of photosynthetic and respiratory genes identified in our experiment are down-regulated during the transition from green to red ripe fruit. Given that the nutritional status of the fruits from MYC and CONT plants was comparable, and all these genes were up-regulated in the MYC fruit, we hypothesize that mycorrhization may help extend the duration of the photosynthetic and photorespiratory activities in tomato fruit.…”

Relationship of Porphobilinogen Deaminase Activity to Chlorophyll Content and Fruit Development in `Heinz 1350' Tomato

“…Plants were trained to a single stem, and replicates of fruit of the same physiological and chronological age were obtained by the procedure of Lyons and Pratt (1964). Developmental stages and chronological age of these fruits corresponded to the stages and visual appearance described by Martin et al (1979).…”