Changes in cell wall polysaccharides and cell wall degrading enzymes during ripening of Fragaria chiloensis and Fragaria × ananassa fruits

• Published in: Scientia horticulturae Vol. 124; no. 4; pp. 454 - 462
• Main Authors: Figueroa, Carlos R., Rosli, Hernán G., Civello, Pedro M., Martínez, Gustavo A., Herrera, Raúl, Moya-León, María A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2010; [Amsterdam; New York, NY]: Elsevier Science; Elsevier
• Subjects: Agronomy. Soil science and plant productions; alpha-N-arabinofuranosidase; beta-galactosidase; Biological and medical sciences; cell wall components; Cell wall polymers; Cell wall-modifying enzymes; endo-1,4-beta-glucanase; enzyme activity; firmness; Fragaria ananassa; Fragaria chiloensis; fruit crops; Fruit softening; fruits (plant anatomy); Fundamental and applied biological sciences. Psychology; germplasm; hemicellulose; pectinesterase; pectins; plant genetic resources; polygalacturonase; polymers; polysaccharides; postharvest physiology; ripening; species differences; strawberries; Strawberry species; xylan 1,4-beta-xylosidase; Fruit softening; Cell wall-modifying enzymes; Strawberry species; Cell wall polymers; Fruit; Horticulture; Small fruits; Enzyme; Rosaceae; Fragaria ananassa; Polymer; Softening; Cell wall; Ripening; Dicotyledones; Strawberry; Angiospermae; Enzymatic digestion; Spermatophyta; Polysaccharide
• ISSN: 0304-4238; 1879-1018
• DOI: 10.1016/j.scienta.2010.02.003

Chilean strawberry ( Fragaria chiloensis) is arising as a new fruit crop that can diversify the world supply of berries. Fruit softening is thought to be linked to an extensive modification of pectin and hemicellulosic cell wall fractions which in turn is determined to a great extent by the action of some cell wall-modifying enzymes. The objective of this work was to compare cell wall changes and the enzyme activities of pectin methylesterase (PME), polygalacturonase (PG), endoglucanase (EGase), α-arabinofuranosidase (AFase), β-galactosidase (βGal), and β-xylosidase (βXyl) between F. chiloensis and Fragaria × ananassa (cv. Chandler) at three fruit developmental stages: large green (LG), turning (T) and ripe (R). A rapid decrease in fruit firmness between LG and T stages was observed in both species; nevertheless firmness reduction in F. chiloensis was steeper than in F. × ananassa. This could be related to a faster loss of HCl-soluble polymers (HSP fraction) presented in F. chiloensis fruit. However, commercial F. × ananassa showed a greater depolymerization of HSP polymers than F. chiloensis. With the exception of PME, the activity of all assayed enzymes was higher in F. chiloensis than in F. × ananassa fruits. The role of PG and EGase seems to be central in both species: these enzymes are correlated to the decrease in the content of HSP and NaOH-soluble polymers (NSP fraction), respectively. In addition, activity levels of βGal and βXyl were significantly correlated with fruit firmness reduction in F. chiloensis and F. × ananassa, respectively.