Fruit ripening in Vitis vinifera: apoplastic solute accumulation accounts for pre-veraison turgor loss in berries |
| |
Authors: | Hiroshi Wada Ken A. Shackel Mark A. Matthews |
| |
Affiliation: | (1) Department of Viticulture and Enology, University of California, One Shields Ave, Davis, CA 95616-86383, USA;(2) Department of Plant Sciences/Pomology, University of California, Davis, CA, USA |
| |
Abstract: | In Vitis vinifera L. berries, the onset of ripening (known as “veraison”) involves loss of turgor (P) in the mesocarp cells. We hypothesized that P loss was associated with an accumulation of apoplastic solutes in mesocarp tissue prior to veraison. Apoplastic sap was extracted from the mesocarp by centrifugation at the appropriate gravity to measure the apoplast solute potential (ΨsA) and assay the sap composition. The ΨsA was about −0.2 MPa early in development, decreased about 1.0 MPa by veraison, and continued to decrease during ripening to almost −4.0 MPa by the end of berry development. Potassium, malate, tartrate, proline, glucose, fructose, and sucrose were quantified in apoplastic sap. The calculated contribution of these solutes was about 50% of the total ΨsA preveraison, but increased to about 75% as fructose and glucose accumulated during ripening. The contribution of the estimated matric potential to apoplast water potential decreased during development and was only 1.5% postveraison. We conclude that high concentrations of solutes accumulated in the mesocarp apoplast prior to veraison, and that P loss was a direct result of decreased ΨsA. Because ΨsA decreased before veraison, our findings suggest that apoplast solutes play an important role in the events of cellular metabolism that lead to the onset of ripening. |
| |
Keywords: | Apoplast Symplast Grape Turgor Cell pressure probe Centrifugation Capillary electrophoresis Symplast contamination Veraison |
本文献已被 PubMed SpringerLink 等数据库收录! |
|