Grape Berry Vacuole: A Complex and Heterogeneous Membrane System Specialized in the Accumulation of Solutes

Abstract

Vacuoles fulfill highly specialized functions depending on cell type and tissue and plant developmental stage. This complex and dynamic organelle is the main reservoir of grape berry cells, playing a major role during fruit development and ripening. Berry development is accompanied by modifications in size, composition, color, texture, flavor, and pathogen susceptibility, primarily because of changes in vacuolar content. Most aroma and flavor compounds are not evenly distributed in the berry, and the number and type of vacuoles may vary depending on the tissue (skin, flesh, and seeds). Together with the lytic and protein storage vacuoles widely distributed in plant cells, phenolic vacuoles are also implicated in cellular storage in grape cells. After veraison, when grape berry growth exclusively results from cell enlargement, tonoplast transporter proteins mediate a massive sugar import and water intake into the vacuole, leading to a large vacuolar expansion. The V-ATPase and V-PPase pumps create a proton electrochemical gradient across the tonoplast, which, in turn, energizes the uptake of charged and uncharged solutes. Several tonoplast proteins mediating the uptake of sugars, organic acids, water, ions, and anthocyanins have been cloned and some have been functionally characterized. The present review focuses on the storage function of vacuoles and on their structure and diversity in relation to development and ripening of the grape berry.

Integrative Effects of Vine Water Relations and Grape Ripeness Level of Vitis vinifera L. cv. Shiraz/Richter 99. I. Physiological Changes and Vegetative-Reproductive Growth Balances

“…The osmotic potential of the berry is also not determined solely by sugar, but an array of compounds, including amino acids, organic acids, inorganic cations and anions, and other taste and flavour compounds, all contributing to the soluble solid/ osmotic status of the berry. Although partial degeneration seems more evident (Krasnow et al, 2008;Fontes et al, 2011), the viability of the internal structure of the berry (mesocarp cell integrity) changes during this time, be it because of compartmentation/membrane breakdown and/or cell death (Dreier et al, 1998;Tilbrook & Tyerman, 2008), hence the decrease in firmness and observed shrivelling (Krasnow et al, 2008). According to Thomas et al (2006), cell membranes (assumed plasmalemma and tonoplast) remain intact post-véraison [the difficulty is that few studies dealing with phloem transport, unloading, berry/cell integrity, etc.…”

“…between auxin and cytokinin, than individual hormonal action (Kamínek et al, 2006). No less important in berry water relations is the role of semi-permeable membranes in the mesocarp cells (Tilbrook & Tyerman, 2009;Fontes et al, 2011). Neither transpiration (suggested to be supported by night fluxes; being in accordance with diurnal VPD fluctuations; and a low stomatal density supporting a cuticular pathway of water loss - Greer & Rogiers, 2009), phloem flow or xylem flow (whether partly or fully functional) (Lang & Düring, 1991;Greenspan et al, 1994;Rebucci et al, 1997;Chatelet et al, 2008aChatelet et al, , 2008b seemed to be able to sustain influx during late ripening and to maintain berry turgor.…”

“…Many aspects, such as cellular compartmentation and xylem embolism, have been disputed (Chatelet et al, 2008a(Chatelet et al, , 2008bFontes et al, 2011). According to Bondada et al (2005), a loss in appropriate driving force or hydrostatic gradient may be involved in the (partial) loss of active xylem function after véraison.…”

Oenology in the Kitchen: The Sensory Experience Offered by Culinary Dishes Cooked with Alcoholic Drinks, Grapes and Grape Leaves

“…Many advances have been made in understanding how grape berry develops and the chemical compounds that are important for winemaking [52]. Such knowledge is equally important when it is intended to make other uses of grape berries, other than in the manufacture of alcoholic beverages.…”

“…These cells comprise large vacuoles, which are the primary sites for the accumulation of sugars, organic acids, aromas, flavors, ions and water, during grape berry ripening. The grape berry vacuole cells have attracted attention principally because their storage function contributes directly to fruit quality [52].…”