Short-Term Postharvest Carbon Dioxide Treatments Induce Selective Molecular and Metabolic Changes in Grape Berries

Abstract

Detached wine grapes ( Vitis vinifera cv. 'Trebbiano', white skinned) were treated for 3 days with 30 kPa of CO(2) and then transferred to air for an additional 9 days to partially dehydrate (about 20% weight loss). At the end of the CO(2) treatment on withering berries, total polyphenols and flavonoids were maintained in the skin, but to a more limited extent in the pulp. An induction of the proanthocyanidin synthesis appeared to be one of the responses to the treatment because both (+)-catechin and (-)-epicatechin concentrations increased in the skin. The skin and pulp of the grape berries showed different molecular responses to a high CO(2) treatment. As revealed by microarray hybridizations, 217 and 75 genes appeared differentially expressed in the skin and pulp of treated samples, respectively. Functional categorization and gene enrichment analyses pointed out that epicarp cells undergo more pronounced changes in transcript profiling at the end of the incubation period. Highly represented categories in both tissues were related to protein, stress, transcript, RNA, and hormone (ethylene, ABA) metabolism. Fermentation, CHO metabolism, and redox regulation functional categories were represented only in the skin.

Skin pectin metabolism during the postharvest dehydration of berries from three distinct grapevine cultivars

“…The soluble solids content also differed among the cultivars, with the Oseleta berries showing more effective sugar concentration during dehydration than the others, possibly reflecting the smaller berry size and lower juice content. The titratable acidity of Corvina berries increased consistently, whereas there was an initial loss of acidity in the other cultivars in agreement with previous reports (Vicens et al 2009, Becatti et al 2010. The reduction in titratable acidity is largely due to the respiration of malic acid but is counterbalanced by juice concentration due to water loss.…”

Molecular analysis of the improvement in rachis quality by high CO2 levels in table grapes stored at low temperature

“…With reference to gene expression, we observed a down-regulation of VvNCED1 15 transcript levels produced by both, low temperature and high CO 2 levels in rachis and skin, so we cannot establish a link with rachis deterioration, but rather with a more general response. Becatti et al, (2010) also observed a down-regulation of NCED in the skin of wine grapes treated with high CO 2 levels. Conversely, our results showed that 3 days of storage at 0 ºC induced a sharp increase in NCED1 accumulation in pulp, whereas high CO 2 levels clearly 20 restrained this induction.…”

“…On the one hand, it is known that CO 2 is an essential cofactor for ACO (Dong et al, 1992;Escribano et al, 1996), and it has been shown to induce ethylene production by enhancing ACS activity and synthesis (reviewed by Mathooko, 1996). In this sense, Becatti et al, (2010) observed that 25 high CO 2 applied to detached wine grapes for 3 days at 20 ºC induced ACO and an ACS-like gene expression in skin and pulp. On the other hand, elevated levels of CO 2 can reduce ethylene biosynthesis mainly by inhibiting ACS gene expression and affecting ACO action (de Wild et al, 2003).…”

Elicitors: A Tool for Improving Fruit Phenolic Content

“…Cold stress in blood oranges induced transcriptomic modifications directed towards increased flavonoid biosynthesis [52]. Similarly, postharvest carbon dioxide treatments induced proanthocyanidin synthesis in grapes [53].…”