Influence of pruning time and viral infection on stilbenoid levels in Pinot noir grape canes

Abstract

BACKGROUND: Grapevine canes represent a large source of waste derived from grape cultivation. In the present study, the effect of different processes of storage and different pruning times on the stilbene accumulation on Pinot noir canes was analyzed. Whether the alteration of the secondary metabolism accompanying leafroll symptom expressions could affect the stilbenoid accumulation in canes harvested at pruning time was also investigated.RESULTS: The maximum accumulation of trans-resveratrol and trans-piceatannol was obtained in canes harvested in October and dried at 40°C. Even in grape canes harvested in October, November, and December and stored for different times at room temperature (20 ± 2°C) a marked increase in trans-resveratrol and trans-piceatannol was evident, which reached a maximum at around 8 weeks of storage. A significant higher accumulation of trans-resveratrol and trans-piceatannol was also found in canes harvested from symptomatic plants compared to those harvested from asymptomatic plants for all the pruning times.CONCLUSION: This study confirms that the biosynthetic enzyme activities and, particularly, those involved in the stilbene pathway, persist during Pinot noir cane storage at different harvest times, with different storage times and conditions, and different sanitary status.

Variability of Constitutive Stilbenoid Levels and Profiles in Grape Cane (Vitis vinifera L.) Depending upon Variety and Clone, Location in the Vineyard, Pruning Time, and Vintage

“…Pinot Noir and Accent. De Bona et al have also found the highest levels in December harvested samples of Italian Pinot Noir canes collected in October, November, and December, when stored long term at room temperature after harvest (as we did). Unlike the mentioned Italian study, however, we added the late pruning point of February.…”

“…Unlike the mentioned Italian study, however, we added the late pruning point of February. While the literature shows an increase for stilbenoid levels from October to December, 10 the subsequent hibernal decrease in stilbenoid amounts that was observed in our study has not been reported before to our knowledge.…”

“…vinifera varieties. Moreover, various grape cane pre-extraction processing factors, like drying temperature, light exposure, and material size, were compared, revealing that the highest yields of stilbenoids were achieved when grape cane was dried at 40 °C under light exclusion as 10 cm long sections . Further detailed studies focused on optimizing stilbenoid extraction by selecting the most suitable extraction solvents, tailoring adequate solvent/solid ratios, and adjusting extraction times and temperatures as well as pH and light exposure.…”

“…Moreover, various grape cane pre-extraction processing factors, like drying temperature, light exposure, and material size, were compared, revealing that the highest yields of stilbenoids were achieved when grape cane was dried at 40 °C under light exclusion as 10 cm long sections. 10 Predominantly, the variety of vine appears to have an immense impact on stilbenoid levels. In comparison to samples from vineyards across different continents, 12−16 Pinot Noir grape cane, for example, has been shown to contain relatively high amounts of stilbenoids of up to 8485 mg/kg of dry weight (DW) when compared to the average of ca.…”

Polyphenol Profiles of Just Pruned Grapevine Canes from Wild Vitis Accessions and Vitis vinifera Cultivars

“…Because the content of polyphenols evolves during storage, ,,− all samples were kept frozen in the dark directly after being collected. Grapevine canes on the same day of pruning were cut into small pieces, frozen in liquid nitrogen, and stored at −80 °C.…”