Grape Endophytic Microbial Community Structures and Berry Volatile Components Response to the Variation of Vineyard Sites

Abstract

Vitis vinifera L. is a commercially important horticultural plant with abundant microbial resources. However, the impact of grape-associated microbiota on grape quality and flavor has been largely overlooked. We integrated volatomics and microbiomics to explore temporal variations in berry volatiles and microbial diversity of ‘Cabernet Sauvignon’ in Ningxia (NX) and Shanxi (SX), and the correlation between microbial communities and volatiles. A total of 38 and 35 free and bound aroma compounds, respectively, were identified in NX berries and SX berries. For free aroma, these 38 compounds were classified into aldehydes (69%), alcohols (22%), acids (4%), aromatics (4%), terpenes (0.6%), esters (0.37%), and norisoprenoids (0.3%). Similarly, the 35 bound aromas were attributed to aromatics (58%), acids (29%), terpenes (4%), esters (3%), alcohols (2.82%), aldehydes (2.78%), and norisoprenoids (0.4%). Additionally, a total of 616 bacterial genera and 254 fungal genera were detected in all samples from both regions. The results demonstrated that vineyard sites significantly shaped the characteristics of berry volatiles and microbial biogeographic patterns. SX berries exhibited more abundant free aroma and higher microbial diversity than NX berries, with three key taxa (Sphingomonas, Massilia, and Bacillus) identified in the bacterial network. Correlation analysis results highlighted that these key taxa might play an important role in berry-free aroma. This study reveals the crucial role of microbes in shaping grape flavor and uncovers the link between microbial diversity and the regional attributes of grapes and wine.