Transcriptome and Metabolomics Integrated Analysis Reveals Terpene Synthesis Genes Controlling Linalool Synthesis in Grape Berries

In this study, four hybrids from the cross between “Italia”
and “Tamina” grapes were chosen to investigate their
distinct monoterpenoids patterns and candidate genes involved. Monoterpenoid
profiles and transcriptome data were generated at four berry developmental
stages. Trans-rose oxide, cis-rose oxide, citronellol, neral, nerol,
nerol oxide, geraniol, geranial, geranic acid, and cis-isogeraniol
were the dominant compounds in R250 hybrid, while linalool, hotrienol,
linalool oxide pyranoside, and cis-furan linalool oxide were the main
compounds in R77 hybrid. Six TPS-g subfamily genes were found related
with the contents of linalool and its related monoterpenoids by weighted
gene coexpression network analysis (WGCNA) and phylogenetic analysis.
Among them, TPS59 was cloned and functionally verified by transient
overexpression in the leaves of Vitis quinquangularis. Meanwhile, NAC (newGene_195), C2C2-GATA (VIT_15s0021g02510), and bHLH (VIT_14s0128g00110) were selected as candidate transcription factors (TFs) that could
regulate the expression of the six TPS-b genes. These data enhanced
our understanding on the regulation of monoterpenoid biosynthesis
in grapes.