Transcriptomic and metabolite analyses of Cabernet Sauvignon grape berry development

Area of Science:

• Plant Biology
• Molecular Genetics
• Biochemistry

Background:

• Grape berry development involves three distinct phases: cell division/expansion, a lag phase, and ripening (véraison).
• Key processes include organic acid, tannin, sugar, anthocyanin, and volatile compound accumulation.
• Understanding the transcriptional network is crucial for controlling berry development and wine quality.

Purpose of the Study:

• To profile mRNA expression across seven developmental stages of Vitis vinifera Cabernet Sauvignon berries.
• To correlate gene expression with metabolite profiles to understand regulatory processes.
• To identify candidate genes involved in grape berry development and ripening.

Main Methods:

• Utilized the Affymetrix GeneChip Vitis oligonucleotide microarray ver. 1.0 for mRNA expression profiling.
• Analyzed seven developmental stages from pea-size to mature berries (E-L stages 31-38).
• Performed parallel metabolite profiling alongside gene expression analysis.

Main Results:

• Over 74% of probes on the microarray were expressed, with 60% showing differential expression across stages.
• Identified 4,151 Unigenes with significant expression changes, categorized into 20 correlated profiles.
• Revealed expression patterns for genes in phytohormone, calcium signaling, cell wall metabolism, flavonoid, and sugar metabolism pathways.
• Highlighted candidate transcription factors and ABA biosynthesis genes involved in véraison and ripening.
• Discovered an alternative glucose and triose phosphate production pathway active from véraison to maturity.

Conclusions:

• Provides the first high-resolution transcriptome dynamics during seven stages of grape berry development.
• Establishes a comprehensive gene expression catalog for future research on berry development regulation.
• Identified novel genes potentially involved in critical fruit development steps for functional testing.