Flower development and sex specification in wild grapevine

Area of Science:

• Plant genetics
• Developmental biology
• Transcriptomics

Background:

• Wild grapevines (Vitis) related to cultivated Vitis vinifera were domesticated around the Caspian Sea.
• Vitis vinifera has hermaphrodite flowers, while Vitis sylvestris is dioecious (male/female flowers).
• The genetic mechanism for grapevine flower sex determination remains unknown.

Purpose of the Study:

• Investigate genes involved in establishing male, female, and complete flowers in grapevine.
• Understand the timing and genetic basis of sexual dimorphism in Vitis flowers.
• Explore the role of gene expression and transcription in grapevine sex determination.

Main Methods:

• Comparative transcriptomic analysis of four developmental stages across three grapevine genders.
• Analysis of gene expression profiles to identify differences between sexes and developmental stages.
• Identification of differentially transcribed regions, including intergenic regions, between sexes.

Main Results:

• Grapevine sex determination is a late developmental event, not directly correlated with ABCDE floral organ identity genes.
• Clusters of differentially expressed genes suggest roles in sex differentiation.
• Differentially transcribed intergenic regions may contribute to subspecies variation.

Conclusions:

• No evidence suggests ABCDE model gene expression differences explain the shift from hermaphroditism to dioecy.
• Sex specification likely occurs after floral organ identity is established, with sex determination genes acting downstream.
• A comprehensive gene expression catalog across developmental stages and genders was created for future research on seed plant sex determination.