A conserved AINTEGUMENTA-REVOLUTA module is a candidate to regulate carpel development in lychee

Area of Science:

• Plant Molecular Biology
• Agricultural Science
• Genetics and Genomics

Background:

• The lychee industry faces significant economic challenges due to unstable flowering and subsequent yield fluctuations.
• Stable pistil development in female flowers is critical for improving lychee yield, but its molecular mechanisms are not well understood.
• APETALA2 (AP2) transcription factors are known regulators of floral organ development, but their role in woody perennials like lychee is uncharacterized.

Purpose of the Study:

• To investigate the molecular regulation of pistil development in lychee, focusing on APETALA2 (AP2) transcription factors.
• To identify key genes and regulatory networks involved in female flower development to enhance lychee crop stability and yield.
• To explore the potential of identified genes for molecular breeding strategies in lychee.

Main Methods:

• Gene expression analysis to identify AP2 genes with specific expression in lychee carpels.
• Identification of direct downstream target genes of the identified AP2 genes using molecular techniques.
• Protein-DNA binding assays to confirm direct interactions between identified transcription factors and target gene promoters.
• Evolutionary analysis to assess the conservation of identified regulatory modules in angiosperms.

Main Results:

• Two AP2 genes, LITCHI007109 (LcANT1) and LITCHI010784, showed high and specific expression in lychee carpels.
• LcANT1, an ortholog of Arabidopsis AINTEGUMENTA (ANT), was found to directly regulate the expression of carpel development-related genes, including LcREV.
• The ANT-REV regulatory module, crucial for carpel development, is highly conserved in angiosperms, particularly within the Sapindaceae family.

Conclusions:

• Established a novel regulatory framework for female flower development in lychee, centered on the LcANT1-LcREV interaction.
• Identified critical gene resources and regulatory networks that can be leveraged for molecular breeding.
• Provides a foundation for developing high-yield and stable lychee cultivars through targeted genetic strategies.