# Florigen Activation Complex Dynamics and SVP‐Mediated Repression Orchestrate Temperature‐Regulated Flowering in Saffron

## TL;DR

This study identifies key genes and proteins involved in temperature-controlled flowering in saffron, offering new insights for improving saffron yield through genetic strategies.

## Contribution

The study reveals the role of Florigen Activation Complex components and CsatSVP2 in temperature-regulated flowering in saffron.

## Key findings

- CsatFT3 and CsatFD2 promote floral induction, while CsatTFL1-3 acts as a floral repressor.
- CsatFT3 and CsatTFL1-3 compete for binding to CsatFD2, modulating floral induction.
- CsatSVP2 inhibits CsatFT3 expression by binding to its promoter under low temperatures.

## Abstract

Saffron, a high‐value spice cultivated worldwide for its therapeutic and culinary uses, is a sterile triploid species, rendering conventional breeding approaches ineffective. This limitation underscores the need for molecular and biotechnological strategies for its genetic improvement. Flowering, a key determinant of saffron yield, is strongly influenced by temperature; however, the genetic regulatory networks underlying this process remain poorly understood. Our study identifies key regulators of saffron's flowering, focusing on the Florigen Activation Complex (FAC) components: FLOWERING LOCUS T (FT), bZIP transcription factor‐FD and TERMINAL FLOWER‐1 (TFL‐1) and demonstrates their temperature‐dependent roles in floral regulation. Spatiotemporal expression analyses suggested that CsatFT3 and CsatFD2, expressed in the floral meristem, promote floral induction, while CsatTFL1‐3 acts as a floral repressor. Protein interaction studies showed that CsatFT3 and CsatTFL1‐3 compete for binding to CsatFD2, and their balance modulates floral induction. Functional validation in Arabidopsis and Saffron confirmed these findings. Furthermore, we identified CsatSVP2, an ortholog of SHORT VEGETATIVE PHASE (SVP), as a low temperature‐responsive repressor that directly binds the CsatFT3 promoter to inhibit its expression. Together, these findings enhance our understanding of temperature‐mediated floral induction in saffron and provide insights and lay the groundwork for genetic interventions to enhance yield under variable temperature conditions.