Jeong Hwan Lee¹, Hak-Seung Ryu¹, Kyung Sook Chung¹, David Pose^2,†, Soonkap Kim¹, Markus Schmid², Ji Hoon Ahn^1,*
 
1Creative Research Initiatives, Department of Life Sciences, Korea University, Seoul 136-701, South Korea.
²Max Planck Institute for Developmental Biology, Department of Molecular Biology, Spemannstrasse 35, 72076 Tubingen, Germany.

^† Present address: Instituto de Hortofruticultura Subtropical y Mediterranea, Universidad de Malaga*Consejo Superior de Investigaciones Cientificas, Departamento de Biologia Molecular y Bioquimica, Facultad de Ciencias, Universidad de Malaga, 29071 Malaga, Spain.

^*Corresponding author : Ji Hoon Ahn

Abstract
Changes in ambient temperature affect flowering time in plants; understanding this phenomenon will be crucial for buffering agricultural systems from the effects of climate change. Here, we show that levels of FLM-β, an alternatively spliced form of the flowering repressor FLOWERING LOCUS M, increase at lower temperatures, repressing flowering. FLM-β interacts with SHORT VEGETATIVE PHASE (SVP); SVP is degraded at high temperatures, reducing the abundance of the SVP-FLM-β repressor complex, and thus allowing the plant to flower. The svp and flm mutants show temperature-insensitive flowering in different temperature ranges. Control of SVP-FLM-β repressor complex abundance via transcriptional and splicing regulation of FLM and post-translational regulation of SVP protein stability provides an efficient, rapid mechanism for plants to respond to ambient temperature changes.