Transcriptome analysis of two Arabidopsis accessions. Col-0 and Kil-0 RNAseq analysis

Plants integrate seasonal cues such as temperature and day length to optimally adjust their flowering time to the environment. Compared to the control of flowering before and after winter by the vernalization and day length pathways, mechanisms that delay or promote flowering during a transient cool or warm period, especially during spring, are less well known. Due to global warming, understanding this ambient temperature pathway has become increasingly important. FLOWERING LOCUS M (FLM) is one critical flowering regulator of this pathway in Arabidopsis thaliana. We identified the Arabidopsis accession Kil-0 as an early flowering strain when compared to the common reference accession Col-0. Genetic mapping of this trait identified a causative region of around 31 kb at the bottom of chromosome one. Within this region, only FLOWERING LOCUS M (FLM) was expressed at a significantly lower level in Kil-0 when comparing RNA-seq (RNA sequencing) data from 10-day old Kil-0 and Col-0 plants grown at 21°C. Furthermore, FLM was also the gene with the greatest reduction in gene expression between Kil-0 and Col-0 when we specifically analyzed 267 genes with a role in flowering time regulation what strongly suggested that FLM is the major locus that results in accelerated flowering in Kil-0.