503 / 2019-02-28 22:52:30

Control of flowering time in response to ambient temperature in natural and engineered summer-annual Arabidopsis thaliana accessions

flowering time control,natural variation,MADS box transcription factors,ambient temperature,FLM,FLC,CRISPR/Cas9,phenotypic pleiotropy

Growth and Development > Growth and Development

The precise biological timing of flowering is one of the most important factors for a plant's reproductive success. Compared to the control of flowering after winter by the vernalization pathway, mechanisms that control flowering in spring are less well understood. Due to global warming, understanding this ambient temperature pathway has gained importance. In Arabidopsis thaliana, the MADS-box transcription factor FLOWERING LOCUS M (FLM) is a critical flowering regulator of the ambient temperature pathway. We identified insertions in the first intron of FLM as causative for earlier flowering in many natural accessions, especially in cool temperatures (Lutz et al., 2015). By association analysis using FLM variant data of 800 accessions and expression analysis we identified regulatory elements in the noncoding region of FLM that fine-tune FLM transcript levels and flowering time. A genetic contribution of FLM to flowering time control in summer-annual accessions was observed (Lutz et al., 2017). In winter-annual accessions effects of FLM and other loci on natural variation of flowering is often masked by the vernalization gene FLOWERING LOCUS C (FLC). Thus, a CRISPR/Cas9 approach was applied to generate FLC deletions in more than 90 winter-annual accessions to precisely determine single genetic contributions of FLM and other loci. This experimental population will be investigated for genetic and environmental interactions, as well as phenotypic pleiotropy of FLC.