Title : Identification of a new thermal mediator from various Arabidopsis accessions with genetics and Next Generation Sequencing analysis
Abstract:
The timing of transition from vegetative to reproductive development is crucial for plant to maximize reproductive success. Plants synchronize this timing of transition by a complex network of flowering genetic pathways in response to internal and external stimuli such as GA, photoperiod, and temperature, etc. Since ambient temperature is one of the major environmental factors modulating plant development and due to global warming, the understanding of this ambient temperature mediated flowering time has been getting importance. Arabidopsis thaliana is one of the major model system to study wide aspects of from genetics to molecular biology in plants, but the classical study has been mainly performed by dissecting traits caused by mutations in a few laboratory Arabidopsis strains such as Col, Ler, and WS. To bypass the limitation of this traditional approach, an alternative approach using wild strains of Arabidopsis has been introduced since the plentiful source of genetic variations can be found within naturally occurring populations of wild Arabidopsis accessions as adaptation to environmental changes. To identify a novel gene which may be responsible for the ambient temperature responsive flowering, flowering time of wild Arabidopsis accessions were observed at the ambient temperature changes, 16°C and 23°C, respectively. To test whether the non-responsive flowering phenotype in these Arabidopsis accessions was caused by already identified thermal mediators such as svp and flm, flowering time of F1 between wild Arabidopsis accessions x svp and wild accessions x flm were measured. After isolating accessions exhibiting complemented flowering time (in other words, close to wild-type flowering time) in this F1 generation, early flowering plants among F2 Arabidopsis accessions x Col grown at 16°C were pooled, DNA extracted, whole genome sequenced and analyzed. Our hypothesis is that early flowering F2 plants at 16°C may have the homozygous gene for the non-responsive flowering phenotype in ambient temperature changes. To further narrow down a responsible gene, 6 backcrosses to Col have been performed by phenotypic selection for early flowering time.
