A genetic and molecular analysis of flowering time in Arabidopsis thaliana using natural variation = Een genetische en moleculaire analyse van bloeitijd in Arabidopsis thaliana gebruikmakend van natuurlijke variatie
The natural allelic variation at flowering time loci between two Arabidopsis thaliana accessions; Landsberg erecta (L er ) and the tropical Cape Verde Island (Cvi) has been analyzed. Quantitative trait locus (QTL) mapping in recombinant inbred lines (RILs) grown under three environments, differing in day-length and/or vernalization treatment, was used to detect and locate flowering loci on the genetic map of Arabidopsis. Four main QTLs were identified, designated EDI , FLF , FLG and FLH , to which most of the flowering time differences could be attributed. At the EDI and FLH loci, Cvi alleles resulted in earliness, whereas at FLF and FLG , Cvi alleles caused lateness. Among these QTL, EDI ( EARLY, DAY-LENGTH INSENSITIVE ) is the main locus responsible for day-length sensitivity. To determine the molecular basis of this natural genetic variation, we have isolated the EDI locus using a map-based cloning strategy. The positional cloning of the EDI QTL showed it to be a novel allele of CRY2 , encoding the blue-light photoreceptor cryptochrome-2, that has previously been shown to promote flowering in long-day photoperiods. It was shown that the unique flowering phenotype in the CRY2 -Cvi allele results from a single amino acid substitution that reduces the down-regulation of the CRY2 protein in plants grown under short photoperiods, leading to early flowering. The genetic interaction between CRY2 and other loci involved in the different flowering promotion pathways was studied. The three different types of CRY2 alleles ( CRY2 -Cvi = EDI , CRY2 -L er , and the CRY2 null mutant fha1-1 ) were combined with the mutants representing the different flowering pathways. This analysis indicated that the so called "vernalization and autonomous pathway" that control FLC ( Flowering locus C ) expression, repress the expression of CRY2 .
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| Format: | Doctoral thesis biblioteca |
| Language: | English |
| Subjects: | arabidopsis thaliana, flowering, flowering date, genetic analysis, genetic variation, molecular genetics, quantitative traits, bloei, bloeidatum, genetische analyse, genetische variatie, kwantitatieve kenmerken, moleculaire genetica, |
| Online Access: | https://research.wur.nl/en/publications/a-genetic-and-molecular-analysis-of-flowering-time-in-arabidopsis |
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