Publication details

Molecular analysis of Frigida (Fri) gene in late-flowering genotypes of Arabidopsis thaliana



Year of publication 2007
Type Article in Proceedings
Conference Plant biotechnology: impact on high quality plant reproduction
MU Faculty or unit

Faculty of Science

Field Genetics and molecular biology
Keywords Arabidopsis thaliana; flowering time; mutation; RT-PCR
Description Flowering time is stimulated by both environmental (light, temperature) and endogenous signals. FLC and FRI genes are the most important endogenous signals controlling onset of flowering in natural populations. FLC is a significant flowering repressor under the control of the FRI gene. Interaction of both genes is the reason of lateness in natural populations. In the FRI gene, two frequent deletions responsible for early-flowering phenotype, Ler- and Col-type are known. These deletions have been identified only in early-flowering plants but never in late-flowering plants. Therefore, our work was focused on molecular analysis of FRI gene in late-flowering ecotypes derived from natural populations in the Czech Republic (Je-4, Je-18, Je-27, Je-28 and Hod) and in four late-flowering mutants (dn, L4, Spi and M73). For this purpose five PCR primers that cover the complete sequence of the FRI gene including the promoter were used. Deletions or insertions were detected by agarose or polyacrylamide gels. Some of the PCR fragments were also sequenced. We confirmed the promoter deletion in early-flowering ecotypes Ler, S96 and Di-G commonly used as wild-type laboratory lines representing the genetic backgrounds of our late-flowering mutants. Surprisingly, we found other larger deletions in the FRI promoter of two late-flowering ecotypes (Je-27 and Je-28), one laboratory late-flowering line (C24) and small deletions or insertions in the rest of the analysed ecotypes (except Je-4). In each of four late-flowering mutants, we found promoter deletions that were the same as in early-flowering ecotypes which represent the genetic background of the mutant (except mutant dn). In two late-flowering ecotypes (Je-27 and Je-28) we revealed new changes in the coding region of FRI gene such as deletion in the first exon, insertion in the first intron or in the second exon. Promoter deletions in the FRI gene in early-flowering plants are connected with the loss of function (basis of earliness), therefore, we analysed FRI expression level by RT-PCR. FRI expression in late-flowering plants and, unexpectedly, also in early- flowering ecotypes was found. The results indicate that promoter deletions in FRI gene can occur not only in early but also in late-flowering genotypes (ecotypes or mutants) without any impact on FRI gene expression and timing of flowering. Our first results also suggest that expression of the FRI can be temporarily suppressed during flowering.
Related projects:

You are running an old browser version. We recommend updating your browser to its latest version.

More info