Lehrstuhl für Pflanzenzüchtung

Unravelling a mechanism for floral transition control in annual, biennial, and perennial Beta species

Project Start: 19.10.2011

Background

The species Beta vulgaris includes annual, biennial, and perennial accessions. Annual beets germinate, bolt, and flower within one season. Biennial beets (winter annuals) such as sugar beets need prolonged exposure to cold temperatures to get vernalized and to acquire floral competence. After reproduction, annual and biennial beets senesce and die off. By contrast, perennial beet plants live several years and repeat flower onset each year or bolt earliest in the third season. We assume that there is at least one common flowering time gene which is responsible for bolting induction in annual, biennial, and perennial beets and that the different regulation of this gene distinguishes between annual and perennial growth. Allelic variants of this gene might also be responsible for bolting resistance of cold-treated non-bolting beets.

 

AnnPerennLifeCycle

Objectives       

  1. Identification of common bolting inducing genes by comprehensive survey of gene expression in annual, biennial, and perennial Beta species
  2. Unraveling genetic mechanisms that lead to perennial growth
    • by identification of QTL/genes that are responsible for death after reproduction and repeated flowering
    • by cloning non-bolting genes that prevent bolting after cold treatment


Results

RNA-sequencing was performed for annual beets before and during bolting. The RNAseq data were processed using an optimized computational pipeline and transcript profiles of about 30,000 B. vulgaris gene models have been calculated. Furthermore, microscopic studies of shoot meristems at different developmental stages have revealed detailed information on shoot morphology and bolting time. Using the same annual accession as crossing partner, different F2 populations were developed that segregate for vernalization requirement as well as mono- and polycarpic reproduction under field and greenhouse conditions. Genetic maps were constructed that include more than 100 markers located near to flowering homologous sequences. First QTL analyses were performed using F2 phenotypic data.

To clone Beta vulgaris genes that prevent bolting after cold treatment, pooled DNA of bolting and non-bolting sugar beets from a segregating F2 population (Pfeiffer et al. 2014) were re-sequenced. A candidate region was identified by computational analysis and verified by marker analysis. Fine-mapping is in progress using about 7600 F2:3 plants and the genome-wide SNP/InDel information obtained before.

Project team

Dr. Conny Tränkner
Dr. Nazgol Emrani
Claudia Havel

Scientific Partners

Ioana Lemnian and Prof. Dr. Ivo Grosse, University of Halle
Dr. Markus Schilhabel, IKMB, University of Kiel
Nina Pfeiffer, Friedrich Kopisch-Obuch and Christian Jung, University of Kiel

Publications

Pfeiffer, N., C. Tränkner, I. Lemnian, I. Grosse, A.E. Müller, C. Jung, F.J. Kopisch-Obuch. 2014. Genetic analysis of bolting after winter in sugar beet (Beta vulgaris L.). Theoretical and Applied Genetics DOI 10.1007/s00122-014-2392-x.

Funding

Funding is provided by the DFG (German Research Foundation) under grant no. TR 1088/1-1.
The project is part of the DFG Priority Program 1530: Flowering Time Control – from Natural Variation to Crop Improvement.

Posters and Oral Presentations

Tränkner, C., I. Lemnian, N. Pfeiffer, N. Emrani, M. Schilhabel, C. Weinholdt, C. Jung, F. Kopisch-Obuch, I. Große. 2014. Identification of post winter bolting resistance genes of sugar beet (Beta vulgaris) by bulked segregant Next Generation Sequencing. GPZ 2014: Genetic Variation in Plant Breeding, Kiel, Sept 23-25, 2014. Poster.

Emrani, N., I. Lemnian, C. Weinholdt, I. Große, N. Pfeiffer, F. Kopisch-Obuch, C. Jung, M. Schilhabel, C. Tränkner. 2014. Identification of bolting failure candidate genes in sugar beet (Beta vulgaris) by Next Generation Sequencing. Genetic Variation of Flowering Time Genes and Applications for Crop Improvement, 24-26 March 2014, Bielefeld. Oral.

Lemnian, I., C. Tränkner, N. Pfeiffer, N. Emrani, C. Weinholdt, F. Kopisch-Obuch, C. Jung, M. Schilhabel, I. Grosse. 2014. Analysis of whole-genome sequencing data for elucidating foral transition and detecting non-bolting genes in Beta vulgaris. Genetic Variation of Flowering Time Genes and Applications for Crop Improvement, 24-26 March 2014, Bielefeld. Poster.

Lemnian, I., C. Tränkner, N. Pfeiffer, C. Weinholdt, F. Kopisch-Obuch, M. Schilhabel, I. Grosse. 2013. Analysis of deep-sequencing data for elucidating floral transition in Beta species. Workshop Floral Transition in Arabidopsis, Tübingen, 16.-18.9.2013. Oral.

Tränkner, C., I. Lemnian, N. Pfeiffer, F. Kopisch-Obuch, M. Schilhabel, H. van Dijk, I. Grosse. 2013. Unraveling a mechanism for floral transition control in annual, biennial, and perennial Beta species. PP 1530 2nd Annual Consortium Meeting, Köln 23.-24.1.2013. oral.

Tränkner, C. I. Lemnian, N. Pfeiffer, C. Weinholdt, M. Kirchhoff, F. Kopisch-Obuch, M. Schilhabel, I. Große. 2012. Towards mapping of bolting failure genes of sugar beet (Beta vulgaris ssp. vulgaris) by next generation sequencing. GPZ Genome Research Working Group 10. Conference – Plant Stress and Genomics, Halle18.-20.09.2012. Poster.

Tränkner, C., N. Pfeiffer, M. Schilhabel, F. Kopisch-Obuch, M. Kirchhoff, I. Lemnian, I. Große. 2012. Strategy for mapping bolting repressor genes of sugar beet by next generation sequencing. 1st Young Investigator Meeting PP 1530, Halle/Saale 18.-20.6.2012. Oral.

Tränkner, C., N. Pfeiffer, M. Kirchhoff, F. Kopisch-Obuch, M. Schilhabel, H. van Dijk, I. Lemnian, I. Grosse. 2012. Unraveling a mechanism for floral transition control in annual, biennial, and perennial Beta species. 1st Young Investigator Meeting PP 1530, Halle/Saale 18.-20.6.2012. Poster.

Höft, N., C. Tränkner, C. Jung, S. Melzer. 2012. Control of flowering in sugar beet and Arabidopsis through activation of flowering time repressors by FLP-FRT recombination. "Breeding crops for sustainable agricultural production" Symposium of GPZ e.V., Gießen 28.2.-1.3.2012. Poster.

Tränkner, C. 2012. Unraveling a mechanism for floral transition control in annual, biennial, and perennial Beta species. DFG Priority Program 1530, Kickoff Meeting, Kiel 22.-24.2.2012. Oral.

 

Updated: 07-Jan-15    Responsible for this webpage: Conny Tränkner

 

Links:
http://www.flowercrop.uni-kiel.de/en/projects/phase-i/traenkner