Lehrstuhl für Pflanzenzüchtung

Flowering Time Control in Rapeseed

 

Flowering time control in rapeseed

Background

The optimal time for flowering varies between crop plants and depends on diverse factors such as the type of product (e.g., fruit or root crop), the cultivar (e.g., spring or winter types) and the climate of the cultivated area. Identification of genes that promote or inhibit flowering may hold an important key for sustainable agriculture under distinct environmental conditions. Considering the increasing evidences suggesting that flowering time regulators may influence hybrid vigor and subsequently plant’s yield, understanding the mechanisms governing flowering time and vernalization requirement in oilseed rape (Brassica napus L.), one of the major sources of edible oil worldwide, can guarantee successful reproduction and seed development which is crucial for rapeseed considering its economic importance in human and animal feeding. In Arabidopsis, a model plant closely related to Brassica species, the main regulatory pathways for flowering time have been uncovered in the last decade. However, despite a close phylogenetic relation, transfer of information from Arabidopsis to B. napus is hindered by the allopolyploid nature of the oilseed rape genome.  

Objectives

The objectives of this project are detection and phenotypic evaluation of new flowering time mutants and sequence variants by TILLING, and unveiling genes responsible for flowering time control in rapeseed through transcriptome analysis.

Results

For TILLING in B. napus flowering time genes, a total of 3488 M2 plants were screened for mutations in three target genes, starting from EMS-mutagenized seeds of the winter-type cultivar Express 617. We have detected more than 110 EMS-generated alleles in paralogs of major flowering time regulators, FRIGIDA (FRI), FLOWERING LOCUS-T (FT), and TERMINAL FLOWER-1 (TFL1). Single locus mutations in BnFRI and BnFT showed effects on flowering time and vernalization responses despite the existence of several gene-copies. Mutations within BnTFL1 paralog had no large effects on flowering time but on yield components. F1 hybrids between BnTFL1 mutants and non-mutated parents had increased seed number per pod and total seeds per plant suggesting that heterozygous mutations in a TFL1 paralog may impact heterosis in rapeseed. The present results shed new light on the interaction of paralog genes in a polyploid plant species.

RNA sequencing (RNA‐seq) in the semi-winter doubled haploid line, Ningyou7, at different developmental stages and temperature regimes was performed to gain a deeper insight into genetic factors controlling floral transition in B. napus. The expression profiles of more than 54,000 gene models were compared between different treatments and developmental stages. Subsequently, the differentially expressed genes were considered as targets for association analysis and genetic mapping to confirm their role in floral transition. Consequently, 36 genes with association to flowering time, seed yield, or both were identified. This study proved the potential of RNA‐seq along with association analysis and genetic mapping to identify candidate genes for floral transition in rapeseed. 

Project team

M.Sc. Smit Shah
Dr. Nazgol Emrani
Prof. Dr. Christian Jung

Scientific Partners

Prof. Ivo Grosse, Institute of Computer Science, Martin-Luther-University Halle-Wittenberg, Germany
Prof. Wei Qian, Southwest University, Chongqing, China
Prof. Habibur Rahman, University of Alberta, Canada
Prof. Rod Snowdon, Dr. Sarah Schiessl, University of Giessen, Germany
Institute of Clinical Molecular Biology (IKMB), Kiel, Germany

Commercial Partners

Norddeutsche Pflanzenzucht Hans-Georg Lembke KG (NPZ)

Publications

Shah S, Weinholdt C, Jedrusik N, Molina C, Zou J, Große I, Schiessl S, Jung C, Emrani N (2018) Whole-transcriptome analysis reveals genetic factors underlying flowering time regulation in rapeseed (Brassica napus L.). Plant, Cell & Environment 41: 1935-1947

Guo, Y., H. Harloff, et al. (2014). Mutations in single FT and TFL1 paralogs of rapeseed (Brassica napus L.) and their impact on flowering time and yield components. Frontiers in Plant Science 5: 282

Zou X, Suppanz I, Raman H, Hou J, Wang J, et al. (2012) Comparative Analysis of FLC Homologues in Brassicaceae Provides Insight into Their Role in the Evolution of Oilseed Rape. PLoS ONE 7(9): e45751. doi:10.1371/journal.pone.0045751

Wang, N., Qian, W., Suppanz, I., Wei, L. , Mao, Z., Long, Y., Meng, J., Müller, A. E. and Jung, C. (2011) Flowering time variation in oilseed rape (Brassica napus L.) is associated with allelic variation in the FRIGIDA homologue BnaA.FRI.a. Journal of Experimental Botany, 62:5641-58

Posters and Oral Presentations

Shah, S.,Emrani, N., Guo, Y., Jedrusik, N., Molina, C., Weinholdt, C., Lemnian, I., Grosse, I., Zou J., and Jung, C. (2018) Identification and characterization of flowering time genes in oilseed rape through mutant and transcriptome analysis. Mini-symposium, Kiel Plant Science Network , Kiel, 19th April, 2018, Oral Presentation

Shah, S.,Emrani, N., Guo, Y., Jedrusik, N., Molina, C., Weinholdt, C., Lemnian, I., Grosse, I., Zou J., and Jung, C. (2018) Identification and characterization of flowering time genes in oilseed rape through mutant and transcriptome analysis. III. International 1530 Symposium, Kiel, March 14th to March 16th, 2018, Oral Presentation

Shah, S.,Emrani, N., Guo, Y., Jedrusik, N., Molina, C., Weinholdt, C., Lemnian, I., Grosse, I., Zou J., and Jung, C. (2018) Identification and characterization of flowering time genes in oilseed rape through mutant and transcriptome analysis. German Plant Breeding Conference (GPBC 2018), February 28 – March 02, 2018, Wernigerode, Oral Presentation

Shah, S.,Emrani, N., Guo, Y., Jedrusik, N., Molina, C., Weinholdt, C., Lemnian, I., Grosse, I., Zou J., and Jung, C. (2017) Identification and characterization of flowering time genes in oilseed rape through TILLING and transcriptome analysis. International Workshop on Genome Engineering and Epigenetic Variation of Flowering Time Genes, June 22 - 23, 2017, IPK Gatersleben, Poster Presentation

Emrani, N., Shah, S., Guo, Y., Jedrusik, N., Molina, C., Weinholdt, C., Lemnian, I., Grosse, I., Zou J., and Jung, C. (2017) Identification and characterization of flowering time genes in oilseed rape through mutant and transcriptome analysis. Annual Retreat “Kiel Life Science” (KLS), November 16 - 17, 2017, Schleswig, Poster Presentation

Shah, S.,Emrani, N., Guo, Y., Jedrusik, N., Molina, C., Weinholdt, C., Lemnian, I., Grosse, I., Zou J., and Jung, C. (2016) Identification and characterization of flowering time genes in oilseed rape through TILLING and transcriptome analysis. PP1530 Workshop on Circadian rhythms, flowering time regulation and crop plant adaptation, January 20-22, 2016, Berlin, Oral Presentation

Shah, S.,Emrani, N., Guo, Y., Jedrusik, N., Molina, C., Weinholdt, C., Lemnian, I., Grosse, I., Zou J., and Jung, C. (2016) A transcriptomic approach to identify flowering time regulators in rapeseed. 2nd Sino-German Rapeseed Symposium: Genetics and Biotechnology of Rapeseed, May 23-26, 2016, Kiel, Germany, Poster presentation

Emrani, N., Shah, S., Guo, Y., Jedrusik, N., Molina, C., Weinholdt, C., Lemnian, I., Grosse, I., Zou J., and Jung, C. (2016) Identification and characterization of flowering time genes in oilseed rape through TILLING and transcriptome analysis. 2nd Sino-German Rapeseed Symposium: Genetics and Biotechnology of Rapeseed, May 23-26, 2016, Kiel, Germany, Oral presentation

Emrani, N., Shah, S., Guo, Y., Jedrusik, N., Molina, C., Weinholdt, C., Lemnian, I., Grosse, I., Zou J., and Jung, C. (2015) Molecular dissection of flowering time regulation in Brassica napus and application for hybrid breeding. 4th Annual Consortium Meeting, April 22-24, 2015, Weihenstephan, Oral Presentation

Shah, S.,Emrani, N., Guo, Y., Jedrusik, N., Molina, C., Weinholdt, C., Lemnian, I., Grosse, I., Zou J., and Jung, C. (2015) Identification and characterization of flowering time genes in oilseed rape through TILLING and transcriptome analysis. GPZ 2015: New Targets for Crops of the Future, September 22-24, 2015, Düsseldorf, Germany, Poster presentation

Jung, C., Guo, Y., Harloff, H., Molina, C. (2015) Induced sequence variations within life cycle genes of rapeseed and their impact on flowering time and hybrid yield. 14th International Rapeseed Congress, Saskatoon, Canada, July 5-9, 2015, Oral Presentation

Guo, Y.,Emrani, N., Jedrusik, N., Molina, C., Weinholdt, C., Lemnian, I., Grosse, I., Zou J., and Jung, C. (2014) Identification and characterization of flowering time genes in oilseed rape through TILLING and transcriptome analysis. Genetic Variation of Flowering Time Genes and Applications for Crop Improvement, Bielefeld, Oral Presentation

Emrani, N., Guo, Y., Jedrusik, N., Molina, C., Weinholdt, C., Lemnian, I., Grosse, I., Zou J., and Jung, C. (2014) Paralog-specific function and expression dynamics during floral transition in Brassica napus. GPZ 2014: Genetic Variation in Plant Breeding, September 23-25, 2014, Kiel, Germany, Poster presentation

Emrani, N., Jedrusik, N., Molina, C., Jung, C. (2013) Expression dynamics of A. thaliana flowering time regulator homologs in B. napus. Workshop on Floral Transition in Arabidopsis, September 16-18, 2013, Tübingen, Oral Presentation

Molina, C., Guo, Y., Emrani, N., Jung, C.(2013) Identification and characterization of flowering time genes in oilseed rape through TILLING and transcriptome analysis. Sino-German Workshop on Genetics and Biotechnology of Rapeseed, Zhejiang, Oral Presentation

Molina, C., Guo, Y., Emrani, N., Jung, C.(2013) Genomic dissection of floral transition in Brassica napus towards crop improvement by life cycle adaptation and hybrid yield increase. PP1530 - II annual consortium meeting, Cologne, Oral Presentation

Guo, Y., Molina, C., Suppanz, I., and Jung, C. (2013) Pleiotropic effects observed on EMS-generated alleles of FTi genes in the allopolyploid Brassica napus.Workshop: Pleiotropic effects of Flowering Time Genes and Impact on Adaptation and Speciation, Cologne, Oral Presentation

Jedrusik, N., Molina, C., Grosse, I., Zou J., and Jung, C. (2012) B. napus transcriptome analysis for flowering time gene identification by RNAseq. DFG Young investigator meeting, Halle, Poster Presentation

Guo, Y., Molina, C., Suppanz, I., Jedrusik, N., and Jung, C. (2012) Screening of TILLING-mutant families suggest non-additive effects in highly similar flowering-gene paralogs/homeologs in the allopolyploid Brassica napus. GPZ conference, Giessen, Poster Presentation 

Financial Support

Funding is provided by the DFG Priority Program 1530: Flowering Time Control – from Natural Variation to Crop Improvement

Updated:  31.07.2018        Responsible for this webpage: M.Sc. Smit Shah