Unraveling bases of polyploidy and aneuploidy responses in flowering plants, using the wheat ploid model – PLOID-PLOID-WHEAT

For this purpose, we have developed an original natural and newly-synthesized polyploid and aneuploid wheat material that mainly allows us to characterize: (i) Mechanisms that underlie genetic and epigenetic changes induced by allopolyploidy and aneuploidy in the context of evidenced or no apparent structural changes and for the first time (ii) Effects of decreasing and then re-increasing a whole chromosome set through polyploidy, or a specific chromosome(s); through aneuploidy.

The Kick-off meeting hold and tasks reviewed and planed.
Preparation of wheat synthetic hexaploids and sampling of tissues.
Preparation of wheat monosmic lines for the chromosomes 1A, 1B and 1D and sampling of tissues.
RNA extracted and mRNA-libraries and small RNA libraries obtained from roots and shoots tissues of one synthetic allohexaploid.
Elaboration of statistical model for analysis of homoeoallele gene expression.

Continue tasks as planed

None

In Eukaryotes, unbalanced losses and/or gain of the whole haploid chromosome set (polyploidy) or of individual chromosome(s) (aneuploidy) are ubiquitous and have profound impacts on biodiversity, dynamics and genome functioning. Most of the underlying mechanisms are poorly understood and several questions remain regarding the relationships between genetic and epigenetic changes induced by polyploidy and aneuploidy and the fate of duplicated genes. Using the wheat species (genera Triticum and Aegilops) model system, our main objectives are to unravel the major mechanisms and decipher the complex dynamic that follows allopolyploid and aneuploid formation. Integrative approaches will be conducted that includes: i) Comparative analysis of the changes occurring at the phenotype, genome structure, transcriptome and transposome levels and then; ii) Integrate and establishment of the relationships between these different effects, as well as iii) Characterizing their epigenetic regulation.
For this purpose, we have developed an original natural and newly-synthesized polyploid and aneuploid wheat material that mainly allows us to characterize: (i) Mechanisms that underlie genetic and epigenetic changes induced by allopolyploidy and aneuploidy in the context of evidenced or no apparent structural changes and for the first time (ii) Effects of decreasing and then re-increasing a whole chromosome set through polyploidy, or a specific chromosome(s); through aneuploidy. Through the comparative analysis of such material we will also unravel similarities and differences of gene and transposon expression across the different ploidy levels and generations as well as characterization of neo- and sub-functionalization of duplicated genes and homoeoalleles.
The proposed project gathers complementary expertise’s in genetics, cytogenetics, genomics, transcriptomics, physiology, agronomy, bioinformatic, biostatistics and modeling, uses the top approaches and tools and federates investigations among research groups from different French institutions in coordination with international efforts in the field.