Scientists reveal the evolutionary mechanism of allopolyploid Arabidopsis

Scientists reveal the evolutionary mechanism of allopolyploid Arabidopsis

Scientists reveal the evolutionary mechanism of allopolyploid Arabidopsis

A.
Conservation and diversity of suecica genome image courtesy of Nanjing Agricultural University

A.
Conservation and diversity of the suecica genome Photo courtesy of Nanjing Agricultural University A.
Conservation and diversity of suecica genome Photo courtesy of Nanjing Agricultural University

Dynamic changes of DNA methylation during the formation and stabilization of allotetraploid Arabidopsis.
Photo courtesy of Nanjing Agricultural University

Dynamic changes of DNA methylation during the formation and stabilization of allotetraploid Arabidopsis.
Photo courtesy of Nanjing Agricultural University

Recently, the polyploid research team of Nanjing Agricultural University published the latest research paper in " Nature Ecology & Evolution " , drawing the natural allotetraploid Arabidopsis A.
suecica and the synthetic one.
The high-quality genome map of the allotetraploid Arabidopsis Allo738, and the analysis of the genetic and epigenetic regulation mechanisms during the evolution of allopolyploid plants
.

Nature Ecology & Evolution )

Polyploidization (doubling of the whole genome ) is widespread in nature and is an important driving force for the evolution and diversity of many plants and some animals
.

Heteropolyploid not only doubles the genome, but also fixes the heterosis among species, usually showing stronger growth potential and better environmental adaptability

) )

Because A.
arenosa is an outcrossing plant and its genome is highly heterozygous, its genome research has been stagnant
.

The synthetic allotetraploid Arabidopsis Allo738 and Allo733 (TTAA) are two independent stable homozygous strains formed by the cross of tetraploid A.

Based on a number of mainstream sequencing technologies, the research assembled and annotated the genomes of A.
suecica and Allo738
.

Because the A subgenome of Allo738 is derived from the genome of A.

Studies have found that a stable genome is accompanied by variation between epigenomes
.

By drawing the genome-wide DNA methylation maps of A.

Interestingly, the methylation level of the A subgenome of the heterotetraploid A.
suecica was significantly lower than that of the parent A.
arenosa, and converged to a methylation level similar to that of the T subgenome
.

The study further divided the decreased differentially methylated regions (DMR) in the A subgenome of A.

The study found that in the convergent DMR, the expression pattern of its related genes also showed convergence among the subgenomes of A.
suecica, thereby reducing the biased expression of these homologous genes
.

These DMRs are significantly enriched in genes related to important developmental pathways such as reproduction

These studies have shown that interspecific hybridization and polyploidization will reduce the differences in subgenomic DNA methylation during long-term evolution, leading to the uniformity of the DNA methylation levels of homologous genes

In summary, this study assembled high-quality genome sequences of allotetraploid A.
suecica and autotetraploid A.
arenosa, and provided epigenetic regulation for interspecific hybridization and long-term evolution of polyploid plants.
Research provides new perspectives
.

(Source: China Science News Li Chen)

Related paper information: https://doi.

https://doi.
org/10.
1038/s41559-021-01523-y