T2T GENOMES OF HIGHER PLANTS

In 2000, a major breakthrough occurred in plant genomics: an article was published reporting the sequencing of the first plant genome, which belonged to Arabidopsis thaliana and had a size of just over 100 million bp. Over the next quarter century, the era of DNA sequencing has yielded approximately 4 thousand genomes of different assembly levels for approximately 2 thousand plant species. Thus, due to the development of DNA sequencing technologies, genomes have begun to be assembled at the chromosomal level from "telomere to telomere," which is termed "T2T sequencing." More than 2 decades later, the Arabidopsis genome was assembled in T2T format, but earlier, similar T2T genomes had been assembled for rice Oryza sativa and banana Musa acuminata. A T2T genome of bread hexaploid wheat Triticum aestivum, with a size of 14.5 billion bp, more than 100 times the size of the Arabidopsis genome, was assembled recently. A total of 166 plant T2T genomes have already been sequenced for 108 plant species from 80 genera. At the same time, most T2T genomes are characterized by mosaic consensus assembly; therefore, T2T plant genomes with phased assembly by haplotypes and T2T pangenomes with similar phased assembly are of greater interest. This is because it is important to know all gene alleles of crossed or edited specimens for breeding and genomic editing.