Research On Genome Swelling Of Representative Angiosperms

There are a large number of repetitive sequences in plant genome,especially the LTR(long terminal repeat)retrotransposons,which make the genome size vary greatly.The11 representative angiosperms were selected to explore whether LTR retrotransposons promote the genome swelling.The repetitive sequences in the genomes of various species were annotated,and the repetitive sequences in the genomes,especially the LTR retrotransposons,were statistically analyzed.It was found that there was a great correlation between the genome size and the proportion of repetitive sequences.The larger the genome size,the higher the proportion of repetitive sequences in the genome.The great differences of genome among different species in the same family may be caused by the amplification and deletion of repeat sequences in the evolution of plant genome.The complete LTR retrotransposons in the genome was further annotated,and the Python script was used for data statistical analysis,found that the larger the genome size of the species,the more complete retrotransposons,and the number of complete Gypsy retrotransposons is higher than that of Copia retrotransposons,however,soybean genome has more Copia transposons.There may be a burst event in the Copia transposons.The dynamic analysis of insertion and deletion of complete retrotransposons with genome size in different species was carried out by using TE package of R programming language.The results showed that the genome size of different species showed different evolutionary trends,such as genome swelling,genome contraction and genome stability.Sequence alignment of complete retrotransposons from different species of the same family showed that the number of transposons with high similarity among species was less,and there was no correlation of genome size evolution among different species of the same family.Analysis of genome size evolution of representative angiosperms can help to understand the distribution and evolution of repetitive sequences in plant genome,and provide important theoretical reference for the study of genome size evolution.Figure 15;Table 12;Reference 92...