Transcriptiona activity of apple Ty1-copia-like retrotransposons during tissue culture
SUN Jun
FANG Jing-gui
Tao Jian-min
CAI Bin-hua
ZHANG Zhen
Abstract：Transcriptionally active Ty1-copia-like retrotransposons were found in apple callus cells propagated on MS solid medium supplemented with 2 mg/L of 2,4-D, 0.2 mg/L of BA and 0.5 mg/L of NAA for a month. RT-PCR was used for amplifying the conserved reverse transcriptase domain of about 270 bp. Twenty-one clones isolated from the callus cells were sequenced and showed high heterogeneity. All 21 clones were different from each other, amino acid ranging from 35.6% to 98.8%. The majority of isolated reverse transcriptase gene were found to lost their function, containing stop codons, frame shifts, deletion, and insertion mutations. The SLYGLKQ, characteristic of plant retrotransposons, contained base substitution mutation in 7 clones. Horizontal transmission of plant retrotransposons had occurred in the past. Searching through the protein GeneBank database, all 21 sequenced clones showed high homology to Ty1-copia-like elements belonging to other plant species. A phylogenetic tree was constructed based on their predicted amino acids. All sequences were divided into three groups, except ART20. Some Ty1-copia-like copies, present in apple, were found to be high methylated. In conclusion, retrotransposons characteristics have contributed to the genetic diversity and evolution of their host species.
Keywords：AppleTy1-copia-like retrotransposonsTranscriptionTissue culture
Publication Date：2005-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 441-445 )