Complex Genome Rearrangements In An Arabidopsis T-Dna Line

In recent years, an increasing number of studies demonstrated that many Arabidopsis T-DNA lines might carry massive genome changes as a direct consequence of the transfer DNA (T-DNA) integration event. In this work, we report an analysis of a segregating T-DNA mutant line (SAIL_218_G01), which contains such genomic rearrangements. The initial PCR analyses did not yield any homozygous plants, suggesting putative gametophyte lethality. However, this result is likely caused by chromosomal translocations, which were clearly identified in several heterozygous plants by a pollen viability assay. Surprisingly, we identified plants that carried the T-DNA and still produced 100% viable pollen. For reciprocal balanced translocations, these plants should be then homozygous for the T-DNA insertion. Yet, the offspring of some of these plants still segregated the T-DNA, suggesting more complex genome rearrangements in the studied Arabidopsis mutant line.