Heavy-ion beam irradiation is recognized as a powerful mutagenesis technique because it induces high mutation frequencies, causes minimal damage to other traits, and has the potential to produce large DNA-fragmentation mutants. Aneuploid cells may have an additional or fewer number of chromosomes compared to their wild-type. The mutant line of flower late pltioleless1 (flpl1) is an ion beam-generated, Arabidopsis thaliana Col-0 based, aneuploid mutant line confirmed by whole genome sequence analysis, DNA quantity measurement using flow cytometry analysis and microscopic observations of an additional chromosome. The mutant shows abnormal leaf shapes, petioleless rosette leaves, elevated trichome bases and later-flowering phenotypes. Segregation analysis confirmed that the amount of additional DNA correlates with the observed phenotype as mutants with intermediate phenotypes possess moderate amounts of additional DNA. A set of candidate causal genes was identified using up and downregulated differentially expressed genes in transcriptome analysis. Gene ontology analysis further supports the mutant’s phenotypic characteristics and provides insights into its functional priorities, including the promotion of cellular structure and energy production. Meanwhile, the downregulation of senescence-related gene ontology terms validates its extended vegetative phase. The whole genome sequence-based chromosome rearrangement prediction and sequence coverage map analysis established the expected chromosomal model for flpl1. Ion beam mutagenesis generates aneuploidy and segmental aneuploidy mutants that may possess fused DNA-fragmented chromosomes.
Nagalla et al. (Wed,) studied this question.