Arabidopsis aneuploidy mutant C30-81-as6, possesses enormous variations in multiple phenotypic characteristics.

Abstract

Heavy-ion beam irradiation can be recognized as one of the powerful mutagenesis techniques because it induces high mutation frequency, minimal damage to the other traits and the possibility of having large DNA fragmental mutations. Aneuploid cells may have an additional or fewer number of chromosomes compared to their wild-type. The mutant line of C30-81-as6 is an ion beam-generated, Arabidopsis Col-0 based, aneuploid mutant line confirmed by whole genome sequence analysis, DNA quantity measurement using flow cytometry analysis and microscopic observations of additional chromosome. The mutant shows abnormal leaf shapes, petioleless rosette leaves, elevated trichome bases and later flowering phenotypes. Segregation analysis confirmed that additional DNA amount is correlated with observed phenotype since mutants showing intermediate phenotype possess moderate DNA quantities. A set of candidate causal genes was identified using up and downregulated differentially expressed genes in transcriptome analysis. Gene ontology analysis further supports mutant phenotypic characteristics and provides insights into its functional priorities, including 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 analysis based chromosome rearrangement prediction and the gene density mapping of upregulated DEGs, suggested that the long arm of chromosome 2 is a main component of the additional chromosome. In addition, the phenotype of C30-81-as6 largely resembles Arabidopsis additional chromosome 2 containing aneuploidy mutant. The ion beam mutagenesis generated aneuploidy mutant that may possess a fused DNA fragmented chromosome and it may successfully challenge the wild-type plants for establishment in nature.