TitleRapid accumulation of mutations during seed-to-seed propagation of mismatch-repair-defective Arabidopsis.
Publication TypeJournal Article
Year of Publication2004
AuthorsHoffman PD, Leonard JM, Lindberg GE, Bollmann SR, Hays JB
JournalGenes Dev
Date Published2004 Nov 01
Arabidopsis, Arabidopsis Proteins, Base Pair Mismatch, DNA Repair, Genomic Instability, Microsatellite Repeats, Mutation, MutS Homolog 2 Protein, Plants, Genetically Modified, Reproduction, Asexual, Seeds

During the many cell divisions that precede formation of plant gametes, their apical-meristem and floral antecedents are continually exposed to endogenous and environmental mutagenic threats. Although some deleterious recessive mutations may be eliminated during growth of haploid gametophytes and functionally haploid early embryos ("haplosufficiency quality-checking"), the multiplicity of plant genome-maintenance systems suggests aggressive quality control during prior diploid growth. To test in Arabidopsis a hypothesis that prior mismatch repair (MMR) is paramount in defense of plant genetic fidelity, we propagated in parallel 36 MMR-defective (Atmsh2-1) and 36 wild-type lines. The Atmsh2-1 lines rapidly accumulated a wide variety of mutations: fifth-generation (G5) plants showed abnormalities in morphology and development, fertility, germination efficiency, seed/silique development, and seed set. Only two Atmsh2-1, but all 36 wild-type lines, appeared normal at G5. Analyses of insertion/deletion mutation at six repeat-sequence (microsatellite) loci showed each Atmsh2-1 line to have evolved its own "fingerprint," the results of as many as 10 microsatellite mutations in a single line. Thus, MMR during diploid growth is essential for plant genomic integrity.

Alternate JournalGenes Dev.
PubMed ID15520284
PubMed Central IDPMC525547