The Arabidopsis DNA mismatch repair gene PMS1 restricts somatic recombination between homeologous sequences

Abstract

The eukaryotic DNA mismatch repair (MMR) system contributes to maintaining the fidelity of genetic information by correcting replication errors and preventing illegitimate recombination events. This study aimed to examine the function(s) of the Arabidopsis thaliana PMS1 gene (AtPMS1), one of three homologs of the bacterial MutL gene in plants. Two independent mutant alleles (Atpms1-1 and Atpms1-2) were obtained and one of these (Atpms1-1) was studied in detail. The mutant exhibited a reduction in seed set and a bias against the transmission of the mutant allele. Somatic recombination, both homologous and homeologous, was examined using a set of reporter constructs. Homologous recombination remained unchanged in the mutant while homeologous recombination was between 1.7- and 4.8-fold higher than in the wild type. This increase in homeologous recombination frequency was not correlated with the degree of sequence divergence. In RNAi lines, a range of increases in homeologous recombination were observed with two lines showing a 3.3-fold and a 3.6-fold increase. These results indicate that the AtPMS1 gene contributes to an antirecombination activity aimed at restricting recombination between diverged sequences.

The transcriptome landscape of Arabidopsis male meiocytes from high‐throughput sequencing: the complexity and evolution of the meiotic process

“…The expression of all Arabidopsis MSH genes in male meicoytes suggests that they function in meiosis (Table S12). AtPMS1 plays an anti‐recombination role in mitosis (Li et al. , 2009).…”

“…The expression of all Arabidopsis MSH genes in male meicoytes suggests that they function in meiosis (Table S12). AtPMS1 plays an antirecombination role in mitosis (Li et al, 2009). The finding of AtPMS1 expression in male meiocytes (Table S12) suggests that it may also function in meiosis.…”

Pathways to meiotic recombination in Arabidopsis thaliana

“…AtMLH1 is also required for recombination in somatic cells (Dion et al, 2007). The role of AtPMS1 appears to be restricted to somatic cells, where it is involved in DNA MMR and the restriction of recombination between homeologous sequences (Jean et al, 1999;Alou et al, 2004;Jackson et al, 2006;Dion et al, 2007;Li et al, 2009). AtMLH3 was identified by sequence homology compared with yeast and mouse .…”

Research on Plants for the Understanding of Diseases of Nuclear and Mitochondrial Origin

“…Results confirmed that frameshift mutations were dependent on MSH2 [37]. In addition, MSH2 , MLH1, or PMS1 were suggested to play essential roles in suppressing recombination between diverged sequences and indicated the involvement of MLH1 and to a lesser extent MSH2 in the stimulation of plant homologous mitotic recombination [35, 38–41]. …”