Mutations at the Arabidopsis CHM locus promote rearrangements of the mitochondrial genome.

Abstract

Nuclear recessive mutations at the chloroplast mutator (CHM) locus of Arabidopsis produce a variegated phenotype that is inherited in a non-Mendelian fashion. Molecular analysis of the cytoplasmic genomes of variegated plants from two independent chm mutant tines, using specific chloroplast and mitochondrial probes, showed that the chm mutations reproducibly induce the appearance of specific new restriction fragments in the mitochondrial genome. The presence of these restriction fragments cosegregated with the variegated phenotype in the progeny of crosses between mutant and wild-type plants. Sequence analysis of one of the new restriction fragments found in the variegated plants suggested that it was the product of a rearrangement event involving regions of the mitochondrial genome. Thus, it appears that the CHM locus may encode a protein involved in the control of specific mitochondrial DNA reorganization events.

Analysis of Leaf Sectors in the NCS6 Mitochondrial Mutant of Maize.

“…We have previously reported that NCS2 pale green leaf sectors have functionally and structurally altered chloroplasts, although the primary defect is in the mitochondrial DNA (Roussell et al, 1991). A mitochondrial DNA rearrangement also appears to be correlated with the maternally inherited variegation of plants carrying the chm ("chloroplast mutator") gene in Arabidopsis (Martínez-Zapater et al, 1992).…”

Interactions of Mitochondrial and Nuclear Genes That Affect Male Gametophyte Development

“…A clue to the possible mode of action of Fr comes from the study of mutations in the Arabidopsis chloroplast mutator (CHM) locus, which result in the loss of mtDNA regions, producing green-white variegated leaves (Martinez-Zapater et al, 1992). Cloning of CHM revealed that it encodes a gene homologous with Escherichia coli MutS, which is involved in mismatch repair and DNA recombination (Abdelnoor et al, 2003).…”

Effects of chloroplast dysfunction in a subpopulation of leaf mesophyll cells on photosynthetic and respiratory activities of a whole leaf: A study using variegated leaves of Hedera helix L.

“…The various causes of this variegation include plastid ribosome deficiency (Han et al 1992, Hess et al 1993, alteration of plastid genome (Stoike and Sears 1998), mitochondrial dysfunction (Martínez-Zapater et al 1992, Sakamoto et al 1996, and deficiencies in carotenoid biosynthesis (Wetzel et al 1994). Variegated plants have played prominent roles in research on genetics (e.g., discovery of non-Mendelian inheritance) and morphology (e.g., analysis of cell lineage in leaf development).…”