title: Sensitivity to Alternaria alternata toxin in citrus because of altered mitochondrial RNA processing.
abstract: Specificity in the interaction between rough lemon (Citrus jambhiri Lush.) and the fungal pathogen Alternaria alternata rough lemon pathotype is determined by a host-selective toxin, ACR-toxin. Mitochondria from rough lemon are sensitive to ACR-toxin whereas mitochondria from resistant plants, including other citrus species, are resistant. We have identified a C. jambhiri mitochondrial DNA sequence, designated ACRS (ACR-toxin sensitivity gene), that confers toxin sensitivity to Escherichia coli. ACRS is located in the group II intron of the mitochondrial tRNA-Ala and is translated into a SDS-resistant oligomeric protein in C. jambhiri mitochondria but is not translated in the toxin-insensitive mitochondria. ACRS is present in the mitochondrial genome of both toxin-sensitive and -insensitive citrus. However, in mitochondria of toxin-insensitive plants, the transcripts from ACRS are shorter than those in mitochondria of sensitive plants. These results demonstrate that sensitivity to ACR-toxin and hence specificity of the interaction between A. alternata rough lemon pathotype and C. jambhiri is due to differential posttranscriptional processing of a mitochondrial gene.
authors.affiliation: United Graduate School of Agricultural Sciences, Department of Life Sciences, Faculty of Agriculture, Kagawa University, Miki, Kagawa 761-0795, Japan.
authors.forename: Kouhei
authors.initials: K
authors.lastname: Ohtani
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Kazuya
authors.initials: K
authors.lastname: Akimitsu
mesh_terms: D001483:Base Sequence; D015153:Blotting, Western; D002957:Citrus / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D017353:Gene Deletion; D016678:Genome; D007438:Introns; D008928:Mitochondria / Q000378:metabolism; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009183:Mycotoxins / Q000494:pharmacology*; D011485:Protein Binding; D012313:RNA / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D000077278:RNA, Mitochondrial; D012344:RNA, Transfer, Ala / Q000378:metabolism; D013110:Sphingosine; D013997:Time Factors
chemical_list: C047996:Alternaria alternata pathotoxin TA; D018076:DNA, Complementary; D009183:Mycotoxins; D000077278:RNA, Mitochondrial; D012344:RNA, Transfer, Ala; D012313:RNA; D013110:Sphingosine