Identical Substitutions in Magnesium Chelatase Paralogs Result in Chlorophyll-Deficient Soybean Mutants. Issue 1 (1st January 2015)

• Record Type: Journal Article
• Authors: Campbell, Benjamin W; Mani, Dhananjay; Curtin, Shaun J; Slattery, Rebecca A; Michno, Jean-Michel; Ort, Donald R; Schaus, Philip J; Palmer, Reid G; Orf, James H; Stupar, Robert M
• Is Part Of: G3. Volume 5:Issue 1(2015)
• Page Start: 123
• Page End: 131
• Publication Date: 2015-01-01
• Subjects: soybean -- photosynthesis -- chlorophyll -- paralog -- duplication; Genetics -- Research -- Periodicals; Genomics -- Periodicals; Genetics; Genomics; Genes; Genetics -- Research; Genomics; Electronic journals; Periodical; Periodicals; Fulltext; Internet Resources; Periodicals; 572.8
• DOI: 10.1534/g3.114.015255
• Languages: English
• ISSNs: 2160-1836

Abstract

Abstract: The soybean [ Glycine max (L.) Merr.] chlorophyll-deficient line MinnGold is a spontaneous mutant characterized by yellow foliage. Map-based cloning and transgenic complementation revealed that the mutant phenotype is caused by a nonsynonymous nucleotide substitution in the third exon of a Mg-chelatase subunit gene (ChlI1a) on chromosome 13. This gene was selected as a candidate for a different yellow foliage mutant, T219H ( Y11y11 ), that had been previously mapped to chromosome 13. Although the phenotypes of MinnGold and T219H are clearly distinct, sequencing of ChlI1a in T219H identified a different nonsynonymous mutation in the third exon, only six base pairs from the MinnGold mutation. This information, along with previously published allelic tests, were used to identify and clone a third yellow foliage mutation, CD-5, which was previously mapped to chromosome 15. This mutation was identified in the ChlI1b gene, a paralog of ChlI1a. Sequencing of the ChlI1b allele in CD-5 identified a nonsynonymous substitution in the third exon that confers an identical amino acid change as the T219H substitution at ChlI1a. Protein sequence alignments of the two Mg-chelatase subunits indicated that the sites of amino acid modification in MinnGold, T219H, and CD-5 are highly conserved among photosynthetic species. These results suggest that amino acid alterations in this critical domain may create competitive inhibitory interactions between the mutant and wild-type ChlI1a and ChlI1b proteins.