ABSTRACT
A cDNA encoding the methionine-rich (19 mol% Met) protein in Brazil nut was placed under the regulation of CaMV 35S promoter and nopaline synthase terminator and introduced into the potato cultivar Russet Burbank via Agrobacterium-mediated transformation. To further enhance the Met content in the transgenic plants, chimeric genes containing four mutant constructs, BoxIa (with 5 additional Met), BoxIIa (2 additional Met), BoxIaIIa (7 additional Met), and BoxIIa2 (7 additional Met), were also generated by sequence modifications of the cDNA and transferred into potato. Analysis of the microtubers and leaves of the transgenic potato plants revealed, in general, with the exception of the BoxIIa2, the presence of mRNA transcripts of the expected size and the correctly processed Met-rich 9 kDa subunit polypeptides. The expression levels in the leaves among the various constructs and individual transgenic plants varied between <0.01% and 0.2% of total protein. The corresponding expression in the tubers was usually 2- to 4-fold lower than in leaves. In the case of BoxIIa2, which contains two tandem repeats of the BoxIIa mutant sequence, a larger (10.5-11 kDa) polypeptide was detected. These findings demonstrated that it is feasible to exploit the variable region of the Brazil Nut 2S protein for enhanced Met contents and perhaps for other desirable properties.
Subject(s)
Methionine/genetics , Nuts/genetics , Plant Proteins/genetics , Plants, Genetically Modified , Solanum tuberosum/genetics , Agrobacterium tumefaciens/genetics , Amino Acid Oxidoreductases/genetics , Amino Acid Sequence , Caulimovirus/genetics , Gene Dosage , Gene Expression , Genes, Plant , Molecular Sequence Data , Nutritive Value , Plant Proteins/analysis , Promoter Regions, Genetic/genetics , RNA, Messenger/analysis , RNA, Plant/analysis , Recombinant Fusion Proteins , Terminator Regions, Genetic/genetics , Transformation, GeneticABSTRACT
A 42-year-old man suffered from low back pain caused by intervertebral diskitis. The condition was diagnosed on plain roentgenogram and computed tomography scans. The infected area was biopsied and grew Eikenella corrodens, a gram-negative anaerobic rod, which grows slowly only after culture on blood agar in 5-10% carbon dioxide. This is the first reported case of E. corrodens intervertebral diskitis causing acute low back pain. Recognition of this organism in this condition emphasizes the importance of aerobic and anaerobic cultures of infected disks. The organism has unusual antibiotic sensitivities. The infection, once appropriately treated, responded rapidly.
