Ocatin. A Novel Tuber Storage Protein from the Andean Tuber Crop Oca with Antibacterial and Antifungal Activities

• Published in: Plant physiology (Bethesda) Vol. 128; no. 4; pp. 1291 - 1302
• Main Authors: Teresita Flores, Alberto Alape-Girón, Marietta Flores-Díaz, Flores, Hector E.
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Biologists 01.04.2002; American Society of Plant Physiologists
• Subjects: Agrobacterium radiobacter; Agrobacterium tumefaciens; Agronomy. Soil science and plant productions; Allergens; Amino Acid Sequence; amino acid sequences; Amino acids; Anti-Bacterial Agents; Anti-Infective Agents; Anti-Infective Agents - pharmacology; antibacterial properties; Antibacterials; antifungal agents; antifungal properties; Bacteria; Bacteria - drug effects; Biological and medical sciences; chemical constituents of plants; chemistry; drug effects; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Fungi; Fungi - drug effects; Fusarium eumartii; Fusarium oxysporum; Gels; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Genetics and breeding of economic plants; isolation & purification; Magnoliopsida; Metabolism; Microbial Sensitivity Tests; microbiology; Molecular Sequence Data; Nitrogen metabolism; Nitrogen metabolism and other ones (excepting carbon metabolism); Nutrition. Photosynthesis. Respiration. Metabolism; ocatin; Oxalis tuberosa; pathogenesis; Pathogens; Pest resistance; pharmacology; Phytophthora cinnamomi; Pith; plant anatomy; plant development; Plant Diseases; Plant Diseases - microbiology; plant extracts; Plant Extracts - chemistry; Plant Extracts - isolation & purification; Plant Extracts - pharmacology; plant morphology; Plant pathogens; Plant physiology and development; plant proteins; Plant Proteins - chemistry; Plant Proteins - isolation & purification; Plant Proteins - pharmacology; Plants; Plants Interacting with Other Organisms; Pseudomonas chlororaphis; root vegetables; Sequence Alignment; Sequence Homology, Amino Acid; Serratia marcescens; Storage proteins; Thanatephorus cucumeris; Tubers; Varietal selection. Specialized plant breeding, plant breeding aims; Pseudomonadales; Storage protein; Plant pathogen; Growth; Phycomycetes; Agrobacterium tumefaciens; Fungi; Characterization; Disease resistance; Antifungal agent; Microorganism resistance; Phytophthora cinnamomi; Dicotyledones; Nectria haematococca; Angiospermae; Serratia marcescens; Tuber; Bacteria; Pseudomonadaceae; Rhizoctonia solani; Ascomycetes; Fungi Imperfecti; Inhibition; Molecular mass; Aminoacid sequence; Gram negative bacteria; Enterobacteriaceae; Thallophyta; Fusarium oxysporum; Purification; Agrobacterium radiobacter; Pathogenesis related protein; Biological activity; Pseudomonas aureofaciens; Sensitivity resistance; Isoelectric point; Spermatophyta; Rhizobiaceae; Antibacterial agent; Biological accumulation; Oxalidaceae
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.010541

The most abundant soluble tuber protein from the Andean crop oca (Oxalis tuberosa Mol.), named ocatin, has been purified and characterized. Ocatin accounts for 40% to 60% of the total soluble oca tuber proteins, has an apparent molecular mass of 18 kD and an isoelectric point of 4.8. This protein appears to be found only in tubers and is accumulated only within the cells of the pith and peridermis layers (peel) of the tuber as it develops. Ocatin inhibits the growth of several phytopathogenic bacteria (Agrobacterium tumefaciens, Agrobacterium radiobacter, Serratia marcescens, and Pseudomonas aureofaciens) and fungi (Phytophthora cinnamomi, Fusarium oxysporum, Rhizoctonia solani, and Nectria hematococcus). Ocatin displays substantial amino acid sequence similarity with a widely distributed group of intracellular pathogenesis-related proteins with a hitherto unknown biological function. Our results showed that ocatin serves as a storage protein, has antimicrobial properties, and belongs to the Betv 1/PR-10/MLP protein family. Our findings suggest that an ancient scaffolding protein was recruited in the oca tuber to serve a storage function and that proteins from the Betv 1/PR-10/MLP family might play a role in natural resistance to pathogens.