| Title |
Characterization and Screening of Plant Probiotic Traits of Bacteria Isolated from Rice Seeds Cultivated in Argentina |
| Author |
Dante Ruiza1, Betina Agaras2, Patrice de Werrab3, Luis G. Wall2, and Claudio Valverde2* |
| Address |
1Nitrasoil Argentina S.A. Av. Centenario 3359, Quilmes, Buenos Aires, Argentina, 2Laboratorio de Bioquímica, Microbiología e Interacciones Biológicas en el Suelo, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña 352, Bernal B1876BXD, Buenos Aires, Argentina, 3Bern University of Applied Sciences, Swiss College of Agriculture SHL, Länggasse 85, CH‐3052 Zollikofen, Switzerland |
| Bibliography |
Journal of Microbiology, 49(6),902-912, 2011,
|
| DOI |
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| Key Words |
rice, seed, plant probiotic bacteria, diversity, root colonization, Pantoea |
| Abstract |
Many seeds carry endophytes, which ensure good chances of seedling colonization. In this work, we have studied the seed-borne bacterial flora of rice varieties cultivated in the northeast of Argentina. Surface-sterilized husked seeds of the rice cultivars CT6919, El Paso 144, CAMBA, and IRGA 417 contained an average of 5×106 CFU/g of mesophilic and copiotrophic bacteria. Microbiological, physiological, and molecular characterization of a set of 39 fast-growing isolates from the CT6919 seeds revealed an important diversity of seed-borne mesophiles and potential plant probiotic activities, including diazotrophy and antagonism of fungal pathogens. In fact, the seed-borne bacterial flora protected the rice seedlings against Curvularia sp. infection. The root colonization pattern of 2 Pantoea isolates from the seeds was studied by fluorescence microscopy of the inoculated axenic rice seedlings. Both isolates strongly colonized the site of emergence of the lateral roots and lenticels, which may represent the entry sites for endophytic spreading. These findings suggest that rice plants allow grain colonization by bacterial species that may act as natural biofertilizers and bioprotectives early from seed germination. |
