ISSN 2736-1756
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 12 (1), pp. 001-005, January, 2018. © International Scholars Journals
Full Length Research Paper
Investigation of endophytic and symbiotic features of Ralstonia sp. TSC1 isolated from cowpea nodules
Papa Saliou Sarr1*, Takeo Yamakawa2, Satoru Asatsuma2, Syunsei Fujimoto3 and Masao Sakai4
1Laboratory of Plant Nutrition, Division of Bioresource and Bioenvironmental Sciences, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
2Department of Plant Resources, Faculty of Agriculture, Laboratory of Plant Nutrition, Division of Soil Science and Plant production, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
3Laboratory of Plant Nutrition, School of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812- 8581, Japan.
4Department of Biochemical Science and Technology, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
Accepted 08 October, 2017
Abstract
Ralstonia sp. TSC1 previously isolated from cowpea nodules was tagged with gfp gene by transposon insertion. The resultant gfp-tagged Ralstonia sp. TSC1 showed no difference in physiological properties such as growth rate, exopolysaccharide formation and colony morphology. When it was co- inoculated with compatible bradyrhizobial strains, the observation of fluorescence microscopy showed that TSC1 strains were colonized in subsurface of cowpea nodules and stems. In addition, TSC1 positively and negatively modulated symbiotic performance with the bradyrhizobia in terms of nodulation and symbiotic nitrogen fixation. The results suggested that Ralstonia sp. TSC1 is an endophyte with beneficial, neutral or detrimental effects on cowpea plants when in presence of effective bradyrhizobia.
Key words: Ralstonia sp., cowpea, endophyte, green fluorescent protein, bradyrhizobium, nodulation.