World Applied Sciences Journal 15 (1): 32-37, 2011 ISSN 1818-4952 © IDOSI Publications, 2011 Corresponding Author: A. Panneerselvam, P.G. and Research Department of Botany, Microbiology, A.V.V.M. Sri Pushpam College (Automomous), Poondi, 613 503, Tamilnadu, India. 32 Characterization of Agrobacterium rhizogenes Isolated from the Nodules of Some Leguminous Plants S. Murugesan, R. Vijayakumar and A. Panneerselvam 1 2 1 P.G. and Research Department of Botany, Microbiology, 1 A.V.V.M. Sri Pushpam College (Automomous), Poondi, 613 503, Tamilnadu, India Department of Microbiology, Bharathidasan University College for Women, 2 Orathanadu, 614 625, Tamilnadu, India Abstract: Agrobacterium strains were isolated from five different leguminous plants viz., Pisum sativum, Sesbania rostrata, Vigna mungo, V. radita and V. ungiculata. The isolated bacteria was characterized and identified as Agrobacterium rhizogenes based on their morphological, biochemical, cultural and pathogenicity tests. Antibiogram and protein profile of isolates were also studied by disc diffusion and SDS-PAGE methods respectively, these studies showed lot of variations in sensitivity pattern of different A. rhizogenes to different antibiotics and electrophorogram of proteins. Key words:Leguminous plants Agrobacterium rhizogenes Characterization Antibiotic sensitivity SDS-PAGE INTRODUCTION morphological, physiological, eco-biological and Agrobacterium has long been recognized as closely convenient method of determining the evolutionary related to Rhizobium and amalgamation of these two relatedness between organisms is based on comparing the genera has often been suggested [1]. Bacteria within the protein, plasmid and fatty acid profile in addition to DNA genera Agrobacterium and Rhizobium have the unique sequencing (16S rDNA sequence Analyses) [3]. The capacity to include such phenomenon as prolific root present study deals with the isolation and characterization formation. In addition to their obvious agricultural of agrobacteria based on their morphological, biochemical importance, these bacteria have become very useful tools and molecular properties from various leguminous plants in attempts to understand better the underlying and compare the strain variations. mechanisms of plant morphogenesis, phytopathogenicity and host parasite relationships [2]. Pathogenic strains of MATERIALS AND METHODS Agrobacterium have been share a common feature they contain at least one large plasmid (the tumour or root Sample Collection: The legume plant such as Pisum inducing Fi and ei respectively) plasmid. Virulence is sativum, Sesbania rostrata (root and stem), Vigna determined by different regions of the plasmid including radiata, V. mungo and V. ungiculata were collected along the transferred DNA (T-DNA) and the virulence gene. with root nodules from Tamil Nadu Agricultural However there was no correlation between this University (TNAU), Coimbatore, Tamilnadu. nomenclature based on pathogenicity characters and the taxonomic structure based on phenotypical and Isolation of Agrobacterium: The nodules were detached genotypical traits of the genus. At present the classification scheme for bacteria is based not only on evolution, but also on convenience, consisting of readily determined characteristics such as biochemical nature of the organism. The most recent and carefully and sterilized thoroughly as per the standard procedure of Sharma et al. [4]. The nodules were kept immersed in 0.1% acidified mercuric chloride solution for 5 min. and washed repeatedly with sterile distilled water.