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Volume 7, Issue 2 (Suppl)
J Ecosyst Ecography, an open access journal
ISSN:2157-7625
September 18-20, 2017
September 18-20, 2017 Toronto, Canada
Joint Conference
International Conference on
International Conference on
Environmental Microbiology and Microbial Ecology
&
Ecology and Ecosystems
Breach of rhizobial host specificity and colonization of
V. radiata
root nodules by
rhizobacteria
Maharshi Pandya
University of Baroda, India
L
egumes develop symbiotic relationship with rhizobia following complex exchange of signals. Regardless of high specificity of
symbiosis, isolation of
rhizobacteria
from surface sterilized root nodules has been reported. To explore how these
rhizobacteria
enter root hairs and colonize root nodules, we hypothesized that host specific
rhizobia
initiate the signaling process to form infection
thread (IT), which is invaded by
rhizobacteria
to breach host specificity. To experimentally prove the hypothesis, fluorescently
tagged predominant
rhizobacteria Pseudomonas fluorescens
and a facultative aerobe
Klebsiella pneumoniae
were coinoculated with
native host nodulating rhizobia
Ensifer adhaerens to Vigna radiata
seedlings and root hair infection was monitored at 5 days post
inoculation (DPI) using confocal microscope. and
K. pneumoniae
adhered to surface and base of root hairs and failed to enter
root hairs independently but successfully colonized root hairs when coinoculated with
E. adhaerens.
Recovery and confirmation of
inoculated tagged strains through confocal laser scanning microscopy and 16S rDNA sequencing validated nodule occupancy by test
rhizobacteria
at 50 DPI. This is the first study that addresses the fundamental question of how non-rhizobia invade root nodules and
experimentally proves that non-rhizobia invade IT of host nodulating native rhizobial strain and colocalize in root nodules. We also
isolated eight non-rhizobia with predominance of gram positive
Paenibacillus
and
Bacillus
among other gram-negative species of
Klebsiella, Ensifer, Agrobacterium, Blastobacter, Dyadobacter and Chitinophaga
from field grown
V. radiata
root nodules.
maharshipandya140985@gmail.comJ Ecosyst Ecography 2017, 7:2 (Suppl)
DOI: 10.4172/2157-7625-C1-030