Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
1996-12-10
pubmed:abstractText
Microbial competition for carbon sources is a primary determinant of rhizosphere ecology. We employed the PCR to examine the population fluctuations of a symbiotic nitrogen-fixing bacterium (Rhizobium etli) during the first 11 days following inoculation of Phaseolus vulgaris seedlings grown in the presence or absence of a common asymbiotic rhizosphere resident (Bacillus polymyxa). When B. polymyxa was applied as a co-inoculant, increases in both early rhizobial root populations and final root population densities were observed as compared to single inoculation with R. etli. Modifications to host plant growth (including increased lateral root formation and nodules number) were found concomitant with elevations in R. etli populations on plants co-inoculated with both bacterial genera. In contrast to the in planta results, population enhancements were not observed when R. etli and B. polymyxa were co-cultured in vitro using minimal media in the absence of the seedling. Addition of seed exudate to the growth media also failed to stimulate the population increases observed during co-release in planta. These results suggest that B. polymyxa acts indirectly (i.e., via the plant host) to increase R. etli populations. Our observed synergism among co-resident bacteria supports the hypothesis that microbial communities which colonize the spermosphere may play a significant role in plant development and rhizosphere ecology.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0378-1097
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
142
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
271-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Bacillus polymyxa stimulates increased Rhizobium etli populations and nodulation when co-resident in the rhizosphere of Phaseolus vulgaris.
pubmed:affiliation
Department of Plant Science, University of British Columbia, Vancouver, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't