October
2005
, Volume
18
, Number
10
Pages
1,061
-
1,068
Authors
Philippe
Jourand
,
1
Adeline
Renier
,
1
Sylvie
Rapior
,
2
Sergio Miana
de Faria
,
1
Yves
Prin
,
1
Antoine
Galiana
,
1
Eric
Giraud
,
1
and
Bernard
Dreyfus
1
Affiliations
1Laboratoire des Symbioses Tropicales et Méditerranéennes, UMR 113 AgroM/CIRAD/INRA/IRD/UMII, TA 10/J, Campus International de Baillarguet, 34398 Montpellier cedex 5, France; 2Laboratoire de Botanique, Phytochimie et Mycologie, UMR 5175 CEFE, Faculté de Pharmacie, 15 Avenue Charles Flahault, BP 14491, 34093 Montpellier cedex 5, France
Go to article:
RelatedArticle
Accepted 14 June 2005.
Abstract
Some rare leguminous plants of the genus Crotalaria are specifically nodulated by the methylotrophic bacterium Methylobacterium nodulans. In this study, the expression and role of bacterial methylotrophy were investigated during symbiosis between M. nodulans, strain ORS 2060T, and its host legume, Crotalaria podocarpa. Using lacZ fusion to the mxaF gene, we showed that the methylotroph genes are expressed in the root nodules, suggesting methylotrophic activity during symbiosis. In addition, loss of the bacterial methylotrophic function significantly affected plant development. Indeed, inoculation of M. nodulans nonmethylotroph mutants in C. podocarpa decreased the total root nodule number per plant up to 60%, decreased the whole-plant nitrogen fixation capacity up to 42%, and reduced the total dry plant biomass up to 46% compared with the wild-type strain. In contrast, inoculation of the legume C. podocarpa with nonmethylotrophic mutants complemented with functional mxa genes restored the symbiotic wild phenotype. These results demonstrate the key role of methylotrophy during symbiosis between M. nodulans and C. podocarpa.
JnArticleKeywords
Additional keyword:
methanol.
Page Content
ArticleCopyright
© 2005 The American Phytopathological Society