Open AccessA cloned cellulase gene from Erwinia carotovora subsp. carotovora is expressed in Rhizobium fredii but does not influence nodulation of cowpea #
Author(s) -
Krishnan Hari B.,
Pueppke Steven G.
Publication year - 1994
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1994.tb06903.x
Subject(s) - rhizobia , cellulase , erwinia , biology , rhizobium , microbiology and biotechnology , plasmid , rhizobiaceae , gene , root hair , botany , bacteria , enzyme , symbiosis , biochemistry , genetics
Symbiotic rhizobia enter roots of their hosts via infection threads in root‐hairs and invade the cortex, where nodules are initiated. We have transferred a cloned cellulase (Cel) gene from Erwinia carotovora subsp. carotovora into rhizobia and examined both the production of the enzyme and its impact on nodulation. Acquisition of a Cel + plasmid allowed cultured cells of Rhizobium fredii, R. meliloti , and R. tropici to produce extracellular enzymes that degrade carboxymethylcellulose. The Cel + plasmid was retained by R. fredii during nodulation of cowpea, and analysis of a gene fusion confirmed that the Cel promoter was active in planta. Cellulase levels in nodules nevertheless were low, and infection and nodulation were unaffected by the presence of the Cel + plasmid.