Expression of a Serratia marcescens chitinase gene in Sinorhizobium fredii USDA191 and Sinorhizobium meliloti RCR2011 impedes soybean and alfalfa nodulation.
A gene encoding chitinase from Serratia marcescens BJL200 was cloned into a broad-host-range vector (pRK415) and mobilized into Sinorhizobium fredii USDA191. Chitinolytic activity was detected in S. fredii USDA191 transconjugants that carried the S. marcescens chiB gene. Chitinase-producing S. fredii USDA191 formed nodules on soybean cultivar McCall. However, there was a delay in nodule formation and a marked decrease in the total number of nodules formed by the chitinase-producing S. fredii in comparison with the wild-type strain. Expression of chitinase in S. meliloti RCR2011 also impeded alfalfa nodulation. Thin-layer chromatography of 14C-labeled Nod factors from chitinase-producing S. fredii USDA191 revealed hydrolysis of lipochitooligosaccharides.
Krishnan
H B
HB
Department of Plant Pathology, University of Missouri, Columbia 65211, USA. KrishnanH@missouri.edu
Kim
K Y
KY
Krishnan
A H
AH
D002688:Chitinases / Q000235:genetics*; D007887:Fabaceae / Q000382:microbiology*; D015870:Gene Expression; D005798:Genes, Bacterial; D000455:Medicago sativa / Q000382:microbiology; D010935:Plant Diseases / Q000235:genetics; D010946:Plants, Medicinal; D012231:Rhizobium / Q000201:enzymology / Q000235:genetics; D012706:Serratia marcescens / Q000201:enzymology* / Q000235:genetics*; D016962:Sinorhizobium meliloti / Q000201:enzymology / Q000235:genetics; D013025:Glycine max / Q000382:microbiology; D013559:Symbiosis
D002688:Chitinases