Open AccessRhizobial secreted proteins as determinants of host specificity in the rhizobium–legume symbiosis
Author(s) -
Fauvart Maarten,
Michiels Jan
Publication year - 2008
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.1574-6968.2008.01254.x
Subject(s) - rhizobia , secretion , biology , symbiosis , host (biology) , secretory protein , rhizobium , bacteria , nod factor , root nodule , microbiology and biotechnology , fabaceae , rhizobiaceae , biochemistry , botany , genetics
Rhizobia are Gram‐negative bacteria than can elicit the formation of specialized organs, called root nodules, on leguminous host plants. Upon infection of the nodules, they differentiate into nitrogen‐fixing bacteroids. An elaborate signal exchange precedes the symbiotic interaction. In general, both rhizobia and host plants exhibit narrow specificity. Rhizobial factors contributing to this specificity include Nod factors and surface polysaccharides. It is becoming increasingly clear that protein secretion is important in determining the outcome of the interaction as well. This paper discusses our current understanding of the symbiotic role played by rhizobial secreted proteins, transported both by secretion systems that are of general use, such as the type I secretion system, and by specialized, host‐targeting secretion systems, such as the type III, type IV and type VI secretion systems.