Previous Article | Next Article ![]()
Appl. Environ. Microbiol., Sep 1995, 3422-3429, Vol 61, No. 9
PM Thomas, KF Golly, RA Virginia and JW Zyskind
Nitrogen-fixing symbiosis between bacteria and the tree legume mesquite
(Prosopis glandulosa) is important for the maintenance of many desert
ecosystems. Genes essential for nodulation and for extending the host range
to mesquite were isolated from cosmid libraries of Rhizobium (mesquite) sp.
strain HW17b and Bradyrhizobium (mesquite) sp. strain HW10h and were shown
to be closely linked. All of the cosmid clones of rhizobia that extended
the host range of Rhizobium (Parasponia) sp. strain NGR234CS to mesquite
also supported nodulation of a Sym- mesquite strain. The cosmid clones of
bradyrhizobia that extended the host range of Rhizobium (Parasponia) sp.
strain NGR234CS to mesquite were only able to confer nodulation ability in
the Sym- mesquite strain if they also contained a nodD-hybridizing region.
Subclones containing just the nodD genes of either genus did not extend the
host range of Rhizobium (Parasponia) sp. to mesquite, indicating that the
nodD gene is insufficient for mesquite nodulation. The nodD gene region is
conserved among mesquite-nodulating rhizobia regardless of the soil depth
from which they were collected, indicating descent from a common ancestor.
In a tree of distance relationships, the NodD amino acid sequence from
mesquite rhizobia clusters with homologs from symbionts that can infect
both herbaceous and tree legumes, including Rhizobium tropici, Rhizobium
leguminosarum bv; phaseoli, Rhizobium loti, and Bradyrhizobium japonicum.
Copyright © 1995, American Society for Microbiology
Cloning of nod gene regions from mesquite rhizobia and bradyrhizobia and nucleotide sequence of the nodD gene from mesquite rhizobia
Biology Department, San Diego State University, California 92182-4614, USA.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»