Regulation of nodulation gene expression by NodD in rhizobia

Schlaman, Helmi R. M.; Okker, R. J. H.; Lugtenberg, Ben

doi:10.1128/jb.174.16.5177-5182.1992

Cited by 154 publications

(104 citation statements)

References 53 publications

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“…Though data for only five published sequences are available at the moment, we found that the topology of an evolutionary tree of NodA protein is quite similar to that of NodC protein. Furthermore, this NodA tree also has the same topology as the NodD tree constructed by other workers (19,27). This analysis suggests that nodA, nodC, and nodD genes have evolved in a similar manner, which agrees with the fact that the nodABCD genes are linked in all known rhizobia.…”

supporting

confidence: 73%

Phylogeny of Sym plasmids of rhizobia by PCR-based sequencing of a nodC segment

et al. 1995

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To understand the host specificity of rhizobia and the relationship between the evolution of Sym plasmids and that of host plants, we determined partial nodC sequences of 10 representative rhizobium strains and then constructed an evolutionary tree for the deduced amino acid sequences with four published sequences. These coding sequences yield a phylogenetic tree similar to that for leghemoglobin of host plants, suggesting that the evolution of common nodulation genes may be linked to host legume evolution and speciation.

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supporting

confidence: 73%

Phylogeny of Sym plasmids of rhizobia by PCR-based sequencing of a nodC segment

et al. 1995

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“…Genes such as nodABC are preceded by conventional nod box promoters (Krishnan & Pueppke, 1991), but other nod genes, including nol] (Boundy-Mills et al, 1994), nolX and nolBTUV (Meinhardt et al, 1993), are not. NodD is the positive transcriptional activator of nod box-associated genes (Schlaman et al, 1992;Pueppke, 1996). It imposes control by binding to the nod box and, after perception of the appropriate flavonoid signal, by bending the DNA helix (Fisher & Long, 1993).…”

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confidence: 99%

The soybean cultivar specificity gene noIX is present, expressed in a nodD-dependent manner, and of symbiotic significance in cultivar-nonspecific strains of Rhizobium (Sinorhizobium) fredii

et al. 1997

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Rhizobium (now Sinorhizobium) fredii is a symbiotic nitrogen-fixing bacterium that can nodulate soybean in a cultivar-specific manner. This process is governed by a set of negatively acting nodulation genes termed nolXWBTUV. These genes prevent R. fredii strain USDA257 from infecting soybean cultivars such as McCall, but they do not block nodulation of cultivar Peking. R. fredii strain USDA191 contains DNA sequences that hybridize to nolXWBTUV, yet it forms normal nitrogen-fixing nodules on both McCall and Peking soybean. These sequences were isolated and their structure and function examined in comparison to nolXWBTUV of strain USDA257. Restriction maps of the two loci are identical, as is a 2-4 kb DNA sequence that corresponds to nolX and its promoter region. Expression of nolX by strain USDAl91 is f lavonoid-dependent in culture and readily detectable in nodules. The gene is not inducible in a mutant of strain USDA191 that lacks the regulatory nodDl gene, and its expression is greatly attenuated in a nodD2 mutant. nolX is also present and flavonoid-inducible in HH103, a second R. fredii strain that nodulates McCall soybean normally. Inactivation of nolX in strain HH103, USDA191 or USDA257 leads to retardation of initial nodulation rates on soybean cultivars such as Peking and to acquisition of the capacity to form nitrogen-fixing nodules on two species of Erythrina. nolX is thus of symbiotic significance in all three strains, even though it regulates soybean cultivar specificity only in strain USDA257.1

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“…Signal exchange begins in the rhizosphere. Rhizobia sense flavonoids secreted by seeds and by the host plant root, which activate the constitutively expressed nodD gene product (reviewed by Schlaman et al, 1992). This step is a determinant of host plant specificity in some Rhizobium-host plant combinations (Horvath et al, processing, which ultimately yields an acidic isolectin that can be isolated from pea roots by affinity chromatography on dextran beads (Díaz et al, 1990;Hoedemaeker et al, 1994).…”

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confidence: 99%

mentioning

confidence: 99%

Sugar-Binding Activity of Pea Lectin Expressed in White Clover Hairy Roots

et al. 1995

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Dénarié et al., 1992). Nodulation is regulated by a two-way exchange of plant and bacterial signal molecules (Fisher and Long, 1992;Spaink et al., 1993). Signal exchange begins in the rhizosphere. Rhizobia sense flavonoids secreted by seeds and by the host plant root, which activate the constitutively expressed nodD gene product (reviewed by Schlaman et al., 1992). This step is a determinant of host plant specificity in some Rhizobium-host plant combinations (Horvath et al., 1987; Spaink et al., 1987). Transcription of structural nod genes is under the control of NodD and results in production and secretion of specific lipochitin oligosaccharides (Nod factors), which act as host plant-specific inducers of nodule morphogenesis (reviewed by Dénarié and Cullimore, 1993;Spaink et al., 1993). Most probably, Nod factors constitute the primary determinants of host-plant specificity of nodulation.Root lectins are plant factors involved in nodulation. Lectins are nonenzymatic sugar-binding (g1yco)proteins characterized by sugar-binding specificity. For example, root PSL is Glc/Man specific (Díaz et al., 1990) and white clover root lectin is 2-deoxyglucose specific (Sherwood et al., 1984). In general, the interaction between RI uiciae and white clover does not proceed beyond root hair curling, and these bacteria are not able to penetrate host plant cells by infection thread formation (Yao and Vincent, 1969;Djordjevic et al., 1986;Huang et al., 1993). However, RI viciae is able to induce infection thread formation and nodulation in a significant percentage of white clover plants with roots transformed with the psl gene, as reported by Díaz et al. (1989Díaz et al. ( , 1995. This heterologous nodulation does not take place when a psl mutant, which encodes a non-sugar-binding protein, is used for transformation of white clover roots (Van Eijsden et al., 1992. These results strongly suggest that (a) PSL is functionally expressed in transgenic white clover roots, (b) conservation of the sugar-binding activity of PSL is necessary for infection of white clover by RI viciae, and (c) root lectin helps to break a host plant-specific barrier for nodulation. The relationship between Nod factor recognition by host plants and Rhizobium recognition by host lectin is not yet clear.PSL is an ellipsoidal, nonglycosylated dimeric lectin with two sugar-binding sites, each located near the top of two identical monomers (Einspahr et al., 1988). PSL is encoded by a single gene (Gatehouse et al., 1987;Kaminski et al., 1987) and is synthesized as a single translation product, a prolectin with a molecular mass of 28 kD. Posttranslational modifications result in a protein that dissociates into two p subunits (18 kD each) and two 01 subunits (6 kD each, Higgins et al., 1983)

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Regulation of nodulation gene expression by NodD in rhizobia

Cited by 154 publications

References 53 publications

Phylogeny of Sym plasmids of rhizobia by PCR-based sequencing of a nodC segment

Phylogeny of Sym plasmids of rhizobia by PCR-based sequencing of a nodC segment

The soybean cultivar specificity gene noIX is present, expressed in a nodD-dependent manner, and of symbiotic significance in cultivar-nonspecific strains of Rhizobium (Sinorhizobium) fredii

Sugar-Binding Activity of Pea Lectin Expressed in White Clover Hairy Roots

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