Rhizobial Lipo-oligosaccharide Signals and Their Role in Plant Morphogenesis; Are Analogous Lipophilic ChitinDerivatives Produced by the Plant?

Spaink, H. P.; Wijfjes, Ahm; van, Vliet Tb; Kijne, JW; Lugtenberg, Bjj

doi:10.1071/pp9930381

Cited by 34 publications

(20 citation statements)

References 35 publications

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“…As a Nod factor-binding protein, LNP could possibly function in Nod factor transport, as a host/strain specific receptor, as a second, less stringent receptor postulated for this process (32), or even perhaps participate in events leading to a modification of the ligand. It also is possible that LNP or homologs of this protein that we have recently identified in the plant may function in the recognition of endogenous Nod-factor like signals that have been proposed to play a role in the regulation of plant growth and organogenesis (33). It is also possible that the expression of LNP may not be limited to the epidermal and root hair cells and that the protein may have a more generic role.…”

Section: Discussionmentioning

confidence: 99%

A nod factor binding lectin with apyrase activity from legume roots

Kalsi

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

151

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A lectin isolated from the roots of the legume, Dolichos biflorus, binds to Nod factors produced by rhizobial strains that nodulate this plant and has a deduced amino acid sequence with no significant homology to any lectin reported to date. This lectin also is an enzyme that catalyzes the hydrolysis of phosphoanhydride bonds of nucleoside di-and triphosphates; the enzyme activity is increased in the presence of carbohydrate ligands. This lectin-nucleotide phosphohydrolase (LNP) has a substrate specificity characteristic of the apyrase category of phosphohydrolases, and its sequence contains four motifs characteristic of this category of enzymes. LNP is present on the surface of the root hairs, and treatment of roots with antiserum to LNP inhibits their ability to undergo root hair deformation and to form nodules on exposure to rhizobia. These properties suggest that this protein may play a role in the rhizobium-legume symbiosis and/or in a related carbohydrate recognition event endogenous to the plant.Oligosaccharide signaling events play important roles in the regulation of plant development, defense, and other interactions of plants with the environment (1-4). The establishment of the nitrogen-fixing symbiotic relationship between rhizobia and leguminous plants depends on such a signaling process. The rhizobia produce lipochitooligosaccharidic signals, called Nod factors, that elicit the differentiation of a new organ, the nodule, in the root cortex. The rhizobia bind to and invade the root hairs, where they proceed to the emerging nodule within infection threads produced by the plant (5). Both the initiation of nodule formation and rhizobial entry are host-strainspecific; this specificity is determined by the type of Nod factor produced by a particular rhizobial strain and by the ability of a leguminous species to recognize that signal.All Nod factors consist of a short, typically tetrapentameric, chitin oligosaccharidic backbone that is N-acylated at the nonreducing end, usually with a common fatty acid, such as cis-vaccenic acid. The Nod factors differ from one another in length of this backbone and the type of substituents that decorate it; these modifications determine the strain specificity of the rhizobium and depend on the set of nodulation genes possessed by that rhizobial strain (4). A related set of signals are the chitin oligosaccharides, themselves, that have been found to elicit defense responses in a wide variety of plants (for review, see ref.3).Although the structures of many of these chitooligosaccharides have been characterized, little is known about the plant proteins that bind these signals, whether as receptors for signal transduction or as binding proteins with other functions. High-affinity binding sites for chitin fragments have been found on membranous fractions prepared from tomato (7) and rice (8) suspension-cultured cells, and a 70-kDa protein that binds to chitin fragments was isolated from the rice membranes (9). Particulate fractions from roots of the legume, Medicago t...

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Section: Discussionmentioning

confidence: 99%

A nod factor binding lectin with apyrase activity from legume roots

Kalsi

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

151

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“…Various factors are thought to be involved in the complex process of nodulation. It is known that lipo-chitin signals induce nodule formation and that they mimic endogenous plant growth regulators (19,53,58,61). Soil microorganisms such as Agrobacterium tumefaciens (13) or Bacillus subtilis (3) can also stimulate nodulation, through the production of bioactive molecules.…”

Section: Discussionmentioning

confidence: 99%

Novel Plant-Microbe Rhizosphere Interaction Involving Streptomyces lydicus WYEC108 and the Pea Plant ( Pisum sativum )

Tokala

Strap

Jung

et al. 2002

Appl Environ Microbiol

355

204

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A previously undescribed plant-microbe interaction between a root-colonizing Streptomyces species, S. lydicus WYEC108, and the legume Pisum sativum is described. The interaction is potentially of great importance to the health and growth in nature of this nodulating legume. The root-colonizing soil actinomycete S. lydicus WYEC108 influences pea root nodulation by increasing root nodulation frequency, possibly at the level of infection by Rhizobium spp. S. lydicus also colonizes and then sporulates within the surface cell layers of the nodules. Colonization leads to an increase in the average size of the nodules that form and improves the vigor of bacteroids within the nodules by enhancing nodular assimilation of iron and possibly other soil nutrients. Bacteroid accumulation of the carbon storage polymer, poly-␤-hydroxybutyrate, is reduced in colonized nodules. Root nodules of peas taken from agricultural fields in the Palouse hills of northern Idaho were also found to be colonized by actinomycete hyphae. We hypothesize that root and nodule colonization is one of several mechanisms by which Streptomyces acts as a naturally occurring plant growth-promoting bacterium in pea and possibly other leguminous plants.Streptomyces lydicus WYEC108 is a root-colonizing actinomycete originally isolated and studied for its properties as an antifungal biocontrol agent. This strain is capable of mycoparasitic colonization of fungal root pathogens and excretion of antifungal metabolites within plant rhizospheres (16,62). Recently, we demonstrated that strain WYEC108 is also a plant growth-promoting bacterium in the absence of fungal pathogen challenge. This may be due to the ability of strain WYEC108 to produce hydroxamate-type siderophores and/or other plant growth-promoting metabolites in the rhizosphere (25). Streptomyces spp. have been previously described as rhizosphere-colonizing bacteria (37, 38), antifungal biocontrol agents useful in controlling fungal root diseases (51), in vitro siderophore producers, and in vitro producers of plant growthpromoting hormones (25). Plant root exudates stimulate rhizosphere growth of actinomycetes that are strongly antagonistic to fungal pathogens, while the actinomycetes utilize root exudates for growth and synthesis of antimicrobial substances (16,62). In addition, actinomycetes synthesize an array of biodegradative enzymes, including chitinases (9, 23, 35), glucanases (18,26,29,32,59,60), peroxidases (48), and other enzymes possibly involved in mycoparasitic activity. Yet, the overall importance, physiological activities, and symbiotic roles of actinomycetes in situ within plant rhizospheres remain little studied at the biochemical or mechanistic levels. We believe that Streptomyces are far more important rhizosphere bacteria than has been generally recognized.Important to the symbiotic relationship between plants and microbes is the acquisition of iron. Although abundant in nature, under aerobic conditions at a neutral or alkaline pH, iron is found in highly insoluble forms not readil...

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“…Dependent on the rhizobial species or biovar, other substituents such as sulfate or O-acetyl groups can be present [42]. Nod factors act as determinants of the host-range ofnodulation [ 14,42,44,45]. The difference in host specificity of nodulation by the biovars R.I. viciae and R.I. trifolii is primarily determined by the nodE gene, the product of which is involved in production of the highly unsaturated fatty acid chain [44].…”

Section: Introductionmentioning

confidence: 99%

Sugar-binding activity of pea (Pisum sativum) lectin is essential for heterologous infection of transgenic white clover hairy roots by Rhizobium leguminosarum biovar viciae

et al. 1995

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Legume lectin stimulates infection of roots in the symbiosis between leguminous plants and bacteria of the genus Rhizobium. Introduction of the Pisum sativum lectin gene (psl) into white clover hairy roots enables heterologous infection and nodulation by the pea symbiont R. leguminosarum biovar viciae (R.l. viciae). Legume lectins contain a specific sugar-binding site. Here, we show that inoculation of white clover hairy roots co-transformed with a psl mutant encoding a non-sugar-binding lectin (PSL N125D) with R.l. viciae yielded only background pseudo-nodule formation, in contrast to the situation after transformation with wild type psl or with a psl mutant encoding sugar-binding PSL (PSL A126V). For every construct tested, nodulation by the homologous symbiont R.l. trifolii was normal. These results strongly suggest that (1) sugar-binding activity of PSL is necessary for infection of white clover hairy roots by R.l. viciae, and (2) the rhizobial ligand of host lectin is a sugar residue rather than a lipid.

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Rhizobial Lipo-oligosaccharide Signals and Their Role in Plant Morphogenesis; Are Analogous Lipophilic ChitinDerivatives Produced by the Plant?

Cited by 34 publications

References 35 publications

A nod factor binding lectin with apyrase activity from legume roots

A nod factor binding lectin with apyrase activity from legume roots

Novel Plant-Microbe Rhizosphere Interaction Involving Streptomyces lydicus WYEC108 and the Pea Plant ( Pisum sativum )

Sugar-binding activity of pea (Pisum sativum) lectin is essential for heterologous infection of transgenic white clover hairy roots by Rhizobium leguminosarum biovar viciae

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