Nitrogen fixation (acetylene reduction) and cross inoculation in 12 Prosopis (mesquite) species

Felker, Peter; Clark, Peter R.

doi:10.1007/bf02211677

Cited by 67 publications

(23 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(Although there is still disagreement about N2-fixation by Prosopis and Olneya in field settings, it is known that greenhouse grown plants can become infected and that the resultant nodules are effective in fixing N2 [1,[4][5][6]. )…”

Section: Methodsmentioning

confidence: 99%

¹⁵N Abundance of Nodules as an Indicator of N Metabolism in N₂-Fixing Plants

Shearer

Feldman²,

Bryan³

et al. 1982

Plant Physiol.

View full text Add to dashboard Cite

This paper expands upon previous reports of '5N elevation in nodules (compared to other tissues) of N2-fixing plants. N2-Fixing nodules of Glycine max (soybeans), Vigna unguiculata (cowpea), Phaseolus vulgaris (common bean), Phaseolus coccineus (scarlet runner bean), Prosopis glandulosa (mesquite), and Olneya tesota (desert ironwood) were The N of whole soybean plants which are grown with atmospheric N2 as the sole source of N has an isotopic composition within approx. 2 6'5N units2 of atmospheric N (2, 8). In contrast, we have consistently observed that soybean nodules are significantly enriched in 1 N (7,14). This observation has been recently confirmed by Turner and Bergersen (15). The difference in 6'5N between soybean nodules and whole plants ranged from +2.8 to +12.8, with an average (for 59 observations) of +8.3. The 15N abundance of other plant parts (roots, stems, foliage, pods, seeds) was much more uniform (7,14). The largest difference between any of the other plant parts was only about 2 815N units, a modest difference in comparison with the usually quite large difference between nodules and other plant parts. The homogeneity of isotopic composition of nonnodular tissue persisted throughout the growing season, even during times of massive mobilization and transport of N from vegetative to reproductive tissues, a time at which isotopic fractionation might be expected to result in the alteration of isotopic abundances. By measuring the '5N abun- strongly correlated with N2-fixing efficiency (9).Kohl et al. (9) previously reported that the 15N abundance of nodules from nonleguminous N2-fixing plants was not elevated. Certainly this difference in nodular 15N abundance between soybeans, with its rhizobial symbiont, and nonlegumes, which are infected with actinomycetes, is a reflection of differences in the metabolism of fixed N. We report here results which contribute to answering the question: How widespread is the elevation of 15N abundance in nodules and what metabolic characteristics distinguish those plants which do and which do not have nodules with elevated 15N abundance? On the basis of previously reported results Kohl et al. (9) rejected the hypothesis that elevated 15N in nodules is the result of the denitrifying capability of the symbiont. Instead they proposed that the 5N abundance in nodules is a result of the difference between isotopic fractionation associated with the synthesis of nodule tissue and that which accompanies the concurrent synthesis of the main form of N transported from the nodule to the rest of the plant. If this hypothesis is correct, then one might expect the "5N abundance of nodules (compared to the rest of the plant) to vary among plant species, depending on the form of the major transport compound. METHODSWe analyzed the concentration and 15N abundance of the total N of various tissues of a number of N2-fixing plants (both legumes and nonlegumes) by methods previously described (12,13

show abstract

Section: Methodsmentioning

confidence: 99%

¹⁵N Abundance of Nodules as an Indicator of N Metabolism in N₂-Fixing Plants

Shearer

Feldman²,

Bryan³

et al. 1982

Plant Physiol.

View full text Add to dashboard Cite

show abstract

“…Their biomass and fruit production which can be very large (Pinto and Riveros, 1989), and their N 2 -fixing ability (Felker and Clark, 1980) are important characteristics to be considered within forestation programs.…”

Section: Introductionmentioning

confidence: 99%

CO₂assimilation in young Prosopis plants

Pinto¹

1989

Ann. For. Sci.

View full text Add to dashboard Cite

“…A TnS insertion mutant derivative of GRH2 (exo-57) Leguminous trees proliferate in arid and semiarid regions of the world which are unsuited for crop production. These leguminous trees are of increasing interest since they provide wood, fiber, gum, and food for animal and human nutrition, protect the soil from erosion, and form nitrogenfixing nodules in symbiotic association with bacteria (2,5,19,24,31,41). Recent studies revealed that leguminous trees are infected by both fast-growing rhizobia and slowly growing bradyrhizobia.…”

mentioning

confidence: 99%

Characterization and symbiotic importance of acidic extracellular polysaccharides of Rhizobium sp. strain GRH2 isolated from acacia nodules

et al. 1993

View full text Add to dashboard Cite

RIizobium sp. wild-type strain GRH2 was originally isolated from root nodules of the leguminous tree Acacia cyanophylla and has a broad host range which includes herbaceous legumes, e.g., Trifolium spp. We examined the extracellular exopolysaccharides (EPSs) produced by strain GRH2 and found three independent glycosidic structures: a high-molecular-weight acidic heteropolysaccharide which is very similar to the acidic EPS produced by Rhizobium leguminosarum biovar trifolii ANU843, a low-molecular-weight native heterooligosaccharide resembling a dimer of the repeat unit of the high-molecular-weight EPS, and low-molecular-weight neutral 13(1,2)-glucans. A TnS insertion mutant derivative of GRH2 (exo-57) Leguminous trees proliferate in arid and semiarid regions of the world which are unsuited for crop production. These leguminous trees are of increasing interest since they provide wood, fiber, gum, and food for animal and human nutrition, protect the soil from erosion, and form nitrogenfixing nodules in symbiotic association with bacteria (2,5,19,24,31,41). Recent studies revealed that leguminous trees are infected by both fast-growing rhizobia and slowly growing bradyrhizobia. Some rhizobial strains isolated from the nodules have a wide host range, even including herbaceous legumes (15,16,24,30,45). This is the case for fast-growing Rhizobium sp. strain GRH2, originally isolated from Acacia cyanophylla (24). Many reports suggest involvement of Rhizobium acidic heteropolysaccharides in infection of legume roots hairs, invasion of nodules, and nitrogen fixation (1,6,11,21,28,32,35,37) and a possible contribution to determination of the bacterial host range (13,14,20,36).Rhizobia with broad host ranges are very useful for investigations of the molecular mechanisms of symbiotic interaction. Rhizobium sp. strain NGR234 is one of the most extensively studied strains with a broad host range, which includes several tropical legumes and the nonlegume Parasponia spp. This strain shows functional and evolutionary genetic equivalence to Rhizobium meliloti (44). In contrast, studies of restriction fragment length polymorphism suggest that broad-host-range Rhizobium sp. strain GRH2 is more closely related to R. leguminosarum (30a). The aim of the present work was to evaluate the extracellular exopolysaccharide (EPS) of strain GRH2 and its role in the root nodule symbiosis between the bacterial symbiont and its leguminous hosts. We show that the EPSs produced by Rhizobium sp. strain GRH2 are very closely related to those produced by wild-type R. leguminosarum bv. tnfolii strain ANU843. * Corresponding author.In addition, a Tn5-induced Exo-mutant derivative of GRH2 which does not produce acidic heteropolysaccharides was obtained and found to be unable to induce nodules on several herbaceous legumes hosts. However, it still nodulated Acacia sp. but infected fewer host cells in the nodule. MATERIALS AND METHODSBacterial strains and genetic manipulations. Rhizobium sp. strain GRH2 was originally isolated from root nodules ofA. cya...

show abstract

Nitrogen fixation (acetylene reduction) and cross inoculation in 12 Prosopis (mesquite) species

Cited by 67 publications

References 14 publications

¹⁵N Abundance of Nodules as an Indicator of N Metabolism in N₂-Fixing Plants

¹⁵N Abundance of Nodules as an Indicator of N Metabolism in N₂-Fixing Plants

CO₂assimilation in young Prosopis plants

Characterization and symbiotic importance of acidic extracellular polysaccharides of Rhizobium sp. strain GRH2 isolated from acacia nodules

Contact Info

Product

Resources

About

Nitrogen fixation (acetylene reduction) and cross inoculation in 12 Prosopis (mesquite) species

Cited by 67 publications

References 14 publications

15N Abundance of Nodules as an Indicator of N Metabolism in N2-Fixing Plants

15N Abundance of Nodules as an Indicator of N Metabolism in N2-Fixing Plants

CO2assimilation in young Prosopis plants

Characterization and symbiotic importance of acidic extracellular polysaccharides of Rhizobium sp. strain GRH2 isolated from acacia nodules

Contact Info

Product

Resources

About

¹⁵N Abundance of Nodules as an Indicator of N Metabolism in N₂-Fixing Plants

¹⁵N Abundance of Nodules as an Indicator of N Metabolism in N₂-Fixing Plants

CO₂assimilation in young Prosopis plants