Relative contributions to nitrogenase (acetylene reducing) activity of stem and root nodules in Sesbania rostrata

1992 ◽  
Vol 38 (6) ◽  
pp. 577-583 ◽  
Author(s):  
J. K. Ladha ◽  
Minviluz Garcia ◽  
R. P. Pareek ◽  
G. Rarivoson
Keyword(s):  
Acetylene Reduction ◽  
Root Nodule ◽  
Nitrogenase Activity ◽  
Root Nodules ◽  
Dry Weight ◽  
Acetylene Reduction Activity ◽  
Sesbania Rostrata ◽  
Reduction Activity ◽  
Acetylene Reducing Activity ◽  
Aerial Stem

Six experiments, two each in the phytotron, greenhouse, and field, were conducted to assess the contribution of nitrogenase activity (acetylene reduction) by stem nodules in the presence and absence of root nodules of Sesbania rostrata (Brem & Oberm). In a greenhouse experiment, the effect of detaching already formed aerial stem nodules on the restoration of root nodules and nitrogenase activity was studied. The field experiment compared nodulation and acetylene-reduction activity by dual-nodulating S. rostrata and root-nodulating Sesbania cannabina. Acetylene-reduction activity expressed per gram of nodule dry weight was higher for stem nodules than for root nodules. Root nodule dry weight and acetylene-reduction activity failed to increase after stem inoculation, but root nodule dry weight and acetylene-reduction activity increased several fold within 15 days of detachment of aerial stem nodules. Stem nodulation, which occurred without inoculation under lowland field condition, suppressed root nodulation, thus accounting for more than 75% of total nitrogenase activity. Sesbania rostrata showed higher acetylene-reduction activity than S. cannabina. In dual-nodulating plants, root and stem nodules appeared to strike a balance in competition for energy, which may be controlled by stem nodulation. Key words: Sesbania rostrata, Azorhizobium caulinodans, stem nodule, root nodule, acetylene-reducing activity.

Effects of Protein Synthesis Inhibitors on Acetylene Reduction Activity of Lupin Root Nodules

1980 ◽  
Vol 7 (3) ◽  
pp. 261 ◽  
Author(s):  
WD Sutton
Keyword(s):  
Protein Synthesis ◽  
Acetylene Reduction ◽  
Nitrogenase Activity ◽  
Root Nodules ◽  
Acetylene Reduction Activity ◽  
Cytoplasmic Protein ◽  
Protein Synthesis Inhibitors ◽  
Cytoplasmic Fraction ◽  
Reduction Activity ◽  
Pure Cultures

Rifampicin and D-threo-chloramphenicol inhibited the incorporation of [35S]methionine into purified bacteroid suspensions, and into the bacteroid fraction but not the plant cytoplasmic fraction of cultured nodules. Cycloheximide and anisomycin inhibited [35S]methionine incorporation into the plant cytoplasmic fraction of cultured nodules; at early times they inhibited incorporation into the bacteroid fraction, but at later times this effect was reversed. Chloramphenicol, rifampicin, spectinomycin, cycloheximide and anisomycin all prevented the induction of acetylene reduction activity in immature nodules; spectinomycin did not prevent induction in nodules containing a spectinomycin-resistant Rhizobium. Neither rifampicin nor chloramphenicol inhibited the acetylene reduction activity of mature nodules, but cycloheximide and anisomycin caused rapid loss of activity. Cycloheximide did not inhibit the acetylene reduction activity of Rhizobium strain 32H1 in pure cultures. The results suggest that both plant cytoplasmic protein synthesis and bacteroid protein synthesis are needed for the induction of nitrogenase activity in developing lupin nodules, and that plant cytoplasmic protein synthesis but not bacteroid protein synthesis is needed for the maintenance of nitrogenase activity at high levels.

Nodule Physiology of a Supernodulating Soybean (Glyine max) Mutant

1987 ◽  
Vol 14 (5) ◽  
pp. 527 ◽  
Author(s):  
AD Day ◽  
GD Price ◽  
KA Schuller ◽  
PM Gresshoff
Keyword(s):  
Plant Growth ◽  
Acetylene Reduction ◽  
Nitrogenase Activity ◽  
Xylem Sap ◽  
Dry Weight ◽  
Acetylene Reduction Activity ◽  
Nodule Number ◽  
Reduction Activity ◽  
Inoculum Dose ◽  
Glycine Max L

The nodule physiology of a supernodulating, nitrate tolerant symbiosis soybean (Glycine max (L.) Merr.) mutant (nts382) was compared to that of its wild-type parent, cv. Bragg. Nodule number and mass were greater in nts382 than cv. Bragg and individual nodule mass, bacteroid and haem content, and acetylene reduction activity per g nodule were less. Acetylene reduction activity expressed per mg bacteroid protein was the same in the two genotypes. In median sections, the ratio of infected to total nodule area was smaller in nts382, infected cell size was smaller and there were fewer bacteroids per peribacteroid envelope. When inoculum dose was decreased from 109 to 103 viable cells per pot, nodule number on nts382 decreased approximately to that on cv. Bragg; nodule size, bacteroid and haem contents increased as did nodule acetylene reduction activity. Application of moderate levels of nitrate, which did not significantly affect symbiotic parameters of cv. Bragg or high inoculum nts382, stimulated nodule growth and nitrogenase activity of low inoculum nts382. A combination of nitrate and low inoculum levels enhanced nodule parameters of nts382 to the level usually seen with cv. Bragg. When supernodulated, plant dry weight of nts382 was less than that of Bragg; decreasing inoculum dose had no significant effect but nitrate application increased plant growth; nitrate plus low inoculum induced similar plant growth to that of cv. Bragg. Nodule carbohydrate content was similar in both genotypes but nodule and xylem sap ureide contents were higher in nts382. In general, nodules of supernodulated nts382 resembled under-developed cv. Bragg nodules; when supernodulation was avoided by using low inoculum doses, ,nts382 nodules resembled those of cv. Bragg. Nitrogen metabolism in the mutant seems to be disturbed, resulting in ureide accumulation.

scholarly journals Diversity and Effectivity of Indigenous Mesorhizobium Strains for Chickpea (Cicer arietinum L.) in Myanmar

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 287 ◽  
Author(s):  
Khin Myat Soe ◽  
Aung Zaw Htwe ◽  
Kyi Moe ◽  
Abiko Tomomi ◽  
Takeo Yamakawa
Keyword(s):  
Sequence Analysis ◽  
Cicer Arietinum ◽  
Acetylene Reduction ◽  
Dry Weight ◽  
Acetylene Reduction Activity ◽  
Rrna Gene ◽  
Cicer Arietinum L ◽  
Reduction Activity ◽  
Legume Production ◽  
High Level

Chickpea (Cicer arietinum L.) is one of the world’s main leguminous crops that provide chief source of food for humans. In the present study, we characterized thirty isolates of indigenous chickpea rhizobia from Myanmar based on the sequence analysis of the bacterial 16S rRNA gene. The sequence analysis confirmed that all isolates were categorized and identified as the genus Mesorhizobium and they were conspecific with M. plurifarium, M. muliense, M. tianshanense, and M. sp. This is the first report describing M. muliense, M. tianshanense, and M. plurifurium from different geographical distribution of indigenous mesorhizobia of chickpea in Myanmar. In order to substitute the use of chemical fertilizers in legume production, there is a need for the production of Biofertilizers with rhizobial inoculants. The effectiveness of Myanmar Mesorhizobim strains isolated from soil samples of major chickpea growing areas of Myanmar for plant growth and nitrogen fixation were studied in pot experiments. The nodule dry weight and acetylene reduction activity of the plant inoculated with Mesorhizobium tianshanense SalCP19 was significantly higher than the other tested isolates in Yezin-4 chickpea variety. But, Mesorhizobium sp. SalCP17 was showed high level of acetylene reduction activity per plant in Yezin-6 chickpea variety.

A survey of angiosperms in Nova Scotia for rhizosphere nitrogenase (acetylene-reduction) activity

1978 ◽  
Vol 56 (18) ◽  
pp. 2218-2223 ◽  
Author(s):  
D. Smith ◽  
D. G. Patriquin
Keyword(s):  
Nova Scotia ◽  
Acetylene Reduction ◽  
Nitrogenase Activity ◽  
Reduction Technique ◽  
Acetylene Reduction Activity ◽  
Forage Grasses ◽  
Reduction Activity ◽  
Tropical Forage ◽  
Poorly Drained Soils

Excised root samples from 901 plants, representing 130 species of nonnodulated angiosperms largely in upland, pioneering habitats, were assayed for nitrogenase activity by the acetylene-reduction technique after overnight preincubation of the samples under low pO2. Most samples and most species exhibited very low excised root acetylene-reducing activities, but for 19 species, maximum values were greater than 50 nmol C2H4∙g−1∙h−1. In situ C2H2 assays, conducted on 10 species which had exhibited maximum excised root activities greater than 10 nmol C2H4∙g−1∙h−1, indicated average belowground N2-fixation rates of 3 to 92 g N∙ha−1∙day−1 and maxima greater than 100 g N∙ha−1∙day−1 for 3 of the 10 species. The highest values were for grasses characteristic of poorly drained soils and for some dicotyledonous weeds. It is concluded that the potential of temperate-zone angiosperms for nitrogenase activity by 'associative symbioses' approaches that of tropical forage grasses.

Stomatal conductance, photosynthesis and acetylene reduction rate in soybean genotypes

1992 ◽  
Vol 72 (2) ◽  
pp. 383-390 ◽  
Author(s):  
A. Djekoun ◽  
C. Planchon
Keyword(s):  
Glycine Max ◽  
Water Stress ◽  
Stomatal Conductance ◽  
Acetylene Reduction ◽  
Nitrogenase Activity ◽  
Leaf Water ◽  
Acetylene Reduction Activity ◽  
Reduction Activity ◽  
Leaf Osmotic Potential ◽  
Glycine Max L

Yield limitation in soybean (Glycine max L. Merr.) can result from decreases in photosynthesis and N2 fixation during periods of water deficiency. In this study, the relationships among stomatal conductance, photosynthesis and N2 fixation were analyzed in connection with drought tolerance of genotypes. Plants were grown in pots and exposed to field conditions. Carbon dioxide exchange rate was measured by gas analysis and nodule activity by the acetylene reduction method. Leaf water status was determined with a pressure bomb, and nodule water potential and leaf osmotic potential were measured psychrometrically. The differing tolerances of the cultivars Kingsoy and Hodgson to leaf water deficit resulted in a more or less developed ability of the lower side of the leaf to maintain good stomatal conductance during water stress. Stomatal conductance affects photosynthetic rate directly and acetylene reduction activity indirectly. Early stomatal closure, by limiting H2O exchange, contributes to conservation of nitrogenase activity. On the contrary, maintenance of high conductance during a water stress decreases soil water availability and nodule water content, which in turn has a decisive and limiting effect on acetylene reduction activity. Thus, if tolerance at low leaf water potentials associated with osmotic adjustment is an important drought mechanism for maintaining photosynthetic processes under water-limited conditions, the result would be obtained at the expense of symbiotic N2 fixation.Key words: Glycine max L. Merr., nitrogenase activity, photosynthesis, drought stress, soybean

An SEM/TEM study of structures associated with bacteroids in peanut (Arachis hyppogaea L.) root nodules

1988 ◽  
Vol 46 ◽  
pp. 288-289
Author(s):  
C. J. Emerson ◽  
A. K. Bal
Keyword(s):  
Arachis Hypogaea ◽  
Acetylene Reduction ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Root Nodules ◽  
Acetylene Reduction Activity ◽  
Reduction Activity ◽  
Dense Bodies ◽  
Growth Chambers ◽  
Large Spherical

Nitrogen-fixing peanut root nodules have highly specialized, large spherical bacteroids and show higher acetylene-reduction activity than the nodules of other legumes induced by the same strain of rhizobia. Differences are also found in their anatomical organization and with regard to bacteroid-associated organelles and other structures (dense bodies) found on the host-symbiont interface. In this investigation, further description of these organelles and structures was made at different stages of development in a correlated SEM/TEM study.Arachis hypogaea L. cv. Jumbo Virginia plants were grown in environmental growth chambers and inoculated with Rhizobium sp. 32Hl. For TEM, slices of nodules were fixed in Karnovsky's fixative in Sorensen's phosphate buffer, pH 7.2 for 1 h at 4°C. Tissues were rinsed in buffer, post-fixed with 1% phosphate-buffered osmium tetroxide for 1 h at 4°C and dehydrated in ethanol. 1% p-phenylenediamine was added at the 70% ethanol step (30 min) to preserve lipids.

Nitrogenase activity, nodulation and seed production inVicia fabaas affected by methabenzthiazuron

1996 ◽  
Vol 127 (3) ◽  
pp. 319-324 ◽  
Author(s):  
J. Martínez ◽  
D. Vidal ◽  
E. Simón
Keyword(s):  
Seed Production ◽  
Vegetative Growth ◽  
Nitrogenase Activity ◽  
Dry Weight ◽  
Inhibitory Effect ◽  
Acetylene Reduction Activity ◽  
N Recovery ◽  
N Fixation ◽  
N Content ◽  
Reduction Activity

SUMMARYThe effects of recommended application rates of the herbicide methabenzthiazuron (MBT) (2·5 and 4 kg ha-1) on vegetative growth, nodulation and N2fixation in faba bean plants were studied in the field at Barcelona during 1990 and 1991. Nodulation, specific nitrogenase activity (SNA) of excised nodules, dry weight of plants and seed nitrogen content at harvest were compared in MBT-treated, hand-weeded (HW) and control plants. In 1990 the higher MBT application (4 kg ha-1) caused a decrease in nodulation and acetylene reduction activity (ARA) per plant during the mid-period of pod-fill, and also in vegetative growth, seed production and N content of seeds, whereas the lower rate (2·5 kg ha-1) did not have a significant effect on any of these factors. However, in 1991, growth and herbicide effects were different from those in the previous year. No inhibitory effect of MBT on nodulation, SNA or ARA per plant was observed and vegetative growth, seed production and N content of seeds were not significantly different from those of plants from HW plots. In 1991, both 4 kg ha-1of MBT and the HW treatment caused a stimulatory effect on seed N recovery and yield compared to control plants. Rates of ARA per plant at late pod-fill were positively related to N recovery by seeds. These differences could have been due to the low rainfall in 1990, which may have permitted MBT to remain in the soil for a longer period and to inhibit N fixation and plant growth in theVicia fabacrop.

Effect of inoculation of Zea mays with Azospirillum brasilense strains under temperate conditions

1981 ◽  
Vol 27 (9) ◽  
pp. 871-877 ◽  
Author(s):  
G. W. O'Hara ◽  
M. R. Davey ◽  
J. A. Lucas
Keyword(s):  
Zea Mays ◽  
Nitrogen Content ◽  
Acetylene Reduction ◽  
Azospirillum Brasilense ◽  
Dry Weight ◽  
Yield Response ◽  
Acetylene Reduction Activity ◽  
Reduction Activity ◽  
Mutant Strains ◽  
Nitrogen Concentrations

Seven strains of Azospirillum brasilense were compared for their effect on the growth of Zea mays grown under temperate conditions in sand–vermiculite pot cultures. Inoculation with all seven strains tested, including Fix− mutant strains, increased dry weight and total nitrogen content of shoots, but nitrogen concentrations were unaffected. Low and variable rates of acetylene reduction activity were observed from excised roots of inoculated plants without preincubation. Estimates of N2-fixing A. brasilense associated with inoculated roots showed differences between strains in establishing themselves in the rhizosphere and endorhizosphere. In some strains enrichment in the endorhizosphere of roots occurred following inoculation, but the relative numbers and location of the strains did not appear to affect the yield response.

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