Factors involved in the amelioration of retarded symbiosis in Tinaroo glycine

1974 ◽  
Vol 25 (4) ◽  
pp. 577 ◽  
Author(s):  
A Diatloff
Keyword(s):  
Nitrogen Fixation ◽  
Ammonium Nitrate ◽  
Root Nodules ◽  
Host Cells ◽  
Starch Accumulation ◽  
Nodule Formation ◽  
Carbon And Nitrogen ◽  
Slow Development ◽  
Structural Differences ◽  
Envelope Membranes

Root nodules formed on Tinaroo glycine (Glycine wightii) were slow to pigment and begin fixing nitrogen. Various carbon and nitrogen compounds enhanced nodule pigmentation, the greening of the plants, and the rate of nitrogen fixation at 42 days. Of these inositol, glucose, ammonium nitrate (as both foliar and root applications) and coconut milk were most effective. Riboflavin, sodium glutamate and nodule infusion had little effect. There were no structural differences between nodules enhanced respectively by glucose and ammonium nitrate. Nodules on control plants showed slow development of the bacteroids and envelope membranes, with copious starch accumulation in uninvaded host cells. It was concluded that the retarded symbiosis in formed nodules was due initially to tardy nodule formation depleting the nitrogen reserves in the seeds before nitrogen fixation began. Because of the interaction of photosynthesis and nitrogen fixation, self-regeneration of nitrogen fixation in chlorotic plants was slow without an external stimulus. It is suggested that by selecting lines of the legume with larger seeds or by incorporating nitrogen in seed pellets the problem might be overcome.

Nodulation and nitrogen fixation by Vigna sinensis and Vicia atropurpurea: The influence of concentration, form, and site of application of combined nitrogen

1970 ◽  
Vol 21 (1) ◽  
pp. 45 ◽  
Author(s):  
PJ Dart ◽  
DC Wildon
Keyword(s):  
Nitrogen Fixation ◽  
Ammonium Nitrate ◽  
Root Nodules ◽  
Primary Root ◽  
Nitrogen Compound ◽  
Potassium Nitrate ◽  
Growth Patterns ◽  
Rhizobium Strain ◽  
Root Nodulation ◽  
Combined Nitrogen

Nitrogen fixation by Vigna sinesis nodulated effectively either by Rhizobium strain QA323 or by strain CB441 is little restricted by applications at sowing of ammonium nitrate up to 24 mg nitrogen per plant. The growth patterns of these two associations are differentially affected by nitrogen level, and are both considerably different from that of unnodulated plants given combined nitrogen. Nitrogen fixation by V. sinensis-strain SU318 may be stimulated by small doses of combined nitrogen at sowing, but for Vicia atvopurpurea all the combined nitrogen levels used in these experiments depressed fixation. Primary root nodulation of V. atropurpurea by the effective Rhizobium strain V27E and the ineffective strain NA6, and of V. sinensis by the effective Rhizobium strain SU318, is influenced by the form and amount of the nitrogen compound applied (ammonium nitrate, potassium nitrate, ammonium sulphate, or urea), and that of V. atropurpurea is also influenced by the Rhizobium strain. These forms of combined nitrogen restrict primary root nodulation on both hosts similarly except that urea has little effect on V. atuopurpurea. In both species many more nodules formed on the secondary roots than on the primary, but numbers of secondary root nodules are little affected by the combined nitrogen. Immersion of the first leaves of V. sinensis seedlings in solutions of combined nitrogen depressed nodulation, but urea slightly increased the dry weight of tops.

INFLUENCE OF ROOT TEMPERATURE ON THE EARLY GROWTH AND SYMBIOTIC NITROGEN FIXATION OF NODULATED LOTUS CORNICULATUS PLANTS

1970 ◽  
Vol 50 (5) ◽  
pp. 569-575 ◽  
Author(s):  
H. T. KUNELIUS ◽  
K. W. CLARK
Keyword(s):  
Nitrogen Fixation ◽  
Ammonium Nitrate ◽  
Environmental Conditions ◽  
Symbiotic Nitrogen Fixation ◽  
Lotus Corniculatus ◽  
Early Growth ◽  
Birdsfoot Trefoil ◽  
Nodule Formation ◽  
Root Temperature ◽  
Nitrogen Yields

Three birdsfoot trefoil (Lotus corniculatus L.) cultivars, inoculated with one of six Lotus rhizobia strains or dependent on ammonium nitrate, were grown in diSPo growth pouches under controlled environmental conditions at five root temperatures (9–30 C) for 35 days after nodule formation. When the plants were dependent on symbiotic nitrogen fixation, the highest dry weights and nitrogen yields per plant were obtained at 18 or 24 C depending on symbiotic combination. At 9 and 12 C, nitrogen fixation was depressed and the growth was poor. The dry weights of plants at 9 C were 19 to 45% of those at 24 C. At 30 C the growth and nitrogen fixation were generally depressed. At all root temperatures the growth of plants dependent on symbiotic nitrogen fixation was inferior to that of plants receiving combined nitrogen (NH4NO3). Significant interactions indicate that the nitrogen fixing ability of cultivars was dependent on both root temperature and the strain of Lotus rhizobia.

scholarly journals A Convenient, Soil-Free Method for the Production of Root Nodules in Soybean to Study the Effects of Exogenous Additives

2018 ◽  
Author(s):  
Swarup Roy Choudhury ◽  
Sarah M. Johns ◽  
Sona Pandey
Keyword(s):  
Nitrogen Fixation ◽  
Biological Nitrogen Fixation ◽  
Root Nodules ◽  
Growth Conditions ◽  
Nodule Development ◽  
Nodule Formation ◽  
Legume Crop ◽  
Simple Protocol ◽  
Biological Nitrogen

Legumes develop root nodules that harbour endosymbiotic bacteria, rhizobia. These rhizobia convert nitrogen to ammonia by biological nitrogen fixation. A thorough understanding of the biological nitrogen fixation in legumes and its regulation is key to develop sustainable agriculture. It is well known that plant hormones affect nodule formation; however, most studies are limited to model legumes due to their suitability for in vitro, plate-based assays. Specifically, it is almost impossible to measure the effects of exogenous hormones or other additives during nodule development in crop legumes such as soybean as they have huge root system in soil. To circumvent this issue, the present research develops suitable media and growth conditions for efficient nodule development under in vitro, soil free conditions in an important legume crop, soybean. Moreover, we also evaluate the effects of all major phytohormones during soybean nodulation under identical conditions. This versatile, inexpensive, scalable and simple protocol provides several advantages over previously established methods. It is extremely time-and resource-efficient, does not require special training or equipment, and produces highly reproducible results. The approach is expandable to other large legumes as well as for other exogenous additives.

scholarly journals Nitrate restricts nodule organogenesis through inhibition of cytokinin biosynthesis in Lotus japonicus

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jieshun Lin ◽  
Yuda Purwana Roswanjaya ◽  
Wouter Kohlen ◽  
Jens Stougaard ◽  
Dugald Reid
Keyword(s):  
Nitrogen Fixation ◽  
Developmental Process ◽  
Root Zone ◽  
Root Nodules ◽  
Lotus Japonicus ◽  
Nodule Development ◽  
Nodule Formation ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cytokinin Biosynthesis

AbstractLegumes balance nitrogen acquisition from soil nitrate with symbiotic nitrogen fixation. Nitrogen fixation requires establishment of a new organ, which is a cytokinin dependent developmental process in the root. We found cytokinin biosynthesis is a central integrator, balancing nitrate signalling with symbiotic acquired nitrogen. Low nitrate conditions provide a permissive state for induction of cytokinin by symbiotic signalling and thus nodule development. In contrast, high nitrate is inhibitory to cytokinin accumulation and nodule establishment in the root zone susceptible to nodule formation. This reduction of symbiotic cytokinin accumulation was further exacerbated in cytokinin biosynthesis mutants, which display hypersensitivity to nitrate inhibition of nodule development, maturation and nitrogen fixation. Consistent with this, cytokinin application rescues nodulation and nitrogen fixation of biosynthesis mutants in a concentration dependent manner. These inhibitory impacts of nitrate on symbiosis occur in a Nlp1 and Nlp4 dependent manner and contrast with the positive influence of nitrate on cytokinin biosynthesis that occurs in species that do not form symbiotic root nodules. Altogether this shows that legumes, as exemplified by Lotus japonicus, have evolved a different cytokinin response to nitrate compared to non-legumes.

Ultrastructure of root nodules formed by ineffective strains of Rhizobium meliloti

1974 ◽  
Vol 20 (5) ◽  
pp. 755-758 ◽  
Author(s):  
C. R. MacKenzie ◽  
D. C. Jordan
Keyword(s):  
Rhizobium Meliloti ◽  
Root Nodules ◽  
Plant Cells ◽  
Host Cells ◽  
Nodule Development ◽  
Nodule Formation ◽  
Starch Granules ◽  
Naturally Occurring ◽  
Intimate Association ◽  
Rough Er

In three ineffective associations between Medicago sativa (alfalfa) and Rhizobium meliloti the initial stages of nodule formation, resulting in the release of the bacteria into the host cells, were found to follow the normal pattern of nodule development. In nodule tissue formed by two laboratory-produced ineffective mutants, a rapid disintegration of the invading bacteria was observed to occur shortly after the release of the bacteria into the plant cells. The disintegrating bacteria were in intimate association with large amounts of rough endoplasmic reticulum (ER). An increase in the number of mitochondria occurred at this stage as well and the peripheries of the plant cells were often lined with starch granules. Only occasionally was the stage of enclosing-membrane formation reached. In the third ineffective association, a naturally occurring one, the bacteria were transformed into the nitrogen-fixing or bacteroidal forms and were surrounded by enclosing membranes. Dissolution of the bacteria occurred at a slightly later stage in this association and was again accompanied by a buildup of rough ER. Evidence is presented to suggest that the plant response, as characterized by this ER buildup in these ineffective associations, was a manifestation of nitrogen starvation.

Novel rhizobia exhibit superior nodulation and biological nitrogen fixation even under high nitrate concentrations

2019 ◽  
Vol 96 (2) ◽  
Author(s):  
Hien P Nguyen ◽  
Hiroki Miwa ◽  
Jennifer Obirih-Opareh ◽  
Takuya Suzaki ◽  
Michiko Yasuda ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Bradyrhizobium Japonicum ◽  
Root Nodules ◽  
Nitrogen Fertilizers ◽  
Nodule Formation ◽  
Nitrogen Fixing ◽  
Nitrogen Fixation Activity ◽  
Nitrate Concentrations ◽  
Nodulation Competitiveness ◽  
Biological Nitrogen

ABSTRACT Legume–rhizobium symbiosis leads to the formation of nitrogen-fixing root nodules. However, externally applied chemical nitrogen fertilizers (nitrate and ammonia) strongly inhibit nodule formation and nitrogen fixation. Here, we isolated several rhizobial strains exhibiting a superior nodulation and nitrogen fixation with soybean at high nitrate concentrations. The nodulation of soybean symbiont Bradyrhizobium diazoefficiens USDA110 was significantly inhibited at 12.5 mM nitrate; however, three isolates (NKS4, NKM2 and NKTG2) were capable of forming nitrogen-fixing nodules, even at 20 mM nitrate. These isolates exhibited higher nodulation competitiveness and induced larger nodules with higher nitrogen-fixation activity than USDA110 at 5 mM nitrate. Furthermore, these isolates induced more nodules than USDA110 even in nitrate-free conditions. These isolates had a distant lineage within the Bradyrhizobium genus; though they were relatively phylogenetically close to Bradyrhizobium japonicum, their morphological and growth characteristics were significantly different. Notably, in the presence of nitrate, expression of the soybean symbiosis-related genes (GmENOD40 and GmNIN) was significantly higher and expression of GmNIC1 that is involved in nitrate-dependent nodulation inhibition was lower in the roots inoculated with these isolates in contrast with inoculation of USDA110. These novel rhizobia serve as promising inoculants for soybeans cultivated in diverse agroecosystems, particularly on nitrate-applied soils.

scholarly journals Laser Microdissection of Pisum sativum L. Nodules Followed by RNA-Seq Analysis Revealed Crucial Transcriptomic Changes During Infected Cell Differentiation

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2504
Author(s):  
Pyotr G. Kusakin ◽  
Tatiana A. Serova ◽  
Natalia E. Gogoleva ◽  
Yuri V. Gogolev ◽  
Viktor E. Tsyganov
Keyword(s):  
Nitrogen Fixation ◽  
Pisum Sativum ◽  
Laser Microdissection ◽  
Host Cells ◽  
Nodule Development ◽  
Nodule Formation ◽  
Rna Seq ◽  
Legume Crop ◽  
Pisum Sativum L ◽  
Transcriptional Changes

Garden pea (Pisum sativum L.) is a globally important legume crop. Like other legumes, it forms beneficial symbiotic interactions with the soil bacteria rhizobia, gaining the ability to fix atmospheric nitrogen. In pea nodules, the meristem is long-lasting and results in the formation of several histological zones that implicate a notable differentiation of infected host cells. However, the fine transcriptional changes that accompany differentiation are still unknown. In this study, using laser microdissection followed by RNA-seq analysis, we performed transcriptomic profiling in the early infection zone, late infection zone, and nitrogen fixation zone of 11-day-old nodules of pea wild-type line SGE. As a result, a list of functional groups of differentially expressed genes (DEGs) in different nodule histological zones and a list of genes with the most prominent expression changes during nodule development were obtained. Their analyses demonstrated that the highest amount of DEGs was associated with the nitrogen fixation zone. Among well-known genes controlling nodule development, we revealed genes that can be novel players throughout nodule formation. The characterized genes in pea were compared with those previously described in other legumes and their possible functions in nodule development are discussed.

scholarly journals Chickpea shows genotype-specific nodulation responses across soil nitrogen environment and root disease resistance categories

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Krista L. Plett ◽  
Sean L. Bithell ◽  
Adrian Dando ◽  
Jonathan M. Plett
Keyword(s):  
Nitrogen Fixation ◽  
Disease Resistance ◽  
Soil Nitrogen ◽  
Cellular Localization ◽  
Expression Patterns ◽  
Nodule Development ◽  
Nodule Formation ◽  
Symbiotic Relationship ◽  
Plant Genotype ◽  
Factors Affecting

Abstract Background The ability of chickpea to obtain sufficient nitrogen via its symbiotic relationship with Mesorhizobium ciceri is of critical importance in supporting growth and grain production. A number of factors can affect this symbiotic relationship including abiotic conditions, plant genotype, and disruptions to host signalling/perception networks. In order to support improved nodule formation in chickpea, we investigated how plant genotype and soil nutrient availability affect chickpea nodule formation and nitrogen fixation. Further, using transcriptomic profiling, we sought to identify gene expression patterns that characterize highly nodulated genotypes. Results A study involving six chickpea varieties demonstrated large genotype by soil nitrogen interaction effects on nodulation and further identified agronomic traits of genotypes (such as shoot weight) associated with high nodulation. We broadened our scope to consider 29 varieties and breeding lines to examine the relationship between soilborne disease resistance and the number of nodules developed and real-time nitrogen fixation. Results of this larger study supported the earlier genotype specific findings, however, disease resistance did not explain differences in nodulation across genotypes. Transcriptional profiling of six chickpea genotypes indicates that genes associated with signalling, N transport and cellular localization, as opposed to genes associated with the classical nodulation pathway, are more likely to predict whether a given genotype will exhibit high levels of nodule formation. Conclusions This research identified a number of key abiotic and genetic factors affecting chickpea nodule development and nitrogen fixation. These findings indicate that an improved understanding of genotype-specific factors affecting chickpea nodule induction and function are key research areas necessary to improving the benefits of rhizobial symbiosis in chickpea.

scholarly journals Mutation in the ntrR Gene, a Member of the vap Gene Family, Increases the Symbiotic Efficiency of Sinorhizobium meliloti

2001 ◽  
Vol 14 (7) ◽  
pp. 887-894 ◽  
Author(s):  
Boglárka Oláh ◽  
Erno Kiss ◽  
Zoltán Györgypál ◽  
Judit Borzi ◽  
Gyöngyi Cinege ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Pathogenic Bacteria ◽  
Sinorhizobium Meliloti ◽  
Root Nodules ◽  
Nifh Gene ◽  
Dry Weight ◽  
Nodule Occupancy ◽  
Gene Encoding ◽  
Symbiotic Efficiency ◽  
Host Interactions

In specific plant organs, namely the root nodules of alfalfa, fixed nitrogen (ammonia) produced by the symbiotic partner Sinorhizobium meliloti supports the growth of the host plant in nitrogen-depleted environment. Here, we report that a derivative of S. meliloti carrying a mutation in the chromosomal ntrR gene induced nodules with enhanced nitrogen fixation capacity, resulting in an increased dry weight and nitrogen content of alfalfa. The efficient nitrogen fixation is a result of the higher expression level of the nifH gene, encoding one of the subunits of the nitrogenase enzyme, and nifA, the transcriptional regulator of the nif operon. The ntrR gene, controlled negatively by its own product and positively by the symbiotic regulator syrM, is expressed in the same zone of nodules as the nif genes. As a result of the nitrogen-tolerant phenotype of the strain, the beneficial effect of the mutation on efficiency is not abolished in the presence of the exogenous nitrogen source. The ntrR mutant is highly competitive in nodule occupancy compared with the wild-type strain. Sequence analysis of the mutant region revealed a new cluster of genes, termed the “ntrPR operon,” which is highly homologous to a group of vap-related genes of various pathogenic bacteria that are presumably implicated in bacterium-host interactions. On the basis of its favorable properties, the strain is a good candidate for future agricultural utilization.

scholarly journals NITROGEN FIXATION BY EXCISED SOY BEAN ROOT NODULES

1954 ◽  
Vol 208 (1) ◽  
pp. 29-39
Author(s):  
M.H. Aprison ◽  
Wayne E. Magee ◽  
R.H. Burris
Keyword(s):  
Nitrogen Fixation ◽  
Root Nodules ◽  
Bean Root
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