Comparison of genome structure between white clover and Medicago truncatula supports homoeologous group nomenclature based on conserved synteny

Genome ◽  
2008 ◽  
Vol 51 (11) ◽  
pp. 905-911 ◽  
Author(s):  
Julie George ◽  
Timothy I. Sawbridge ◽  
Noel O.I. Cogan ◽  
Anthony R. Gendall ◽  
Kevin F. Smith ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
White Clover ◽  
Agronomic Traits ◽  
Genome Structure ◽  
Draft Genome ◽  
Gene Location ◽  
Pasture Production ◽  
Model Legume ◽  
Nomenclature System ◽  
Translocation Event

Computational analysis has been used to align the genetic map of white clover ( Trifolium repens L.) with the draft genome sequence of the model legume species Medicago truncatula Gaertn. In silico comparison based on white clover expressed sequence tags that contain simple sequence repeat loci revealed substantial macrosynteny between the genomes of these two species, which are closely related within the Trifolieae tribe of the Fabaceae family. Six of the eight homoeologous chromosome groups (HGs) of allotetraploid white clover show predominant relationships with single M. truncatula (Mt) chromosomes, while the two remaining groups may have participated in an evolutionary reciprocal translocation event. On this basis, a new chromosome nomenclature system for allotetraploid white clover is proposed such that HG A = 3, HG B = 8, HG C = 7, HG D = 4, HG E = 1, HG F = 2, HG G = 5, and HG H = 6. A rationalized linkage map ordering system has also been demonstrated. Improved knowledge of the relationships between agricultural and model forage legume genomes will facilitate prediction of gene location for key agronomic traits for pasture production.

Resistance to Subterranean clover mottle virus in Medicago truncatula and genetic mapping of a resistance locus

2009 ◽  
Vol 60 (5) ◽  
pp. 480 ◽  
Author(s):  
Muhammad Saqib ◽  
Simon R. Ellwood ◽  
Roger A. C. Jones ◽  
Michael G. K. Jones
Keyword(s):  
Medicago Truncatula ◽  
Recombinant Inbred Lines ◽  
Genome Structure ◽  
Subterranean Clover ◽  
Mottle Virus ◽  
Resistance Locus ◽  
Hypersensitive Resistance ◽  
Phenotypic Data ◽  
Model Legume ◽  
And Function

Subterranean clover mottle virus (SCMoV), which causes an important disease of annual clover pastures, was inoculated to the annual pasture legume Medicago truncatula, a model legume species used to help understand legume genome structure and function. Two hundred and nine accessions representing the core collection of M. truncatula were inoculated with infective sap containing SCMoV to determine their disease phenotypes. Forty-two of these accessions remained uninfected systemically and so were potentially resistant to the virus. Accession DZA315.16 developed a localised hypersensitive resistance reaction. In an F8 mapping population from a cross between the susceptible parent Jemalong 6/A17 and resistant accession DZA315.16, a total of 166 F8 recombinant inbred lines (RILs) were phenotyped for resistance and susceptibility to SCMoV. Resistant and susceptible lines showed parental phenotypic responses: 84 were susceptible and 82 were resistant, suggesting presence of a single resistance (R) gene. The phenotypic data were combined with genotypic data (76 polymorphic molecular markers) for this RIL population to provide a framework map. Genetic analysis located a single resistance locus termed RSCMoV1 on the long arm of chromosome 6. These results provide a basis for fine mapping the RSCMoV1 gene.

Transgenic technologies for enhanced molecular breeding of white clover (Trifolium repens L.)

2013 ◽  
Vol 64 (1) ◽  
pp. 26 ◽  
Author(s):  
J. W. Forster ◽  
S. Panter ◽  
A. Mouradov ◽  
J. Mason ◽  
G. C. Spangenberg
Keyword(s):  
White Clover ◽  
Molecular Breeding ◽  
Agronomic Traits ◽  
Insect Pests ◽  
Current Status ◽  
Aluminium Tolerance ◽  
Transgenic Technology ◽  
Environmental Benefit ◽  
Pasture Grass ◽  
Transgenic Technologies

White clover is an important pasture legume of temperate regions, generally through co-cultivation with a pasture grass in a mixed-sward setting. White clover provides herbage with high nutritional quality to grazing animals, along with the environmental benefit of biological nitrogen fixation. Several key agronomic traits are amenable to modification in white clover through use of transgenic technology. Efficient methods for Agrobacterium-mediated transformation of white clover have been developed. The current status of transgenic research is reviewed for the following traits: resistance to viruses and insect pests; aluminium tolerance and phosphorus acquisition efficiency; control of leaf senescence and seed yield; biosynthesis of flavonoids and rumen bypass proteins for bloat safety and enhanced ruminant nutrition; cyanogenesis; and drought tolerance. Future prospects for transgenic technology in molecular breeding in white clover are also discussed.

scholarly journals An improved genome release (version Mt4.0) for the model legume Medicago truncatula

BMC Genomics ◽  
2014 ◽  
Vol 15 (1) ◽  
pp. 312 ◽  
Author(s):  
Haibao Tang ◽  
Vivek Krishnakumar ◽  
Shelby Bidwell ◽  
Benjamin Rosen ◽  
Agnes Chan ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Model Legume

scholarly journals Guidelines for Genetic Nomenclature and Community Governance for the Model Legume Medicago truncatula

2001 ◽  
Vol 14 (12) ◽  
pp. 1364-1367 ◽  
Author(s):  
Kathryn A. VandenBosch ◽  
Julia Frugoli
Keyword(s):  
Medicago Truncatula ◽  
Rapid Growth ◽  
Model System ◽  
Gene Nomenclature ◽  
Community Governance ◽  
Model Legume ◽  
The Past ◽  
Genetic Nomenclature ◽  
International Collaborations

At the 2nd Medicago meeting (a satellite of the 1999 IS-MPMI meeting in Amsterdam), investigators perceived a need for standardization of genetic nomenclature in Medicago truncatula, due to the rapid growth of research on this species in the past few years. Establishment of such standards grew out of discussions begun at this meeting and continued electronically throughout the M. truncatula community. The proposed standards presented here are the consensus results of those discussions. In addition to standards for gene nomenclature, a method for community governance and a website for cataloging gene names and submitting new ones are presented. The purpose of implementing these guidelines is to help maintain consistency in the literature, to avoid redundancy, to contribute to the accuracy of databases, and, in general, to aid the international collaborations that have made M. truncatula a model system for legume biology.

scholarly journals Structure and antimicrobial activity of NCR169, a nodule-specific cysteine-rich peptide of Medicago truncatula

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Noriyoshi Isozumi ◽  
Yuya Masubuchi ◽  
Tomohiro Imamura ◽  
Masashi Mori ◽  
Hironori Koga ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Medicago Truncatula ◽  
Mechanism Of Action ◽  
Disulfide Bonds ◽  
Sinorhizobium Meliloti ◽  
Bound State ◽  
Disulfide Linkage ◽  
Model Legume ◽  
Nmr Structures ◽  
And Function

AbstractA model legume, Medicago truncatula, has over 600 nodule-specific cysteine-rich (NCR) peptides required for symbiosis with rhizobia. Among them, NCR169, an essential factor for establishing symbiosis, has four cysteine residues that are indispensable for its function. However, knowledge of NCR169 structure and mechanism of action is still lacking. In this study, we solved two NMR structures of NCR169 caused by different disulfide linkage patterns. We show that both structures have a consensus C-terminal β-sheet attached to an extended N-terminal region with dissimilar features; one moves widely, whereas the other is relatively stapled. We further revealed that the disulfide bonds of NCR169 contribute to its structural stability and solubility. Regarding the function, one of the NCR169 oxidized forms could bind to negatively charged bacterial phospholipids. Furthermore, the positively charged lysine-rich region of NCR169 may be responsible for its antimicrobial activity against Escherichia coli and Sinorhizobium meliloti. This active region was disordered even in the phospholipid bound state, suggesting that the disordered conformation of this region is key to its function. Morphological observations suggested the mechanism of action of NCR169 on bacteria. The present study on NCR169 provides new insights into the structure and function of NCR peptides.

Functional specialization of Arf paralogs in nodules of model legume, Medicago truncatula

2016 ◽  
Vol 81 (3) ◽  
pp. 501-510 ◽  
Author(s):  
Elif Yüzbaşıoğlu ◽  
Eda Dalyan ◽  
Abdülrezzak Memon ◽  
Gül Öz ◽  
Bayram Yüksel
Keyword(s):  
Medicago Truncatula ◽  
Functional Specialization ◽  
Model Legume

scholarly journals Caucasian clover was more productive than white clover in grass mixtures under drought conditions

2000 ◽  
pp. 183-188 ◽  
Author(s):  
A.D. Black ◽  
R.J. Lucas
Keyword(s):  
White Clover ◽  
Festuca Arundinacea ◽  
Perennial Grass ◽  
Moisture Stress ◽  
Annual Rainfall ◽  
Grass Species ◽  
Pasture Production ◽  
Trifolium Ambiguum ◽  
Dry Conditions ◽  
Schedonorus Phoenix

This experiment compared the productivity of caucasian or white clover when established with five perennial grass species over 6 years in a dry lowland environment. Hexaploid 'Endura' caucasian clover or 'Grasslands Demand' white clover were sown in December 1994 with high endophyte 'Yatsyn' perennial ryegrass, 'Grasslands Wana' cocksfoot, 'Grasslands Advance' tall fescue, 'Grasslands Gala' grazing brome, or 'Grasslands Maru' phalaris into a deep, fertile silt loam. Initial establishment of clovers was poor with ryegrass and grazing brome. Some volunteer white clover established in all 10 treatments. After the first 14 months, no irrigation was applied over the following 4 years. Sheep grazed plots about six times each year. The legume cover in 15-month-old pastures was higher when sown with white clover (29%) than caucasian clover (21%) but dry conditions during 1997/1998 (60% of 680 mm mean annual rainfall) and 1998/1999 (66% of mean rainfall) decreased the percentage of legume in white clover pastures. In February 1998 and March 1999, legume contributed 37% and 21% of the dry matter (DM) in caucasian clover pastures, but only 4% and 1% in pastures sown with white clover. Rainfall during the sixth season (1999/2000) was more favourable (111% of mean rainfall). Total DM production from July 1999 to June 2000 was 10.0 t DM/ha from caucasian clover pastures and 8.7 t DM/ha from pastures sown with white clover. The mean proportion of legume in white clover pastures ranged from 9% when sown with ryegrass and phalaris to 1% with cocksfoot. In contrast, mean caucasian clover legume contents were similar across all grass treatments at 20%, but reached 46% with cocksfoot during summer. It was concluded that caucasian clover is more tolerant of summer moisture stress than white clover when in association with perennial grass species. Keywords: botanical composition, Bromus stamineus, Dactylis glomerata, legume content, Lolium perenne, moisture stress, pasture production, Phalaris aquatica, Schedonorus phoenix syn. Festuca arundinacea, Trifolium ambiguum, T. repens

scholarly journals Comparison of nodule endophyte composition, diversity, and gene content between Medicago truncatula genotypes

2021 ◽  
Author(s):  
Mannix Burns ◽  
Brendan Epstein ◽  
Liana Burghardt
Keyword(s):  
Functional Groups ◽  
Medicago Truncatula ◽  
Root Nodules ◽  
Bacterial Endophytes ◽  
Host Genotype ◽  
Model Legume ◽  
Symbiotic Relationships ◽  
Functional Assays ◽  
Altered Gene ◽  
Significant Direct Effect

Leguminous plants form symbiotic relationships with rhizobia. These nitrogen-fixing bacteria live in specialized root organs called nodules. While rhizobia form the most notable host relationship within root nodules, other bacterial endophytes also inhabit these root nodules and can influence host-rhizobia interactions as well as exert effects of their own, whether beneficial or detrimental. In this study, we investigate differences in nodule communities between genotypes (A17 and R108) of a single plant species, the model legume Medicago truncatula. While diversity of endophytes in nodules was similar across hosts, both nodule endophyte composition and gene functional groups differed. In contrast to the significant direct effect of host genotype, neither the presence nor identity of a host in the previous generation (either A17 or R108) had a significant effect on the nodule endophyte diversity or composition. However, whether or not a host was present altered gene functional groups. We conclude that genetic variation within a legume host species can play an important role in the establishment of nodule microbiomes. Further studies, including GWAS and functional assays, can open the door for engineering and optimizing nodule endophyte communities that promote growth or have other beneficial qualities.

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