Life Sciences Commons^™

Confirming Presence And Mobilization Of Partner Quality Genes In Sinorhizobium Meliloti, Ethan Perez, Ivan Sosa Marquez, Katy Heath

PRECS student projects

• Mutualism is an interaction in which two organisms benefit from each other.
• The symbiotic relationship between the bacterium Sinorhizobium meliloti and the plant Medicago truncatula is dictated by the bacterial plasmids.
• The Heath lab has a collection of 191 Sinorhizobium meliloti strains with different symbiotic plasmids that vary across populations (Riley et al., 2022).
• Each strain can be a better or worse partner for its plant host in symbiosis with the variation in fitness being called partner quality (Fig. 1)
• These traits can be traced back to the genetic elements that underlie this effect (Batstone et al.,
• These genetic elements …

Towards A Comparative Map Of White Clover (Trifolium Repens) And Barrel Medic (Medicago Truncatula), M. Febrer, G. Jenkins, M. T. Abberton, D. Milbourne

IGC Proceedings (1997-2023)

Grassland is of pivotal importance to the Irish agricultural industry. This dependence of grass is reflected in the large proportion of land area under grass, approx. 80% of the total land acreage in Ireland. The presence of white clover (Trifolium repens L.) in grassland significantly improves the overall nutritional value of the forage by increasing the relative amounts of nitrogen present. Genetic improvement of white clover through breeding of varieties should increase the productivity of grasslands. Advances in plant biotechnology offer the possibility of developing tools that will radically enhance our ability to breed improved plant varieties. The objective …

A Medicago Truncatula Population Segregating For Aluminum Tolerance, M. Sledge, B. Narasimhamoorthy, G. Jiang

IGC Proceedings (1997-2023)

Aluminium (Al) toxicity, manifested in inhibition of root elongation and reduced plant growth, is a major cause of poor crop yields on acid soils, which comprise up to 40% of the world’s arable land. Al toxicity associated with acid soils has been a major obstacle in alfalfa (Medicago sativa) production in the USA, as well as in tropical areas of the world. Recent molecular marker mapping studies indicate that the genomes of M. truncatula and M. sativa are highly similar (Choi et al., 2004). Thus, M. truncatula could be used as a source of genes that could …

Application Of Synthetic Peptide Cep1 Increases Nutrient Uptake Rates Along Plant Roots, Sonali Roy, Marcus Griffiths, Ivone Torres-Jerez, Bailey Sanchez, Elizabeth Antonelli, Divya Jain, Nicholas Krom, Shulan Zhang, Larry M. York, Wolf-Rüdiger Scheible, Michael Udvardi

Agricultural and Environmental Sciences Faculty Research

The root system of a plant provides vital functions including resource uptake, storage, and anchorage in soil. The uptake of macro-nutrients like nitrogen (N), phosphorus (P), potassium (K), and sulphur (S) from the soil is critical for plant growth and development. Small signaling peptide (SSP) hormones are best known as potent regulators of plant growth and development with a few also known to have specialized roles in macronutrient utilization. Here we describe a high throughput phenotyping platform for testing SSP effects on root uptake of multiple nutrients. The SSP, CEP1 (C-TERMINALLY ENCODED PEPTIDE) enhanced nitrate uptake rate per unit root …

Development And Genetic Analysis Of A Mapping Population On Medicago Truncatula, Zhenwu Wei, Zhanhua Yang, Lifang Zhang

IGC Proceedings (1997-2023)

No abstract provided.

Functional Characterization Of Petiolule-Like Pulvinus (Plp) Gene In Abscission Zone Development In Medicago Truncatula And Its Application To Genetic Improvement Of Alfalfa, Juan Du, Shaoyun Lu, Maofeng Chai, Chuanen Zhou, Liang Sun, Yuhong Tang, Jin Nakashima, Jaydeep Kolape, Zhaozhu Wen, Marjan Behzadirad, Tianxiu Zhong, Juan Sun, Yunwei Zhang, Zeng-Yu Wang

Nebraska Center for Biotechnology: Faculty and Staff Publications

Alfalfa (Medicago sativa L.) is one of the most important forage crops throughout the world. Maximizing leaf retention during the haymaking process is critical for achieving superior hay quality and maintaining biomass yield. Leaf abscission process affects leaf retention. Previous studies have largely focused on the molecular mechanisms of floral organ, pedicel and seed abscission but scarcely touched on leaf and petiole abscission. This study focuses on leaf and petiole abscission in the model legume Medicago truncatula and its closely related commercial species alfalfa. By analysing the petiolule-like pulvinus (plp) mutant in M. truncatula at phenotypic level …

Functional Characterization Of Petiolule-Like Pulvinus (Plp) Gene In Abscission Zone Development In Medicago Truncatula And Its Application To Genetic Improvement Of Alfalfa, Juan Du, Shaoyun Lu, Maofeng Chai, Chuanen Zhou, Liang Sun, Yuhong Tang, Jaydeep Kolape, Zhaozhu Wen, Marjan Behzadirad, Tianxiu Zhong, Juan Sun, Yunwei Zhang, Zeng-Yu Wang

Department of Agronomy and Horticulture: Faculty Publications

Alfalfa (Medicago sativa L.) is one of the most important forage crops throughout the world. Maximizing leaf retention during the haymaking process is critical for achieving superior hay quality and maintaining biomass yield. Leaf abscission process affects leaf retention. Previous studies have largely focused on the molecular mechanisms of floral organ, pedicel and seed abscission but scarcely touched on leaf and petiole abscission. This study focuses on leaf and petiole abscission in the model legume Medicago truncatula and its closely related commercial species alfalfa. By analysing the petiolule-like pulvinus (plp) mutant in M. truncatula at phenotypic level (breakstrength and shaking …

Functional Characterization Of Petiolule-Like Pulvinus (Plp) Gene In Abscission Zone Development In Medicago Truncatula And Its Application To Genetic Improvement Of Alfalfa, Juan Du, Shaoyun Lu, Maofeng Chai, Chuanen Zhou, Liang Sun, Yuhong Tang, Jin Nakashima, Jaydeep Kolape, Zhaozhu Wen, Marjan Behzadirad, Tianxiu Zhong, Juan Sun, Yunwei Zhang, Zeng-Yu Wang

Nebraska Center for Biotechnology: Faculty and Staff Publications

Alfalfa (Medicago sativa L.) is one of the most important forage crops throughout the world. Maximizing leaf retention during the haymaking process is critical for achieving superior hay quality and maintaining biomass yield. Leaf abscission process affects leaf retention. Previous studies have largely focused on the molecular mechanisms of floral organ, pedicel and seed abscission but scarcely touched on leaf and petiole abscission. This study focuses on leaf and petiole abscission in the model legume Medicago truncatula and its closely related commercial species alfalfa. By analysing the petiolule-like pulvinus (plp) mutant in M. truncatula at phenotypic level (breakstrength and …

Prediction, Isolation, Overexpression And Antifungal Activity Analysis Of Medicago Truncatula Var. Truncatula Putative Thaumatin Like Proteins (Tlp-1, -2, -3, -4 And -5), Maryam Saeidi, Reza Zareie

Turkish Journal of Biology

Pathogenesis-related proteins (PR-proteins) are induced in response to environmental stresses such as osmotic and drought stress, wounding, microbial infections and treatment with specific plant hormones and elicitors. These proteins are classified into several groups (PR-1 through PR-17) based on their amino acid sequence and biochemical functions. The present study focuses on prediction, isolation, over-expression and analysis of the antifungal activities of the thaumatin-like proteins (i.e. PR-5) in the model legume M. truncatula var. truncatula. Analysis of M. truncatula genome sequence, available freely on the NCBI website, indicated the presence of at least 15 PR-5 Open Reading Frames (ORFs), 5 of …

A Comparative Study Of Medicago Truncatula Transcriptomes As They Relate To Saponin Defenses Against Insect Pests, Audra Mae Rogers

Graduate Theses and Dissertations

Triterpene saponins are a class of defensive plant-derived compounds, which have a

variety of functions including antimicrobial, insecticidal, and nematicidal activities. This

research assessed the performance of the beet armyworm, Spodoptera exigua, following ad

libero feeding on Medicago truncatula accessions differing in specialized metabolite and

saponin profiles. Insect performance did not directly relate to the foliar saponin levels in the

accessions, which was measured using HPLC mass spectrometry. Accession ESP105 had the lowest foliar saponins overall, yet had similar levels of soyasaponins compared to the other accessions. Conversely, accessions A17, PRT178, and GRC43 had high foliar saponins with particularly high …

Specialized Replication Operons Control Rhizobial Plasmid Copy Number In Developing Symbiotic Cells, Clarice Lorraine Perry

Theses and Dissertations

The rhizobium – legume symbiosis is a complex process that involves genetic cooperation from both bacteria and plants. Previously, our lab described naturally occurring accessory plasmids in rhizobia that inhibit this cooperation. A transposon mutagenesis was performed on the plasmids to detect the genetic factor that blocked nitrogen fixation. Several of the plasmids were found to possess a replication operon that when disrupted by transposon insertion, restored symbiotic function. This study describes an in-depth investigation into one of those plasmids, pHRC377, and into its replication operon. The operon, which we have called repA2C2, comes from the repABC family of …

The Cell Division Gene Ftsz2 Of Sinorhizobium Meliloti Is Expressed At High Levels In Host Plant Medicago Truncatula Nodules In The Absence Of Sini, Muhamad Ali K. Shakhatreh, Jayne B. Robinson

Jayne B. Robinson

In this study, we investigated the role of quorum sensing (QS) in expression of the Sinorhizobium meliloti cell division gene ftsZ2 in free-living cells and within nodules of its host plant, Medicago truncatula. Using a ftsZ2 promoter reporter fusion, we were able to track the expression of this gene in wild-type S. meliloti cells and QS mutant backgrounds in planta. Our findings revealed that expression of ftsZ2 in free-living cells was changed or reduced in sinI mutant cells compared with wild-type cells while expression in planta was substantially higher in the absence of sinI. The results further clarify the involvement …

Characterization Of Cp43 And Pif1 Gwas Selected Candidate Genes In Medicago Truncatula And Their Contribution To Rhizobia Symbiosis And Phenotypes Of Interest Using An Hprna Based Rnai Platform, Nathaniel Henning

Departmental Honors Projects

Medicago truncatula is a model organism used to study the symbiotic relationship between plants and nitrogen fixing soil bacteria of the genus rhizobia. By studying the genes that are involved in this symbiosis we can accomplish the goal of transplanting the symbiotic relationship into agriculture staples (e.g. corn, wheat, etc.) that do not utilize similar symbiotic relationships with nitrogen fixers. This would help to reduce our reliance on nitrogen-based fertilizers. In order to identify plant genes that might be important for establishing and regulating optimal nitrogen-fixing symbioses, a large-scale Genome Wide Association Study (GWAS) was performed. This study identified …

Genetic And Functional Analysis Of Host Genes Involved In Pathogenic And Symbiotic Legume-Microbe Interactions, Fang Tang

Theses and Dissertations--Plant and Soil Sciences

Legumes form symbiotic and pathogenic interactions with microbes. Understanding the molecular mechanisms underlying the legume-microbe interactions would help us to improve crop production in a sustainable manner. This thesis covers two independent research projects. The first project was to study the role of alternative splicing in RCT1-mediated disease resistance. RCT1 is a TIR-NBS-LRR-type plant resistance (R) gene in Medicago truncatula that confers broad-spectrum resistance to Colletotrichum trifolii, a fungal pathogen that causes anthracnose disease in Medicago. RCT1 undergoes alternative splicing at both coding and 3'-untranslated regions, thereby producing multiple transcript variants in its expression profile. …

Genome-Wide Determination Of Poly(A) Sites In Medicago Truncatula: Evolutionary Conservation Of Alternative Poly(A) Site Choice, Xiaohui Wu, Bobby Gaffney, Arthur G. Hunt, Qingshun Q. Li

Plant and Soil Sciences Faculty Publications

BACKGROUND: Alternative polyadenylation (APA) plays an important role in the post-transcriptional regulation of gene expression. Little is known about how APA sites may evolve in homologous genes in different plant species. To this end, comparative studies of APA sites in different organisms are needed. In this study, a collection of poly(A) sites in Medicago truncatula, a model system for legume plants, has been generated and compared with APA sites in Arabidopsis thaliana.

RESULTS: The poly(A) tags from a deep-sequencing protocol were mapped to the annotated M. truncatula genome, and the identified poly(A) sites used to update the annotations of 14,203 …

Identification Of A Dominant Gene In Medicago Truncatula That Restricts Nodulation By Sinorhizobium Meliloti Strain Rm41, Jinge Liu, Shengming Yang, Qiaolin Zheng, Hongyan Zhu

Plant and Soil Sciences Faculty Publications

BACKGROUND: Leguminous plants are able to form a root nodule symbiosis with nitrogen-fixing soil bacteria called rhizobia. This symbiotic association shows a high level of specificity. Beyond the specificity for the legume family, individual legume species/genotypes can only interact with certain restricted group of bacterial species or strains. Specificity in this system is regulated by complex signal exchange between the two symbiotic partners and thus multiple genetic mechanisms could be involved in the recognition process. Knowledge of the molecular mechanisms controlling symbiotic specificity could enable genetic improvement of legume nitrogen fixation, and may also reveal the possible mechanisms that restrict …

Morphological And Genetic Changes Induced By Excess Zn In Roots Of Medicago Truncatula A17 And A Zn Accumulating Mutant, Ricky W. Lewis, Guiliang Tang, David H. Mcnear

Plant and Soil Sciences Faculty Publications

BACKGROUND: Nutrient fluxes associated with legume-rhizobia symbioses are poorly understood and little is known regarding the influence of abiotic stresses on development and maintenance of N-fixing nodules and root system architecture (RSA). We examined effects of Zn on nodule development and structure, root architecture, and expression of nodulation-related miRNAs in Medicago truncatula and the mutant, raz (requires additional Zn).

FINDINGS: Excess Zn increased root and shoot associated Zn in both genotypes, however, raz plants had lower root associated Zn than WT plants. Roots of raz plants exposed to excess Zn had less volume, surface area, and total length compared to …

The Cell Division Gene Ftsz2 Of Sinorhizobium Meliloti Is Expressed At High Levels In Host Plant Medicago Truncatula Nodules In The Absence Of Sini, Muhamad Ali K. Shakhatreh, Jayne B. Robinson

Biology Faculty Publications

In this study, we investigated the role of quorum sensing (QS) in expression of the Sinorhizobium meliloti cell division gene ftsZ2 in free-living cells and within nodules of its host plant, Medicago truncatula. Using a ftsZ2 promoter reporter fusion, we were able to track the expression of this gene in wild-type S. meliloti cells and QS mutant backgrounds in planta. Our findings revealed that expression of ftsZ2 in free-living cells was changed or reduced in sinI mutant cells compared with wild-type cells while expression in planta was substantially higher in the absence of sinI. The results further clarify the involvement …

Analysis Of The Response Of Medicago Truncatula Calcium Oxalate Mutants To Abiotic Stress, Wayra Gabriela Navia-Gine

Graduate Theses and Dissertations

Calcium oxalate crystals are found in most plant species. In Medicago truncatula wild-type A17, crystals accumulate in leaves along the secondary veins and the only role attributed to them so far is defense against chewing insects. Calcium oxalate deficient (cod) mutants were isolated in M. truncatula; the cod mutants include cod5, which completely lack crystals in the leaves and cod6 that accumulates fewer and smaller crystals compared to A17. We analyzed gene expression in the cod mutants and A17 using GeneChip® Medicago Genome Arrays and found important differences in transcriptome between the three genotypes. In particular, we found a gene …

Recent Advances In Medicago Truncatula Genomics, Jean-Michel Ané, Hongyan Zhu, Julia Frugoli

Plant and Soil Sciences Faculty Publications

Legume rotation has allowed a consistent increase in crop yield and consequently in human population since the antiquity. Legumes will also be instrumental in our ability to maintain the sustainability of our agriculture while facing the challenges of increasing food and biofuel demand. Medicago truncatula and Lotus japonicus have emerged during the last decade as two major model systems for legume biology. Initially developed to dissect plant-microbe symbiotic interactions and especially legume nodulation, these two models are now widely used in a variety of biological fields from plant physiology and development to population genetics and structural genomics. This review highlights …

Map-Based Cloning Of An Anthracnose Resistance Gene In Medicago Truncatula, Shengming Yang

University of Kentucky Doctoral Dissertations

Anthracnose, caused by the fungal pathogen Colletotrichum trifolii, is one of the most destructive diseases of alfalfa worldwide. Cloning and characterization of the host resistance (R) genes against the pathogen will improve our knowledge of molecular mechanisms underlying host resistance and facilitate the development of resistant alfalfa cultivars. However, the intractable genetic system of cultivated alfalfa, owing to its tetrasomic inheritance and outcrossing nature, limits the ability to carry out genetic analysis in alfalfa. Nonetheless, the model legume Medicago truncatula, a close relative of alfalfa, provides a surrogate for cloning the counterparts of many agronomically important genes in …

Stocking Rates On Cyprus Barrel Medic In The Northern Wheatbelt, R J. Parkin

Journal of the Department of Agriculture, Western Australia, Series 4

IN May 1963, some three weeks after germination, a 4th year stand of Cyprus barrel medic was stocked with Merino wethers.

These same sheep are still grazing the area after three years.

Barrel Medics For Eastern Wheatbelt Pastures, D B. Argyle

Journal of the Department of Agriculture, Western Australia, Series 4

There is a big potential for the use of barrel medic in wheatbelt pastures, and prospects have been further improved by the advent of the early-maturing Cyprus strain.

In this article Merredin Agricultural Adviser D. B. Argyle gives some hints on establishment and management of barrel medic pastures in the eastern wheatbelt.

Much of what he says also applies to other areas; contact your local adviser for further information.