Gene Expression Profiling of the nip Mutant in Medicago truncatula

Gene Expression Profiling of the nip Mutant in Medicago truncatula

Date: August 2007
Creator: McKethan, Brandon Lee
Description: The study of root nodule symbiosis between nitrogen-fixing bacteria and leguminous plant species is important because of the ability to supplement fixed nitrogen fertilizers and increase plant growth in poor soils. Our group has isolated a mutant called nip in the model legume Medicago truncatula that is defective in nodule symbiosis. The nip mutant (numerous infections with polyphenolics) becomes infected by Sinorhizobium meliloti but then accumulates polyphenolic defense compounds in the nodule and fails to progress to a stage where nitrogen fixation can occur. Analysis of the transcriptome of nip roots prior to inoculation with rhizobia was undertaken using Affymetric Medicago Genome Array microarrays. The total RNA of 5-day old uninoculated seedlings was analyzed in triplicate to screen for the NIP gene based on downregulated transcript levels in the mutant as compared to wild type. Further microarray data was generated from 10 days post inoculation (dpi) nip and wild type plants. Analysis of the most highly downregulated transcripts revealed that the NIP gene was not identifiable based on transcript level. Putative gene function was assigned to transcripts with altered expression patterns in order to characterize the nip mutation phenotypically as inferred from the transcriptome. Functional analysis revealed a large number ...
Contributing Partner: UNT Libraries
Map-based cloning of the NIP gene in model legume Medicago truncatula.

Map-based cloning of the NIP gene in model legume Medicago truncatula.

Date: May 2007
Creator: Morris, Viktoriya
Description: Large amounts of industrial fertilizers are used to maximize crop yields. Unfortunately, they are not completely consumed by plants; consequently, this leads to soil pollution and negative effects on aquatic systems. An alternative to industrial fertilizers can be found in legume plants that provide a nitrogen source that is not harmful for the environment. Legume plants, through their symbiosis with soil bacteria called rhizobia, are able to reduce atmospheric nitrogen into ammonia, a biological nitrogen source. Establishment of the symbiosis requires communication on the molecular level between the two symbionts, which leads to changes on the cellular level and ultimately results in nitrogen-fixing nodule development. Inside the nodules hypoxic environment, the bacterial enzyme nitrogenase reduces atmospheric nitrogen to ammonia. Medicago truncatula is the model legume plant that is used to study symbiosis with mycorrhiza and with the bacteria Sinorhizobium meliloti. The focus of this work is the M. truncatula nodulation mutant nip (numerous infections and polyphenolics). The NIP gene plays a role in the formation and differentiation of nodules, and development of lateral roots. Studying this mutant will contribute knowledge to understanding the plant response to infection and how the invasion by rhizobia is regulated. Previous genetic mapping placed NIP ...
Contributing Partner: UNT Libraries
Physical Map between Marker 8O7 and 146O17 on the Medicago truncatula Linkage Group 1 that Contains the NIP Gene

Physical Map between Marker 8O7 and 146O17 on the Medicago truncatula Linkage Group 1 that Contains the NIP Gene

Date: December 2007
Creator: Lee, Yi-Ching
Description: The Medicago truncatula NIP gene is located on M. truncatula Linkage Group 1. Informative recombinants showed crossovers that localize the NIP gene between markers 146O17 and 23C16D. Marker 164N9 co-segregates with the NIP gene, and the location of marker 164N9 is between markers 146O17 and 23C16D. Based upon data from the Medicago genome sequencing project, a subset of the model legume Medicago truncatula bacterial artificial chromosomes (BACs) were used to create a physical map on the DNA in this genetic internal. BACs near the potential NIP gene location near marker 164N9 were identified, and used in experiments to predict the physical map by a BAC-by-BAC strategy. Using marker 164N9 as a center point, and chromosome walking outward, the physical map toward markers 146O17 and 23C16D was built. The chromosome walk consisted of a virtual walk, made with existing sequence of BACs from the Medicago genome project, hybridizations to filters containing BAC DNA, and PCR reactions to confirm that predicted overlapping BACs contained DNA that yielded similar PCR products. In addition, the primers which are made for physical mapping via PCR could be good genetic markers helpful in discovering the location of the NIP gene. As a result of efforts repotted ...
Contributing Partner: UNT Libraries
Characterization of infection arrest mutants of Medicago truncatula and genetic mapping of their respective genes.

Characterization of infection arrest mutants of Medicago truncatula and genetic mapping of their respective genes.

Access: Use of this item is restricted to the UNT Community.
Date: May 2005
Creator: Veereshlingam, Harita
Description: In response to compatible rhizobia, leguminous plants develop unique plant organs, root nodules, in which rhizobia fix nitrogen into ammonia. During nodule invasion, the rhizobia gain access to newly divided cells, the nodule primordia, in the root inner cortex through plant-derived cellulose tubes called infection threads. Infection threads begin in curled root hairs and bring rhizobia into the root crossing several cell layers in the process. Ultimately the rhizobia are deposited within nodule primordium cells through a process resembling endocytosis. Plant host mechanisms underlying the formation and regulation of the invasion process are not understood. To identify and clone plant genes required for nodule invasion, recent efforts have focused on Medicago truncatula. In a collaborative effort the nodulation defect in the lin (lumpy infections) mutant was characterized. From an EMS-mutagenized population of M. truncatula, two non-allelic mutants nip (numerous infections with polyphenolics) and sli (sluggish infections) were identified with defects in nodule invasion. Infection threads were found to proliferate abnormally in the nip mutant nodules with only very rare deposition of rhizobia within plant host cells. nip nodules were found to accumulate polyphenolic compounds, indicative of a host defense response. Interestingly, nip was also found to have defective lateral root ...
Contributing Partner: UNT Libraries
An IRE-Like AGC Kinase Gene, MtIRE, Has Unique Expression in the Invasion Zone of Developing Root Nodules in Medicago truncatula

An IRE-Like AGC Kinase Gene, MtIRE, Has Unique Expression in the Invasion Zone of Developing Root Nodules in Medicago truncatula

Date: June 2007
Creator: Pislariu, Catalina I. & Dickstein, Rebecca
Description: This article discusses AGC kinase genes. The authors report here the isolation and characterization of the first AGC kinase gene identified in Medicago truncatula, MtIRE.
Contributing Partner: UNT College of Arts and Sciences
New Genetic Markers Aid in Identifying the NIP Locus in Medicago

New Genetic Markers Aid in Identifying the NIP Locus in Medicago

Date: Spring 2008
Creator: Spoor, Erich
Description: Thesis written by a student in the UNT Honors College discussing symbiotic nitrogen fixation that takes place between a bacterium and a legume.
Contributing Partner: UNT Honors College
nip, a Symbiotic Medicago truncatula Mutant that Forms Root Nodules with Aberrant Infection Threads and Plant Defense-Like Response

nip, a Symbiotic Medicago truncatula Mutant that Forms Root Nodules with Aberrant Infection Threads and Plant Defense-Like Response

Date: November 2004
Creator: Veereshlingam, Harita; Haynes, Janine G.; Penmetsa, R. Varma; Cook, Douglas R.; Sherrier, D. Janine & Dickstein, Rebecca
Description: Article on nip, a symbiotic Medicago truncatula mutant that forms root nodules with aberrant infection threads and plant defense-like response.
Contributing Partner: UNT College of Arts and Sciences
MATE2 Mediates Vacuolar Sequestration of Flavonoid Glycosides and Glycoside Malonates in Medicago truncatula

MATE2 Mediates Vacuolar Sequestration of Flavonoid Glycosides and Glycoside Malonates in Medicago truncatula

Date: April 2011
Creator: Zhao, Jian; Huhman, David; Shadle, Gail; He, Xian-Zhi; Sumner, Lloyd W.; Tang, Yuhong et al.
Description: Article on MATE2 mediating vacuolar sequestration of flavonoid glycosides and glycoside malonates in Medicago truncatula.
Contributing Partner: UNT College of Arts and Sciences
A Putative Transporter is Essential for Integrating Nutrient and Hormone Signaling with Lateral Root Growth and Nodule Development in Medicago truncatula

A Putative Transporter is Essential for Integrating Nutrient and Hormone Signaling with Lateral Root Growth and Nodule Development in Medicago truncatula

Date: 2010
Creator: Yendrek, Craig R.; Lee, Yi-Ching; Morris, Viktoriya; Liang, Yan; Pislariu, Catalina I.; Burkart, Graham et al.
Description: This article discusses a putative transporter for integrating nutrient and hormone signaling with lateral root growth and nodule development in Medicago truncatula.
Contributing Partner: UNT College of Arts and Sciences
Rapid Analysis of Legume Root Nodule Development Using Confocal Microscopy

Rapid Analysis of Legume Root Nodule Development Using Confocal Microscopy

Date: 2004
Creator: Haynes, Janine G.; Czymmek, Kirk J.; Carlson, Carol A.; Veereshlingam, Harita; Dickstein, Rebecca & Sherrier, D. Janine
Description: This article discusses the rapid analysis of legume root nodule development using confocal microscopy.
Contributing Partner: UNT College of Arts and Sciences
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