Award Abstract #0421676
Use of Interfering RNAs to Identify Gene Function in Medicago Truncatula

NSF Org:	IOS Division of Integrative Organismal Systems
Initial Amendment Date:	June 21, 2004
Latest Amendment Date:	August 10, 2007
Award Number:	0421676
Award Instrument:	Continuing grant
Program Manager:	Diane Jofuku Okamuro IOS Division of Integrative Organismal Systems BIO Directorate for Biological Sciences
Start Date:	October 1, 2004
Expires:	September 30, 2010 (Estimated)
Awarded Amount to Date:	$2117256
Investigator(s):	James Gantt gantt001@tc.umn.edu (Principal Investigator) Kathryn VandenBosch (Co-Principal Investigator) Carroll Vance (Co-Principal Investigator) Ernest Retzel (Co-Principal Investigator) Maria Harrison (Co-Principal Investigator)
Sponsor:	University of Minnesota-Twin Cities 200 OAK ST SE MINNEAPOLIS, MN 55455 612/624-5599
NSF Program(s):	PLANT GENOME RESEARCH PROJECT
Field Application(s):
Program Reference Code(s):	BIOT, 9251, 9109, 9104, 1228
Program Element Code(s):	1329

ABSTRACT

ABSTRACT

Grain and forage legumes are grown on some 180 million Ha, or about 15% of the Earth's arable land and account for 27% of the world's primary crop production. Legumes are distinguished by their ability to form symbiotic associations with both rhizobial bacteria and mycorrhizal fungi. In the rhizobial association, the bacteria fix atmospheric nitrogen, providing the major source of biologically available nitrogen in the biosphere. The fungal symbiosis results in improved phosphorous acquisition. Nitrogen and phosphorus are the major mineral nutrients required for plant growth. Despite the agricultural and ecological importance of legumes, relatively little is known about the genes that are involved in the development of bacterial or fungal symbioses.

The legume research community has developed many resources around the model legume Medicago truncatula. These include a large collection of ESTs (expressed sequence tags) from which many of the genes that are active in roots during symbiosis have been identified. Efficient transformation protocols have been developed and a genome sequencing project is ongoing. These resources and techniques will be combined with RNA interference (RNAi) technology to silence gene expression and identify genes involved in the plant-microbe symbioses.

Analysis of sequence databases and gene expression studies will be used to identify genes that are possibly involved in symbiosis and 1,500 of these will be targeted for silencing via RNAi. Silencing will be carried out in transgenic roots and the effects on symbiosis will be examined. The results will be reported to the research community through a publicly available project web-site. The gene-targeting sequences will be made available at Clemson University Genomics Center without restriction to the research community in an easy to use, multifunctional vector.

This research project integrates a variety of scientific fields including molecular biology, microbiology, plant biology and bioinformatics. The research also employs one of the latest and most powerful genomic technologies, RNAi, which is being used in a variety of applications from investigations into basic biology to the development of human therapeutics. The research team will introduce selected undergraduate students to many aspects the research which will expose them to the excitement of modern biological research. Additionally, collaborators at Gustavus Adolphus College, an undergraduate institution, will develop a laboratory course that follows the general protocols described in the research proposal. The materials and protocols that are developed through the research project are an excellent resource for this effort. The outcome of this effort will be the description of a series of experiences that undergraduate students in plant biology, plant molecular biology, or plant physiology can obtain in one semester course.

Resources Generated: Publicly accessible database of root and symbiotic phenotypes and traits. Information on genomic experiments will be located at

MtDB[http://medicago.org] , the Concensus Legume database www.legumes.org and

[http://decifr.ccgb.umn.edu].

PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH

Harrison, M.J. "Signaling in the arbuscular mycorrhizal symbiosis.," Annual Reviews of Microbiology, v.59, 2005, p. 19.

Liu, J., Miller, S.S., Graham, M., Bucciarelli, B., Catalano, C.M., Sherrier, D.J., Samac, D.A., Ivashuta, S., Fedorova, M., Matsumoto, P., Gantt, J.S. and Vance. "Recruitment of Novel Calcium-Binding Proteins for Root Nodule Symbiosis in Medicago truncatula.," Plant Physiology, v.141, 2006, p. 167.

Liu, J., Miller, S.S., Graham, M., Bucciarelli, B., Catalano, C.M., Sherrier, D.J., Samac, D.A., Ivashuta, S., Fedorova, M., Matsumoto, P., Gantt, J.S. and Vance. "Recruitment of Novel Calcium-Binding Proteins for Root Nodule Symbiosis in Medicago," Plant Physiology, v.141, 2006, p. 167.

Oldroyd, G.E.D., Harrison, M.J. and Udvardi, M. "Peace talks and trade deals: keys to long-term harmony in legume-microbe symbioses.," Plant Physiology, v.137, 2005, p. 1205.

Sergey Ivashuta, Jinyuan Liu, Junqi Liu, Dasharath P. Lohar, Sajeet Haridas, Bruna Bucciarelli, Kathryn A. VandenBosch, Carroll P. Vance, Maria J. Harrison, and J. Stephen Gantt. "RNA Interference Identifies a Calcium-Dependent Protein Kinase Involved in Medicago truncatula Root Development," Plant Cell, v.17, 2005, p. 2911.

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