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作者 Soosaar, Jennifer Miller
書名 Cloning of RCY1 and characterization of its role in cucumber mosaic virus resistance in Arabidopsis thaliana
國際標準書號 9780542653803
book jacket
說明 154 p
附註 Source: Dissertation Abstracts International, Volume: 67-04, Section: B, page: 1838
Adviser: S. P. Dinesh-Kumar
Thesis (Ph.D.)--Yale University, 2006
Cucumber mosaic virus (CMV) is a devastating crop pathogen with a broad host range at greater than 1200 species. Understanding natural forms of resistance to this pathogen will enable the generation of crops with genetic resistance. The Yellow strain of CMV infects Arabidopsis thaliana, but is unable to replicate and spread in the A. thaliana ecotype C24. I mapped and cloned in C24 the Resistance (R) gene RCY1, a single dominant gene that confers CMV-Y resistance. RCY1 is the third functional allele of this resistance locus with each protein conferring resistance to an unrelated pathogen. The proteins encoded by these alleles have putatively undergone positive selection, resulting in this altered pathogen specificity. RCY1 contains a nucleotide binding site and a leucine-rich repeat domain, domains conserved in innate immunity in mammals and Drosophila. The conservation of these domains between organisms that diverged millennia ago indicates that R gene-mediated innate immunity is an ancient defense mechanism
Upon recognition of a pathogen, defense signaling is transduced through hormones. By crossing hormone signaling mutants to C24, I determined that the signaling hormones salicylic acid and ethylene are required for RCY1-mediated resistance to CMV-Y, while jasmonic acid is not. I also performed yeast two-hybrid screens with different domains of RCY1 in order to identify proteins that may be necessary to mount a defense response to CMV-Y. R&barbelow;CY1 interacting aspartic p&barbelow;rotease, RASP, was isolated through this screen. RASP and RCY1 colocalize to the endoplasmic reticulum of plant cells. Upon transgenic overexpression of RASP in C24, resistance to CMV-Y is lost, and the virus replicates and spreads through out the plant. Knock-down of RASP expression has no affect on resistance. I propose that RASP is cleaving a positive regulator of RCY1-mediated defense signaling
School code: 0265
DDC
Host Item Dissertation Abstracts International 67-04B
主題 Biology, Molecular
Agriculture, Plant Culture
Agriculture, Plant Pathology
Biology, Plant Physiology
0307
0479
0480
0817
Alt Author Yale University
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