| |
Dr.
Andris Kleinhofs
.jpg) 509-335-4389
andyk@wsu.edu
Professor, Crop and Soil Sciences and School of Molecular Biosciences. Ph.D. 1968,
University of Nebraska.
Research
Plant diseases have always been a major concern to food production and the most economical and environmentally friendly way to control them is through genetic resistance. Although many plant disease resistance genes have been identified in all crop species, relatively few have been cloned and very little is known about how they work. The research in my laboratory focuses on cloning and studying barley rust resistance genes and their function. Map-based or transcript-based cloning of crop plant genes is itself a major project, but the interesting work starts once a disease resistance gene is cloned. So far we have cloned 3 rust resistance genes, 2 that confer resistance to the rust fungus Puccinia graminis forma specialis tritici (Pgt) and one that confers resistance to the same pathogen, but forma specialis secalis (Pgs). To understand how these genes confer resistance we are analyzing them at the mRNA and protein level and how the proteins interact with the pathogen avirulence factors and other cellular proteins. Molecular, genetic and biochemical tools are utilized for example yeast two-hybrid, microarrays, in vivo and in vitro generated mutants, immunology and transgenics.
The Rpg1 gene, conferring resistance to many pathotypes of Pgt, is novel in that it contains two tandem protein kinase domains of which only one is an active kinase, but both are required for disease resistance. Two tandem kinase domains were previously only known in one mammalian gene family, the Janus kinases. The Rpg1 gene is also notable for its durability having protected barley crops from rust for over 60 years. We know that the encoded protein is cytoplasmic and that it is degraded when the plant interacts with the pathogen and the degradation is essential for resistance. We have identified several other proteins that the RPG1 protein interacts with in yeast and are actively analyzing their function. We have identified, by in vivo mutagenesis, and cloned one gene that is required for Rpg1 function. This gene, designated Rpr1 for required for Puccinia resistance, is also a protein kinase and functions downstream of the Rpg1 gene.
The rpg4 gene, conferring resistance to Pgt pathotype QCCJ, encodes an actin depolymerizing factor protein, which is highly unusual in that it is unlike any other previously identified plant disease resistance gene. The Rpg5 gene, conferring resistance to Pgs pathotype 92-MN-90 is also novel because it combines all three of the major disease resistance domains (NBS, LRR and protein kinase) in a single gene, a feature that has not been previously identified in any other disease resistance gene.
Characterization of the mode of action of these three rust resistance genes and any interacting partners will facilitate development of crops with improved rust resistance. Understanding their structure function relationships will facilitate engineering of disease resistance genes for improved durability.
Selected
Publications
Zhang, L., L. Lavery, U. Gill, K. Gill. B. J. Steffenson, G. Yan, X. Chen and A. Kleinhofs. 2008. Loss of function of the barley NecS1 gene, encoding a cation/proton exchanging protein, results in necrosis and defense response to stem rust. Theoretical and Applied Genetics (accepted w/changes).
Mirlohi, A., R. Brueggeman, T. Drader, J. Nirmala, B. J. Steffenson, and A. Kleinhofs. 2008. Allele sequencing of the barley stem rust resistance gene Rpg1 identifies regions relevant to disease resistance. Phytopathology (in press).
Brueggeman, R., A. Druka, J. Nirmala, T. Cavileer, T. Drader, N. Rostoks, A. Mirlohi|, H. Bennypaul, U. Gill, D. Kudrna, C. Whitelaw, A. Kilian, F. Han, Y. Sun, K. Gill, B. Steffenson, and A. Kleinhofs. 2008. The barley stem rust resistance gene Rpg5 encodes a novel protein containing three disease resistance gene domains: nucleotide binding site, leucine rich repeat, and protein kinase. Proc. Natl. Acad. Sci. USA (in press).
Druka, A., E. Potokina Z. Luo N. Bonar I. Druka L. Zhang D. F. Marshall B. J. SteVenson T. J. Close R. P. Wise A. Kleinhofs R. W. Williams M. J. Kearsey and R. Waugh. 2008. Exploiting regulatory variation to identify genes underlying quantitative resistance to the wheat stem rust pathogen. Theor. Appl. Genet. (DOI 10.1007/s00122-008-0771-x).
Zhang, L., C. Castell-Miller, S. Dahl, B. J. Steffenson and A. Kleinhofs. 2008. Parallel expression profiling of barley stem rust interactions. Functional and Integrative Genomics 8:187-198.
Nirmala, J., S. Dahl, B. J. Steffenson, C. G. Kannangara, D. von Wettstein, X. Chen and A. Kleinhofs. 2007. Proteolysis of the barley receptor-like protein kinase RPG1 by a proteasome pathway is correlated with Rpg1-mediated stem rust resistance. Proc. Natl. Acad. Sci. 104:10276-10281.
Wenzl, P., H. Li, J. Carling, M. Zhou, H. Raman, E. Edie, P. Hearnden, C. Maier, L. Xia, V. Caig, J. Ovesna, M. Cakir, D. Poulsen, J. Wang, R. Raman, K. P. Smith, G. J. Muehlbauer, K. J. Chalmers, A. Kleinhofs, E. Huttner and A. Kilian. 2006. A high-density consensus map of barley linking DArT markers to SSR, RFLP and STS loci and agricultural traits. BMC Genomics 7:206 .
Brueggeman, R., T. Drader and A. Kleinhofs. 2006. The barley serine/threonine kinase gene Rpg1 providing resistance to stem rust belongs to a gene family with five other members encoding kinase domains. Theoretical and Applied Genetics 113:1147-1158.
Zhang, L., T. Fetch, J. Nirmala, D. Schmierer, R. Brueggeman, B. Steffenson and A. Kleinhofs. 2006. Rpr1, a gene required for Rpg1-dependent resistance to stem rust in barley. Theoretical and Applied Genetics 113:847-855.
Nirmala, J., R. Brueggeman, C. Maier, C. Clay, N. Rostoks, C. G. Kannangara, D. von Wettstein, B. Steffenson and A. Kleinhofs. 2006. Sub-cellular localization and functions of the barley stem rust resistance receptor-like serine/threonine-specific protein kinase RPG1. Proc. Natl. Acad. Sci. 103:7518-7523.
Druka, A., G. Muehlbauer, I. Druka, R. Caldo, U. Baumann, N. Rostoks, A. Schreiber, R. Wise, T. Close, A. Kleinhofs, A. Graner, A. Schulman, P Langridge, K. Sato, P. Hayes, J. McNicol, D Marshall and R. Waugh. 2006. An atlas of gene expression from seed to seed through barley development. Functional and Integrative Genomics 6:202-211.
Rostoks, N., D. Schmierer, S. Mudie, T. drader, R. Brueggeman, D. G. Caldwell, R. Waugh and A. Kleinhofs. 2005. Barley necrotic locus nec1 encodes the cyclic nucleotide-gated ion channel 4 homologous to the Arabidopsis HLM1. Molecular Genetics and Genomics 275:159-168.
Wenzl, P., J. Carling, D. Kudrna, D. Jaccoud, E. Huttner, A. Kleinhofs, and A. Kilian. 2004. Diversity arrays technology (DArT) for whole-genome profiling of barley. Proc. Natl. Acad. Sci. USA 101:9915-9920.
Rostoks, N., B. J. Steffenson, and A. Kleinhofs. 2004. Structure and expression of the barley stem rust resistance gene Rpg1. Physiology and Molecular Plant Pathology 64:91-101.
Close, T. J., S. Wanamaker, R. A. Caldo, S. M. Turner, D. A. Ashlock, J. A. Dickerson, R. A. Wing, G. J. Muehlbauer, A. Kleinhofs, and R. P. Wise, 2004. A new resource for cereal genomics: 22K barley GeneChip comes of age. Plant Physiol. 134:960-968.
Bulgarelli, D., N. C. Collins, G. Tacconi, E. Dellaglio, R. Brueggeman, A. Kleinhofs, A. M. Stanca, and G. Vale. 2004. High-resolution genetic mapping of the leaf stripe resistance gene Rdg2a in barley. Theor. Appl. Genet. 108:1401-1408.
Rostoks, N., D. Schmierer, D. Kudrna, and A. Kleinhofs. 2003. Barley putative hypersensitive induced reaction genes: genetic mapping, sequence analyses and differential expression in disease lesion mimic mutants. Theor. Appl. Genet. 107:1094-1101.
Horvath, H., N. Rostoks, R. Brueggeman, B. Steffenson, D. von Wettstein, and A. Kleinhofs. 2003. Genetically engineered stem rust resistance in barley using the Rpg1 gene. Proc. Natl. Acad. Sci. USA 100:364-369.
Rostoks, N., J. M. Zale, J. Soule, R. Brueggeman, A. Druka, D. Kudrna, B. Steffenson, and A. Kleinhofs. 2002. A barley gene family homologous to the maize rust resistance gene Rp1-D. Theor. Appl. Genet. 104:1298-1306.
Druka, A., D. Kudrna, C. G. Kannangara, D. von Wettstein, and A. Kleinhofs. 2002. Physical and genetic mapping of barley (Hordeum vulgare) germin-like cDNAs. Proc. Natl. Acad. Sci. USA 99:850-855.
Brueggeman, R., N. Rostoks, D. Kudrna, A. Kilian, F. Han, J. Chen, A. Druka, B. Steffenson, and A. Kleinhofs. 2002. The barley stem rust-resistance gene Rpg1 is a novel disease-resistance gene with homology to receptor kinases. Proc. Natl. Acad. Sci. USA 99:9328-9333.
|
|
|
|
|
|
