OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data OA All Versions of this Article: 150/1/295    most recent pp.108.134551v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Meyer, J. D.F. Articles by Graham, M. A. Search for Related Content PubMed PubMed Citation Articles by Meyer, J. D.F. Articles by Graham, M. A. Pubmed/NCBI databases Protein Agricola Articles by Meyer, J. D.F. Articles by Graham, M. A. Related Collections Legume Biology

PLANTS INTERACTING WITH OTHER ORGANISMS

Identification and Analyses of Candidate Genes for Rpp4-Mediated Resistance to Asian Soybean Rust in Soybean^1,[W],[OA]

United States Department of Agriculture-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, Iowa 50011 (J.D.F.M., R.C.S., M.A.G.); Embrapa Soja, Londrina, Parana, Brazil 86001–970 (D.C.G.S., R.V.A.); Universidade Estadual Paulista, Jaboticabal, Sao Paulo, Brazil 14884–900 (D.C.G.S.); Department of Plant Pathology (C.Y., C.Z., M.v.d.M., J.H.H., S.A.W.) and Department of Agronomy (R.C.S., M.A.G.), Iowa State University, Ames, Iowa 50011; and United States Department of Agriculture-Agricultural Research Service, Foreign Disease-Weed Science Research Unit, Fort Detrick, Maryland 21702 (K.F.P.)

Asian soybean rust is a formidable threat to soybean (Glycine max) production in many areas of the world, including the United States. Only five sources of resistance have been identified (Resistance to Phakopsora pachyrhizi1 [Rpp1], Rpp2, Rpp3, Rpp4, and Rpp5). Rpp4 was previously identified in the resistant genotype PI459025B and mapped within 2 centimorgans of Satt288 on soybean chromosome 18 (linkage group G). Using simple sequence repeat markers, we developed a bacterial artificial chromosome contig for the Rpp4 locus in the susceptible cv Williams82 (Wm82). Sequencing within this region identified three Rpp4 candidate disease resistance genes (Rpp4C1–Rpp4C3 [Wm82]) with greatest similarity to the lettuce (Lactuca sativa) RGC2 family of coiled coil-nucleotide binding site-leucine rich repeat disease resistance genes. Constructs containing regions of the Wm82 Rpp4 candidate genes were used for virus-induced gene silencing experiments to silence resistance in PI459025B, confirming that orthologous genes confer resistance. Using primers developed from conserved sequences in the Wm82 Rpp4 candidate genes, we identified five Rpp4 candidate genes (Rpp4C1–Rpp4C5 [PI459025B]) from the resistant genotype. Additional markers developed from the Wm82 Rpp4 bacterial artificial chromosome contig further defined the region containing Rpp4 and eliminated Rpp4C1 (PI459025B) and Rpp4C3 (PI459025B) as candidate genes. Sequencing of reverse transcription-polymerase chain reaction products revealed that Rpp4C4 (PI459025B) was highly expressed in the resistant genotype, while expression of the other candidate genes was nearly undetectable. These data support Rpp4C4 (PI459025B) as the single candidate gene for Rpp4-mediated resistance to Asian soybean rust.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Michelle A. Graham (michelle.graham{at}ars.usda.gov).

^[W] The online version of this article contains Web-only data.

^[OA] Open Access articles can be viewed online without a subscription.

www.plantphysiol.org/cgi/doi/10.1104/pp.108.134551

^* Corresponding author; e-mail michelle.graham{at}ars.usda.gov.

Received December 17, 2008; accepted February 24, 2009; published February 27, 2009.