Cloning of a conserved receptor-like protein kinase gene and its use as a functional marker for homoeologous group-2 chromosomes of the triticeae species

PLoS One. 2012;7(12):e49718. doi: 10.1371/journal.pone.0049718. Epub 2012 Dec 13.

Abstract

Receptor-like kinases (RLKs) play broad biological roles in plants. We report on a conserved receptor-like protein kinase (RPK) gene from wheat and other Triticeae species. The TaRPK1 was isolated from the Triticum aestivum cv. Prins - Triticum timopheevii introgression line IGVI-465 carrying the powdery mildew resistance gene Pm6. The TaRPK1 was mapped to homoeologous chromosomes 2A (TaRPK1-2A), 2D (TaRPK1-2D) and the Pm6-carrier chromosome 2G (TaRPK1-2G) of IGVI-465. Under the tested conditions, only the TaRPK1-2G allele was actively transcribed, producing two distinct transcripts via alternative splicing. The predicted 424-amino acid protein of TaRPK1-2G contained a signal peptide, a transmembrane domain and an intracellular serine/threonine kinase domain, but lacked a typical extracellular domain. The expression of TaRPK1-2G gene was up-regulated upon the infection by Blumeria graminis f.sp. tritici (Bgt) and treatment with methyl jasmonate (MeJA), but down-regulated in response to treatments of SA and ABA. Over-expression of TaRPK1-2G in the powdery mildew susceptible wheat variety Prins by a transient expression assay showed that it slightly reduced the haustorium index of the infected Bgt. These data indicated that TaRPK1-2G participated in the defense response to Bgt infection and in the JA signaling pathway. Phylogenetic analysis indicated that TaRPK1-2G was highly conserved among plant species, and the amino acid sequence similarity of TaRPK1-2G among grass species was more than 86%. Based on its conservation, the RPK gene-based STS primers were designed, and used to amplify the RPK orthologs from the homoeologous group-2 chromosomes of all the tested Triticeae species, such as chromosome 2G of T. timopheevii, 2R of Secale cereale, 2H of Hordeum vulgare, 2S of Aegilops speltoides, 2S(l) of Ae. longissima, 2M(g) of Ae. geniculata, 2S(p) and 2U(p) of Ae. peregrina. The developed STS markers serve as conserved functional markers for the identification of homoeologous group-2 chromosomes of the Triticeae species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosome Mapping
  • Chromosomes / ultrastructure
  • Chromosomes, Artificial, Bacterial / ultrastructure
  • Chromosomes, Plant*
  • Cloning, Molecular
  • Crosses, Genetic
  • Gene Expression Profiling
  • Genes, Plant
  • Genetic Markers
  • Models, Statistical
  • Peptides / chemistry
  • Phylogeny
  • Plant Proteins / genetics
  • Polymorphism, Genetic
  • Protein Kinases / genetics*
  • Protein Kinases / metabolism
  • RNA Splicing
  • Triticum / genetics*
  • Triticum / metabolism

Substances

  • Genetic Markers
  • Peptides
  • Plant Proteins
  • Protein Kinases

Grants and funding

This research was supported by grants from the Chinese High Tech Program of China (No. 2011AA1001), the Natural Science Foundation of Jiangsu Province (No. BK2006720), Important National Science and Technology Specific Projects of Transgenic Research (No. 2011ZX08002-001), the Program of Introducing Talents of Discipline to Universities (No. B08025) and A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD). Research in Daowen Wang's group is supported in part by a grant (2011BAD07B02-2) from the Ministry of Science and Technology of China. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.