title: Molecular analysis of three new receptor-like kinase genes from hexaploid wheat and evidence for their participation in the wheat hypersensitive response to stripe rust fungus infection.
abstract: Considerable progress has been made in understanding the function of receptor-like kinase (RLK) genes in model plants. However, much less is known about these genes in crop species. Here we report the characterization of three new wheat RLK genes (TaRLK-R1, 2 and 3). The primary structure of the putative proteins TaRLK-R1, 2 and 3 contained a signal peptide, a cysteine-rich extracellular domain, a transmembrane domain, and a predicted intracellular kinase domain. The fusions between TaRLK-R1, 2 or 3 and the green fluorescence protein (GFP) were targeted to the plasma membrane; such targeting required the signal peptide, extracellular domain and transmembrane domain. Transcription of TaRLK-R1, 2 and 3 was found mainly in the green organs, and was regulated by light. Transcript levels of TaRLK-R1, 2 and 3 increased during the hypersensitive reaction (HR) to stripe rust fungus. In addition, the TaRLK-R3 transcript level was also upregulated by abiotic stresses. Further experiments revealed that the recombinant kinase domain of TaRLK-R3 exhibited auto-phosphorylation activity in vitro. Knocking down the transcript levels of TaRLK-R1, 2 or 3 individually or all together by virus-induced gene silencing compromised the wheat HR to stripe rust fungus. The demonstration of TaRLK-R1, 2 and 3 as positive contributors in the wheat HR to stripe rust fungus suggests a new direction for further functional studies of this important family of RLK genes, and may facilitate the breeding of wheat varieties resistant to stripe rust disease.
authors.affiliation: The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Huanbin
authors.initials: H
authors.lastname: Zhou
authors.forename: Shaofang
authors.initials: S
authors.lastname: Li
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Deng
authors.forename: Xianping
authors.initials: X
authors.lastname: Wang
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.forename: Jinsong
authors.initials: J
authors.lastname: Zhang
authors.forename: Shouyi
authors.initials: S
authors.lastname: Chen
authors.forename: Hongqing
authors.initials: H
authors.lastname: Ling
authors.forename: Aimin
authors.initials: A
authors.lastname: Zhang
authors.forename: Daowen
authors.initials: D
authors.lastname: Wang
authors.forename: Xiangqi
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D001487:Basidiomycota / Q000254:growth & development / Q000276:immunology; D020868:Gene Silencing; D017343:Genes, Plant; D007113:Immunity, Innate; D008027:Light; D008969:Molecular Sequence Data; D009997:Osmotic Pressure; D018384:Oxidative Stress; D010766:Phosphorylation; D010770:Phosphotransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D010935:Plant Diseases / Q000276:immunology*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016415:Sequence Alignment; D014158:Transcription, Genetic; D014908:Triticum / Q000201:enzymology / Q000235:genetics* / Q000276:immunology / Q000382:microbiology
chemical_list: D010940:Plant Proteins; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; D010770:Phosphotransferases; D017346:Protein Serine-Threonine Kinases