title: Hrip1, a novel protein elicitor from necrotrophic fungus, Alternaria tenuissima, elicits cell death, expression of defence-related genes and systemic acquired resistance in tobacco.
abstract: Here, we report the identification, purification, characterization and gene cloning of a novel hypersensitive response inducing protein secreted by necrotrophic fungus, Alternaria tenuissima, designated as hypersensitive response inducing protein 1 (Hrip1). The protein caused the formation of necrotic lesions that mimic a typical hypersensitive response and apoptosis-related events including DNA laddering. The protein-encoding gene was cloned by rapid amplification of cDNA ends (RACE) method. The sequence analysis revealed that the cDNA is 495 bp in length and the open reading frame (ORF) encodes for a polypeptide of 163 amino acids with theoretical pI of 5.50 and molecular weight of 17 562.5 Da. Hrip1 induced calcium influx, medium alkalinization, activation of salicylic acid-induced protein kinase and several defence-related genes after infiltration in tobacco leaves. Cellular damage, restricted to the infiltrated zone, occurred only several hours later, at a time when expression of defence-related genes was activated. After several days, systemic acquired resistance was also induced. The tobacco plant cells that perceived the Hrip1 generated a cascade of signals acting at local, short, and long distances, and caused the coordinated expression of specific defence responses in a way similar to hypersensitivity to tobacco mosaic virus. Thus, Hrip1 represents a powerful tool to investigate further the signals and their transduction pathways involved in induced disease resistance in necrotrophic fungi.
authors.affiliation: Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Beijing 100081, China. qiudewen@caas.net.cn
authors.forename: Mahesh
authors.initials: M
authors.lastname: Kulye
authors.forename: Hua
authors.initials: H
authors.lastname: Liu
authors.forename: Yuliang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Hongmei
authors.initials: H
authors.lastname: Zeng
authors.forename: Xiufen
authors.initials: X
authors.lastname: Yang
authors.forename: Dewen
authors.initials: D
authors.lastname: Qiu
mesh_terms: D000528:Alternaria / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism; D016923:Cell Death / Q000502:physiology*; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D017931:DNA Primers; D015180:Electrophoresis, Gel, Two-Dimensional; D005656:Fungal Proteins / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal / Q000502:physiology*; D017343:Genes, Plant; D008969:Molecular Sequence Data; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014026:Nicotiana / Q000235:genetics / Q000382:microbiology*
chemical_list: D017931:DNA Primers; D005656:Fungal Proteins; D017382:Reactive Oxygen Species; D002118:Calcium