title: A high-throughput screen of cell-death-inducing factors in Nicotiana benthamiana identifies a novel MAPKK that mediates INF1-induced cell death signaling and non-host resistance to Pseudomonas cichorii.
abstract: A high-throughput overexpression screen of Nicotiana benthamiana cDNAs identified a gene for a mitogen-activated protein kinase kinase (MAPKK) as a potent inducer of the hypersensitive response (HR)-like cell death. NbMKK1 protein is localized to the nucleus, and the N-terminal putative MAPK docking site of NbMKK1 is required for its function as a cell-death inducer. NbMKK1-mediated leaf-cell death was compromised in leaves where NbSIPK expression was silenced by virus-induced gene silencing. A yeast two-hybrid assay showed that NbMKK1 and NbSIPK physically interact, suggesting that NbSIPK is one of the downstream targets of NbMKK1. Phytophthora infestans INF1 elicitor-mediated HR was delayed in NbMKK1-silenced plants, indicating that NbMKK1 is involved in this HR pathway. Furthermore, the resistance of N. benthamiana to a non-host pathogen Pseudomonas cichorii was compromised in NbMKK1-silenced plants. These results demonstrate that MAPK cascades involving NbMKK1 control non-host resistance including HR cell death.
authors.affiliation: Iwate Biotechnology Research Center, 22-174-4, Narita, Kitakami, Iwate 024-0003, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Khairun Hisam Bin
authors.initials: KH
authors.lastname: Nasir
authors.forename: Akiko
authors.initials: A
authors.lastname: Ito
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kanzaki
authors.forename: Hideo
authors.initials: H
authors.lastname: Matsumura
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Saitoh
authors.forename: Shizuko
authors.initials: S
authors.lastname: Fujisawa
authors.forename: Sophien
authors.initials: S
authors.lastname: Kamoun
authors.forename: Ryohei
authors.initials: R
authors.lastname: Terauchi
mesh_terms: D016923:Cell Death / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism; D015870:Gene Expression; D006861:Hydrogen Peroxide / Q000378:metabolism; D007113:Immunity, Innate / Q000502:physiology*; D020935:MAP Kinase Signaling System / Q000502:physiology; D020929:Mitogen-Activated Protein Kinase Kinases / Q000502:physiology*; D010935:Plant Diseases; D011549:Pseudomonas / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D014026:Nicotiana
chemical_list: D006861:Hydrogen Peroxide; D020929:Mitogen-Activated Protein Kinase Kinases