Activation of a Rac GTPase by the NLR family disease resistance protein Pit plays a critical role in rice innate immunity.
The nucleotide-binding domain and leucine-rich repeat-containing (NLR) family proteins recognize pathogen-derived molecules and trigger immune responses in both plants and animals. In plants, the direct or indirect recognition of specific pathogen effectors by NLRs culminates in a hypersensitive response (HR) and the production of reactive oxygen species (ROS), key components of the plant defense response. However, the molecules activated by NLRs and how they induce immune responses are largely unknown. We found that the rice GTPase OsRac1 at the plasma membrane interacts directly with Pit, an NLR protein that confers resistance to the rice blast fungus. OsRac1 contributes to Pit-mediated ROS production as well as the HR and is required for Pit-mediated disease resistance in rice. Furthermore, the active form of Pit induces the activation of OsRac1 at the plasma membrane. Thus, OsRac1 is activated by Pit during pathogen attack and plays a critical role in Pit-mediated immunity in rice.
Kawano
Yoji
Y
Laboratory of Plant Molecular Genetics, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan.
Akamatsu
Akira
A
Hayashi
Keiko
K
Housen
Yusuke
Y
Okuda
Jun
J
Yao
Ai
A
Nakashima
Ayako
A
Takahashi
Hiroki
H
Yoshida
Hitoshi
H
Wong
Hann Ling
HL
Kawasaki
Tsutomu
T
Shimamoto
Ko
K
D007113:Immunity, Innate; D008954:Models, Biological; D012275:Oryza / Q000276:immunology*; D010940:Plant Proteins / Q000378:metabolism*; D025941:Protein Interaction Mapping; D017382:Reactive Oxygen Species / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000378:metabolism*
D010940:Plant Proteins; D017382:Reactive Oxygen Species; D020744:rac GTP-Binding Proteins