miRNA863-3p sequentially targets negative immune regulator ARLPKs and positive regulator SERRATE upon bacterial infection.
Plant small RNAs play important roles in gene regulation during pathogen infection. Here we show that miR863-3p is induced by the bacterial pathogen Pseudomonas syringae carrying various effectors. Early during infection, miR863-3p silences two negative regulators of plant defence, atypical receptor-like pseudokinase1 (ARLPK1) and ARLPK2, both lacking extracellular domains and kinase activity, through mRNA degradation to promote immunity. ARLPK1 associates with, and may function through another negative immune regulator ARLPK1-interacting receptor-like kinase 1 (AKIK1), an active kinase with an extracellular domain. Later during infection, miR863-3p silences SERRATE, which is essential for miRNA accumulation and positively regulates defence, through translational inhibition. This results in decreased miR863-3p levels, thus forming a negative feedback loop to attenuate immune responses after successful defence. This is an example of a miRNA that sequentially targets both negative and positive regulators of immunity through two modes of action to fine-tune the timing and amplitude of defence responses.
Department of Plant Protection, Nanjing Agriculture University, Nanjing 210095, China.|Department of Plant Pathology and Microbiology, Center for Plant Cell Biology and Institute for Integrative Genome Biology, University of California, Riverside, California 92521, USA.
Dongdong
D
Niu
Department of Plant Pathology and Microbiology, Center for Plant Cell Biology and Institute for Integrative Genome Biology, University of California, Riverside, California 92521, USA.
Yifan E
YE
Lii
Department of Plant Pathology and Microbiology, Center for Plant Cell Biology and Institute for Integrative Genome Biology, University of California, Riverside, California 92521, USA.
Padmanabhan
P
Chellappan
Department of Plant Pathology, University of California, Davis, California 95616, USA.
Lei
L
Lei
Department of Plant Pathology and Microbiology, Center for Plant Cell Biology and Institute for Integrative Genome Biology, University of California, Riverside, California 92521, USA.
Karl
K
Peralta
Department of Plant Protection, Nanjing Agriculture University, Nanjing 210095, China.|Department of Plant Pathology and Microbiology, Center for Plant Cell Biology and Institute for Integrative Genome Biology, University of California, Riverside, California 92521, USA.
Chunhao
C
Jiang
Department of Plant Protection, Nanjing Agriculture University, Nanjing 210095, China.
Jianhua
J
Guo
Department of Plant Pathology, University of California, Davis, California 95616, USA.
Gitta
G
Coaker
Department of Plant Pathology and Microbiology, Center for Plant Cell Biology and Institute for Integrative Genome Biology, University of California, Riverside, California 92521, USA.
Hailing
H
Jin
D017360:Arabidopsis / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D001665:Binding Sites; D025461:Feedback, Physiological; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000235:genetics* / Q000276:immunology; D010935:Plant Diseases / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D057865:Plant Immunity / Q000235:genetics; D014176:Protein Biosynthesis; D044224:Pseudomonas syringae / Q000472:pathogenicity / Q000502:physiology; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000276:immunology; D015398:Signal Transduction
D029681:Arabidopsis Proteins; C000626371:MIRN863 microRNA, Arabidopsis; D035683:MicroRNAs; D016601:RNA-Binding Proteins; C000606277:SE protein, Arabidopsis