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Silencing of At RAP , a target gene of a bacteria‐induced small RNA , triggers antibacterial defense responses through activation of LSU 2 and down‐regulation of GLK 1
Author(s) -
Wang Huan,
Seo JangKyun,
Gao Shang,
Cui Xinping,
Jin Hailing
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14654
Subject(s) - biology , gene silencing , mutant , microbiology and biotechnology , rna interference , pseudomonas syringae , downregulation and upregulation , rna , genetics , gene
Summary Plants fine‐tune their sophisticated immunity systems in response to pathogen infections. We previously showed that Atlsi RNA ‐1, a bacteria‐induced plant endogenous small interfering RNA , silences the At RAP gene, which encodes a putative RNA binding protein. In this study, we demonstrate that At RAP functions as a negative regulator in plant immunity by characterizing molecular and biological responses of the knockout mutant and overexpression lines of At RAP upon bacterial infection. At RAP is localized in chloroplasts and physically interacts with Low Sulfur Upregulated 2 ( LSU 2), which positively regulates plant defense. Our results suggest that At RAP negatively regulates defense responses by suppressing LSU 2 through physical interaction. We also detected downregulation of the transcription factor GOLDEN 2‐ LIKE 1 ( GLK 1 ) in atrap‐1 using microarray analysis. The glk1 glk2 double mutant showed enhanced resistance to Pseudomonas syringae pv. tomato , which is consistent with a previous study showing enhanced resistance of a glk1 glk2 double mutant to Hyaloperonospora arabidopsidis . Taken together, our data suggest that silencing of At RAP by Atlsi RNA ‐1 upon bacterial infection triggers defense responses through regulation of LSU 2 and GLK 1.