Author
NIU, DONGDONG - University Of California | |
LII, YIFAN - University Of California | |
Padmanabhan, Chellappan | |
LEI, LEI - University Of California | |
PERALTA, KARL - University Of California | |
JIANG, CHUNHAO - University Of California | |
GUO, JIANHUA - University Of California | |
COAKER, GITTA - University Of California | |
JIN, HAILNG - University Of California |
Submitted to: Nature Communications
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/15/2016 Publication Date: 4/25/2016 Citation: Niu, D., Lii, Y.E., Padmanabhan, C., Lei, L., Peralta, K., Jiang, C., Guo, J., Coaker, G., Jin, H. 2016. miRNA863-3p sequentially targets negative regulators—atypical receptor-like Pseudokinases—and serrate, a positive regulator of plant immunity upon infection. Nature Communications. doi: 10.1038/ncomms11324; 7:11324. Interpretive Summary: The plant pathogenic bacteria cause severe damage to crop plants worldwide. In this study, we were interested in using the gene silencing technology to evaluate the mechanism of disease resistance in a model plant (Arabidopsis) against tomato bacterial spot disease. Three host genes involved in natural defense response systems were identified. In this model plant study, expression of these genes in susceptible plants could offer durable resistance to the bacteria spot disease. Application of this technology could open up a new avenue for bacterial disease management in crop plants. Technical Abstract: Plant small RNAs (sRNAs) play important roles in regulating gene expression during pathogen infection. We identified miR863-3p, which is specifically induced by the avirulent bacterial pathogen Pseudomonas syringae pv. tomato DC3000 carrying the effector avrRpt2. During early infection stages, miR863-3p targets two membrane-bound receptor-like kinases (RLKs) lacking extracellular domains and kinase activity, Atypical Receptor-like Pseudokinase1 (ARLPK1) and ARLPK2. ARLPK1 interacts with and likely functions through another active RLK with an extracellular domain, ARLPK1- INTERACTING RECEPTOR-LIKE KINASE 1 (AKIK1). All three kinases are negative regulators of plant immunity. During late infection stages, miR863-3p targets SERRATE (SE), which is a positive regulator of immunity. SE is essential for the accumulation of miRNAs, and silencing SE results in the decrease of miR863-3p levels, thus forming a negative feedback loop. This is the first instance of a miRNA sequentially targeting both negative and positive regulators of immunity to regulate the timing and amplitude of defense responses. |