Dufulin activates HrBP1 to produce antiviral responses in tobacco.
BACKGROUND
Dufulin is a new antiviral agent that is highly effective against plant viruses and acts by activating systemic acquired resistance (SAR) in plants. In recent years, it has been used widely to prevent and control tobacco and rice viral diseases in China. However, its targets and mechanism of action are still poorly understood.


RESULTS
Here, differential in-gel electrophoresis (DIGE) and classical two-dimensional electrophoresis (2-DE) techniques were combined with mass spectrometry (MS) to identify the target of Dufulin. More than 40 proteins were found to be differentially expressed (≥1.5 fold or ≤1.5 fold) upon Dufulin treatment in Nicotiana tabacum K(326). Based on annotations in the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, these proteins were found to be related to disease resistance. Directed acyclic graph (DAG) analysis of the various pathways demonstrated harpin binding protein-1 (HrBP1) as the target of action of Dufulin. Additionally, western blotting, semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), and real time PCR analyses were also conducted to identify the specific mechanism of action of Dufulin. Our results show that activation of HrBP1 triggers the salicylic acid (SA) signaling pathway and thereby produces antiviral responses in the plant host. A protective assay based on lesion counting further confirmed the antiviral activity of Dufulin.


CONCLUSIONS
This study identified HrBP1 as a target protein of Dufulin and that Dufulin can activate the SA signaling pathway to induce host plants to generate antiviral responses.
State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, China.
Zhuo
Z
Chen
Mengjiao
M
Zeng
Baoan
B
Song
Chengrui
C
Hou
Deyu
D
Hu
Xiangyang
X
Li
Zhenchao
Z
Wang
Huitao
H
Fan
Liang
L
Bi
Jiaju
J
Liu
Dandan
D
Yu
Linhong
L
Jin
Song
S
Yang
D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology*; D052160:Benzothiazoles / Q000737:chemistry / Q000494:pharmacology*; D002352:Carrier Proteins / Q000378:metabolism*; D019295:Computational Biology; D060467:Disease Resistance / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D010935:Plant Diseases / Q000235:genetics / Q000517:prevention & control; D018515:Plant Leaves / Q000737:chemistry; D010940:Plant Proteins / Q000378:metabolism*; D020543:Proteome; D040901:Proteomics; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D014027:Tobacco Mosaic Virus / Q000187:drug effects
D000998:Antiviral Agents; D052160:Benzothiazoles; D002352:Carrier Proteins; D010940:Plant Proteins; D020543:Proteome; C576734:dufulin; D020156:Salicylic Acid