A petunia ethylene-responsive element binding factor, PhERF2, plays an important role in antiviral RNA silencing.
Virus-induced RNA silencing is involved in plant antiviral defense and requires key enzyme components, including RNA-dependent RNA polymerases (RDRs), Dicer-like RNase III enzymes (DCLs), and Argonaute proteins (AGOs). However, the transcriptional regulation of these critical components is largely unknown. In petunia (Petunia hybrida), an ethylene-responsive element binding factor, PhERF2, is induced by Tobacco rattle virus (TRV) infection. Inclusion of a PhERF2 fragment in a TRV silencing construct containing reporter fragments of phytoene desaturase (PDS) or chalcone synthase (CHS) substantially impaired silencing efficiency of both the PDS and CHS reporters. Silencing was also impaired in PhERF2- RNAi lines, where TRV-PhPDS infection did not show the expected silencing phenotype (photobleaching). In contrast, photobleaching in response to infiltration with the TRV-PhPDS construct was enhanced in plants overexpressing PhERF2 Transcript abundance of the RNA silencing-related genes RDR2, RDR6, DCL2, and AGO2 was lower in PhERF2-silenced plants but higher in PhERF2-overexpressing plants. Moreover, PhERF2-silenced lines showed higher susceptibility to Cucumber mosaic virus (CMV) than wild-type (WT) plants, while plants overexpressing PhERF2 exhibited increased resistance. Interestingly, growth and development of PhERF2-RNAi lines were substantially slower, whereas the overexpressing lines were more vigorous than the controls. Taken together, our results indicate that PhERF2 functions as a positive regulator in antiviral RNA silencing.
Department of Landscape Architecture and Arts, Northwest A&F University, Yangling, Shaanxi 712100, China Department of Plant Sciences, University of California Davis, Davis, CA 95616, USA.
Daoyang
D
Sun
Department of Plant Pathology, University of California Davis, Davis, CA 95616, USA.
Raja Sekhar
RS
Nandety
Department of Landscape Architecture and Arts, Northwest A&F University, Yangling, Shaanxi 712100, China.
Yanlong
Y
Zhang
Department of Plant Sciences, University of California Davis, Davis, CA 95616, USA.
Michael S
MS
Reid
Department of Landscape Architecture and Arts, Northwest A&F University, Yangling, Shaanxi 712100, China niulixin@nwsuaf.edu.cn cjiang@ucdavis.edu.
Lixin
L
Niu
Crops Pathology and Genetic Research Unit, United States Department of Agriculture, Agricultural Research Service, Davis, CA 95616, USA niulixin@nwsuaf.edu.cn cjiang@ucdavis.edu.
Cai-Zhong
CZ
Jiang
D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D032306:Petunia / Q000235:genetics* / Q000821:virology; D010935:Plant Diseases / Q000821:virology*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D010942:Plant Viruses / Q000235:genetics*; D034622:RNA Interference; D012328:RNA Viruses / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics
D004268:DNA-Binding Proteins; D010940:Plant Proteins; D012367:RNA, Viral; C093680:ethylene-responsive element binding protein
Argonaute; RNA-dependent RNA polymerase; cucumber; dicer-like enzyme; mosaic; rattle; tobacco; transcription factor; virus; virus-induced gene silencing.