title: Host-mediated gene silencing of a single effector gene from the potato pathogen Phytophthora infestans imparts partial resistance to late blight disease.
abstract: RNA interference (RNAi) has proved a powerful genetic tool for silencing genes in plants. Host-induced gene silencing of pathogen genes has provided a gene knockout strategy for a wide range of biotechnological applications. The RXLR effector Avr3a gene is largely responsible for virulence of oomycete plant pathogen Phytophthora infestans. In this study, we attempted to silence the Avr3a gene of P. infestans through RNAi technology. The P. infestans inoculation resulted in lower disease progression and a reduction in pathogen load, as demonstrated by disease scoring and quantification of pathogen biomass in terms of Pi08 repetitive elements, respectively. Transgenic plants induced moderate silencing of Avr3a, and the presence and/or expression of small interfering RNAs, as determined through Northern hybridization, indicated siRNA targeted against Avr3a conferred moderate resistance to P. infestans. The single effector gene did not provide complete resistance against P. infestans. Although the Avr3a effector gene could confer moderate resistance, for complete resistance, the cumulative effect of effector genes in addition to Avr3a needs to be considered. In this study, we demonstrated that host-induced RNAi is an effective strategy for functional genomics in oomycetes.
authors.affiliation: ICAR-Central Potato Research Institute, Shimla, 171001, Himachal Pradesh, India.
authors.forename: Suman
authors.initials: S
authors.lastname: Sanju
authors.affiliation: ICAR-Central Potato Research Institute, Shimla, 171001, Himachal Pradesh, India. sundareshas8@gmail.com.
authors.forename: Sundaresha
authors.initials: S
authors.lastname: Siddappa
authors.affiliation: ICAR-Central Potato Research Institute, Shimla, 171001, Himachal Pradesh, India.
authors.forename: Aditi
authors.initials: A
authors.lastname: Thakur
authors.affiliation: Sam Higginbottom Institute of Agriculture, School of Biological Sciences, Allahabad, 211007, Uttara Pradesh, India. pradeepshuklak@yahoo.co.in.
authors.forename: Pradeep K
authors.initials: PK
authors.lastname: Shukla
authors.affiliation: Banasthali University, Rajasthan, 304022, India. nidhiscientist@gmail.com.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Srivastava
authors.affiliation: ICAR-National Research Centre for Plant Biotechnology, IARI, New Delhi, 110012, India. debasispattanayak@yahoo.co.in.
authors.forename: Debasis
authors.initials: D
authors.lastname: Pattanayak
authors.affiliation: ICAR-Central Potato Research Institute, Shimla, 171001, Himachal Pradesh, India.
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Sharma
authors.affiliation: ICAR-Central Potato Research Institute, Shimla, 171001, Himachal Pradesh, India.
authors.forename: B P
authors.initials: BP
authors.lastname: Singh
mesh_terms: D060467:Disease Resistance / Q000235:genetics*; D020868:Gene Silencing; D054884:Host-Pathogen Interactions; D055750:Phytophthora infestans / Q000235:genetics* / Q000472:pathogenicity; D032322:Solanum / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D037521:Virulence Factors / Q000235:genetics*
chemical_list: C562170:AVR3a protein, Phytophthora infestans; D037521:Virulence Factors
keywords: Avr3a effector; Late blight; Plant microbe interaction; siRNA