title: Plant-generated artificial small RNAs mediated aphid resistance.
abstract: BACKGROUND
  RNA silencing is an important mechanism for regulation of endogenous gene expression and defense against genomic intruders in plants. This natural defense system was adopted to generate virus-resistant plants even before the mechanism of RNA silencing was unveiled. With the clarification of that mechanism, transgenic antiviral plants were developed that expressed artificial virus-specific hairpin RNAs (hpRNAs) or microRNAs (amiRNAs) in host plants. Previous works also showed that plant-mediated RNA silencing technology could be a practical method for constructing insect-resistant plants by expressing hpRNAs targeting essential genes of insects.
  
  
  RESULTS
  In this study, we chose aphid Myzus persicae of order Hemiptera as a target insect. To screen for aphid genes vulnerable to attack by plant-mediated RNA silencing to establish plant aphid resistance, we selected nine genes of M. persicae as silencing targets, and constructed their hpRNA-expressing vectors. For the acetylcholinesterase 2 coding gene (MpAChE2), two amiRNA-expressing vectors were also constructed. The vectors were transformed into tobacco plants (Nicotiana tabacum cv. Xanti). Insect challenge assays showed that most of the transgenic plants gained aphid resistance, among which those expressing hpRNAs targeting V-type proton ATPase subunit E-like (V-ATPaseE) or tubulin folding cofactor D (TBCD) genes displayed stronger aphicidal activity. The transgenic plants expressing amiRNAs targeting two different sites in the MpAChE2 gene exhibited better aphid resistance than the plants expressing MpAChE2-specific hpRNA.
  
  
  CONCLUSIONS
  Our results indicated that plant-mediated insect-RNA silencing might be an effective way to develop plants resistant to insects with piercing-sucking mouthparts, and both the selection of vulnerable target genes and the biogenetic type of the small RNAs were crucial for the effectiveness of aphid control. The expression of insect-specific amiRNA is a promising and preferable approach to engineer plants resistant to aphids and, possibly, to other plant-infesting insects.
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China; National Plant Gene Research Center, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China; National Plant Gene Research Center, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Song
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Guiling
authors.initials: G
authors.lastname: Wang
authors.affiliation: School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Libo
authors.initials: L
authors.lastname: Niu
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China; National Plant Gene Research Center, Beijing, China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China; National Plant Gene Research Center, Beijing, China.
authors.forename: Rongxiang
authors.initials: R
authors.lastname: Fang
mesh_terms: D000110:Acetylcholinesterase / Q000172:deficiency / Q000235:genetics; D000818:Animals; D001042:Aphids / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D003001:Cloning, Molecular; D005818:Genetic Engineering; D055029:Inverted Repeat Sequences; D035683:MicroRNAs / Q000235:genetics*; D030821:Plants, Genetically Modified; D034622:RNA Interference; D018749:RNA, Plant / Q000235:genetics*; D014026:Nicotiana / Q000235:genetics / Q000502:physiology
chemical_list: D035683:MicroRNAs; D018749:RNA, Plant; D000110:Acetylcholinesterase