RNAi-based reverse genetics in the chelicerate model Tetranychus urticae: A comparative analysis of five methods for gene silencing

• Published in: PloS one Vol. 12; no. 7; p. e0180654
• Main Authors: Suzuki, Takeshi, Nunes, Maria Andreia, España, María Urizarna, Namin, Hooman Hosseinzadeh, Jin, Pengyu, Bensoussan, Nicolas, Zhurov, Vladimir, Rahman, Tawhid, De Clercq, Rebecca, Hilson, Pierre, Grbic, Vojislava, Grbic, Miodrag
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 12.07.2017; Public Library of Science (PLoS)
• Subjects: Acari - genetics; Agricultural pests; Agriculture; Agrochemicals; Animals; Arthropods; ATP; Biology; Biology and Life Sciences; Chelicerates; Chemical and Process Engineering; Comparative analysis; Crop damage; Crops; Damage; Double-stranded RNA; Engineering Sciences; Fecundity; Feeding; Fitness; Floating; Food engineering; Gene expression; Gene Silencing; Gene Targeting - methods; Genetics; Genomes; H+-transporting ATPase; Insect Proteins - genetics; Insect Proteins - metabolism; Interference; Leaves; Life Sciences; Methods; Mites; Ornamental plants; Pesticides; Pests; Phenotypes; Physiological aspects; Plants; Populations; Proteins; Research and Analysis Methods; Ribonucleic acid; RNA; RNA interference; RNA polymerase; RNA-mediated interference; Scale (ratio); Screens; Soaking; Tetranychus urticae; Transgenic plants; Vacuolar Proton-Translocating ATPases - genetics; Vacuolar Proton-Translocating ATPases - metabolism; Vegetal Biology; Belgium; Ontario Canada; Canada
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0180654

RNA interference (RNAi) can be used for the protection against agricultural pests through the silencing of genes required for pest fitness. To assess the potential of RNAi approaches in the two-spotted spider mite, Tetranychus urticae, we compared 5 methods for the delivery of double-stranded RNA (dsRNA). These methods include mite feeding on either (i) leaves floating on a dsRNA solution, (ii) dsRNA-expressing plants, (iii) artificial diet supplemented with dsRNA, or (iv) dsRNA-coated leaves, and (v) mite soaking in a dsRNA solution. In all cases, the gene targeted for method validation was the Vacuolar-type H+-ATPase (TuVATPase), encoding a constitutively expressed ATP-driven proton pump located in the membrane. Down-regulation of TuVATPase increased mortality and/or reduced fecundity in all methods, but with variable efficiency. The most efficient methods for dsRNA delivery were direct soaking of mites in the dsRNA solution and mite feeding on dsRNA-coated leaves that mimics dsRNA application as a sprayable pesticide. Both resulted in a dark-body phenotype not observed in mites treated with a control dsRNA. Although with lower efficiency, dsRNA designed for TuVATPase silencing and expressed in transgenic Arabidopsis plants impacted the fitness of mites feeding on these plants. RNAi may thus be a valuable strategy to control spider mite populations, either as a sprayable pesticide or through transgenic crops. This comparative methodological study focusing on the induction of RNAi-based gene silencing in T. urticae paves the way for reverse genetics approaches in this model chelicerate system and prepares large-scale systematic RNAi screens as a first step towards the development of specific RNA-based pesticides. Such alternative molecules may help control spider mites that cause significant damages to crops and ornamental plant species, as well as other chelicerates detrimental to agriculture and health.