Identifying potential RNAi targets in aphid species (Macrosiphum rosae, Rhopalosiphum maidis, Sitobion avenae, Toxoptera aurantii) in sub-tropical region with extreme summer

Abstract

RNA interference is a useful and efficient tool that had been used to incorporate tolerance against different stresses. Five unigene sequences were selected from exotic grain aphid that were reported to be an ideal RNAi targets. Aphids (Macrosiphum rosae, Rhopalosiphum maidis, Sitobion avenae, Toxoptera aurantii) were reared on Rosa indica, Zea mays, Triticum aestivum, Chrysanthemum hibiscus, Solanum melongena, Abelmoschus esculentus. PCR of unigene 28469 and 21789 was positive for all aphids and there is no ortholog found for them so unique and effective to be used in RNAi technology. Cytochrome c oxidase was found to be positive for M. rosae, S. avenae, T. aurantii and negative for R. maidis. Zinc finger protein was found to be positive for R. maidis, S. avenae and negative for M. rosae, and T. aurantii. Cuticular proteins was found to be positive for S. avenae and M. rosae and negative for R. maidis and T. aurantii. Genes identified in the aphids are defense and as important structural genes and their suppression with RNAi technology will be important target to have insect resistant crops. From these gene sequences cytochrome c oxidase is reported as bar coding gene and can be used in future for interspecific genetic variation in these aphids. Results revealed the high expression of these sequences in local aphid species and can be used as RNAi target for them. That can be used in future or applications as pest management, monitoring and plant quarantine.

Management of yellow dwarf disease in Europe in a post‐neonicotinoid agriculture

“…As overall development cost of transgenic RNAi crops are high and the use of transgenic plants and GMOs is still widely decried in Europe, new GMO‐free RNAi approaches are being developed which facilitate RNAi activation through the direct exogenous delivery of RNA molecules [double‐stranded RNAs (dsRNAs) and/or small interfering RNAs (siRNAs)] in plants. This RNAi technology shows potential to downregulate the expression of specific genes in insects . While feeding on plants, aphids take up either dsRNA or siRNA which has been applied to the crop, initiating the diffusion of the silencing signal beyond the digestive tract (systemic RNAi and cell autonomous RNAi) to the whole insect body .…”

“…While feeding on plants, aphids take up either dsRNA or siRNA which has been applied to the crop, initiating the diffusion of the silencing signal beyond the digestive tract (systemic RNAi and cell autonomous RNAi) to the whole insect body . Several studies have screened optimal RNAi targets in the grain aphid, identifying five genes and four RNAi targets which cause developmental stunting, and lead to higher mortality . As a tool to overcome pesticide resistance, success has already been achieved in developing transgenic lines of wheat targeting the carboxylesterase gene (CbE E4, linked to insecticide resistance) in the grain aphid …”