RNA Interference Based Approach to Down Regulate Osmoregulators of Whitefly (Bemisia tabaci): Potential Technology for the Control of Whitefly

Authors: RAZA, AMIR - NATIONAL INSTITUTE OF BIOTECHNOLOGY AND GENETIC ENGINEERING (NIBGE); MALIK, HASSAN JAMIL - NATIONAL INSTITUTE OF BIOTECHNOLOGY AND GENETIC ENGINEERING (NIBGE); SHAFIQ, MUHAMMAD - NATIONAL INSTITUTE OF BIOTECHNOLOGY AND GENETIC ENGINEERING (NIBGE); AMIN, IMRAN - NATIONAL INSTITUTE OF BIOTECHNOLOGY AND GENETIC ENGINEERING (NIBGE); Scheffler, Jodi; Scheffler, Brian; MANSOOR, SHAHID - NATIONAL INSTITUTE OF BIOTECHNOLOGY AND GENETIC ENGINEERING (NIBGE)

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/5/2016
Publication Date: 4/22/2016
Publication URL: http://handle.nal.usda.gov/10113/62717
Citation: Raza, A., Malik, H., Shafiq, M., Amin, I., Scheffler, J.A., Scheffler, B.E., Mansoor, S. 2016. RNA Interference Based Approach to Down Regulate Osmoregulators of Whitefly (Bemisia tabaci): Potential Technology for the Control of Whitefly. PLoS One. 11:e0153883.

Interpretive Summary: Chemical pesticides are being used throughout the world for the control of pests and diseases of economically important crops. Use of insecticides for the control of insect pests is a major economic, environmental and health concern. Over time, insects also become resistant to these chemicals, thereby worsening the problem. Over the past decade, RNAi technology has shown promise as a tool for controlling insect pests of important crops. RNAi is a gene silencing technology that targets a specific gene(s) and decreases it’s expression. Plants can be genetically engineered to induce an RNAi response in insects that feed on the plant. This study targeted whiteflies (Bemisia tabaci) which feed on liquid plant sap and the uptake of the sap depends on the osmotic pressure within the insect body. Based on this physiological mechanism, transgenic plants of Nicotiana tabacum were generated expressing double stranded RNA (dsRNA) against two genes involved in osmotic pressure maintenance with the aim to disrupt the osmotic pressure balance within the insect and cause the whiteflies to die. In this study, whitefly adults feeding on transgenic plants exhibited 70% mortality compared to 16% non-transgenic control plants. Down-regulation of genes related to osmotic pressure maintenance in sucking insects such as whiteflies could be a practical alternative for the control of this important pest of cotton and a number of other crops.

Technical Abstract: Over the past decade RNA interference (RNAi) technology has emerged as a successful tool not only for functional genomics, but in planta expression of short interfering RNAs (siRNAs) could offer potential for insect pest management. Insects feeding exclusively on plant sap depend on osmotic pressure within the insect body to uptake the liquid food. Based on this physiological mechanism, transgenic plants of Nicotiana tabacum were generated expressing double stranded RNA (dsRNA) against both aquaporin (AQP) and a sucrase gene alpha glucosidase (AGLU). These two genes are involved in osmotic pressure maintenance in a number of insects, and the aim was to disrupt osmoregulation within the insect and cause increased insect mortality. Whiteflies (Bemisia tabaci) were fed on transgenic or non-transgenic control plants for six days, then real time qRT-PCR was performed to assess the suppression of gene expression in the whiteflies and whitefly mortality assessed. Feeding of insects on plants expressing dsRNA significantly reduced the transcript level of the target genes in whitefly adults after six days of feeding, and more than 70% mortality was observed in the adults fed on transgenic plants compared to the control plants. The results indicated that down-regulation of genes related to osmoregulation may find practical applications for the control of this important pest in cotton and other crops.