The effects of RNA interference on the expression level of pea aphid ( Acyrthosiphon pisum) sugar transporter gene (Ap_ST1)

The pea aphid (Acyrthosiphon pisum) is a serious pest which attacks a number of important crops worldwide, including grains, corn, potatoes and alfalfa, and it spreads viral diseases among the plants it feed on. It reproduces sexually and asexually and, since it occurs within a short period aphids can establish many colonies and spread easily. Interestingly, it has been found that pea aphids have a high number of sugar transporter facilitator encoding genes, and the most highly expressed of these is Ap_ST1, which is expressed in the aphid’s gut, which functions as a transporter for the sugar molecules; mainly mannose and glucose. The newly discovered tool RNA interference (RNAi) has become a powerful technique to improve plants resistance against insects due to its high specificity. This study demonstrates that using conventional dsRNA against the sugar transporter gene Ap_ST1 reduces the gene’s expression level. Using a range of dsRNA concentrations proves that RNAi trigger effect can be occur when applying dsRNA in a small quantity. The effect of RNAi was only observed on the gene expression level and there was no alteration noticed on the phenotype or the pest movement. This is due to the presence of the other sugar transporter encoding gene Ap_ST3, which facilitates the transportation of the sugar molecules into the gut. Thus, this study shows that RNAi could be a promising alternative biological tool in the control and management of pea aphids.