Transgenic expression of Pinellia ternata agglutinin (PTA) and Arisaema heterophyllum agglutinin (AHA) in wheat confers resistance against the grain aphid, Sitobion miscanthi

Abstract

The present study investigated the feeding behaviour and life-table parameters of the grain aphid Sitobion miscanthi in response to being fed on transgenic wheat lines expressing Pinellia ternata agglutinin (PTA) and Arisaema heterophyllum agglutinin (AHA), both of which originate from Chinese medicinal plants. The findings revealed that the feeding behaviour of S. miscanthi on transgenic wheat lines was negatively affected. The aphids that feed on the PTA and AHA transgenic wheat lines had longer total non-probing (np) periods than the aphids that feed on non-transformed lines but exhibited shorter durations of salivation (E1), phloem sap ingestion phase (E2) and sustained ingestion (E2 > 10 min). Moreover, aphids feeding on the 171 line, which expresses PTA, displayed a significant increase in the number of np patterns and time taken to initiate the first probe. Furthermore, the lifespan of S. miscanthi feeding on any of the wheat lines expressing PTA and AHA was found to reduce significantly. The maximum fecundity of the aphids on the AHA-expressing wheat lines was significantly lower than that of the control group. The net reproductive rate (R0) and intrinsic rate of increase (rm) were also significantly lower for the aphids feeding on the PTA and AHA transgenic wheat than for the aphids feeding on the non-transformed control plants. These findings indicate successful detection of resistance to S. miscanthi in the PTA- and AHA-expressing wheat lines, providing a new option for engineering protection against crop pests by expressing unique proteins that occur naturally in medicinal plants.