Plants can defend themselves indirectly against herbivory by emitting blends of volatile organic compounds that recruit herbivore natural enemies. Of the different classes of volatiles that are released, C11 homoterpene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) and the C16 homoterpene (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) have been shown to play a key role in attraction of parasitic wasps. At present, the study of DMNT and TMTT biosynthetic pathway in plants has been an international research hotspot.

Recently, researchers at State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection of CAAS used techniques of chemical ecology combined with high-throughput sequencing and gene function studies to reveal the key two terpene synthase genes (Pltps3 and Pltps4) on the DMNT and TMTT biosynthesis pathways in Lima beans. The results showed that the transgenic rice plants could significantly attract the female parasitoid wasp Cotesia chilonis, the natural enemy of the striped rice stemborer Chilo suppressalis. This pest is one of the most important pests of rice in East Asia, India and Indonesia. This study revealed the molecular mechanism of DMNT and TMTT biosynthesis pathway in lima bean and demonstrates that the transformation of rice to produce volatile DMNT and TMTT has the potential to enhance plant indirect defence through natural enemy recruitment.

Behavioural responses of the parasitic wasps

This study was supported by the International Science and Technology Cooperation Program of China (No.: 2013DFG32230). The research finding has been published in Plant Cell & Environment. online on 30 March, 2017 (DOI:10.1111/pce.12959). More details are available on the bellow links:
http://onlinelibrary.wiley.com/doi/10.1111/pce.12959/full

By Guirong Wang
wangguirong@caas.cn