The Rice-Produced Insecticide Orysata

A study recently discovered the insecticidal activity of Orysata, a lectin from rice (Oryza sativa L.) belonging to the family of jacalin-related lectins. The efficacy of Orysata in controlling insect pests was investigated against three important insect pests: the beet armyworm (Spodoptera exigua) and two aphids pests: green peach aphid (Myzus persicae) and pea aphid (Acyrthosiphon pisum)

Orysata was overexpressed constitutively in tobacco plants. An artificial diet of tobacco leaves containing increasing concentrations of the purified recombinant Orysata was then fed to the insect pests. Intoxicated larval stages of S. exigua revealed significant mortality, reductions in larval weight gain and a retardation of development. Similarly, feeding on leaves expressing Orysata increased the mortality of the green peach aphids significantly. In pea aphids, mortality was already high at relatively low lectin concentrations with the estimated 50% lethal concentration only at 79 μg/ml.

The study revealed that Orysata possessed strong insecticidal activity and could be considered as a valuable candidate for control agent against both biting-chewing and piercing-sucking pest insects.

For more information on the study, you can visit: http://www.sciencedirect.com/science/article/pii/S0168945214000211.