Karakterisasi Gen Odorant Receptor (OR) Parsial Serangga Penggerek Batang Padi Kuning Scirpophaga incertulas (Walker)

Abstract

Yellow rice stem borer S. incertulas (Lepidoptera: Crambidae) is an important insect causes the damage of the rice crop. The females of S. incertulas naturally release sex pheromones and then captured by pheromone binding protein (PBP) in the haemolymph of male antennaes; subsequently sent to the odorant receptor proteins located on the olfactory sensory neuron dendrites on the antennae sensillae membrane which detect the chemical stimuli. The aim of this study was to characterize the odorant receptor (OR) gene that mediates the chemical information systems on the mating behavior of S. incertulas. RNA was extracted from male and female imago antennaes collected from Karawang and from rearing in Indonesian Centre for Agricultural Biotechnology and Genetic Resources Research and Development (BB-BIOGEN). The OR gene amplification from cDNA was performed by standard PCR, touchdown PCR and nested-touchdown PCR. The characterization of partial OR gene of S. incertulas male successfully performed by using touchdown-nested PCR. The OR partial gene sequence of S. incertulas revealed 133 bp size was homolog to the OR gene sequence of Ostrinia nubilalis (Lepidoptera: Crambidae) OnubOR7a (GenBank Accession No. AB597005.1). The homologous part showed that 133 bp sequence of S. incertulas was a candidate of OR genes that mediated the chemical information systems on the mating behavior of yellow rice stem borer. This study also successfully amplified beta-actin gene sequence 681 bp size from both male and female insects as the verification to the success of RNA extraction.