Identification and Characterization of a Rice Promoter Specifically Responsive to the Attack of Brown Planthopper (Nilaparvata lugens)

Rice brown planthopper (Nilaparvata lugens), is an important herbivore on the rice. Attack of N. lugens triggers comprehensive defense of rice. Rice allene oxide synthase 1 (OsAOS1) plays key roles in jasmonic acid synthesis, it was highly and specifically up-regulated by feeding of N. lugens. The putative promoter region, spanning from –1889 to the transcriptional initiation site was isolated, fused to the GUS gene (β-glucuronidase reporter gene) and introduced by Agrobacterium-mediated transformation to rice. At 6 h after insect feeding, GUS activity was significantly induced by 4.1 times in sheaths, compared to non-infested plants. The promoter was truncated gradually from 5’-end, and a series of deletion mutants were constructed. Analysis of GUS activity of mutants revealed three regions (–1573 to –1311, –979 to –646 and -426 to -180) that might have positively regulating cis-element, and one regions (-646 to -426) that might have negatively regulating cis-element. In the future, we will identify the cis-elements responsible for N. lugens attack using deletion mutation, site-specific mutation and electrophoretic mobility shift assay. This work will provide new issue to explain the mechanism of interactions between insects and rice.

Key words: Rice; Allene oxide synthase; Nilaparvata lugens; Insect responsive promoter