Poster: Plant Insect/Nematode Interactions

Abs # 686: Characterization of insect herbivory-inducible genes in rice, Oryza sativa

Presenter:	Imboden, Lori A, limbode@uark.edu
Authors	Imboden, Lori A (A)   Yang, Yinong  (A)   Zhou, Xiang-Jun  (A)   Korth, Kenneth L (A)
Affiliations:	(A): University of Arkansas

Elicitors in insect oral secretions cause a variety of defense responses in plants damaged by insect herbivory. An early indicator of the response is the induction of defense-related genes following damage. This has been characterized in several economically significant species but information on chewing-insect responses in the staple crop rice, Oryza sativa, is lacking. A macroarray collection of subtracted cDNAs, isolated from jasmonic acid- and benzothiadiazole-treated rice leaves, was screened using labeled cDNA from undamaged and insect damaged plants. An RNA blot comparison of the transcripts present in insect damaged, mechanically damaged and undamaged rice plants reveals several differentially expressed genes. Transcript accumulation in leaves was measured following herbivory by the beet armyworm, Spodoptera exigua. Insect inducible genes include those bearing high similarity to the ethylene-insensitive-3 gene (ein3) of Arabidopsis and a sequence encoding a putative MtN3-like, transmembrane protein. Several other cDNAs, lacking similarity with genes of known function, were also strongly expressed after insect herbivory. Differential gene expression in response to jasmonic acid and oral factors derived from regurgitant of tobacco hornworm, Manduca sexta, will also be determined.