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Title: Elicitor-induced Plant Defense and Pathogenesis-Related Gene Expression in Carica papaya L.

item Moore, Paul
item ZHU, Y. - HARC

Submitted to: CTAHR Student Research Symposium
Publication Type: Other
Publication Acceptance Date: 3/3/2006
Publication Date: 4/5/2007
Citation: Agbayani, R., Nishijima, W.T., Moore, P.H., Zhu, Y.J. 2007. Elicitor-induced Plant Defense and Pathogenesis-Related Gene Expression in Carica papaya L. 19th Annual CTAHR Student Research Symposium. April 7-8, 2006. Honolulu, Hawaii. Abstract #84. pg 51.

Interpretive Summary:

Technical Abstract: The basic elements of a papaya systemic acquired resistance (SAR) pathway have been reported to resemble that described in Arabidopsis thaliana. An NPR1 (nonexpresser of pathogenesis-related genes) homolog (CpNPR1) was isolated from papaya and partially characterized (Zhu et al., 2003). To characterize the expression of pathogenesis-related (PR) genes in papaya and potentially to increase the resistance of papaya to root rot caused by Phytophthora palmivora, we produced papaya plants transformed to over-express CpNPR1 or to express the Arabidopsis NPR1 gene (AtNPR1). Transgenic plants were challenged with either the oligopeptide elicitor Pep-13 from Phytophthora, benzothiadiazole (BTH, a functional analog of salicylic acid), P. palmivora zoospores, or dH2O. Treated leaves were collected at different times after inoculation. Changes in the level of PR1 gene expression were measured using Northern blots, and quantitative RT-PCR. Western blot analysis, using an NPR1 antibody, was conducted to determine transgenic protein production. When transformed lines in tissue culture were challenged with P. palmivora zoospores, a DAS ELISA for Phytophthora quantified the amount of pathogen present after treatment to show that pathogen growth was reduced and that the CpNPR1 lines were more resistant than the AtNPR1 lines. Zhu, Y.J. (2003) Physiol Mol Plant Pathol 63, 237-248