Skip to main content
ARS Home » Research » Publications at this Location » Publication #152968
Title: ISOLATION AND EXPRESSION PROFILING OF GENES IN PAPAYA SYSTEMIC ACQUIRED RESISTANCE.

Author
item QIU, X. - UNIVERSITY OF HAWAII
item WANG, M. - HARC
item ZHU, Y. - HARC
item BORTH, W. - UNIVERSITY OF HAWAII
item HU, J. - UNIVERSITY OF HAWAII
item Moore, Paul
item Albert, Henrik

Submitted to: CTAHR Student Research Symposium
Publication Type: Proceedings
Publication Acceptance Date: 4/24/2003
Publication Date: 4/24/2003
Citation: Qiu, X., Wang, M., Zhu, Y.J., Borth, W.B., Hu, J., Moore, P.H., Albert, H.H. 2003. Isolation and expression profiling of genes in papaya systemic acquired resistance.. CTAHR Student Research Symposium. (Abstracts) P. 26.

Interpretive Summary: ABSTRACT ONLY

Technical Abstract: Systemic acquired resistance (SAR) is an inducible defense response in plants and this broad-spectrum resistance can be activated by benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH). The onset of SAR is correlated with the expression of a variety of pathogenesis-related (PR) genes and many of them encode antimicrobial or cell-wall-strengthening proteins. In this study, we have cloned a set of genes induced in papaya by BTH treatment, and tried to use these genes for global profiling of genes induced during the papaya SAR response. Based on suppression subtractive hybridization (SH), a subtracted cDNA library was constructed to clone genes up-regulated by BTH and therefore presumably involved in papaya SAR. 26 unique expression sequences tags (ESTs) isolated from the subtracted cDNA library have been confirmed by northern blot analysis to be up-regulated by BTH more than 1.5 fold. The up-regulated genes identified include ESTs for 5 different PR proteins: one PR-1 protein, two chitinases, one osmotin-like protein, and one peroxidase. In addition, we isolated the papaya NPR1 homolog, a positive regulator of SAR. Our study indicates that papaya SAR is similar to that of Arabidopsis at least in the major aspects. We are using ESTs for the 5 PR genes to study the defense response of papaya to various pathogens. Additionally, papaya transformed for overexpression of NPR1 are being produced to test for possibly enhanced broad-spectrum disease resistance.