Development of a Screening System for Plant Defense-Inducing Agent using Transgenic Tobacco Plant with PR-1a Promoter and GUS Gene |
Sang Keun Oh, Seon Woo Lee, Suk Yoon Kwon, Do Il Choi |
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Abstract |
Pathogenesis-related protein-1a (PR-1a) is strongly induced in tobacco plants by pathogen attack, exogenous salicylic acid (SA) application and by other developmental processes. In order to develop a rapid screening system for the selection of plant defenseinducing compounds originated from various sources,we have transformed tobacco Samsun NN plants with a chimeric construct consisting of GUS (β-glucuronidase).In the T1 generation, three transgenic lines having stable GUS expression were selected for further promoter analysis. Using GUS histochemical assay, we observed strong GUS induction driven by PR-1a promoter in PR1a-GUS transgenic tobacco leaves in response to the exogenous application of SA or benzol (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester (BTH), a SAderivative compound. In addition, GUS expression was maintained locally or systemically in PR1a-GUS transgenic line # 5 (T2 generation) until after 3 days when they were treated with same chemicals. Our results suggested that the PR1a-GUS reporter gene system in tobacco plants may be applicable for the large-scale screening of defense-inducing substances. |
Key Words:
chemical screening, pathogenesis-related protein-1a, PR1a promoter-GUS transgenic tobacco plants, salicylic acid |
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