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Author Li, Li ♦ Steffens, John C.
Source SpringerLink
Content type Text
Publisher Springer-Verlag
File Format PDF
Copyright Year ©2002
Language English
Subject Domain (in DDC) Social sciences ♦ Sociology & anthropology
Abstract Polyphenol oxidases (PPOs; EC 1.10.3.2 or EC 1.14.18.1) catalyzing the oxygen-dependent oxidation of phenols to quinones are ubiquitous among angiosperms and assumed to be involved in plant defense against pests and pathogens. In order to investigate the role of PPO in plant disease resistance, we made transgenic tomato (Lycopersicon esculentum Mill. cv. Money Maker) plants that overexpressed a potato (Solanum tuberosum L.) PPO cDNA under control of the cauliflower mosaic virus 35S promoter. The transgenic plants expressed up to 30-fold increases in PPO transcripts and 5- to 10-fold increases in PPO activity and immunodetectable PPO. As expected, these PPO-overexpressing transgenic plants oxidized the endogenous phenolic substrate pool at a higher rate than control plants. Three independent transgenic lines were selected to assess their interaction with the bacterial pathogen Pseudomonas syringae pv. tomato. The PPO-overexpressing tomato plants exhibited a great increase in resistance to P. syringae. Compared with control plants, these transgenic lines showed less severity of disease symptoms, with over 15-fold fewer lesions, and strong inhibition of bacterial growth, with over 100-fold reduction of bacterial population in the infected leaves. These results demonstrate the importance of PPO-mediated phenolic oxidation in restricting plant disease development.
ISSN 00320935
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2002-03-22
Publisher Place Berlin/Heidelberg
e-ISSN 14322048
Journal Planta
Volume Number 215
Issue Number 2
Page Count 9
Starting Page 239
Ending Page 247


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Source: SpringerLink