Overexpression of polyphenol oxidase in transgenic tomato plants results in enhanced bacterial disease resistance
Overexpression of polyphenol oxidase in transgenic tomato plants results in enhanced bacterial disease resistance
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DOI：
10.1007/s00425-002-0750-4
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发表时间：
2002-06-01
期刊：
影响因子：
4.3
通讯作者：
Steffens, JC
中科院分区：
文献类型：
--
作者：
Li, L;Steffens, JC
多酚氧化酶（PPO; EC 1.10.3.2或EC 1.14.18.1）催化酚类的氧依赖性氧化为醌类，在被子植物中普遍存在，并被认为参与植物对害虫和病原体的防御。为了研究多酚氧化酶在植物抗病性中的作用，我们利用转基因番茄（Lycopersicon esculentum Mill.）CV. Money Maker）植物，过表达马铃薯（Solanum tuberosum L.）在花椰菜花叶病毒35 S启动子控制下的PPO cDNA。转基因植物的PPO转录表达增加了30倍，PPO活性和免疫检测PPO增加了5至10倍。正如预期的那样，这些PPO过表达的转基因植物氧化的内源性酚类底物池在一个更高的速度比对照植物。选择三个独立的转基因品系来评估它们与细菌病原体假单胞菌的相互作用。丁香番茄过表达PPO的番茄植株表现出对番茄疫霉的抗性显著增加。与对照植株相比，这些转基因株系表现出较轻的病害症状严重程度，病害减少超过15倍，并且对细菌生长具有强烈的抑制作用，感染叶片中的细菌种群减少超过100倍。这些结果表明PPO介导的酚类氧化在限制植物病害发展中的重要性。
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.