Chemical facilitation and induced pathogen resistance mediated by a root-secreted phytotoxin.
Chemical facilitation and induced pathogen resistance mediated by a root-secreted phytotoxin.
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DOI：
10.1111/j.1469-8137.2006.01964.x
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发表时间：
2007-03
期刊：
影响因子：
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通讯作者：
B. Prithiviraj;L. Perry;D. Badri;J. Vivanco
中科院分区：
文献类型：
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作者：
B. Prithiviraj;L. Perry;D. Badri;J. Vivanco
黄酮醇(+/-)-儿茶素是一种由入侵杂草Centaurea maculosa(斑点响尾藻)产生的化感物质。(+/-)-儿茶素对原生和引种黄连的植物群落的全部影响仍不确定。在这里，通过在植物生长介质中添加(+/-)-儿茶素，我们表明低(+/-)-儿茶素浓度可能会诱导邻近植物的生长和防御反应。低于最低抑制浓度(MIC)的化感物质剂量诱导了拟南芥的生长；25微克毫升(-1)(+/-)-儿茶素处理的植株积累的生物量是未经处理的对照植株的两倍多。此外，用低浓度的(+/-)-儿茶素对紫丁香假单胞菌诱导根产生抗性。番茄叶中的DC3000。低剂量的(+/-)-儿茶素导致处理植株分生组织中活性氧物种(ROS)的适度增加，这可能使细胞壁松散，从而促进生长。突变体的实验表明，(+/-)-儿茶素通过上调病程相关蛋白1(NPR1)依赖的水杨酸(SA)/非表达因子(NPR1)途径上调防御基因，从而诱导病原菌抗性。我们的结果表明，(+/-)-儿茶素的生长和防御诱导作用是浓度依赖的，因为(+/-)-儿茶素在较高浓度下具有植物毒性，因此在自然界中可能发生兴奋作用。
The flavonol (+/-)-catechin is an allelochemical produced by the invasive weed Centaurea maculosa (spotted knapweed). The full effects of (+/-)-catechin on plant communities in both the native and the introduced ranges of C. maculosa remain uncertain. Here, by supplementing plant growth media with (+/-)-catechin, we showed that low (+/-)-catechin concentrations may induce growth and defense responses in neighboring plants. Doses of the allelochemical lower than the minimum inhibitory concentration (MIC) induced growth in Arabidopsis thaliana; plants treated with 25 microg ml(-1) (+/-)-catechin accumulated more than twice the biomass of untreated control plants. Further, pretreatment of A. thaliana roots with low concentrations of (+/-)-catechin induced resistance to the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 in A. thaliana leaves. Low doses of (+/-)-catechin resulted in moderate increases in reactive oxygen species (ROS) in the meristems of treated plants, which may have loosened the cell walls and thus increased growth. Experiments with A. thaliana mutants indicated that (+/-)-catechin induces pathogen resistance by up-regulating defense genes via the salicylic acid (SA)/nonexpressor of pathogenesis related protein 1 (NPR1)-dependent pathway. Our results suggest that the growth and defense-inducing effects of (+/-)-catechin are concentration dependent, as (+/-)-catechin at higher concentrations is phytotoxic, thus suggesting the potential for hormesis to occur in nature.