Oxalic acid, a pathogenicity factor for Sclerotinia sclerotiorum, suppresses the oxidative burst of the host plant
Oxalic acid, a pathogenicity factor for Sclerotinia sclerotiorum, suppresses the oxidative burst of the host plant
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DOI：
10.1105/tpc.12.11.2191
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发表时间：
2000-11-01
期刊：
影响因子：
11.6
通讯作者：
Low, PS
中科院分区：
文献类型：
--
作者：
Cessna, SG;Sears, VE;Low, PS
菌核菌的有效发病需要草酸的分泌。研究确定草酸盐是否通过调节宿主植物的氧化爆发来辅助病原体相容性。接种草酸缺乏的无致病性菌丝体烟草叶片可诱导可测量的氧化生物合成，而接种草酸分泌菌株则没有。草酸盐抑制烟草和大豆培养细胞系中H2O2的产生，其中位抑制浓度为4至5 mM，低于毒性真菌制剂中的浓度。一些观察结果还表明，草酸盐的抑制作用在很大程度上独立于其酸度和对Ca2+的亲和力。这些和其他数据表明，草酸盐可能抑制位于氧化酶组装/激活上游的信号步骤，但位于Ca2+通量进入植物细胞质的下游。
Effective pathogenesis by the fungus Sclerotinia sclerotiorum requires the secretion of oxalic acid. Studies were conducted to determine whether oxalate aids pathogen compatibility by modulating the oxidative burst of the host plant. Inoculation of tobacco leaves with an oxalate-deficient nonpathogenic mutant of S. sclerotiorum induced measurable oxidant biosynthesis, but inoculation with an oxalate-secreting strain did not. Oxalate inhibited production of H2O2 in tobacco and soybean cultured cell lines with a median inhibitory concentration of similar to4 to 5 mM, a concentration less than that measured in preparations of the virulent fungus. Several observations also indicate that the inhibitory effects of oxalate are largely independent of both its acidity and its affinity for Ca2+. These and other data demonstrate that oxalate may inhibit a signaling step positioned upstream of oxidase assembly/activation but downstream of Ca2+ fluxes into the plant cell cytosol.