Endogenous hydrogen peroxide is a key factor in the yeast extract-induced activation of biphenyl biosynthesis in cell cultures of Sorbus aucuparia
Endogenous hydrogen peroxide is a key factor in the yeast extract-induced activation of biphenyl biosynthesis in cell cultures of Sorbus aucuparia
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DOI：
10.1007/s00425-011-1545-2
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发表时间：
2012-01-01
期刊：
影响因子：
4.3
通讯作者：
Liu, Benye
中科院分区：
文献类型：
--
作者：
Qiu, Xiaofang;Lei, Caiyan;Liu, Benye
联苯是一种独特的植物抗毒素，由属于梨亚科的植物产生，梨亚科是经济上重要的蔷薇科植物的一个亚族。桃叶花楸细胞培养物中的酵母提取物（YE）可诱导桃叶花楸素（一种众所周知的联苯）的形成。然而，潜在的分子机制，叶诱导的联苯生物合成的激活仍然未知。在这里，我们证明了添加YE的细胞培养物的结果在活性氧（ROS，H2 O2和O-2（-））的爆发，随后的联苯合成酶1基因（BIS 1）编码的联苯生物合成途径和桃叶珊瑚苷积累的关键酶的转录激活。用ROS清除剂二氢硫辛酸和NADPH氧化酶特异性抑制剂二亚苯基碘鎓预处理细胞培养物，可消除上述所有的YE诱导的生物学事件。而用超氧化物歧化酶特异性抑制剂N，N-二乙基二硫代氨基甲酸预处理后，虽然O-2（-）仍继续产生，但H2 O2积累、BIS 1表达和桃叶珊瑚肝素合成均被阻断。有趣的是，在0.05-10 mM范围内的外源性H2 O2供应未能诱导桃叶珊瑚肝素积累。这些结果表明，内源性H2 O2的产生而不是O-2（-）的产生是YE诱导S.桃金娘
Biphenyls are unique phytoalexins produced by plants belonging to Pyrinae, a subtribe of the economically important Rosaceae family. The formation of aucuparin, a well-known biphenyl, is induced by yeast extract (YE) in cell cultures of Sorbus aucuparia. However, the molecular mechanism underlying YE-induced activation of biphenyl biosynthesis remains unknown. Here we demonstrate that the addition of YE to the cell cultures results in a burst of reactive oxygen species (ROS; H2O2 and O-2(-)), followed by transcriptional activation of the biphenyl synthase 1 gene (BIS1) encoding the key enzyme of the biphenyl biosynthetic pathway and aucuparin accumulation. Pretreatment of the cell cultures with ROS scavenger dihydrolipoic acid and NADPH oxidase-specific inhibitor diphenylene iodonium abolished all of the above YE-induced biological events. However, when the cell cultures was pretreated with superoxide dismutase specific inhibitor N,N-diethyldithiocarbamic acid, although O-2(-) continued to be generated, the H2O2 accumulation, BIS1 expression and aucuparin production were blocked. Interestingly, exogenous supply of H2O2 in the range of 0.05-10 mM failed to induce aucuparin accumulation. These results indicate that endogenous generation of H2O2 rather than that of O-2(-) is a key factor in YE-induced accumulation of biphenyl phytoalexins in cell cultures of S. aucuparia.