Cytochrome P450 CYP81A12 and CYP81A21 Are Associated with Resistance to Two Acetolactate Synthase Inhibitors in Echinochloa phyllopogon
Cytochrome P450 CYP81A12 and CYP81A21 Are Associated with Resistance to Two Acetolactate Synthase Inhibitors in Echinochloa phyllopogon
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DOI：
10.1104/pp.113.232843
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发表时间：
2014-06-01
期刊：
影响因子：
7.4
通讯作者：
Inamura, Tatsuya
中科院分区：
文献类型：
--
作者：
Iwakami, Satoshi;Endo, Masaki;Inamura, Tatsuya
先前的研究已经证明了加州的稗草（Echinochloa phyllopogon）种群对多种除草剂的抗性，稗草是水稻田的一种有害杂草。结果表明，烟草对苄嘧磺隆（BSM）和五氟磺草胺（PX）这两类乙酰乳酸酯酶抑制型除草剂的抗性可能是由除草剂代谢细胞色素P450活性增强引起的。本文研究了BSM在E. phyllopogon，最初收集自加州的不同地区。R植物比S植物更快地通过O-去甲基化代谢BSM。本研究在现有水稻抗除草剂信息的基础上，分离并分析了水稻CYP 81 A亚家族P450基因。叶芒草两个基因，CYP 81 A12和CYP 81 A21，在R植物中比S植物更活跃地转录。表达两种基因中任一种的转基因拟南芥在含有BSM或PX的培养基中以野生型停止生长的水平存活。从R和S植株杂交的F2代中的抗性分离表明，对BSM和PX的抗性各自受单一调控元件控制。在F6重组自交系中，BSM和PX抗性与CYP 81 A12和CYP 81 A21转录水平的增加共分离。酵母（Saccharomyces cerevisiae）中异源产生的CYP 81 A12和CYP 81 A21蛋白通过O-去甲基化代谢BSM。我们的研究结果表明，两个P450基因的过表达赋予了对两类乙酰乳酸合成酶抑制剂的耐药性。叶芒草在E.叶芒草
Previous studies have demonstrated multiple herbicide resistance in California populations of Echinochloa phyllopogon, a noxious weed in rice (Oryza sativa) fields. It was suggested that the resistance to two classes of acetolactate synthase-inhibiting herbicides, bensulfuron-methyl (BSM) and penoxsulam (PX), may be caused by enhanced activities of herbicide-metabolizing cytochrome P450. We investigated BSM metabolism in the resistant (R) and susceptible (S) lines of E. phyllopogon, which were originally collected from different areas in California. R plants metabolized BSM through O-demethylation more rapidly than S plants. Based on available information about BSM tolerance in rice, we isolated and analyzed P450 genes of the CYP81A subfamily in E. phyllopogon. Two genes, CYP81A12 and CYP81A21, were more actively transcribed in R plants compared with S plants. Transgenic Arabidopsis (Arabidopsis thaliana) expressing either of the two genes survived in media containing BSM or PX at levels at which the wild type stopped growing. Segregation of resistances in the F2 generation from crosses of R and S plants suggested that the resistance to BSM and PX were each under the control of a single regulatory element. In F6 recombinant inbred lines, BSM and PX resistances cosegregated with increased transcript levels of CYP81A12 and CYP81A21. Heterologously produced CYP81A12 and CYP81A21 proteins in yeast (Saccharomyces cerevisiae) metabolized BSM through O-demethylation. Our results suggest that overexpression of the two P450 genes confers resistance to two classes of acetolactate synthase inhibitors to E. phyllopogon. The overexpression of the two genes could be regulated simultaneously by a single trans-acting element in the R line of E. phyllopogon.