Safener responsiveness and multiple herbicide resistance in the weed black-grass (Alopecurus myosuroides)
Safener responsiveness and multiple herbicide resistance in the weed black-grass (Alopecurus myosuroides)
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DOI：
10.1111/j.1467-7652.2009.00445.x
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发表时间：
2009-10-01
影响因子：
13.8
通讯作者：
Edwards, Robert
中科院分区：
文献类型：
--
作者：
Cummins, Ian;Bryant, David N.;Edwards, Robert
安全剂通过提高作物的解毒率，提高了杀禾本科除草剂（如精恶唑禾草灵）在谷物中的选择性。在研究恶唑禾草灵在小麦中的选择性时，我们确定了安全剂吡唑解草酯和解草唑乙酯也增强了竞争杂草黑草（大穗看麦娘）的除草剂耐受性。在小麦和黑草中，精恶唑禾草灵通过与谷胱甘肽结合而解毒，所得代谢产物加工成相应的半胱氨酸衍生物，然后进行N-糖基化。在黑草中，这些解毒途径仅被安全剂略微增强，这表明单独的代谢不太可能解释除草剂耐受性的增加。相反，确定安全化与谷胱甘肽和羟甲基谷胱甘肽以及具有抗氧化功能的酶的积累有关，所述酶包括分别作为谷胱甘肽过氧化物酶和巯基转移酶具有活性的φ和λ谷胱甘肽转移酶。这些安全剂引起的变化密切反映了在两个独立的黑草种群，已获得多个除草剂抗性（MHR）在该领域确定的。除了增强谷胱甘肽代谢外，安全剂处理和MHR均导致黑草植物叶子中黄酮类化合物水平升高，特别是黄酮-C-糖苷和花青素。我们的研究结果表明，安全在一个杂草是与一个。抗氧化剂和次生代谢中的可诱导活化，其反映了对多种除草剂具有抗性的植物中表现出的生化表型。
Safeners enhance the selectivity of graminicidal herbicides such as fenoxaprop ethyl in cereals, by increasing their rates of detoxification in the crop. While studying the selectivity of fenoxaprop ethyl in wheat, we determined that the safeners mefenpyr diethyl and fenchlorazole ethyl also enhanced herbicide tolerance in the competing weed black-grass (Alopecurus myosuroides). Fenoxaprop ethyl was detoxified by conjugation with glutathione in both wheat and black-grass, with the resulting metabolites processed to the respective cysteine derivatives, which were then N-glycosylated. in black-grass, these detoxification pathways were only slightly enhanced by safeners, suggesting that metabolism alone was unlikely to account for increased herbicide tolerance. instead, it was determined that safening was associated with an accumulation of glutathione and hydroxymethylglutathione and enzymes with antioxidant functions including phi and lambda glutathione transferases, active as glutathione peroxidases and thiol transferases respectively. These safener-induced changes closely mirrored those determined in two independent black-grass populations that had acquired multiple herbicide resistance (MHR) in the field. In addition to enhanced glutathione metabolism, both safener treatment and MHR resulted in elevated levels of flavonoids in the foliage of black-grass plants, notably flavone-C-glycosides and anthocyanins. Our results demonstrate that safening in a grass weed is associated with an. inducible activation in antioxidant and secondary metabolism which mirrors the biochemical phenotype exhibited in plants that are resistant to multiple classes of herbicides.