水稻乙酰乳酸合酶Ala179Val突变赋予ALS抑制剂类除草剂广谱抗性

Ala179Val Mutation in Rice Acetolactate Synthase Confers Broad-spectrum Resistance to ALS Inhibitor Herbicides

为了鉴定新型水稻突变体ALS179对乙酰乳酸合酶(ALS,acetolactate synthase)抑制剂类除草剂的抗性,本研究以野生型水稻华航31(HH31)、耐咪唑啉酮除草剂水稻ALS627突变体和甲基磺酸乙酯(EMS,ethyl methyl sulfone)诱变的新型水稻突变体ALS179为试验材料,通过不同浓度下的4类乙酰乳酸合酶抑制剂类除草剂包衣浸种和苗期喷施处理,进一步测定表型及相关酶活性指标来探究突变体ALS179的抗性。结果表明,经过除草剂包衣浸种以及苗期喷施处理后,突变体ALS179对苯磺隆、咪唑乙烟酸、双草醚及啶磺草胺具有不同程度的抗性,且乙酰乳酸合酶、过氧化物酶、过氧化氢酶和超氧化物歧化酶的活性随除草剂浓度的升高呈下降趋势。除了20×,30×的咪唑乙烟酸处理条件下过氧化氢酶和过氧化物酶的酶活性低于野生型HH31外,其他处理条件下ALS179的乙酰乳酸合酶、超氧化物歧化酶、过氧化氢酶和过氧化物酶的酶活性均高于野生型HH31。因此,本研究发现Ala179Val突变赋予了对ALS抑制剂类除草剂的广谱抗性,为后续ALS类除草剂广谱抗性水稻品系的培育提供遗传种质资源。

To characterize the resistance of the novel rice mutant ALS179 to acetolactate synthase(ALS)inhibiting herbicides,this study analyzed the Ethyl Methyl Sulfone(EMS)-mutagenized novel rice mutant ALS179,together with wild-type Huahang31(HH31),imidazolinone-tolerant rice ALS627 mutant,treated by four types of ALS-inhibiting herbicides by either seed coating or seedling spray treatment at different concentrations.The phenotypes and enzyme activity indexes were further determined to investigate the resistance of the mutant ALS179.The results showed that the mutant ALS179 showed various degrees of resistance to benensulfuron,imazethapyr,bispyribac-sodium and pyroxsulam after herbicide coating for seed soaking and seedling spraying,and the activities of acetolactate synthase,peroxidase,catalase and superoxide dismutase tended to decrease with increasing herbicide concentration.The enzyme activities of acetolactate synthase,superoxide dismutase,catalase,and peroxidase were higher in ALS179 than in wild-type HH31 under all treatment conditions,except for imidazoleisonicotinic acid treatment condition at high concentration where the enzyme activities of catalase and peroxidase were lower than those of wild-type HH31.Collectively,we found that the Ala179Val mutation conferred broad-spectrum resistance to ALS-inhibiting herbicides and provided genetic germplasm resources for the subsequent breeding of ALS-inhibiting herbicide broad-spectrum resistant rice lines.