BACKGROUNDMonochoria korsakowii is a common broadleaf weed found in rice (Oryza sativa) fields. Acetolactate synthase (ALS) inhibitor herbicides are commonly used to control broadleaf weeds in rice fields. However, prolonged herbicide use has exacerbated resistance issues. In this study, we evaluated the resistance to ALS inhibitors in populations where the same mutation occurred separately and simultaneously in the two ALS homoeologous genes (ALS1 and ALS2) and investigated the resistance mechanisms in M. korsakowii.RESULTSMonochoria korsakowii exhibited high resistance to bensulfuron‐methyl, low resistance to penoxsulam, and sensitivity to imazethapyr. Three resistant populations were identified: M‐1 and M‐2, which independently evolved the Pro‐197‐Ser mutation in ALS1 and ALS2, respectively, and M‐3, which harbored this mutation in both ALS1 and ALS2. The sensitivity of ALS isolated from these populations to herbicide inhibition corresponded to the whole‐plant resistance levels. Subsequently, we cloned and transformed Pro‐197‐Ser‐mutated ALS1 and ALS2 into Arabidopsis thaliana. The resistance of homozygous A. thaliana to bensulfuron‐methyl and penoxsulam aligned with bioassay trends. Furthermore, we measured the ploidy, relative expression, and copy number of ALS1 and ALS2, and found no significant differences, suggesting that the evolution of resistance was primarily attributed to the Pro‐197‐Ser mutation. Finally, we developed a derived cleaved amplified polymorphic sequence marker for detecting Pro‐197‐Ser mutation in ALS.CONCLUSIONThe same mutation occurring separately in homoeologous genes resulted in similar resistance levels, whereas simultaneous mutations in homoeologous genes led to increased resistance levels. © 2024 Society of Chemical Industry.

中文翻译：

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乙酰乳酸合酶 （ALS） 同源基因中的 Pro-197-Ser 突变组合影响 Monochoria korsakowii 的 ALS 抑制剂除草剂抗性水平


背景Monoochoria korsakowii 是一种常见的阔叶杂草，生长在稻田 （Oryza sativa） 中。乙酰乳酸合酶 （ALS） 抑制剂除草剂通常用于控制稻田中的阔叶杂草。然而，长期使用除草剂加剧了耐药性问题。在这项研究中，我们评估了在两个 ALS 同源基因 （ALS1 和 ALS2） 中分别和同时发生相同突变的群体中对 ALS 抑制剂的耐药性，并研究了 M. korsakowii 的耐药机制。结果Monochooria korsakowii 对甲基苯嘧磺隆表现出高耐药性，对 penoxsulam 低耐药，对 imazethapyr 敏感。确定了三个耐药群体： M-1 和 M-2，分别在 ALS1 和 ALS2 中独立进化 Pro-197-Ser 突变，以及 M-3，在 ALS1 和 ALS2 中都携带该突变。从这些种群中分离的 ALS 对除草剂抑制的敏感性对应于全株抗性水平。随后，我们克隆了 Pro-197-Ser-突变的 ALS1 和 ALS2 并将其转化为拟南芥。纯合子拟南芥对甲基苯嘧隆和戊螺酰胺的抗性与生物测定趋势一致。此外，我们测量了 ALS1 和 ALS2 的倍性、相对表达和拷贝数，发现没有显着差异，表明耐药性的进化主要归因于 Pro-197-Ser 突变。最后，我们开发了一种衍生的裂解扩增多态性序列标记物，用于检测 ALS 中的 Pro-197-Ser 突变。结论同源基因中单独发生的相同突变导致相似的耐药水平，而同源基因同时突变导致耐药水平增加。© 2024 化工学会.