Characterisation of ALS genes in the polyploid species Schoenoplectus mucronatus and implications for resistance management
Characterisation of ALS genes in the polyploid species Schoenoplectus mucronatus and implications for resistance management
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DOI：
10.1002/ps.1883
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发表时间：
2010-03-01
影响因子：
4.1
通讯作者：
Varotto, Serena
中科院分区：
文献类型：
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作者：
Scarabel, Laura;Locascio, Antonella;Varotto, Serena
背景：多倍体杂草Schoenoplectus mucronatus（L.）Palla已经在意大利水稻作物中进化出对ALS抑制除草剂的靶点抗性。抗性机制的分子和遗传特征与除草剂抗性的进化和管理有关。作者的目的是（a）研究两个野外选择的S。（B）鉴定赋予ALS抑制剂抗性的突变，并通过使用转基因确定这些突变的作用，以及（c）分析对S.结果：鉴定了两个具有内含子的完整ALS基因（ALS 1和ALS 2）和第三个部分无内含子ALS基因（ALS 3）。通过Southern印迹分析证实了多个ALS基因的存在，并且通过检查胞嘧啶甲基化来表征ALS基因座。In S.结果表明，在假单胞菌叶片中，ALS 1、ALS 2和ALS 3的转录本均被检测到。在两个抗性群体中发现了两个赋予抗性的突变（Pro，97至His和Trp（574）至Leu），但频率不同。转化烟草植株的结果表明，Pro，97-替换为His的等位基因对SU和TP除草剂具有抗性，而Trp（574）-替换为Leu的等位基因对SU、TP、IMI和PTB除草剂具有交叉抗性。这两个突变的等位基因被证明是负责ALS抗性。在种群水平上，抗性模式取决于各种抗性基因型的频率，这影响了各种ALS抑制除草剂的功效。(C)2009年化学工业协会
BACKGROUND: The polyploid weed Schoenoplectus mucronatus (L.) Palla has evolved target-site resistance to ALS-inhibiting herbicides in Italian rice crops. Molecular and genetic characterisation of the resistance mechanism is relevant to the evolution and management of herbicide resistance. The authors aimed (a) to study the organisation of the target-site loci in two field-selected S. mucronatus populations with different cross-resistance patterns, (b) to identify the mutations endowing resistance to ALS inhibitors and determine the role of these mutations by using transgenesis and (c) to analyse the implications for the management of the S. mucronatus populations.RESULTS: Two complete ALS genes (ALS1 and ALS2) having an intron and a third partial intronless ALS gene (ALS3) were identified. The presence of multiple ALS genes was confirmed by Southern blot analyses, and ALS loci were characterised by examining cytosine methylation. In S. mucronatus leaves, the transcripts of ALS1, ALS2 and ALS3 were detected. Two mutations endowing resistance (Pro,97 to His and Trp(574) to Leu) were found in both resistant populations, but at different frequencies. Tobacco plants transformed with the two resistant alleles indicated that the Pro,97-to-His substitution conferred resistance to SU and TP herbicides, while the allele with the Trp(574)-to-Leu substitution conferred cross-resistance to SU, TP, IMI and PTB herbicides.CONCLUSION: Schoenoplectus mucronatus has multiple ALS genes characterised by methylated sites that can influence the expression profile. The two mutated alleles proved to be responsible for ALS resistance. At population level, the resistance pattern depends on the frequency of various resistant genotypes, and this influences the efficacy of various ALS-inhibiting herbicides. (C) 2009 Society of Chemical Industry