Md Mazharul Islam, Bikram S. Gill, Jenna M. Malone, Christopher Preston, Mithila Jugulam
{"title":"澳大利亚抗草甘膦 Hordeum glaucum 和 Bromus diandrus 中 EPSPS 基因扩增的细胞遗传学特征。","authors":"Md Mazharul Islam, Bikram S. Gill, Jenna M. Malone, Christopher Preston, Mithila Jugulam","doi":"10.1111/tpj.17128","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>As a result of extensive selection, two polyploid grass weeds, <i>Hordeum glaucum</i> (northern barley grass; 2<i>n</i> = 4<i>x</i> = 28) and <i>Bromus diandrus</i> (ripgut brome; 2<i>n</i> = 8<i>x</i> = 56), have evolved resistance to glyphosate, in Australia. Previous research suggested amplification of 5-enolpyruvylshikimate-3-Phosphate synthase (<i>EPSPS</i>) gene confers resistance in these two weed species. The objective of this research was to investigate the genomic organization of the <i>EPSPS</i> gene in these two species through molecular cytogenetic analyses of fluorescence <i>in situ</i> hybridization (FISH) to understand possible mechanism of amplification of this gene. <i>EPSPS</i> copy number of <i>H. glaucum</i> and <i>B. diandrus</i> plants was estimated via quantitative polymerase chain reaction. The susceptible plants of both species had one copy of <i>EPSPS</i>, whereas the resistant plants of <i>H. glaucum</i> and <i>B. diandrus</i> had 14–17 and 16–32 copies, respectively. FISH analysis of glyphosate-susceptible (Hg-RWS) <i>H. glaucum</i>, revealed four faint signals of the <i>EPSPS</i> gene in two pairs of homologous chromosomes, at the telomeric region. The glyphosate-resistant <i>H. glaucum</i> (Hg-YP1) also showed amplification of <i>EPSPS</i> gene at telomeric regions in two pairs of homologous chromosomes, but the signals were brighter and appeared as cluster of <i>EPSPS</i> genes. Similarly, the glyphosate-susceptible <i>B. diandrus</i> (Bd-S) plants showed faint signals of <i>EPSPS</i> gene on two homologous chromosomes, at the telomeric position. However, samples of two glyphosate-resistant, <i>B. diandrus</i>, Bd-SA988 and Bd-Vic showed much brighter hybridization signals of <i>EPSPS</i> gene, located at the telomere on two homologous chromosomes, suggesting an increase in <i>EPSPS</i> gene copies at this position. Overall, unequal crossover during meiosis may have triggered the initial <i>EPSPS</i> gene duplication sparking the evolution of glyphosate resistance.</p>\n </div>","PeriodicalId":233,"journal":{"name":"The Plant Journal","volume":"120 6","pages":"2553-2562"},"PeriodicalIF":6.2000,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Cytogenetic characterization of EPSPS gene amplification in glyphosate-resistant Hordeum glaucum and Bromus diandrus from Australia\",\"authors\":\"Md Mazharul Islam, Bikram S. Gill, Jenna M. 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The susceptible plants of both species had one copy of <i>EPSPS</i>, whereas the resistant plants of <i>H. glaucum</i> and <i>B. diandrus</i> had 14–17 and 16–32 copies, respectively. FISH analysis of glyphosate-susceptible (Hg-RWS) <i>H. glaucum</i>, revealed four faint signals of the <i>EPSPS</i> gene in two pairs of homologous chromosomes, at the telomeric region. The glyphosate-resistant <i>H. glaucum</i> (Hg-YP1) also showed amplification of <i>EPSPS</i> gene at telomeric regions in two pairs of homologous chromosomes, but the signals were brighter and appeared as cluster of <i>EPSPS</i> genes. Similarly, the glyphosate-susceptible <i>B. diandrus</i> (Bd-S) plants showed faint signals of <i>EPSPS</i> gene on two homologous chromosomes, at the telomeric position. 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引用次数: 0
摘要
经过广泛的选择,澳大利亚的两种多倍体禾本科杂草 Hordeum glaucum(北方大麦草;2n = 4x = 28)和 Bromus diandrus(ripgut brome;2n = 8x = 56)对草甘膦产生了抗性。先前的研究表明,5-烯醇丙酮酰石蒜碱-3-磷酸合成酶(EPSPS)基因的扩增赋予了这两种杂草抗性。本研究的目的是通过荧光原位杂交(FISH)的分子细胞遗传学分析,研究这两种杂草中 EPSPS 基因的基因组组织,以了解该基因扩增的可能机制。通过定量聚合酶链式反应估算了 H. glaucum 和 B. diandrus 植物的 EPSPS 拷贝数。两个物种的易感植株都有一个 EPSPS 拷贝,而 H. glaucum 和 B. diandrus 的抗性植株分别有 14-17 和 16-32 个拷贝。对草甘膦易感植物(Hg-RWS)H. glaucum 的 FISH 分析显示,在两对同源染色体的端粒区有四个 EPSPS 基因的微弱信号。抗草甘膦的 H. glaucum(Hg-YP1)也在两对同源染色体的端粒区出现了 EPSPS 基因的扩增,但信号更亮,表现为 EPSPS 基因簇。同样,对草甘膦敏感的 B. diandrus(Bd-S)植株也在两条同源染色体的端粒位置出现了微弱的 EPSPS 基因信号。然而,两种草甘膦抗性 B. diandrus(Bd-SA988 和 Bd-Vic)的样本显示,位于两条同源染色体端粒位置的 EPSPS 基因杂交信号要明亮得多,这表明该位置的 EPSPS 基因拷贝有所增加。总之,减数分裂过程中的不等交叉可能引发了最初的 EPSPS 基因复制,引发了草甘膦抗性的进化。
Cytogenetic characterization of EPSPS gene amplification in glyphosate-resistant Hordeum glaucum and Bromus diandrus from Australia
As a result of extensive selection, two polyploid grass weeds, Hordeum glaucum (northern barley grass; 2n = 4x = 28) and Bromus diandrus (ripgut brome; 2n = 8x = 56), have evolved resistance to glyphosate, in Australia. Previous research suggested amplification of 5-enolpyruvylshikimate-3-Phosphate synthase (EPSPS) gene confers resistance in these two weed species. The objective of this research was to investigate the genomic organization of the EPSPS gene in these two species through molecular cytogenetic analyses of fluorescence in situ hybridization (FISH) to understand possible mechanism of amplification of this gene. EPSPS copy number of H. glaucum and B. diandrus plants was estimated via quantitative polymerase chain reaction. The susceptible plants of both species had one copy of EPSPS, whereas the resistant plants of H. glaucum and B. diandrus had 14–17 and 16–32 copies, respectively. FISH analysis of glyphosate-susceptible (Hg-RWS) H. glaucum, revealed four faint signals of the EPSPS gene in two pairs of homologous chromosomes, at the telomeric region. The glyphosate-resistant H. glaucum (Hg-YP1) also showed amplification of EPSPS gene at telomeric regions in two pairs of homologous chromosomes, but the signals were brighter and appeared as cluster of EPSPS genes. Similarly, the glyphosate-susceptible B. diandrus (Bd-S) plants showed faint signals of EPSPS gene on two homologous chromosomes, at the telomeric position. However, samples of two glyphosate-resistant, B. diandrus, Bd-SA988 and Bd-Vic showed much brighter hybridization signals of EPSPS gene, located at the telomere on two homologous chromosomes, suggesting an increase in EPSPS gene copies at this position. Overall, unequal crossover during meiosis may have triggered the initial EPSPS gene duplication sparking the evolution of glyphosate resistance.
期刊介绍:
Publishing the best original research papers in all key areas of modern plant biology from the world"s leading laboratories, The Plant Journal provides a dynamic forum for this ever growing international research community.
Plant science research is now at the forefront of research in the biological sciences, with breakthroughs in our understanding of fundamental processes in plants matching those in other organisms. The impact of molecular genetics and the availability of model and crop species can be seen in all aspects of plant biology. For publication in The Plant Journal the research must provide a highly significant new contribution to our understanding of plants and be of general interest to the plant science community.