背景:对除草剂的非靶位点抗性(NTSR)是一种威胁农业杂草化学控制的多基因性状。NTSR涉及植物次生代谢途径的差异调节,但其精确的遗传决定机制仍相当不清楚。先前已实施全转录组测序以鉴定NTSR基因。然而,这种方法通常适用于单一杂草种群,限制了我们对NTSR机制多样性的了解。这里,我们试图通过调查来自法国不同地区的六个田间种群来探索普通参草(AmbrosiaartemisiifoliaL.)的NTSR机制的多样性。
结果:从头转录组组装(51,242个重叠群,80.2%的完整性)作为参考,以寻求在六个种群的敏感和抗性植物之间差异表达的基因。总的来说,确定了4,609个组成型差异表达基因,其中没有一个是所有人口所共有的,只有197个被几个人口共享。同样,研究早期除草剂反应时,观察到群体特异性转录组反应.基因本体论富集分析强调了应激反应和调节途径的参与,治疗前后。121个候选组成型NTSR基因的表达,包括CYP71,CYP72,CYP94,氧化还原酶,ABC运输商,在220个表型植物中测量葡萄糖和糖基转移酶。对于28个候选基因,在至少一个杂草群体中验证差异表达。我们研究了某些候选基因组合的表达模式是否可以预测表型。在人群中,当应用于额外的、独立的工厂采样。总的来说,与NTSR相关的各种各样的基因被鉴定在和杂草种群中,在我们的实验中只捕获了其中的一个子集。
结论:我们的结果强调了NTSR机制的复杂性和多样性,这些机制可以在杂草物种中响应除草剂选择压力而进化。他们强烈指出一个非多余的,在禾本科植物中NTSR对ALS抑制剂的群体特异性进化。它还提醒人们,常见的raw草可能会快速适应剧烈的环境或人为驱动的选择压力。
BACKGROUND: Non-target site resistance (NTSR) to herbicides is a polygenic trait that threatens the chemical control of agricultural weeds. NTSR involves differential regulation of plant secondary metabolism pathways, but its precise genetic determinisms remain fairly unclear. Full-transcriptome sequencing had previously been implemented to identify NTSR genes. However, this approach had generally been applied to a single weed population, limiting our insight into the diversity of NTSR mechanisms. Here, we sought to explore the diversity of NTSR mechanisms in common ragweed (Ambrosia artemisiifolia L.) by investigating six field populations from different French regions where NTSR to acetolactate-synthase-inhibiting herbicides had evolved.
RESULTS: A de novo transcriptome assembly (51,242 contigs, 80.2% completeness) was generated as a reference to seek genes differentially expressed between sensitive and resistant plants from the six populations. Overall, 4,609 constitutively differentially expressed genes were identified, of which none were common to all populations, and only 197 were shared by several populations. Similarly, population-specific transcriptomic response was observed when investigating early herbicide response. Gene ontology enrichment analysis highlighted the involvement of stress response and regulatory pathways, before and after treatment. The expression of 121 candidate constitutive NTSR genes including CYP71, CYP72, CYP94, oxidoreductase, ABC transporters, gluco and glycosyltransferases was measured in 220 phenotyped plants. Differential expression was validated in at least one ragweed population for 28 candidate genes. We investigated whether expression patterns at some combinations of candidate genes could predict phenotype. Within populations, prediction accuracy decreased when applied to an additional, independent plant sampling. Overall, a wide variety of genes linked to NTSR was identified within and among ragweed populations, of which only a subset was captured in our experiments.
CONCLUSIONS: Our results highlight the complexity and the diversity of NTSR mechanisms that can evolve in a weed species in response to herbicide selective pressure. They strongly point to a non-redundant, population-specific evolution of NTSR to ALS inhibitors in ragweed. It also alerts on the potential of common ragweed for rapid adaptation to drastic environmental or human-driven selective pressures.