Sablok Gaurav, Amiryousefi Ali, He Xiaolan, Hyvönen Jaakko, Poczai Péter
Finnish Museum of Natural History (Botany Unit), University of Helsinki, Helsinki, Finland.
Organismal Evolution and Biology, Faculty of Biology and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.
Front Plant Sci. 2019 Feb 28;10:218. doi: 10.3389/fpls.2019.00218. eCollection 2019.
We report the first plastome sequence of giant ragweed (); with this new genome information, we assessed the phylogeny of Asteraceae and the transcriptional profiling against glyphosate resistance in giant ragweed. Assembly and genic features show a normal angiosperm quadripartite plastome structure with no signatures of deviation in gene directionality. Comparative analysis revealed large inversions across the plastome of giant ragweed and the previously sequenced members of the plant family. Asteraceae plastid genomes contain two inversions of 22.8 and 3.3 kb; the former is located between S-GCU and G-UCC genes, and the latter between E-UUC and T-GGU genes. The plastid genome sequences of and the related species, , are identical in gene content and arrangement, but they differ in length. The phylogeny is well-resolved and congruent with previous hypotheses about the phylogenetic relationship of Asteraceae. Transcriptomic analysis revealed divergence in the relative expressions at the exonic and intronic levels, providing hints toward the ecological adaptation of the genus. Giant ragweed shows various levels of glyphosate resistance, with introns displaying higher expression patterns at resistant time points after the assumed herbicide treatment.
我们报道了豚草（）的首个质体基因组序列；利用这一新的基因组信息，我们评估了菊科的系统发育以及豚草对草甘膦抗性的转录谱。组装和基因特征显示出正常的被子植物四分体质体基因组结构，基因方向性没有偏差迹象。比较分析揭示了豚草质体基因组与该植物科先前测序成员之间存在大的倒位。菊科质体基因组包含两个分别为22.8 kb和3.3 kb的倒位；前者位于S - GCU和G - UCC基因之间，后者位于E - UUC和T - GGU基因之间。豚草及其相关物种的质体基因组序列在基因内容和排列上相同，但长度不同。系统发育关系得到了很好的解析，与之前关于菊科系统发育关系的假设一致。转录组分析揭示了外显子和内含子水平上相对表达的差异，为该属的生态适应性提供了线索。豚草表现出不同程度的草甘膦抗性，在假定的除草剂处理后的抗性时间点，内含子显示出更高的表达模式。
