PDF(Pubmed)
Abstract：
BACKGROUND: Independent origins of carnivory in multiple angiosperm families are fabulous examples of convergent evolution using a diverse array of life forms and habitats. Previous studies have indicated that carnivorous plants have distinct evolutionary trajectories of plastid genome (plastome) compared to their non-carnivorous relatives, yet the extent and general characteristics remain elusive.
RESULTS: We compared plastomes from 9 out of 13 carnivorous families and their non-carnivorous relatives to assess carnivory-associated evolutionary patterns. We identified inversions in all sampled Droseraceae species and four species of Utricularia, Pinguicula, Darlingtonia and Triphyophyllum. A few carnivores showed distinct shifts in inverted repeat boundaries and the overall repeat contents. Many ndh genes, along with some other genes, were independently lost in several carnivorous lineages. We detected significant substitution rate variations in most sampled carnivorous lineages. A significant overall substitution rate acceleration characterizes the two largest carnivorous lineages of Droseraceae and Lentibulariaceae. We also observe moderate substitution rates acceleration in many genes of Cephalotus follicularis, Roridula gorgonias, and Drosophyllum lusitanicum. However, only a few genes exhibit significant relaxed selection.
CONCLUSIONS: Our results indicate that the carnivory of plants have different effects on plastome evolution across carnivorous lineages. The complex mechanism under carnivorous habitats may have resulted in distinctive plastome evolution with conserved plastome in the Brocchinia hechtioides to strongly reconfigured plastomes structures in Droseraceae. Organic carbon obtained from prey and the efficiency of utilizing prey-derived nutrients might constitute possible explanation.
RESULTS: We compared plastomes from 9 out of 13 carnivorous families and their non-carnivorous relatives to assess carnivory-associated evolutionary patterns. We identified inversions in all sampled Droseraceae species and four species of Utricularia, Pinguicula, Darlingtonia and Triphyophyllum. A few carnivores showed distinct shifts in inverted repeat boundaries and the overall repeat contents. Many ndh genes, along with some other genes, were independently lost in several carnivorous lineages. We detected significant substitution rate variations in most sampled carnivorous lineages. A significant overall substitution rate acceleration characterizes the two largest carnivorous lineages of Droseraceae and Lentibulariaceae. We also observe moderate substitution rates acceleration in many genes of Cephalotus follicularis, Roridula gorgonias, and Drosophyllum lusitanicum. However, only a few genes exhibit significant relaxed selection.
CONCLUSIONS: Our results indicate that the carnivory of plants have different effects on plastome evolution across carnivorous lineages. The complex mechanism under carnivorous habitats may have resulted in distinctive plastome evolution with conserved plastome in the Brocchinia hechtioides to strongly reconfigured plastomes structures in Droseraceae. Organic carbon obtained from prey and the efficiency of utilizing prey-derived nutrients might constitute possible explanation.
摘要：
背景：多个被子植物家族中肉食性的独立起源是使用多种生命形式和栖息地进行趋同进化的绝佳例子。先前的研究表明，食肉植物与非食肉近亲相比，质体基因组（质体）具有不同的进化轨迹，然而，程度和一般特征仍然难以捉摸。
结果：我们比较了13个食肉家庭中的9个及其非食肉亲属的质体，以评估食肉相关的进化模式。我们确定了所有采样的Droseraceae物种和四种Utricularia物种的倒置，腹股沟,Darlingtonia和Triphyllum。一些食肉动物在反向重复边界和整体重复内容上显示出明显的变化。许多ndh基因，以及其他一些基因，在几个食肉谱系中独立消失。我们在大多数采样的食肉谱系中检测到显着的替代率变化。显着的总体替代率加速表征了Droseraceae和Lentbulliaceae的两个最大的食肉谱系。我们还观察到毛囊三尖杉许多基因的中等取代率加速，Roridulagorgonias,和LusitanicumDrosophyllum.然而,只有少数基因表现出明显的宽松选择。
结论：我们的结果表明，植物的食肉性对不同食肉谱系的质体进化有不同的影响。食肉生境下的复杂机制可能导致了独特的质体进化，其中在刺竹中保守的质体进化为Droseraceae中强烈重构的质体结构。从猎物中获得的有机碳和利用猎物来源的营养素的效率可能构成可能的解释。
结果：我们比较了13个食肉家庭中的9个及其非食肉亲属的质体，以评估食肉相关的进化模式。我们确定了所有采样的Droseraceae物种和四种Utricularia物种的倒置，腹股沟,Darlingtonia和Triphyllum。一些食肉动物在反向重复边界和整体重复内容上显示出明显的变化。许多ndh基因，以及其他一些基因，在几个食肉谱系中独立消失。我们在大多数采样的食肉谱系中检测到显着的替代率变化。显着的总体替代率加速表征了Droseraceae和Lentbulliaceae的两个最大的食肉谱系。我们还观察到毛囊三尖杉许多基因的中等取代率加速，Roridulagorgonias,和LusitanicumDrosophyllum.然而,只有少数基因表现出明显的宽松选择。
结论：我们的结果表明，植物的食肉性对不同食肉谱系的质体进化有不同的影响。食肉生境下的复杂机制可能导致了独特的质体进化，其中在刺竹中保守的质体进化为Droseraceae中强烈重构的质体结构。从猎物中获得的有机碳和利用猎物来源的营养素的效率可能构成可能的解释。
