UNESP - São Paulo State University, School of Agricultural and Veterinarian Sciences, Department of Agricultural and Environmental Biotechnology, Campus Jaboticabal, CEP 14884-900 SP, Brazil.
UNESP - São Paulo State University, School of Agricultural and Veterinarian Sciences, Department of Biology, Laboratory of Plant Systematics, Campus Jaboticabal, CEP 14884-900 SP, Brazil.
Mol Phylogenet Evol. 2023 Apr;181:107711. doi: 10.1016/j.ympev.2023.107711. Epub 2023 Jan 21.
Utricularia and Genlisea are highly specialized carnivorous plants whose phylogenetic history has been poorly explored using phylogenomic methods. Additional sampling and genomic data are needed to advance our phylogenetic and taxonomic knowledge of this group of plants. Within a comparative framework, we present a characterization of plastome (PT) and mitochondrial (MT) genes of 26 Utricularia and six Genlisea species, with representatives of all subgenera and growth habits. All PT genomes maintain similar gene content, showing minor variation across the genes located between the PT junctions. One exception is a major variation related to different patterns in the presence and absence of ndh genes in the small single copy region, which appears to follow the phylogenetic history of the species rather than their lifestyle. All MT genomes exhibit similar gene content, with most differences related to a lineage-specific pseudogenes. We find evidence for episodic positive diversifying selection in PT and for most of the Utricularia MT genes that may be related to the current hypothesis that bladderworts' nuclear DNA is under constant ROS oxidative DNA damage and unusual DNA repair mechanisms, or even low fidelity polymerase that bypass lesions which could also be affecting the organellar genomes. Finally, both PT and MT phylogenetic trees were well resolved and highly supported, providing a congruent phylogenomic hypothesis for Utricularia and Genlisea clade given the study sampling.
狸藻属和狸藻属是高度特化的肉食性植物，其系统发育历史利用系统基因组学方法研究甚少。需要更多的采样和基因组数据来推进我们对该植物类群的系统发育和分类学知识。在比较框架内，我们对 26 种狸藻属和 6 种狸藻属物种的质体（PT）和线粒体（MT）基因进行了特征描述，这些物种代表了所有亚属和生长习性。所有的 PT 基因组都保持着相似的基因内容，在 PT 连接处之间的基因上存在微小的变异。一个例外是与小单拷贝区中 ndh 基因的存在和缺失模式不同的主要变异，这似乎遵循了物种的系统发育历史，而不是它们的生活方式。所有的 MT 基因组都表现出相似的基因内容，大多数差异与谱系特异性假基因有关。我们在 PT 中发现了正选择的证据，以及大多数狸藻属的 MT 基因都有证据表明，这可能与目前的假设有关，即膀胱草的核 DNA 不断受到 ROS 氧化 DNA 损伤和不寻常的 DNA 修复机制的影响，或者甚至是低保真度的聚合酶，它可以绕过可能影响细胞器基因组的病变。最后，PT 和 MT 系统发育树都得到了很好的解决和高度支持，为研究采样提供了一个一致的狸藻属和狸藻属系统发育假说。
