Zhong Furong, Ke Wenjia, Li Yirou, Chen Xiaoyan, Zhou Tao, Xu Binjie, Qi Luming, Yan Zhuyun, Ma Yuntong
State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
Front Plant Sci. 2023 May 29;14:1166420. doi: 10.3389/fpls.2023.1166420. eCollection 2023.
plants (Ranunculaceae) contain high levels of isoquinoline alkaloids and have a long history of medicinal use. species are of great value in pharmaceutical industries and scientific research. Mitochondria are considered as one of the central units for receiving stress signals and arranging immediate responses. Comprehensive characterizations of plant mitogenomes are imperative for revealing the relationship between mitochondria, elucidating biological functions of mitochondria and understanding the environmental adaptation mechanisms of plants. Here, the mitochondrial genomes of , and were assembled through the Nanopore and Illumina sequencing platform for the first time. The genome organization, gene number, RNA editing sites, repeat sequences, gene migration from chloroplast to mitochondria were compared. The mitogenomes of , and have six, two, two circular-mapping molecules with the total length of 1,425,403 bp, 1,520,338 bp and 1,152,812 bp, respectively. The complete mitogenomes harbors 68-86 predicted functional genes including 39-51 PCGs, 26-35 tRNAs and 2-5 rRNAs. mitogenome host the most abundant repeat sequences, while mitogenome has the largest number of transferred fragments from its chloroplasts. The large repeat sequences and foreign sequences in the mitochondrial genomes of species were related to substantial rearrangements, changes in relative position of genes and multiple copy genes. Further comparative analysis illustrated that the PCGs under selected pressure in mitochondrial genomes of the three species mainly belong to the mitochondrial complex I (NADH dehydrogenase). Heat stress adversely affected the mitochondrial complex I and V, antioxidant enzyme system, ROS accumulation and ATP production of the three species. The activation of antioxidant enzymes, increase of T-AOC and maintenance of low ROS accumulation in under heat stress were suggested as the factors for its thermal acclimation and normal growth at lower altitudes. This study provides comprehensive information on the mitogenomes and is of great importance to elucidate the mitochondrial functions, understand the different thermal acclimation mechanisms of plants, and breed heat-tolerant varieties.
毛茛科植物含有高水平的异喹啉生物碱，并且有着悠久的药用历史。该科物种在制药行业和科学研究中具有重要价值。线粒体被认为是接收应激信号并安排即时反应的核心单元之一。对植物线粒体基因组进行全面表征对于揭示线粒体之间的关系、阐明线粒体的生物学功能以及理解植物的环境适应机制至关重要。在此，首次通过纳米孔和Illumina测序平台组装了[具体物种1]、[具体物种2]和[具体物种3]的线粒体基因组。比较了基因组组织、基因数量、RNA编辑位点、重复序列以及从叶绿体到线粒体的基因迁移情况。[具体物种1]、[具体物种2]和[具体物种3]的线粒体基因组分别有六个、两个、两个环状分子，总长度分别为1,425,403 bp、1,520,338 bp和1,152,812 bp。完整的线粒体基因组包含68 - 86个预测的功能基因，包括39 - 51个蛋白质编码基因（PCGs）、26 - 35个tRNA和2 - 5个rRNA。[具体物种1]的线粒体基因组拥有最丰富的重复序列，而[具体物种2]的线粒体基因组具有来自其叶绿体的最大数量的转移片段。[具体物种3]物种线粒体基因组中的大重复序列和外源序列与大量重排、基因相对位置的变化以及多拷贝基因有关。进一步的比较分析表明，这三个[具体物种3]物种线粒体基因组中受到选择压力的PCGs主要属于线粒体复合体I（NADH脱氢酶）。热胁迫对这三个[具体物种3]物种的线粒体复合体I和V、抗氧化酶系统、活性氧积累和ATP产生产生了不利影响。热胁迫下[具体物种1]中抗氧化酶的激活、总抗氧化能力（T - AOC）的增加以及低活性氧积累的维持被认为是其热适应和在较低海拔正常生长的因素。本研究提供了关于[具体物种3]线粒体基因组的全面信息，对于阐明线粒体功能、理解[具体物种3]植物不同的热适应机制以及培育耐热品种具有重要意义。
