Multichromosomal structure and foreign tracts in the Ombrophytum subterraneum (Balanophoraceae) mitochondrial genome
Multichromosomal structure and foreign tracts in the Ombrophytum subterraneum (Balanophoraceae) mitochondrial genome
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DOI：
10.1007/s11103-020-01014-x
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发表时间：
2020-05
影响因子：
5.1
通讯作者：
M. Roulet;L. E. Garcia;C. Gandini;Héctor A Sato;Gabriela Ponce;M. V. Sanchez-Puerta
中科院分区：
文献类型：
--
作者：
M. Roulet;L. E. Garcia;C. Gandini;Héctor A Sato;Gabriela Ponce;M. V. Sanchez-Puerta
水平基因转移（HGT）是寄生植物线粒体中频繁发生的现象，是寄主-寄生物关系中建立的维管连接的结果。最近的研究表明，全寄生植物Lophophytum mirabile（蛇菰科）前所未有的收购了大量的线粒体序列从其豆科宿主。我们专注于一个近亲，通性holoparasiteOmbrophytum subjumeum，研究线粒体基因组（mtDNA）中HGT事件的发生率。O.亚染色体装配成54条环状染色体，其中只有34条含有51个全长编码区。HGT从菊科宿主中获得了大量的外来片段（约100 kb，约占mtDNA的14%），其中包括12个完整的基因，其中9条染色体集中了大部分区域，8条染色体几乎完全是外来的。每个外源基因的天然同源物共存于mtDNA中，并具有潜在的功能。大部分短片段与豆科植物有关（约110 kb，15.4%），其中一些与L.不可思议我们还发现了外来序列捐赠的被子植物谱系没有报告为主机（夹竹桃科，大戟科，唇形科，锦葵属）的证据。我们提出了一个进化假说，涉及从豆科宿主的共同祖先Ombrophytum和Lophophytum的古老转移，其次是最近的转移事件L。奇迹。此外，theO。亚被子植物mtDNA也经历了来自不同被子植物谱系的额外HGT事件，包括来自菊科和唇形科的大的和最近的转移。
Horizontal gene transfer (HGT) is frequent in parasitic plant mitochondria as a result of vascular connections established in host-parasite relationships. Recent studies of the holoparasitic plantLophophytum mirabile(Balanophoraceae) revealed the unprecedented acquisition of a large amount of mitochondrial sequences from its legume host. We focused on a close relative, the generalist holoparasiteOmbrophytum subterraneum, to examine the incidence of HGT events in the mitochondrial genome (mtDNA). The mtDNA ofO. subterraneumassembles into 54 circular chromosomes, only 34 of which contain the 51 full-length coding regions. Numerous foreign tracts (totaling almost 100 kb, ~ 14% of the mtDNA), including 12 intact genes, were acquired by HGT from the Asteraceae hosts. Nine chromosomes concentrate most of those regions and eight are almost entirely foreign. Native homologs of each foreign gene coexist in the mtDNA and are potentially functional. A large proportion of shorter regions were related to the Fabaceae (a total of ~ 110 kb, 15.4%), some of which were shared withL. mirabile. We also found evidence of foreign sequences donated by angiosperm lineages not reported as hosts (Apocynaceae, Euphorbiaceae, Lamiaceae, and Malvales). We propose an evolutionary hypothesis that involves ancient transfers from legume hosts in the common ancestor ofOmbrophytumandLophophytumfollowed by more recent transfer events inL. mirabile.Besides, theO. subterraneummtDNA was also subjected to additional HGT events from diverse angiosperm lineages, including large and recent transfers from the Asteraceae, and also from Lamiaceae.