Oak genome reveals facets of long lifespan

First author: Christophe Plomion; Affiliations: Université de Bordeaux (波尔多大学): Cestas, France

Corresponding author: Christophe Plomion

Oaks are an important part of our natural and cultural heritage. Not only are they ubiquitous (普遍存在的) in our most common landscapes but they have also supplied human societies with invaluable services, including food and shelter, since prehistoric times (史前时期). With 450 species spread throughout Asia, Europe and America, oaks constitute a critical global renewable resource (可再生资源). The longevity of oaks (several hundred years) probably underlies their emblematic cultural (象征文化) and historical importance. Such long-lived sessile organisms (固着生物) must persist in the face of a wide range of abiotic and biotic threats over their lifespans. We investigated the genomic features associated with such a long lifespan by sequencing, assembling and annotating the oak genome. We then used the growing number of whole-genome sequences for plants (including tree and herbaceous species) to investigate the parallel evolution of genomic characteristics potentially underpinning tree longevity. A further consequence of the long lifespan of trees is their accumulation of somatic mutations during mitotic divisions of stem cells present in the shoot apical meristems. Empirical and modelling approaches have shown that intra-organismal genetic heterogeneity (遗传异质性) can be selected for and provides direct fitness benefits in the arms race with (军备竞赛) short-lived pests and pathogens through a patchwork (拼凑) of intra-organismal phenotypes. However, there is no clear proof that large-statured trees consist of a genetic mosaic (遗传嵌合) of clonally distinct cell lineages within and between branches. Through this case study of oak, we demonstrate the accumulation and transmission of somatic mutations and the expansion of disease-resistance gene families in trees.

橡树是我们重要的的自然和文化遗产。橡树不仅仅再我们身边随处可见，而且从史前时期以来就给人类社会提供了食物和庇护等宝贵的服务。大约有450个物种横跨亚洲、欧洲及美洲分布，其中，橡树组成了一个全球性的重要可再生资源。橡树一般能够存活数百年，这种长寿可能是其象征文化和历史重要性的原因。这种长寿的固着生物在其漫长的生命长河中必定会经历广泛的生物和非生物胁迫。作者本文通过测序、组装和注释橡树基因组，对与长寿相关的基因组特性进行了研究。作者还通过日渐增长的已测序的植物基因组数据，主要包括木本和草本植物，研究了林木长寿潜在基因组区域的平行演化。林木的长寿还会导致的另一个问题就是茎尖分生组织干细胞的有丝分裂会不断积累体细胞突变。经验建模的方法显示生物体内的遗传异质性会受到选择，并通过拼凑不同的生物体内表型在林木与短寿昆虫及病原菌的抵抗斗争中提供直接的适应性。然而，并没有证据显示高大的林木在分枝内部或不同分枝之间存在不同无性细胞系的遗传嵌合现象。本文对于橡树基因组的研究揭示了林木中体细胞突变的积累、传送及抗病基因的扩张。

通讯：Christophe Plomion(https://www6.bordeaux-aquitaine.inra.fr/biogeco/Personnel/Annuaire/M-P/Plomion-Christophe)

个人简介：1992年，雷恩国立农业大学，植物育种工程学学位；1995年，雷恩国立农业大学，博士。

研究方向：橡树的区域适应性及物种形成。

doi: https://doi.org/10.1111/tpj.13945

Journal: Nature Plants

Published Online: 18 June, 2018

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