Genome sequencing and population genomic analyses provide insights into the adaptive landscape of silver birch
Genome sequencing and population genomic analyses provide insights into the adaptive landscape of silver birch
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DOI：
10.1038/ng.3862
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发表时间：
2017-06-01
期刊：
影响因子：
30.8
通讯作者：
Kangasjarvi, Jaakko
中科院分区：
文献类型：
--
作者：
Salojarvi, Jarkko;Smolander, Olli-Pekka;Kangasjarvi, Jaakko
白桦（Betula pendula）是北方森林的先锋树种，可在1年内诱导开花。其快速的生命周期，小（440-Mb）基因组和先进的种质资源使桦树成为森林生物技术的一个有吸引力的模型。我们组装和染色体锚定了一个近交的B. pendula个体的核基因组。来自古六倍体事件的基因重复被富集用于转录调控，而串联重复则被环境反应过度代表。对80个个体的种群重排序显示，在气候剧变的主要点上，有效的种群规模崩溃。选择性扫描在编码关键发育和生理触发功能的多倍体重复体中富集，表明局部适应调节了植物基本过程之间的时间和串扰。紧密相连的光响应基因PHYC和FRS10周围的变异与经纬度和温度相关，并与PHYC的降水量相关。促进生长的细胞分裂素反应调节因子ARR1以及木材发育基因KAK和MED5A也存在类似的关联。
Silver birch (Betula pendula) is a pioneer boreal tree that can be induced to flower within 1 year. Its rapid life cycle, small (440-Mb) genome, and advanced germplasm resources make birch an attractive model for forest biotechnology. We assembled and chromosomally anchored the nuclear genome of an inbred B. pendula individual. Gene duplicates from the paleohexaploid event were enriched for transcriptional regulation, whereas tandem duplicates were overrepresented by environmental responses. Population resequencing of 80 individuals showed effective population size crashes at major points of climatic upheaval. Selective sweeps were enriched among polyploid duplicates encoding key developmental and physiological triggering functions, suggesting that local adaptation has tuned the timing of and cross-talk between fundamental plant processes. Variation around the tightly-linked light response genes PHYC and FRS10 correlated with latitude and longitude and temperature, and with precipitation for PHYC. Similar associations characterized the growth-promoting cytokinin response regulator ARR1, and the wood development genes KAK and MED5A.