Insights into the Existence of Isomeric Plastomes in Cupressoideae (Cupressaceae).
Insights into the Existence of Isomeric Plastomes in Cupressoideae (Cupressaceae).
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DOI：
10.1093/gbe/evx071
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发表时间：
2017-04-01
影响因子：
3.3
通讯作者：
Yi TS
中科院分区：
文献类型：
--
作者：
Qu XJ;Wu CS;Chaw SM;Yi TS
柏科（柏科）具有高度重排的质体，缺乏一对大的倒置重复序列，通常在陆地植物中发现。据报道，一些柏树物种含有异构体质体，但异构体质体的存在是否在科中普遍存在，仍有待于更广泛的分类抽样研究。在这项研究中，我们对最大的柏树亚科——柏科10种柏树的完整质体进行了测序。与柏科其他亚科相比，柏科在非同义位点和同义位点上的取代速率相对较快。我们的PCR和reads图谱分析共同表明，10个测序的柏科物种中有8个存在同分异构体质体。在4种柏科9个野生居群176个个体中检测到同分异构体质体。在Calocedrus macrolepis中，我们发现了一种新的异构体质体，可能是由11-bp重复介导的同源重组产生的。我们得出结论，异构体质体普遍存在于柏科植物中，从而增加了质体的复杂性。
The cypress family (Cupressaceae) possesses highly rearranged plastomes that lack a pair of large inverted repeats typically found in land plants. A few cypress species have been reported to contain isomeric plastomes, but whether the existence of isomeric plastomes is ubiquitous in the family remains to be investigated with a broader taxon sampling. In this study, we sequenced the complete plastomes of ten species in Cupressoideae, the largest cypress subfamily. Cupressoideae showed relatively accelerated rates of substitutions at both nonsynonymous and synonymous sites as compared with other subfamilies of Cupressaceae. Our PCR and read mapping analyses together suggested the existence of isomeric plastomes in eight of the ten sequenced Cupressoideae species. The isomeric plastomes were also detected in 176 individuals from nine wild populations of four Cupressoideae species. Within Calocedrus macrolepis, we discovered a new type of isomeric plastomes that was likely derived from homologous recombination mediated by an 11-bp repeat. We conclude that isomeric plastomes are commonly present in Cupressoideae, thereby contributing to increased plastomic complexity.