The walnut (Juglans regia) genome sequence reveals diversity in genes coding for the biosynthesis of non-structural polyphenols
The walnut (Juglans regia) genome sequence reveals diversity in genes coding for the biosynthesis of non-structural polyphenols
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DOI：
10.1111/tpj.13207
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发表时间：
2016-09-01
期刊：
影响因子：
7.2
通讯作者：
Neale, David B.
中科院分区：
文献类型：
--
作者：
Martinez-Garcia, Pedro J.;Crepeau, Marc W.;Neale, David B.
核桃(Juglans Regia L.)是原产于中亚山区的二倍体树种，是世界上分布最广的树种之一，也是世界上主要的核桃栽培树种。王果的高营养价值与丰富的多酚化合物有关，其完整的生物合成途径尚不清楚。为了发现目的基因和其他未知基因，从‘钱德勒’品种中获得了一个王氏豆腐病菌的基因组序列。用两种不同的方法(SOAPdenovo2和Masurca)组装了667-Mbp的基因组，N50骨架大小为464 955bp(基于基因组大小606 Mbp)，221 640个重叠群，GC含量为37%。用Maker-P和其他基因组资源进行注释，得到32 498个基因模型。以前对核桃的研究依赖于组织特异性方法，只发现了一个多酚氧化酶(PPO)基因(JrPPO1)。在王氏杆菌基因组序列的支持下，发现了PPO的第二个同源物(JrPPO2)。此外，还检测到大没食子酸1-β-葡萄糖基转移酶(GGT)超家族约130个基因。具体地说，JrGGT1和JrGGT2两个基因与栎树GGT(QrGGT)有显著的同源性，QrGGT参与合成1-O-没食子酰β-D-葡萄糖，1-O-没食子酰-β-D-葡萄糖是合成可水解性单宁的前体。王氏藻的参考基因组提供了对合成多酚所需的复杂途径的有意义的洞察。核桃基因组序列为加速育种和促进复杂性状的遗传解剖提供了重要的工具和方法。
The Persian walnut (Juglans regia L.), a diploid species native to the mountainous regions of Central Asia, is the major walnut species cultivated for nut production and is one of the most widespread tree nut species in the world. The high nutritional value of J. regia nuts is associated with a rich array of polyphenolic compounds, whose complete biosynthetic pathways are still unknown. A J. regia genome sequence was obtained from the cultivar 'Chandler' to discover target genes and additional unknown genes. The 667-Mbp genome was assembled using two different methods (SOAPdenovo2 and MaSuRCA), with an N50 scaffold size of 464 955 bp (based on a genome size of 606 Mbp), 221 640 contigs and a GC content of 37%. Annotation with MAKER-P and other genomic resources yielded 32 498 gene models. Previous studies in walnut relying on tissue-specific methods have only identified a single polyphenol oxidase (PPO) gene (JrPPO1). Enabled by the J. regia genome sequence, a second homolog of PPO (JrPPO2) was discovered. In addition, about 130 genes in the large gallate 1-beta-glucosyltransferase (GGT) superfamily were detected. Specifically, two genes, JrGGT1 and JrGGT2, were significantly homologous to the GGT from Quercus robur (QrGGT), which is involved in the synthesis of 1-O-galloyl-beta-D-glucose, a precursor for the synthesis of hydrolysable tannins. The reference genome for J. regia provides meaningful insight into the complex pathways required for the synthesis of polyphenols. The walnut genome sequence provides important tools and methods to accelerate breeding and to facilitate the genetic dissection of complex traits.