Lineage-specific evolution of flavin-containing monooxygenases involved in aliphatic glucosinolate side-chain modification
Lineage-specific evolution of flavin-containing monooxygenases involved in aliphatic glucosinolate side-chain modification
复制标题
参与脂肪族芥子油苷侧链修饰的含黄素单加氧酶的谱系特异性进化。
DOI：
10.1111/jse.12289
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发表时间：
2018-03-01
影响因子：
3.7
通讯作者：
Li, Jing
中科院分区：
文献类型：
--
作者：
Cang, Wei;Sheng, Yu-Xin;Li, Jing
芥子油苷是十字花目特有的一类特殊代谢物，其生物活性多样，在很大程度上取决于其侧链结构。由FMOGS - OX基因编码的含黄素单加氧酶（FMOs）已被发现在蛋氨酸衍生的脂肪族芥子油苷合成过程中催化侧链修饰。在拟南芥中已鉴定出7个FMOGS - OX基因，但在包括许多具有重要经济价值蔬菜的十字花科中，这些基因的进化情况却鲜为人知。在本研究中，对12个已测序的十字花科物种的FMOGS - OX基因的系统发育和同线性关系进行了分析。我们的研究结果表明，FMOGS - OX基因包括两个串联阵列，即FMOGS - OX2 - 4组（A组）和FMOGS - OX5 - 7组（B组）。在十字花科中，FMOGS - OX的A组和B组的进化历史相似，但在这两个独立的物种谱系从阿拉伯糖芥（Aethionema arabicum (L.) Andrz. ex DC.）分化之后，出现了两条谱系特异性的进化路径。在谱系I路径中，由于大多数物种中频繁的串联重复事件以及亚麻荠（Camelina sativa (L.) Crantz）的全基因组三倍化，FMOGS - OX基因拷贝数趋于增加。在谱系II路径中，由于缺失事件，基因拷贝数减少。将这些结果与先前的研究结果相结合，我们推测FMOGS - OX基因源自一个具有广泛表达分布和广泛底物范围的祖先基因，然后经历了亚功能化，产生了在空间表达或底物结构上受限的后代。此外，在一些含有FMOGS - OX5的物种中缺乏FMOGS - OX5底物，这可能表明这些基因发生了新功能化。
Glucosinolates, a class of specialized metabolites specific to the order Brassicales, have diverse bioactivities that are largely dependent on the structures of their side chains. Flavin-containing monooxygenases (FMOs) encoded by the FMOGS-OX genes have been found to catalyze side-chain modifications during the synthesis of methionine-derived aliphatic glucosinolates. Seven FMOGS-OX genes have been identified in Arabidopsis Heynh., but the evolution of these genes in the Brassicaceae, a family including many economically important vegetables, is poorly understood. In this study, the phylogenetic and syntenic relationships of the FMOGS-OX genes belonging to 12 sequenced Brassicaceae species were analyzed. Our results showed that the FMOGS-OX genes included two tandem arrays, the FMOGS-OX2-4 group (group A) and the FMOGS-OX5-7 group (group B). The evolutionary histories of the FMOGS-OX groups A and B were similar across the Brassicaceae, but two lineage-specific evolutionary routes developed after these two separate species lineages diverged from Aethionema arabicum (L.) Andrz. ex DC. In the lineage I route, FMOGS-OX gene copies tended to increase due to frequent tandem duplication events in most species and a whole genome triplication in Camelina sativa (L.) Crantz. In the lineage II route, gene copies decreased due to deletion events. Combining these results with those of previous studies, we speculated that the FMOGS-OX genes were derived from an ancestral gene with a broad expression distribution and a broad range of substrates, which then underwent subfunctionalization to generate progeny limited in either spatial expression or substrate structure. Furthermore, the absence of FMOGS-OX5 substrates in some FMOGS-OX5-containing species may suggest neofunctionalization of these genes.