Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou 570228, China.
College of Tropical Crops & College of Life Sciences, Hainan University, Haikou 570228, China.
Int J Mol Sci. 2023 Mar 2;24(5):4837. doi: 10.3390/ijms24054837.
is one of the homologous crops used as a medicinal food containing an abundance of anthraquinones. Type III polyketide synthases (PKSs) are key enzymes that catalyze polyketide formation; in particular, the chalcone synthase-like (CHS-L) genes are involved in anthraquinone production. Tandem duplication is a fundamental mechanism for gene family expansion. However, the analysis of the tandem duplicated genes (TDGs) and the identification and characterization of PKSs have not been reported for . Herein, we identified 3087 TDGs in the genome; the synonymous substitution rates (Ks) analysis indicated that the TDGs had recently undergone duplication. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the type III were the most enriched TDGs involved in the biosynthesis of the secondary metabolite pathways, as evidenced by 14 tandem duplicated genes. Subsequently, we identified 30 type III with complete sequences in the genome. Based on the phylogenetic analysis, the type III PKSs were classified into three groups. The protein conserved motifs and key active residues showed similar patterns in the same group. The transcriptome analysis showed that the chalcone synthase (CHS) genes were more highly expressed in the leaves than in the seeds in . The transcriptome and qRT-PCR analysis showed that the genes had a higher expression in the seeds than in other tissues, particularly seven tandem duplicated ////// genes. The key active-site residues and three-dimensional models of the CHS-L2/3/5/6/9/10/13 proteins showed slight variation. These results indicated that the rich anthraquinones in seeds might be ascribed to the expansion from tandem duplication, and the seven key ////// genes provide candidate genes for further research. Our study provides an important basis for further research on the regulation of anthraquinones' biosynthesis in .
是一种同源药用作物，含有丰富的蒽醌类化合物。III 型聚酮合酶（PKSs）是催化聚酮形成的关键酶；特别是查尔酮合酶样（CHS-L）基因参与蒽醌类物质的生成。串联重复是基因家族扩增的基本机制。然而，尚未报道用于 的串联重复基因（TDGs）分析以及 PKSs 的鉴定和表征。在此，我们在 基因组中鉴定了 3087 个 TDGs；同义替代率（Ks）分析表明，这些 TDGs 最近发生了复制。京都基因与基因组百科全书（KEGG）富集分析表明，III 型 PKSs 是参与次生代谢途径生物合成的最丰富的 TDGs，这一点可由 14 个串联重复的 基因得到证明。随后，我们在 基因组中鉴定了 30 个具有完整序列的 III 型 PKSs。基于系统发育分析，III 型 PKSs 分为三组。同一组中，蛋白质保守基序和关键活性残基表现出相似的模式。转录组分析表明，在 中，类黄酮合酶（CHS）基因在叶片中的表达高于在种子中的表达。转录组和 qRT-PCR 分析表明， 基因在种子中的表达高于其他组织，特别是七个串联重复的 ////// 基因。CHS-L2/3/5/6/9/10/13 蛋白的关键活性位点残基和三维模型显示出轻微的变化。这些结果表明， 种子中丰富的蒽醌类化合物可能归因于串联重复的扩展，而七个关键的 ////// 基因可能为进一步的研究提供候选基因。我们的研究为进一步研究 中蒽醌类物质生物合成的调控提供了重要基础。
