Understanding the convergent evolution of a complex metabolic trait, the Betalains, through comparative genomics and co-expression networks

通过比较基因组学和共表达网络了解复杂代谢性状甜菜碱的趋同进化

• 批准号: 436841671
• 负责人: Professor Dr. Boas Pucker
• 金额: --
• 依托单位: Institut für Pflanzenbiologie
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/436841671?language=en
• 关键词: Understanding; convergent; evolution; complex; metabolic

Plants display a vast diversity of complex specialized metabolic traits in order to adapt to thechallenges of their environment. Several mechanisms are involved in the evolution of thesemetabolic traits including expansion of specialised metabolic gene families, gene co-option frompreviously existing metabolic pathways, and the formation of gene clusters. In the floweringplant order Caryophyllales, a unique class of specialised metabolites, termed betalain pigments,have recently been shown to have convergently evolved four times. At least one origin isassociated with the formation of a gene cluster. The convergent origins of betalain pigmentsoffer an ideal system in which to explore the evolutionary assembly of complex metabolic traitsand the assembly of gene clusters. Therefore, the overarching goal of this project is to employdensely sampled and integrated transcriptomic and genomic datasets to dissect the evolution ofbetalain pigments, focussing on phenomena of convergence. Genomic characteristics andmodular gene expression structure associated with each evolutionary origin of betalainpigmentation will be explored. The underlying hypotheses suggest that the genomic and geneexpression structure associated with the different origins will reveal commonalities, but will also reveal distinct patterns of gene co-option, genetic regulation, and genomic gene clustering.My specific objectives are:1) To understand the repeated evolution of a complex trait by using phylogenetic andnetwork methods applied to RNA-seq data to analyze the integration and connectivity ofgenetic elements over multiple origins of betalain pigmentation. This objective will drawheavily on a modular understanding of gene expression underpinning specialisedmetabolism.2) To explore the genomic precursors of betalain pigmentation by assembling andannotating the genomes of two taxa diverging prior to the earliest inferred duplications ofbetalain pathway. To conduct comparative genomic analyses against otherCaryophyllales genomes to explore genomic structure and re-organisation acrossmultiple origins of betalain pigmentation.

为了适应环境的挑战，植物表现出各种复杂的特化代谢特征。这些代谢性状的进化涉及多种机制，包括专门的代谢基因家族的扩展、先前存在的代谢途径的基因共选择以及基因簇的形成。在开花植物中，有一类特殊的代谢产物，称为甜菜色素，最近被证明已经进化了四次。至少有一个起源与基因簇的形成有关。甜菜色素的趋同起源为探索复杂代谢特征的进化组装和基因簇的组装提供了一个理想的系统。因此，该项目的总体目标是采用密集采样和整合的转录组学和基因组数据集来剖析甜菜色素的进化，重点关注收敛现象。基因组特征和模块化基因表达结构与每个进化起源的甜菜色素沉着将进行探讨。本论文的主要目的是：1）通过系统发育和网络方法分析甜菜色素色素多个来源间遗传元件的整合和连接，了解复杂性状的重复进化过程。2）通过组装和注释在甜菜色素途径最早推断的重复之前发散的两个分类群的基因组，探索甜菜色素色素沉着的基因组前体。对其他卡氏藻目基因组进行比较基因组分析，以探索甜菜色素色素沉着的多个起源的基因组结构和重组。