Evolutionary adaptations of the plastid transcription machinery as one key element in plant terrestrialisation

质体转录机制的进化适应作为植物陆化的关键要素

• 批准号: 527848546
• 负责人: Professor Dr. Thomas Pfannschmidt
• 金额: --
• 依托单位: Institut für Botanik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/527848546?language=en
• 关键词: Evolutionary; adaptations; plastid; transcription; machinery

Evolutionary emergence of land plants (the backbone of the terrestrial biosphere) traces back to a singular event in which freshwater algae conquered land, a process referred to as terrestrialisation. This transition to land required a plethora of molecular adaptations that allowed the ancestor of plants to survive under the harsh environmental conditions of the new habitat. One of the most important requirements was the physiological adaptation of the chloroplast that is especially susceptible to environmental stressors. Key element of this process was the coordination of gene expression between cell nucleus and organelle in order to guarantee proper build-up and maintenance of the photosynthetic machinery. This research proposal focusses on the evolution of the plastid transcription machinery and its multiple novel protein components proposing it as crucial evolutionary innovation during and for terrestrialization. The function and regulation of the eubacterial plastid RNA polymerase (PEP) inherited from the cyanobacteria-like progenitor was supplemented with additional PEP associated proteins (PAPs) and novel sigma factors and further put under the control of a nuclear encoded phage-type RNA polymerase (NEP). Most of these protein factors evolved in streptophyte algae and a complete set of the corresponding genes appeared for the first time in Chara braunii. The project combines phylogenetic, molecular-genetic and biochemical approaches. It investigates the precise phylogenetic appearance of these components, their evolutionary adaptations within various streptophyte model organisms (including a dual nucleo-plastid localization for bi-partite gene regulation) and the structural evolution of the PEP complex.

陆地植物（陆地生物圈的支柱）的进化出现可以追溯到淡水藻类征服陆地的单一事件，这一过程被称为陆地化。这种向陆地的过渡需要大量的分子适应，使植物的祖先能够在新栖息地的恶劣环境条件下生存。最重要的要求之一是叶绿体的生理适应，特别是对环境压力敏感。这一过程的关键要素是细胞核和细胞器之间的基因表达协调，以保证光合机制的适当建立和维持。这项研究计划的重点是质体转录机制及其多种新型蛋白质组分的进化，将其作为地球化过程中和地球化过程中的关键进化创新。真细菌质体RNA聚合酶（PEP）的功能和调节遗传自蓝藻样祖细胞补充了额外的PEP相关蛋白（PAP）和新的西格玛因子，并进一步置于核编码的噬菌体型RNA聚合酶（NEP）的控制下。这些蛋白质因子大多在链藻中进化而来，并在布朗轮藻中首次出现了完整的基因组。该项目结合了系统发育、分子遗传和生物化学方法。它调查了这些组件的精确系统发育外观，它们在各种链霉菌模式生物（包括双核质体定位的二分基因调控）和PEP复合物的结构进化的进化适应。