Evolution of gametophytic communication systems by analyzing RALF and ROS signaling

通过分析 RALF 和 ROS 信号传导配子体通讯系统的进化

• 批准号: 456689835
• 负责人: Professor Dr. Thomas Dresselhaus
• 金额: --
• 依托单位: Lehrstuhl für Zellbiologie und Pflanzenbiochemie
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/456689835?language=en
• 关键词: Evolution; gametophytic; communication; systems; analyzing

The evolution of reproductive organs and gametes of land plants was accompanied by numerous changes and adaptations of gametic/gametophytic communication systems. While gametes of opposite mating types of single celled algae like Chlamydomonas communicate in a watery environment, bryophytes and ferns generate mobile sperm cells, which are attracted by egg cells in a moist environment. Adaptations to dry environments in gymnosperms and angiosperms were accompanied by loss of sperm cell mobility and the invention of pollen grains (male gametophyte), that protect and carry sperm cells by wind or animals over long distances to female flower organs. Moreover, pollen grains form a tube that growths deeply into the maternal flower organs to release its sperm cell cargo for fertilization inside the embryo sac (female gametophyte). The complexity of gametic cross-talk in single celled algae towards gametophytic cross-talk in angiosperms has enormously increased during land plant evolution. By using the angiosperm model plants Arabidopsis and maize, a lot of progress has been made in the past 15 years to elucidate molecules and mechanisms involved in gametophyte communication. Especially secreted polymorphic cysteine-rich peptides (CRPs) appear to play a central role during pollen tube germination, growth, guidance and reception. Among these, pollen tube-specific RALF (Rapid ALkalinization Factor) peptides were recently shown to regulate pollen tube integrity and sperm release in Arabidopsis. While single celled algae do not contain RALF genes, an ancient RALF clade consisting of a few genes exists in mosses, and the number of RALF genes was strongly amplified during evolution to 37 genes, for example, in Arabidopsis. Until now, to our knowledge, only RALF genes related to the ancient clade have been functionally characterized and activate ROS production in Arabidopsis. The aim of this project therefore is to contribute to the understanding of the evolution of gametophytic cross-talk by studying two gene families and their interaction(s). (i) We will study the evolution, diversification and specification of members of the RALF gene family including functional studies of ancient RALFs in a moss and a novel clade in maize lacking the typical RALF peptide signature. Studies will also include complementation analyses of Arabidopsis and maize pollen mutants using RALFs from different land plant. Interaction studies will be performed with known receptors. (ii) We will further investigate and compare the conservation of RALF-triggered ROS production in mosses and angiosperms in collaboration, and (iii) study major ROS-producing RBOH genes in papilla hair cell of maize after pollen adhesion.

陆地植物生殖器官和配子的进化伴随着配子/配子体通信系统的大量变化和适应。相反交配类型的单细胞藻类（如衣藻）的配子在水环境中进行交流，苔藓植物和蕨类植物产生可移动的精子细胞，这些精子细胞在潮湿环境中被卵细胞吸引。裸子植物和被子植物对干燥环境的适应伴随着精子细胞流动性的丧失和花粉粒（雄性配子体）的发明，花粉粒通过风或动物保护和携带精子细胞长距离到达雌花器官。此外，花粉粒形成一个管状体，深入母体花器官，释放精细胞，在胚囊内受精（雌性配子体）。在陆地植物的进化过程中，单细胞藻类配子体与被子植物配子体相互作用的复杂性大大增加。利用被子植物模式植物拟南芥和玉米，近15年来对配子体通讯的分子和机制的研究取得了很大进展。特别是分泌的多态性富含半胱氨酸肽（CRPs）在花粉管萌发、生长、引导和接受过程中起着核心作用。其中，花粉管特异性RALF（快速碱化因子）肽最近被证明可调节拟南芥花粉管完整性和精子释放。虽然单细胞藻类不含有RALF基因，但在苔藓中存在一个由少数基因组成的古老RALF分支，并且在进化过程中，RALF基因的数量被强烈扩增到37个基因，例如在拟南芥中。到目前为止，据我们所知，只有与古老进化枝相关的RALF基因被功能表征并激活拟南芥中ROS的产生。因此，本项目的目的是通过研究两个基因家族及其相互作用来促进对配子体串扰进化的理解。(i)我们将研究RALF基因家族成员的进化、多样化和规范，包括苔藓中古老RALF的功能研究和缺乏典型RALF肽特征的玉米新进化支。研究还将包括利用来自不同陆地植物的ralf对拟南芥和玉米花粉突变体进行互补分析。将与已知受体进行相互作用研究。（ii）我们将进一步研究和比较ralf在苔藓和被子植物中引发ROS产生的保守性；（iii）研究花粉粘附后玉米乳头毛细胞中产生ROS的主要RBOH基因。