条斑紫菜PyMAPK2(促分裂原活化蛋白激酶）应答干出/复水胁迫分子机制的研究

The MAPKs cascades, as the conservative signal transduction system among the eukaryotes, play the important roles in responding to water stress. Pyropia yezoensis is the representative of seaweeds inhabiting intertidal zone. The researches in our group showed, PyMAPK2 is very sensitive to desiccation. Based on the research limitation and the current progresses in our group, in this research, we will focus on those MAPKs genes including PyMAPK2 responding to water stress at transcript and translation levels, and comprehensively reveal the response patterns under water stress. By the protein interactome technology, the identification of the target protein of PyMAPK2 and the regulators will elucidate the regulation networks of P. yezoensis adaption to water stress. Our researches will be benefit to understand P. yesoensis adaption mechanisms to water stress and extend the cognition of plant tolerance against the drought, which also provide the supports for the drought tolerance breeding of P. yezoensis .

促分裂原活化蛋白激酶途径（ MAPK cascade）是真核生物中保守的信号转导系统，在调节植物响应水分胁迫中发挥重要作用。条斑紫菜是潮间带大型海藻的典型代表，具有高效的水分胁迫适应机制。目前条斑紫菜MAPK级联途径应答水分胁迫机制的研究报道有限，项目组研究发现，条斑紫菜TDY型PyMAPK2对失水胁迫响应灵敏，但在进化上独立于高等植物TDY型MAPK, 暗示其拥有特殊调控机制。. 本项目以PyMAPK2为出发点，系统揭示其在转录、翻译和酶活性水平对水分胁迫的响应模式，通过蛋白互作技术筛选PyMAPK2激活的下游靶因子，阐释PyMAPK2所在的级联途径应答水分胁迫的调控机制。以期深入理解条斑紫菜对水分胁迫的适应机制，拓展对植物适应干旱胁迫机制的认识，为条斑紫菜抗逆育种提供重要支持。

促分裂原活化蛋白激酶途径（ MAPK cascade）是真核生物中保守的信号转导系统， 在调节植物响应水分胁迫中发挥重要作用。条斑紫菜是潮间带大型海藻的典型代表，具有高效的水分胁迫适应机制。本项目完成了PyMAPK2基因的克隆及分析，发现PyMAPK2含有典型MAPK的11个保守结构域，包括了典型的MAPK结构域、ATP结合结构域、丝氨酸/苏氨酸蛋白激酶活性位点以及蛋白激酶结构域等。TDY型PyMAPK2在结构上与高等植物TDY型相似，但进化分析独立于高等植物TDY型MAPK。采用Real-time、western-blotting及技术免疫共沉淀技术首次在mRNA、蛋白及酶活等水平研究了PyMAPK2应对不同环境因子的表达模式，结果表明PyMAPK2为条斑紫菜失水胁迫下的重要响应分子，在mRNA、protein及酶活水平均有不同程度的响应。同时也发现PyMAPK2在mRNA、protein及酶活水平参与了应对温度及渗透压胁迫。进一步采用Y2H文库筛选了与PyMAPK2相互作用的靶蛋白，经过验证获得了与PyMAPK2相互作用的16个候选下游靶蛋白，发现这些候选靶蛋白在失水胁迫下亦被调控。由此推测，PyMAPK2是条斑紫菜响应环境胁迫的重要因子，其在多水平应答了环境胁迫；作为MAPK级联通路中的下游因子，PyMAPK2通过磷酸化下游多个靶蛋白，调控其响应失水胁迫。本项目为进一步认识条斑紫菜响应失水胁迫的分子机制提供了科学证据。