榛子授粉控制子房分化起始的IAA信号转导机制研究

榛子有“坚果之王”的美誉，有重要的经济价值。正常子房发育是产量形成的基础，榛子子房在授粉后才开始分化发育，且在早期多数发育停滞，这种独特的子房分化发育机制还不明确。经初步研究，榛子子房分化发育习性与IAA信号调控相关。本项目以榛子雌花/子房为材料，进行IAA及其运输抑制剂处理，通过花粉管、花粉管腔、子房发育进程的显微观察及IAA时空定位等分析，正反验证IAA在子房发育进程中的作用；进而开展IAA响应因子CoARFs家族成员的克隆、比对及进化树构建、时空表达特征研究，筛选调控子房分化发育的关键CoARFs，并进行瞬时侵染、亚细胞定位及过表达/抑制表达遗传转化等研究，验证其在子房发育调控中的功能；最后，通过染色体免疫共沉淀-高通量测序等研究获得关键CoARFs的靶序列信息，鉴定IAA信号通路下游直接调控子房发育的重要基因。本研究有望建立IAA调控榛子子房发育的新信号通路。

Hazelnut has a good reputation as king of nuts, and has important economic value. Normal ovary development is the base of nuts yield formation. The differentiation of hazel ovary initiates after pollination, and the growth of most ovary stops during early developmental stage. The unique mechanism of hazel ovary initiation regulated by pollination almost remains unknown. Our previous study results indicated that IAA signal transduction was involved in the regulation of ovary development in hazelnut. Female inflorescence or young fruit during different ovary developmental stages will be used as study materials in present study, and IAA and its polar transport inhibitor treatments will be carried out. After development process observation of pollen tube, pollen tube cavity and ovary, accompanied by IAA temporal and spatial localization, IAA’s regulation function during ovary development will be verified from pros and cons sides. Then, auxin response factors CoARFs clone, sequence comparison, evolutionary tree construction and their temporal and spatial expression will be performed to screen key CoARFs which are involved in the regulation of ovary differentiation and development. CoARFs’ instantaneous infection, subcellular localization, promoter methylation and genetic transformation of over expression/ inhibition expression analysis will be carried out to confirm their function during different ovary developmental stage. Chromatin Immunoprecipitation and High-Throughput Sequencing will be used to obtain CoARFs’ key target sequences, and important IAA downstream genes which regulate ovary development will be identified. A new auxin signal pathway controlling hazelnut ovary development will be constructed in present study.