IAA介导的转录因子ARF调控文冠果雄花雌蕊败育机理研究

植物激素以及基因互作在雌蕊选择性发育中起关键作用。雌雄比例低是导致文冠果种子低产的主要因素，两性花芽分化后期雌蕊败育导致雄花形成。我们发现IAA对文冠果雌蕊发育有重要调控作用，性别分化期雌雄花生长素响应因子ARF及其调控因子Aux/IAA、bZIP、miR160、miR319等表达差异显著，但以ARF为核心的雌蕊发育网络调控模式尚不清楚。本项目以临近性别分化期、分化期、分化后的雌雄花雌蕊为材料，探索ARF时空表达模式；通过全转录组测序、WGCNA分析构建共表达网络，富集共表达结构基因、转录因子、miRNA，分析以ARF为核心的IAA信号转导途径；结合Aux/IAA等转录因子、miR160等miRNA发掘调控网络；遗传转化验证ARF等基因的功能。研究结果将揭示IAA介导的转录因子ARF对文冠果雄花雌蕊败育调控网络和机理，为利用生理、分子和栽培技术提高雌雄比例，进而提高种子产量提供理论依据。

Plant hormones and genes interaction play a key role in the process of pistil selective development. The primary reason for low seed production in Xanthoceras sorbifolium Bunge is the low ratio of female to male flowers. In the late development period of bisexual flower buds, the pistil’s abortion leads to the formation of male flowers. We found that IAA showed an important regulatory effect on pistil development. During sex differentiation Auxin Response Factor (ARF) and its regulatory factors, such as Aux/IAA, bZIP, miR160 and miR319, showed significantly different expressions between female and male flowers. However, the pattern of ARF regulatory net for pistil development is still unclear. In this project, before, during and after sex differentiation, we will take the pistils in female and male flowers, respectively, as materials. The spatiotemporal expression patterns of ARF gene will be elucidated. The gene co-expression network will be constructed using whole transcriptome sequencing and WGCNA analysis. The co-expressed structural genes, transcription factors, and miRNAs will be concentrated. We will analyze auxin signal transduction pathway with ARF as its core. Transcription factors such as Aux/IAA and miRNAs such as miR160 will be combined to explore the mechanism of genetic regulatory net. The regulatory effect on pistil abortion of genes like ARF will be verified by genetic transformation. The results will discover the regulatory pattern and mechanism of IAA-mediated transcription factor ARF on pistil abortion in Xanthoceras sorbifolium, thus to provide an important theoretical basis for enhancing the ratio of female to flowers, and further increasing seed yield by physiological, molecular and cultural techniques.