PtDAL1在油松营养生长时相转变中的功能与作用机制

生殖发育是影响高等植物种质延续、良种生产与遗传改良过程的核心生物学问题，营养生长时相转变是多年生林木生殖发育研究最关注的问题之一。目前被子植物中以miR156为核心的营养生长时相转变分子调控网络已经被基本阐明，然而针叶树中的相关研究却十分滞后。前期研究表明，DAL1是针叶树营养生长时相转变关键候选调控因子，本项目拟以油松为材料，对PtDAL1的具体功能与作用机制进行研究：（1）鉴定PtDAL1的功能并观测其表达对外源或内源信号的响应;（2）鉴定PtDAL1在油松中的靶基因并构建其多层次调控网络;（3）阐明PtDAL1基因表达产物及其调控信号长距离运输特性。本项目旨在基于油松原生质体转化体系、RNA-seq分析、hGRNs网络构建、拟南芥微嫁接及不同龄级油松嫁接等技术的综合联用，以阐明针叶树DAL1在营养生长时相转变中的具体功能与作用机制，从而为针叶树特异的生殖发育调控网络提供新的数据支撑。

The reproductive development is one of the most important biological events that affects the germplasm conservation, seed production and genetic improvement of higher plants. The vegetative phase change (transition from juvenile to adult period) is one of the most concerned issues in the research on reproductive development of perennial trees. Although the molecular regulation network of vegetative phase change with the miR156 as the core player in angiosperms has been well elucidated, we still know very little about what controls that process in perennial conifers, especially for the conifer specific regulatory mechanisms. Previous studies have indicating that DAL1 is a key candidate regulator of vegetative phase change in conifers. We will investigate the function and regulatory mechanisms of the PtDAL1 homologous in Pinus tabuliformis. First, we will identified the function of PtDAL1 and analyses its expression response to external and endogenous signals. Then we will identified the target genes, discover and verify the hierarchical gene regulatory networks of PtDAL1. Finally, we will explore the long distance transport characteristics of the molecular product of PtDAL1 gene and its downstream signals. In the course of the investigation, some new methods and techniques including protoplast transformation system of P. tabuliformis, RNA-seq, transcription factor directed hierarchical gene regulatory networks analysis, transgenic Arabidopsis micro-grafting, and grafting of different age P. tabuliformis will be used to determine the specific roles and regulatory mechanism of DAL1 in the vegetative phase change in conifers. The results of this investigation will provide new data support for the understanding of conifer specific reproductive development regulatory networks.