铁皮石斛GRAS转录因子家族分析及其成员DoSCL14抗逆功能研究

Dendrobium officinale, a medicinal and mycorrhizal orchid, is rare and endangered in China. As a result of large market demand, the wild resource of D. officinale has reduced gradually. In recent years, the artificial cultivation of D. officinale has developed quickly in Zhejiang, Yunnan, Anhui and etc. As the growing year and area being expanded, various problems in cultivation are growing and become even worse, such as high cost, product varies in quality, poor resistant in seedling and etc. GRAS genes, a plant-specific family of transcription factor, play critical roles in the process, such as plant growth, stress resistance and environment interaction. For example, GRAS transcription factors are associated with axillary shoot meristem formation, radial root patterning, plant and mycorrhizal fungi interaction, abiotic/biotic stress and phytohormones (gibberellins) signal transduction. This project involves design at two levels. Firstly, the genome and RNA-seq data will reveal the sequence structure, evolutionary relationship, expression in different tissue and prokaryocyte expression of all GRAS members in D. officinale. Secondly, based on genetically modified technology, we will identify the role of DoSCL14 (LISCL subfamily) in salt and heat stress resistance. The results may provide scientific basis for the medicinal and mycorrhizal orchid researches, solve practical problems in the artificially cultivation of medicinal Dendrobium and reach the goal of sustainable use of natural resources.

铁皮石斛是我国珍稀濒危的兰科药用和菌根植物，随着市场需求增加，野生石斛资源逐渐殆尽。近年来，铁皮石斛种植产业在浙江、云南、安徽等地发展迅速，随着种植年限的增加和种植面积的扩大，各类问题开始凸现，如生产成本较高、质量参差不齐、幼苗抗性较差等。研究发现，作为转录因子的GRAS家族基因，在植物生长发育、逆境胁迫和环境互作等方面发挥十分重要的作用，如可促进根、茎的分支，提高菌根化程度，增强植株抗性，参与赤霉素信号转导等。本项目拟从两个层次开展：①从基因组和转录组水平，研究铁皮石斛GRAS家族基因所有成员的序列特征、进化关系、组织表达差异、原核表达水平等。②以LISCL亚家族的DoSCL14为例，采用转基因技术，开展抗高温和干旱的功能学验证。研究结果，可推动兰科药用植物和兰科菌根的分子研究，为有效解决实际种植的问题，实现铁皮石斛资源可持续利用，提供科学依据和参考。

铁皮石斛是我国传统中药材中最珍稀名贵的品种之一，具有一定的观赏、经济价值。干旱、盐渍、极端温度等环境胁迫，制约植物的生长发育，在长期的进化过程中，植物为了抵抗和适应各种环境胁迫，在形态、细胞、生理生化等方面形成了一系列独特的防御机制，其中GRAS转录因子在植物抵御非生物胁迫过程中发挥重要作用。本项目拟通过两个层次展开研究，首先是全面分析铁皮石斛GRAS基因家族分子特征，其次是LISCL亚家族DoSCL14基因功能验证。按照《资助计划书》要求，研究目标、考核指标等均已在期限内完成。首先，完成铁皮石斛GRAS家族基因的克隆和测序分析，在铁皮石斛基因组中共发现47个家族成员，并分析其结构特征、潜在功能。其次，完成了DoSCL14的基因克隆、蛋白表达、抗体制备及功能验证等，发现其具备调节和增强铁皮石斛抗高温、抗盐渍等功能。