西伯利亚白刺耐盐代谢机理及关键耐盐基因调控特征研究

Plant metabolites are the result of the interaction between genes and the environment, and they are also the contributors to the special physiological and ecological functions of plants in specific environmental conditions. Plant metabolites enable plants to grow under harsh environmental conditions by modulating the plant's own protective mechanisms and coordinating the plant's interactions with the environment. The halophytes, which possess a series of special survival strategies under the salt environment after they evolved specific salt tolerance mechanisms during the long-term evolution, are ideal systems for studying and dissecting the salt-tolerance metabolism mechanism and molecular regulation mechanism. This project intends to use the Nitraria sibirica Pall , a salt tolerance and predominant tree species in the wide saline-alkali distribution area in the northern China, as the studying materials. Advanced GC-TOF/MS and LC-TOF/MS techniques will be used to study the metabolic profile changes under salt stress, based on which we will screen for significant changed metabolites, and then identify key metabolites and metabolic pathways involved in salt tolerance. At the same time, we will use high-throughput sequencing technology to study gene expression under salt stress condition, screen for differentially expressed genes, and then employ mathematical modeling to build regulatory networks. The salt-tolerant metabolites and key salt-tolerant genes will be searched by association study and analysis, and qPCR and transgenic techniques will be used for expression analysis and functional validation. According to the dynamic changes of metabolites and genes under salt stress, key salt-tolerant metabolic pathways and gene regulatory networks will be recognized, and then the key salt-tolerant metabolites and salt-tolerant genes will be identified. We will elucidate the salt-tolerance metabolism and gene regulatory mechanisms. This study aims to unveil the salt-tolerance mechanisms by studying both metabolites and gene expression, and analyzing them independently and then jointly. The key metabolic products and candidate genes identified will be applicable for the development of new varieties of salt-tolerant plants. This project will establish new methodology and systems that are more efficient in identifying the key metabolic and molecular mechanisms, facilitating selection of elite germ-plasma resources from salt tolerance plants.

植物代谢物是基因与环境互作结果，是特定环境植物特殊生理功能的赋予者。盐生植物在长期演化中形成了一系列适应盐生环境的生存策略，进化出特殊耐盐机制，是研究和解析耐盐代谢机理及分子调控机制的理想材料。本项目以北方盐碱区广域分布的盐生灌木西伯利亚白刺为材料，采用GC-TOF/MS、LC-TOF/MS技术，研究盐胁迫下代谢谱变化，筛选差异显著代谢物，挖掘关键代谢途径。同时，利用高通量测序技术，研究盐胁迫下所有基因转录水平变化，筛选差异显著基因，并用数学模型构建调控网络。然后通过关联分析查找耐盐标志性代谢物和关键耐盐基因，并运用qPCR和转基因技术进行表达分析及功能验证，阐释植物耐盐代谢机制及基因调控特征。本研究从代谢产物和基因表达谱两方面入手，独立和联合分析并用，有可能建立新的耐盐研究方法和体系，并挖掘出植物耐盐代谢和分子机理，对建立植物耐盐性代谢产物和基因库、培育耐盐新品种具有重要理论与应用价值。

盐胁迫是制约植物生长发育的主要非生物胁迫因素之一，深入研究植物耐盐调控机理能够为选育/创制耐盐林草新品种提供重要理论基础，具有理论与实际应用价值。西伯利亚白刺是一种典型的盐生植物，能在极端干旱条件和盐碱环境中生存，具有很强的耐盐性和环境适应性。本项目以西伯利亚白刺为研究材料，首先利用高通量测序技术解析了盐胁迫下基因的表达谱，KEGG结果表明，盐胁迫下差异基因主要富集在β-丙氨酸、精氨酸、脯氨酸和甘氨酸的氨基酸代谢、糖酵解的碳代谢、糖异生、半乳糖、淀粉和蔗糖代谢、植物激素信号转导和剪接体。接着采用GC-TOF/MS、LC-TOF/MS技术对盐胁迫下的代谢谱变化进行了挖掘，差异代谢物主要是氨基酸(脯氨酸、天冬氨酸等)、有机酸(草酰乙酸、延胡索酸等)。最后本项目对转录组和代谢组数据进行关联分析，进一步明确了AMY2、BAM1、GPAT3、ASP1和CBL5等基因以及L-半胱氨酸、脯氨酸、4-氨基丁酸和草酰乙酸酯等代谢产物在西伯利亚白刺耐盐性调控中的重要作用。此外，本项目对联合分析挖掘到的一类钙调蛋白NsCBL5进行功能验证，结果证明通过本项目筛选到的基因在植物耐盐性调控中发挥了重要作用，也证明了本项目获得数据具有很高的可靠性。本研究从代谢产物和基因表达谱两方面入手，独立和联合分析并用，解析了西伯利亚白刺独特的耐盐代谢和分子机理。本项目是对西伯利亚白刺耐盐机理的进一步完善，将为盐碱地的治理和盐生植物的栽培提供理论依据和技术支持。本项目累计发表学术论文6篇，其中SCI文章3篇；授权发明专利1项；项目主持人晋升为二级研究员，并入选2021年度山东省“黄河三角洲学者”；培养博士研究生1名，硕士研究生3名，支撑1名博士后工作；获得2020年梁希科学技术奖技术发明二等奖。