谷子萌芽期抗旱相关基因克隆及功能分析

Drought is the main abiotic stress restricting crop production in the world, the loss caused by drought equivalent to the sum of loss caused by other biotic stress. Scientists from many countries pay more attention to exploration and study on plant drought resistance ability, improving plant drought resistance ability and developing biological water saving potential, study on drought resistance has become hot. Foxtail millet [Setaria italica (L.) Beauv.] has strong drought resistance and sterility tolerance, rich nutrition, extensive adaptability and it is a typical drought tolerant crop. On the basis of drought resistance identification at germination stage in foxtail millet, genes related drought resistance would be mapped using segregating population which was constructed by drought resistance material and sensitive to drought material screened by drought resistance identification, then transcriptome sequencing technology was used to scan differentially expressed genes under drought between parents at germination stage, bioinformatics was used to analyze the function of these genes, and combine with the gene mapping interval to mine genes related to drought resistance at germination stage in foxtail millet, preliminary illuminate expression pattern and gene regulation mode of these genes, provide scientific theory basis for revealing the molecular mechanism of drought resistance of foxtail millet.

干旱是世界范围内限制作物生产的主要非生物逆境，全球平均每年因干旱造成的农业损失相当于其他非生物自然灾害造成的损失的总和。对植物抗旱能力的研究及探索，提高植物抗旱能力，开发生物节水潜力，一直是各国科学家关注的重要问题，也是当前研究的热点。谷子具有抗旱耐瘠、营养丰富、适应性广等特点，是典型的耐旱作物。本研究拟在谷子萌芽期抗旱性鉴定的基础上，利用筛选到的抗旱材料与对干旱敏感的材料构建分离群体，进行谷子抗旱基因定位；同时在萌芽期对亲本材料进行转录组测序分析，筛选亲本间在干旱胁迫前后差异表达的基因，并通过生物信息学的方法进行基因功能分析，结合抗旱基因定位区间，挖掘谷子萌芽期抗旱相关基因，初步阐明抗旱相关基因的表达调控模式，为解析谷子抗旱的分子机制提供科学的理论依据。

干旱是世界范围内限制作物生产的主要非生物逆境，全球平均每年因干旱造成的农业损失相当于其他非生物自然灾害造成的损失的总和。谷子是一种优异的抗旱资源，定位、克隆谷子抗旱相关基因，明确基因功能，阐述基因在水分代谢途经中的作用，探索其调控网络已经成为谷子抗旱研究的重点。本研究利用山西2010（萌发抗旱指数0.9261）和K359*M4-1（萌发抗旱指数0.6391）构建的F2分离群体进行了谷子萌芽期抗旱相关基因的定位。共定位到20个QTLs,其中，3个与谷子萌发抗旱指数相关（SIDR），可解释变异12.4%-14.3%；3个与谷子相对发芽活力（RGV）相关，可解释变异13.1%-16.6%；3个与正常发芽条件下的萌发指数（PI-C）相关，可解释变异11.2%-14.4%；3个与干旱胁迫条件下的萌发指数（PI-D）相关，可解释变异13%-13.7%；2个与正常发芽条件下的发芽率（GR-C）相关，可解释变异13.3%-14.2%；2个与干旱胁迫条件下的发芽率（GR-D）相关，可解释变异11.4%-15.9%；1个与正常发芽条件下的发芽活力（GV-C）相关，可解释变异14.1%；3个与干旱胁迫条件下的发芽活力（GV-D）相关，可解释变异10.1%-16.3%。对山西2010和K359*M4-1进行干旱处理，分别对四份材料（两份处理和两份对照）取样，采用RNA-sequence的方法，进行了测序分析。结果表明，在两份材料中共有的差异基因有1268个，山西2010特有的差异基因有1032个，K359*M4-1特有的差异基因有2384个。山西2010和K359*M4-1差异转录基因中获得显著性GO富集的条目分别有52个和21个, 共有条目17个。从差异表达基因中随机挑选28个差异表达基因进行实时荧光定量PCR 检验。结果表明，在干旱胁迫条件下28个基因的变化趋势与转录组测序的结果一致。构建了Si018222和Si021907两个基因的超表达载体，并采用农杆菌侵染的方法转入到拟南芥中。实验已进行到T1代抗性筛选阶段。