桑寄生顽拗性种子对低温敏感的响应机制研究

Taxillus chinensis (DC.）Danser is a well known traditional chinese medicine but whose breeding is very difficult. The seeds of Taxillus chinensis (DC.）Danser are typical recalcitrant which are fast inactivation and very sensitive to desiccation, what's more, the seeds are the only reproductive materials. Recently, there are many studies focus on the preservation of recalcitrant seeds, however, successful cases is little, the main reason is there is little known about the mechanism of the death of desiccation sensitivity. The key scientific problem of the death of recalcitrant seeds is desiccation sensitivity.Therefore, this reseach intends to study on the seeds of Taxillus chinensis (DC.）Danser. The purpose of the reseach is to find out the result of the change of microstructure, ultrastructure, physiology and biochemistry, internal gene and protein of Taxillus chinensis (DC.）Danser in low temperature sensitive response process. Combined with the group has the research on the dehydration sensitivity mechanism, comprehensive revelation the seeds of Taxillus chinensis (DC.）Danser are not resistant to low temperature, intolerant dehydration, difficult to save and the mechanism of inactivation fast.The study not only provides theory basis for the key technology in the preservation of Taxillus chinensis (DC.）Danser seeds, but also new knowledge and technology for other recalcitrant seed's preservation.

桑寄生是地位重要而又繁育困难的特殊药材，其种子为典型的顽拗性种子，失活快，低温敏感性强。而种子是唯一的繁殖材料，严重制约其繁育。目前对顽拗性种子的低温保存技术研究较多，但成功实例较少，其根本原因是对低温敏感的响应机制知之甚少，而种子低温敏感性是引起顽拗性种子死亡的关键科学问题。故本项目拟围绕桑寄生种子低温敏感响应过程中的细胞显微与超微结构、生理生化、内部基因表达及差异蛋白进行研究，结合课题组已有对其脱水敏感性机理的研究基础，从结构、生理、基因及蛋白水平等综合揭示桑寄生顽拗性种子不耐低温、不耐脱水、难以保存而失活快的机理，不仅为研制桑寄生种子保存关键技术提供理论依据，还为其它科属顽拗性种子的保存提供新的知识与技术。

桑寄生是地位重要而又繁育困难的特殊药材，其种子为典型的顽拗性种子，失活快，低温敏感性强。而种子是唯一的繁殖材料，严重制约其繁育。目前对顽拗性种子的低温保存技术研究较多，但成功实例较少，其根本原因是对低温敏感的响应机制知之甚少，而种子低温敏感性是引起顽拗性种子死亡的关键科学问题。本项目重点围绕桑寄生种子低温敏感响应过程中的生理生化变化、细胞超微结构以及内部基因表达及差异蛋白进行研究，结合课题组已有对其脱水敏感性机理的研究基础，从结构、生理、基因及蛋白水平等综合揭示桑寄生顽拗性种子不耐低温、不耐脱水、难以保存而失活快的机理。研究结果表明桑寄生种子对低温极度敏感，低于0℃已严重丧失种子活力，低温条件下其内源激素、电导率、可溶性糖含量、淀粉含量、可溶性蛋白含量、过氧化氢酶(CAT)活性、超氧化物歧化酶(SOD)活性和抗坏血酸过氧化物酶(APX)活性等均受到了不同程度的影响甚至破坏；同时其种子的内部结构遭受到一定程度的破坏，原生质膜己经受到破坏，变得模糊不清，原生质体缩成一团细胞壁解体大多数细胞内不见完整的细胞器结构，细胞器残片及颗粒遍布于细胞中。转录和蛋白质组研究结果表明寄生种子响应低温胁迫主要与苯丙烷的生物合成、刺激响应、核糖体结构与生物发生、脂质转运和代谢等生物过程。项目发表了4篇研究论文，其中SCI论文1篇，中文核心期刊论文1篇。获授权发明专利1项，申请发明专1项，获立项广西地方标准1项，完成制定广西地方标准1项；正在培养博士1名。该研究结果不仅为研制桑寄生种子保存关键技术提供理论依据，还为其它科属顽拗性种子的保存提供新的知识与技术。