荷能粒子对微藻作用机理及诱变株筛选方法的研究

Since the discovery of low-energy-ion irradiation induced biological effects, big achievement has been made in both research and application of the ion-irradiation biotechnology. To further improve the efficiency of this technology, it is necessary to gain the in-depth insight into the mechanisms for the interaction between energetic particles and biological systems, and also, to develop new methods for rapid and high-throughput sceening of the mutants produced by ion-irradiation. With our recent progress in the research on both aspects, this project aims to investigate the biological effects in microalgea induced by ion-beam/plasma irradiations, and also to exploit new approaches based on micro-spectroscopy and imaging. For this purpose, we choose Haematococcus pluvialis (a freshwater species of Chlorophyta from the family Haematococcaceae, well known for its high content of the strong antioxidant astaxanthin) as our studying object, and employ infrared and Raman micro-spectroscopy and imaging to observe the effects of reactive oxygen species (ROS) and other radicals on the growing states, astaxanthin production and cellular structures of H. pluvialis, and in the meantime, to search for effective screening methods based on the spectroscopic imaging and chemical mapping of astaxanthin and other metabolites. Our ambition is to establish the connections among the spectroscopic imaging data, microalgea metabolism (metabolic process and products), and the biological effects induced by the ion-beam/plasma irradiations. As such, this research may not only deepen the understanding of the mechanisms for the interaction between energetic particles and biological systems, but also provide new methods which can facilite the rapid and high-throughput screening of mutants.

自发现粒子辐射诱导生物效应以来，荷能粒子辐照诱变育种技术在应用及基础研究方面取得诸多成果。但是要继续推广这项技术，需要对诱变作用机理、突变体筛选方法等进行更深入、全面的研究。近年来我们在辐射作用机理方面取得新的进展，并且基于光谱技术提出一些新的研究方法。本项目拟应用振动光谱及光谱显微成像技术，研究荷能粒子对微藻的作用机理并探索筛选有效突变株的方法。选择雨生红球藻作为研究对象，它是自然界中高产天然虾青素（一种强抗氧化剂）的微生物。利用红外和拉曼光谱及显微成像方法，一方面探测粒子辐照引起的生物学效应，研究荷能粒子通过直接和间接作用对雨生红球藻状态、细胞组分、细胞微结构的影响，另一方面探测微藻生长代谢过程、虾青素产量等，根据光谱图像对诱变株进行早期快速筛选，通过数据分析建立起辐射、突变株、光谱图像三者之间的联系。该项研究不仅有助于深化辐射作用机理的认识，而且可为微藻诱变育种提供新的快速筛选方法。

自发现荷能粒子辐射诱导生物效应以来，荷能粒子辐照诱变育种技术在应用及基础研究方面取得诸多成果。但是要继续推广这项技术，需要对诱变作用机理、突变体筛选方法等进行更深入、全面的研究。项目研究按照申请书研究内容进行，执行顺利。在项目组成员努力下，课题研究达到并超过预期目的，取得多项研究成果。主要研究内容及创新性成果包括：1）发展了等离子体处理微藻和诱变技术；2）发展了相关的微藻红外、拉曼和荧光光谱测量、分析即微观成像技术；3）得到高产虾青素的雨生红球藻诱变株；4）研究了低温等离子体诱变雨生红球藻的效应和作用机理，并探讨了诱变株高产虾青素的原因等。研究成果相继发表在相关专业的重要国际期刊上，如：Phycologia、Letters in Applied Microbiology、Plasma Chem. Plasma Process、Applied Spectroscopy、Scientific Reports等，由本基金资助并标注基金课题号(11475217)所发表的SCI收录文章达30篇。研究成果同时也得到同行专家关注，项目负责人多次受邀参加国内外相关会议并做大会报告。总之，在国家自然科学基金的资助和支持下，经过四年来不懈的努力，无论在等离子体诱变机理还是光谱分析方法上都取得了持续和重要的进展。另外，在研究中还发现并提出了一些新的科学问题，这为以后进一步拓展和深入关于雨生红球藻高产虾青素荷能粒子辐射诱变株育种及光谱筛选方法研究、以及其它微生物诱变育种技术应用打下了坚实的基础。