摘要：High-precision bioengineering and synthetic biology require fine-tuning gene expression at both transcriptional and posttranscriptional *** transcription is tightly regulated by promoters and *** determine the timing,tissues and cells,and levels of the expression of *** mediate transcription termination of genes and affect mRNA levels posttranscriptionally,e.g.,the 3′-end processing,stability,translation efficiency,and nuclear to cytoplasmic export of *** promoter and terminator combination affects gene *** the present article,we review the function and features of plant core promoters,proximal and distal promoters,and terminators,and their effects on and benchmarking strategies for regulating gene expression.

摘要：研究目的:利用响应面优化茶果皮多糖(TFPP)提取条件,用乙醇分级分段得到4个多糖组分(TFPP-0、TFPP-20、TFPP-40和TFPP-60),并研究其理化性质、抗氧化活性和对α-葡萄糖苷酶抑制作用,为综合高效利用茶果皮多糖资源提供理论基础。创新要点:1.首次将茶果皮作为一种潜在生物资源研究;2.首次研究茶果皮多糖这一功能成分;3.将工艺优化、理化性质和生物活性结合研究。研究方法:三因素三水平响应面设计(见表1),傅里叶转换红外光谱法分析茶果皮粗多糖的功能团结构(见图3),高效液相色谱法检测单糖组分(见表2),2,2'-氨基-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐(ABTS)自由基清除法(见图4a)和铁离子还原能力法(FRAP)(见图4b)分析茶果皮多糖抗氧化活性。重要结论:1.茶果皮多糖是一种水溶性的酸性杂多糖蛋白复合物;2.乙醇分级是一种有效多糖分离手段;3.茶果皮多糖具有出色的生物活性;4.茶果皮资源可以作为一种可再生生物资源进行深度的开发。