真核细胞翻译起始因子5A(eIF5A)研究进展

真核细胞翻译起始因子5A(eIF5A)是真菌、动植物体内普遍存在的蛋白质翻译起始因子。研究发现其不仅仅在部分蛋白质翻译起始中发挥作用,还在人体癌症发生、促进动植物细胞增殖、细胞衰老和死亡以及一些植物环境胁迫应答等方面都有一定的调控作用。进一步研究真核细胞翻译起始因子5A(eIF5A)的功能,对其生产实践中应用具有非常重要的意义。     

Scent profiling of Cymbidium ensifolium by electronic nose

The performance of electronic nose (E-nose) for Chinese Cymbidium scent profiling has been evaluated. Changes in scent profiles of two Cymbidium ensifolium cultivars have been monitored at different flowering stages (initial flowering, full flowering, and terminal flowering) and different times combined with two gas collecting devices. Samples were collected by static headspace (SHS) method. How E-nose can be used for pattern recognition and for studying the releasing of flower scent were proposed. Data obtained were subjected to principal component analysis (PCA) and discriminant function analysis (DFA). PCA was performed on the initially instrumental data to explore the structure of each data set and such result showed that the sensory data contained information related to the cultivar and to time spots. DFA was performed to improve the results, leading to clear separations between the sample groups. Gas collecting device did not seriously affect the result of PCA and DFA. Relative aroma intensity (RAI) was proposed as an alternative concept to compare scent intensity between samples on different time points. These results demonstrate the potential application of the E-nose to evaluate the scent profile of flower.     

固相微萃取技术收集水稻挥发物的比较

【目的】探讨用固相微萃取技术（SPME）不同萃取头萃取到的水稻诱导挥发物的异同,为研究植物挥发物提供方法依据。【方法】用茉莉酸甲酯处理水稻,分别用3种萃取头：100 µm聚二甲基硅氧烷（PDMS）、7 µm PDMS和85 µm聚丙烯酸酯（PA）萃取水稻的挥发物。用GC-MS和GC对挥发物进行定性定量分析,比较3种萃取头在萃取水稻挥发物的总量、成份和组成方面的异同,并与动态顶空收集法（DHS）收集的挥发物成份相比较。【结果】在同样条件下,100 µm PDMS萃取的挥发物总量和种类最多,7 µm PDMS最少。SPME法与DHS法获得的挥发物组成类别相似,但有些组分不同。【结论】不同萃取头对水稻挥发物的萃取效率和选择性是不同的。用SPME法研究水稻等植物挥发物,需根据目标组分的性质选择合适的萃取头。SPME法与DHS法在植物挥发物的收集和分析中各有优缺点。     

Functional Analysis of DHS by Virus-induced Gene Silencing in Nicotiana benthamiana

With the progress in plant genomics research, the study direction is turned into the discovery and functional analysis of important genes. But an effective method is needed to investigate the biological function of eDNA sequences in large-scale （Wang et al., 2005）. With the newly developed technique-virus-induced gene silencing （VIGS）, plants infected with virus vector carrying host-derived sequence inserts will show loss-of-function or reduced-expression mutants in the host gene. The symptoms will tell the functional information of the gene （Liu et al., 2004; Burton et al., 2000）. Normally the process of constructing a virus vector and monitoring symptoms on infected plants can be completed within a few weeks, such that VIGS provides a simple, rapid and high throughput means of analyzing the function of sequenced genes.