第58屆Intel ISEF中國參賽項目：銀杏D1蛋白基因克隆與幼苗葉片發(fā)育時表達(dá)的研究
成都市第七中學(xué) 高二 杜瑋 周陳晨 張典
銀杏（Ginkgo bioloba L.）是現(xiàn)存種子植物中最古老的世界著名活化石之一，是中國所特有的第四紀(jì)冰川孑遺植物。為了了解銀杏幼苗葉片發(fā)育時光合基因的表達(dá)，及其與細(xì)胞核質(zhì)互作和葉片光合功能實現(xiàn)的關(guān)系，本文首次利用RT-PCR和3’RACE方法，擴(kuò)增銀杏D1蛋白基因的編碼區(qū)（已在Genbank登陸）。對序列測定結(jié)果進(jìn)行生物信息學(xué)分析和進(jìn)化分析；利用分子雜交和免疫印跡方法，對銀杏幼苗葉片發(fā)育中重要光合基因基因psbA和cab表達(dá)的mRNA和蛋白質(zhì)水平進(jìn)行了定量的分析。初步探討了銀杏幼苗葉片發(fā)育中光合作用基因表達(dá)、細(xì)胞核質(zhì)互作的關(guān)系。在銀杏幼苗發(fā)育初期，類囊體膜處于變化中，葉綠素合成加快，組分比例改變和葉綠體的發(fā)育狀態(tài)會不同程度地影響光系統(tǒng)II亞基的代謝水平。
A Study of psbA Gene Cloning and Expression in the Leaves of Ginkgo Seedlings
Plant Sciences
Du Wei, Zhou Chenchen, Zhang Dian 17, No. 7 Middle School of Chengdu City
Ginkgo (Ginkgo biloba L.), one of the oldest living tree species, is the only living member of the gymnosperms division Ginkgophyta. It is considered a “living fossil”, unchanged since the time of dinosaurs, and seen as one of the wonders of the world. Due to such unique characteristics, it has attracted worldwide interest in biomedical and botanic research. However, there have been limited investigations of Ginkgo biloba at the molecular level.
The objective of this project is to understand how the chloroplast-encoded photosynthesis genes are expressed in the leaves of Ginkgo seedlings, and whether the nuclei and chloroplast genetic systems participate in a concerted manner in the early phases of Ginkgo biloba seedling growth. For the first time, we applied RT-PCR and 3’-RACE methods to clone a cDNA fragment of the psbA gene, which encodes the protein D1 of photochemical reaction center, from Ginkgo biloba. Protein sequence showed that the Ginkgo D1 protein is identical to D1 protein found in many other plants. Both Western blot and Northern blot were used to analyze the levels of protein and mRNA of psbA and cab genes. Our project results suggest that the thylakoid membrane goes through constant changes and chlorophyll synthesis speeds up during the early phases of leaf growth. The structural and functional status of chloroplast may influence the expression of photosystem II subunits during ginkgo seedling development.
