全國中小學科展

紫茉莉生物時鐘機制的研究

科展類別

臺灣國際科展

屆次

2003年

科別

植物學

學校名稱

國立臺南第一高級中學

指導老師

黃浩仁、林靜吟

作者

張哲瑜

關鍵字

紫茉莉,生物時鐘

摘要或動機

Mirabilis Jalapa is a wild flower, which is often seen in countryside of Taiwan. This plant blossom regularly every day around PM 3:00-6:00. Since its regular behavior, it has the potential to become a model plant for research on circadian ryhtem. According to the on spot observation, a Mirabilis Jalapa will bloom consistently, whereas a minority of flower will bloom earlier or later. First, we observe how Mirabilis Jalapa response to disparate environmental conditions. Under a short period of light(8h) and an average period of light(12), Mirabilis Jalapa acts as normal. But under a long period of light, it flowers approximately 1h ahead of time. When under a continuous light, Mirabilis Jalapa shows a regular flowering in the first four day, and after that, circadian rythem of flowering terminate. The ripe flower buds mentain unbloom for 10 days or more, finally end up withered. Meanwhile, floral meristems are also suppressed. Temperature alter seems affct the flowering slightly. Second, we use SDS-page to detect protein divergence 6h interval.But as many of the earlier attempt, the floral stimuli is not sensible for average protein qualitative analysis. So we decide to take more direct approch by genetic experiment. From supplemental material of article” Orchestrated Transcription of Key Pathways in Arabidopsis by the Circadian” we obtain a group of genes regulared by bioclock in Arabidopsis.With Bio Informatics we choose 41 single gene, and compare with sequences in other species, designing promotors to isolate similar genes in Mirabilis Jalapa. Use rt-PCR to detect the level of certain gene expression,and compare characters of those genes in Mirabilis Jalapa with those genes in Arabidopsis. We also blast those 453 genes to the database of animal, trying to recognize some genes that is widely separated between disparat species. And test these genes in Mirabilis Jalapa to confirm this result.本實驗先針對紫茉莉開花生物時鐘的特性進行觀察,並以不同的變因測試對紫茉莉開花時鐘的影響,紫茉莉個別花朵開花生物時鐘並不一致,長日照會對植株造成開花時間提早(約1 小時)的影響,全日照則會對花芽分生及開花行為造成抑制,溫度對於開花影響不明顯。而後利用蛋白質電泳對不同時間點的樣本進行分析,由於開花激素存量極微,故並電泳結果無明顯差異。再來以阿拉伯芥已知與生物時鐘有關的基因中經過生物資訊(Bio Informatics)預測在紫茉莉中存在與開花及光週期有關之基因(CAA75629 CAB56039 AAB60305 AAC49807 AAA82068),針對該基因進行表現量的測定,驗證該基因與開花生物時鐘的關聯性。針對動物界與植物界中已知與生物時鐘相關的基因進行交叉比對,希望找出跨界廣泛存在的生物時鐘基因,接著測試紫茉莉中該基因的存在與否及表現狀況與其他物種的差異,驗證該基因分布的廣泛性。

紫茉莉生物時鐘機制的研究

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