https://scholars.lib.ntu.edu.tw/handle/123456789/139406
標題: | 玉米β-澱粉酶基因啟動子活性表現因子之分析 Analysis of β-amylase Promoter Activity in Maize |
作者: | 陳立岡 Chen, Li-Kang |
關鍵字: | 玉米;β-澱粉酶;啟動子;β-amylase;Promoter;Maize | 公開日期: | 2004 | 摘要: | 本論文旨在探討影響玉米β-澱粉酶(ZmBA)啟動子基因表現的因子。以3天玉米糊粉層以及4天、8天之小苗初生葉片和22天植株之成熟葉片等組織為材料,進行粒子槍短暫表現系統實驗,配合GUS報告基因(uidA),以分析β-澱粉酶啟動子的表現活性情形。本論文發現在幼嫩初生葉中,外加GA處理對β-澱粉酶啟動子表現的促進性不明顯,而ABA處理會使表現量下降90%,若GA+ABA同時處理時,GA有拮抗ABA抑制機制的作用。在完全展開的剛成熟葉片中,β-澱粉酶啟動子的活性表現微弱,若外加糖類處理時,其表現量則可上升4倍,而外加GA處理可提高10倍以上的活性表現。在刪除啟動子上特定順式調控因子之實驗結果得知,刪除啟動子中的3個amybox1(TAACARA, GARE)或2個amybox2 (TATCCAT/C)時,啟動子活性下降約40%,同時也減弱ABA的敏感性。且GA拮抗ABA抑制作用的能力也減少,尤以刪除amybox1為甚。另外,細究序列不同的amybox1之對啟動子影響,發現TAACAAA對於玉米β-澱粉酶啟動子的表現較為重要。而刪除ABRE(YACGTGGC)時,ABA 的抑制量從90%下降到45-50%,顯然刪除ABRE可以減弱ABA的抑制作用。朱齡22天植株之已展開成熟葉中,β-澱粉酶的表現低微,以GA處理會促進β-澱粉酶活性的表現,但隨著組織年齡向葉尖增加GA的促進性會逐漸失去。實驗分析利用ZmBA△ABRE::GUS質粒在幼嫩和剛成熟初生葉的表現,測試ABRE在葉齡與β-澱粉酶基因活性之間的可能角色關係,在剛成熟之初生葉組織中,ZmBA△ABRE的活性表現比全長啟動子的活性高了3倍,顯示ABRE與成熟葉片中β-澱粉酶啟動子活性之下降,有密切的關係;又刪除ABRE之ZmBA△ABRE的活性仍因外加ABA處理,而降低了50%的活性,此暗示在β-澱粉酶啟動子中除了ABRE之外,仍存在與ABA之作用有關的序列。 In this study, I analyzed the activity of maize (-amylase promoter via particle bombardment-transient expression assay using uidA as a reporter gene. Aleurone layers isolated from 3-day-old seedlings, 4-day-old developing and 8-day-old fully expanded primary leaves, and mature foliage leaves were used as experiment tissues. The full-length (1.6 kb) promoter can express in aleurone layers and developing primary leaves, but the activity was much reduced in the fully expanded leaves. Full-length promoter in aleurone layers and developing leaves showed no significant increase in response to GA treatment. However, upon treatment with ABA, the activity dropped to 10% of the control level. In the presence of both GA and ABA, the activity was restored to the level of GA-treatment alone. Application of sugar and GA to mature leaves enhanced the promoter activity by 4- and 10-fold, respectively. There are three amybox 1, two amybox 2 and one ABRE cis-elements in the maize (-amylase promoter. Deletion of amybox 1 or amybox 2 caused a reduction in promoter activity by 40% and a decrease in sensitivity to ABA treatment. Deletion of amybox1 eliminated the antagonistic efficacy of GA against to ABA inhibition. Deletion of ABRE showed no influence on the promoter activity, but it did interfere with the ABA effect. There is an age gradient from base to tip in a fully expanded blade of a 22-day-old plant, and the activity of |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/57951 | 其他識別: | zh-TW |
顯示於: | 植物科學研究所 |
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ntu-93-R90226020-1.pdf | 23.31 kB | Adobe PDF | 檢視/開啟 |
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