水稻蔗糖轉運蛋白質基因OsSUT2及OsSUT4之表現分析

Analysis of expressions of rice sucrose transporter genes OsSUT2 and OsSUT4

蕭惠心(Hui-Hsin Hsiao)

指導教授 ： 王淑珍

國立臺灣大學/生物資源暨農學院/農藝學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.01857

摘要

高等植物體內，蔗糖從細胞間質裝載進入韌皮部進行運送及由韌皮部卸載至周圍細胞的過程中，蔗糖轉運蛋白 (sucrose transporters; SUTs) 扮演極重要的角色。水稻 (Oryza sativa L.) 蔗糖轉運蛋白基因家族成員為 OsSUT1、2、3、4及5。本研究主要藉由 OsSUT2 啟動子 POsSUT2::GUS 及 OsSUT4 啟動子 POsSUT4::GUS 轉殖水稻探討兩基因之組織專一性表現及生長發育上之差異表現。分析結果顯示 OsSUT2 及 OsSUT4 基因於根及葉部均具維管束韌皮部表現專一性；在穎花發育過程中，OsSUT2 及 OsSUT4 在抽穗前主要表現於內及外穎之穎脈，隨著抽穗、開花及授粉，穎脈專一性表現消失，轉而於雌蕊及雄蕊有明顯之表現。在充實穀粒中，OsSUT2 及 OsSUT4 主要在胚及糊粉層具顯著表現。在研究根系生長發育過程中，發現 OsSUT2 及 OsSUT4 啟動子主要於細胞生長快速之部位表現，例如種子根之根尖延長區及側根形成處。藉由外加醣類處理之試驗，得知 3% 之蔗糖及葡萄糖會促進 OsSUT2 及 OsSUT4 基因表現，而甘露醇與未處理醣類之表現差異不大。另外，利用 real-time RT-PCR 分析發現 OsSUT2 及 OsSUT4 兩基因之表現於機械傷害後 15 分鐘及 1 小時內即會被大量誘導，然而隨著時間增長，此兩基因之表現將逐漸下降。

關鍵字

蔗糖轉運蛋白 ； 水稻 ； 啟動子 ； 醣類 ； 機械傷害

並列摘要

In higher plants, sucrose transporters (SUTs) play important roles for the sucrose loading , which sucrose enters into phloem for further transportation and then unloads to surrounding cells. The rice (Oryza sativa L.) SUT gene family are composed of five members, OsSUT1 to 5. This study focused on the investigation of the tissue-specific and developmental regulation of OsSUT2 and OsSUT4 promoter in POsSUT2::GUS and POsSUT4::GUS transgenic rice plants. The results showed that GUS was specifically expressed in phloem tissue, both in OsSUT2 and OsSUT4. In developing caryopses, the activities of OsSUT2 and OsSUT4 promoters, were obviously observed in vascular bundles of lemma and palea at pre-heading stage. After heading and flowering, expression GUS in lemma and palea become undetectable but can be found in ovaries and anthers. In germinating seeds, OsSUT2 and OsSUT4 promoter activities were dominantly presented in embryos and aleurone layers. In developing roots, OsSUT2 and OsSUT4 promoters were both active in rapid growing regions, such as elongation zone of seminal roots and the sites of lateral root formation. Expression of OsSUT2 and OsSUT4 could be enhanced by 3% sucrose and glucose in root tissues. Real-time RT-PCR analysis showed that OsSUT2 and OsSUT4 mRNA levels in leaves would quickly increase after wounding treatment for 15 min and 1 hr, respectively, but following the mRNA levels declined gradually.

並列關鍵字

sucrose transporter ； rice (Oryza sativa L.) ； promoter ； sugars ； wounding

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