Müller-Röber B, La Cognata U, Sonnewald U, Willmitzer L
Institut für Genbiologische Forschung Berlin GmbH, Germany.
Plant Cell. 1994 May;6(5):601-12.
ADP-glucose pyrophosphorylase (AGPase) is a key regulatory enzyme in starch biosynthesis in higher plants. A 3.2-kb promoter of the large subunit gene of the AGPase from potato has been isolated and its activity analyzed in transgenic potato and tobacco plants using a promoter-beta-glucuronidase fusion system. The promoter was active in various starch-containing cells, including guard cells, tuber parenchyma cells, and the starch sheath layer of stems and petioles. No expression was observed in mesophyll cells. Analysis of various promoter derivatives showed that with respect to expression in petioles and stems, essential elements must be located in the 5' distal region of the promoter, whereas elements important for expression in tuber parenchyma cells are located in an internal fragment comprising nucleotides from positions -500 to -1200. Finally, a 0.3-kb 5' proximal promoter fragment was identified that was sufficient to obtain exclusive expression in guard cells of transgenic potato and tobacco plants. The implications of our observations are discussed with respect to starch synthesis in various tissues and the use of the newly identified promoter as a tool for stomatal biology.
ADP - 葡萄糖焦磷酸化酶（AGPase）是高等植物淀粉生物合成中的关键调节酶。已从马铃薯中分离出AGPase大亚基基因的一个3.2 kb启动子，并使用启动子 - β - 葡萄糖醛酸酶融合系统在转基因马铃薯和烟草植株中分析了其活性。该启动子在各种含淀粉细胞中具有活性，包括保卫细胞、块茎薄壁细胞以及茎和叶柄的淀粉鞘层。在叶肉细胞中未观察到表达。对各种启动子衍生物的分析表明，就叶柄和茎中的表达而言，必需元件必定位于启动子的5' 远端区域，而对块茎薄壁细胞中表达重要的元件位于一个内部片段中，该片段包含从 - 500到 - 1200位置的核苷酸。最后，鉴定出一个0.3 kb的5' 近端启动子片段，该片段足以在转基因马铃薯和烟草植株的保卫细胞中获得特异性表达。我们结合各种组织中的淀粉合成以及将新鉴定的启动子用作气孔生物学工具的用途，讨论了我们观察结果的意义。
