Expression of the granule-bound starch synthase I (Waxy) gene from snapdragon is developmentally and circadian clock regulated
Expression of the granule-bound starch synthase I (Waxy) gene from snapdragon is developmentally and circadian clock regulated
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DOI：
10.1104/pp.120.2.401
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发表时间：
1999-06-01
期刊：
影响因子：
7.4
通讯作者：
Romero, JM
中科院分区：
文献类型：
--
作者：
Mérida, A;Rodríguez-Galán, JM;Romero, JM
颗粒结合淀粉合酶 I（GBSSI 或蜡质）酶催化淀粉合成的酶促步骤之一。这种酶负责直链淀粉的合成，也参与构建支链淀粉的最终结构。关于 GBSSI 基因在贮藏器官以外的组织中的表达知之甚少，例如种子、胚乳和块茎。我们从金鱼草 (Antirhinum majus) 中分离出了编码 GBSSI 的基因。该基因在金鱼草基因组中以单拷贝形式存在。它在花中的表达有精确的空间和发育调节。 GBSSI 表达在早期发育阶段的所有花轮中都观察到，但仅限于开花前的心皮。这些结果为淀粉在种子灌浆等后期生殖事件中的作用提供了新的见解。在叶子中，GBSSI 的 mRNA 水平受到内源生物钟的调节，表明从白天到夜晚的转变可能伴随着淀粉合成基因表达的消除。当在黑暗中生长时，这种机制在库组织（例如根）中不起作用。
The granule-bound starch synthase I (GBSSI or waxy) enzyme catalyzes one of the enzymatic steps of starch synthesis. This enzyme is responsible for the synthesis of amylose and is also involved in building the final structure of amylopectin. Little is known about expression of GBSSI genes in tissues other than storage organs, such as seeds, endosperm, and tuber. We have isolated a gene encoding the GBSSI from snapdragon (Antirrhinum majus). This gene is present as a single copy in the snapdragon genome. There is a precise spatial and developmental regulation of its expression in flowers. GBSSI expression was observed in all floral whorls at early developmental stages, but it was restricted to carpel before anthesis These results give new insights into the role of starch in later reproductive events such as seed filling. In leaves the mRNA level of GBSSI is regulated by an endogenous circadian clock, indicating that the transition from day to night may be accompanied by abolition of expression of starch synthesis genes. This mechanism does not operate in sink tissues such as roots when grown in the dark.