Mechanisms of biosynthesis and transport of ADP-glucose in rice endosperm cells

水稻胚乳细胞ADP-葡萄糖生物合成与转运机制

• 批准号: 18580086
• 负责人: ITO Hiroyuki
• 金额: $ 2.5万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18580086/
• 关键词: ADP-glucose pyrophosphorylase; starch biosynthesis; endosperm cells; ADP-glucose; transporter; ADPglucose pyrophosphorylase; ADPglucose; ADP-glucose pyrophosphorylase

Plants accumulate storage starch in amyloplasts of heterotrophic organs as an energy source for the next generations. We have utilized the storage starch, which is a natural and highly accessible biomass, as not only calorie sources but also various industrial raw materials. Thus, to understand the plant starch biosynthesis is a critical issue that is directly linked to ensuring and increasing of energy. ADPglucose pyrophsophorylase (AGPase) is a key enzyme in the starch biosynthesis and catalyzes the synthesis of ADPglucose (ADPG). Unlike the other plants, cereal plants have two types of AGPases in amyloplasts and cytosol of the endosperm cells and therefore the specific system that synthesizes ADPG in cytosol and transports it to amyloplasts. The physiological significance of this system, however, remains to be defined. The aim in this study was to construct a novel molecular basis for the improvement of rice plant productivity, focusing on the cereal specific system.The cDNA for ADPG transporter was isolated from rice seed cDNA mixture. Analysis using RT-PCR showed that the mRNA predominantly accumulates in seeds. The expression system in Escherichia coli cells suggested that the other host cell or vector is required for this membrane protein.The subunit compositions for cytosolic and plastidic AGPases were estimated by the organ-specific gene expression profiles of six subunit genes for rice AGPases. The recombinant cytosolic and plastidic enzymes were purified from E. coli and the kinetic properties were investigated. Although, compared with the plastidic form, the cytosolic form was predicted to be more active in vivo by iodine staining, the kinetic properties showed that the plastidic form has a higher activity than the cytosolic form. This suggests that there is an unknown activating factor for the cytosolic AGPase in rice endosperm cells.

植物在异养器官的造粉体中积累贮藏淀粉，作为下一代的能量来源。我们已经利用了储存淀粉，这是一种天然的和高度可获得的生物质，不仅作为热量来源，而且还作为各种工业原料。因此，了解植物淀粉的生物合成是一个直接关系到能量保证和增加的关键问题。ADP葡萄糖焦磷酸化酶（ADP glucose pyrophsophorylase，AGG）是淀粉生物合成的关键酶，催化ADP葡萄糖（ADP glucose，ADPG）的合成。与其他植物不同，谷类植物胚乳细胞的造粉体和胞质中有两种类型的AGPases，因此在胞质中合成ADPG并将其运输到造粉体的特定系统。然而，该系统的生理意义仍有待确定。本研究从水稻种子cDNA混合物中克隆了ADPG转运蛋白的cDNA，并将其克隆到水稻种子中，构建了ADPG转运蛋白的特异表达载体，为水稻生产力的提高奠定了分子基础。利用RT-PCR分析表明，mRNA主要积累在种子中。在大肠杆菌中的表达系统表明，这种膜蛋白需要另一种宿主细胞或载体。从E.大肠杆菌中进行了初步研究，并考察了其动力学性质。虽然，与质体形式相比，胞质形式被预测为在体内更活跃的碘染色，动力学性质表明，质体形式具有比胞质形式更高的活性。这表明水稻胚乳细胞中存在一种未知的胞质AGEs激活因子。

项目成果

A novel wound-responsive cis-element, VWRE, for the vascular system-specific expression of a tobacco peroxidase gene, tpoxN1.

一种新型伤口响应顺式元件 VWRE，用于烟草过氧化物酶基因 tpoxN1 的血管系统特异性表达。

• 发表时间: 2006
• 期刊: Plant Molecular Biology 62
• 作者: Sasaki. K.;et. al.
• 通讯作者: et. al.

イネADP-glucose pyrophosphorylaseアイソザイムの発現特性と酵素特性

水稻ADP-葡萄糖焦磷酸化酶同工酶的表达特性及酶性质

• 发表时间: 2007
• 作者: 西村祐美;ら
• 通讯作者: ら

インゲンマメisoamylaseアイソザイムの精製と反応特性

芸豆异淀粉酶同工酶的纯化及反应特性

• 发表时间: 2006
• 作者: 高嶋美範;ら
• 通讯作者: ら

Purification and characterization of isoamylase isozymes from kidney bean seeds.

菜豆种子中异淀粉酶同工酶的纯化和表征。

• 发表时间: 2006
• 作者: Takashima;Y.;et. al.
• 通讯作者: et. al.

Two novel AP2/ERF domain proteins interact with cis-element VWRE for wound-induced expression of the Tobacco tpoxN1 gene.

• DOI: 10.1111/j.1365-313x.2007.03111.x
• 发表时间: 2007-04
• 期刊: The Plant journal : for cell and molecular biology
• 作者: K. Sasaki;I. Mitsuhara;S. Seo;Hiroyuki Ito;H. Matsui;Y. Ohashi