The control of ascorbate biosynthesis: the role of light and GDP-L-galactose phosphorylase

抗坏血酸生物合成的控制：光和 GDP-L-半乳糖磷酸化酶的作用

• 批准号: BB/G021678/1
• 负责人: Nicholas Smirnoff
• 金额: $ 47.8万
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FG021678%2F1
• 关键词: control; ascorbate; biosynthesis; role; light

Ascorbic acid (vitamin C) is essential for plant growth and is synthesised by plant leaves in large amounts. It is important as an antioxidant (antioxidants are compounds that protect against the damaging effects of reactive oxygen species that are produced from oxygen by all living organisms) and is also needed as an enzyme cofactor for production of collagen (in animals) and hormones (in animals and plants). Understanding the factors that control how much vitamin C accumulates in leaves is important for two reasons. Firstly, it provides vitamin C in the human diet. Secondly, plants with low vitamin C are susceptible to damage caused by various environmental stresses. It has been found that leaf vitamin C content is very closely related to light intensity, most probably because it is needed for protection against potentially damaging reactive oxygen species that are inevitably formed during photosynthesis. This project will determine the biochemical mechanisms that control the concentration of vitamin C in leaves. Part of the research will focus on identifying the contribution of each step in the pathway of vitamin C synthesis to increasing vitamin C in leaves exposed to high light. The other part will be a detailed investigation of two genes (VTC2 and VTC5) which both encode an enzyme involved in vitamin C synthesis (GDP-L-galactose phosphorylase). While the control of the rate of synthesis of products such as vitamin C is generally shared between a number of steps in its synthresis pathway, the evidence strongly implicates VTC2 and perhaps VTC5 as major control points in the pathway. In this project we aim to determine how the activity of VTC2 and VTC5 are controlled in relation to light and photosynthesis and how this contributes, along with other steps in the pathway, to the very precise control of vitamin C concentration in leaves.

抗坏血酸（维生素C）是植物生长所必需的，由植物叶子大量合成。它作为一种抗氧化剂非常重要（抗氧化剂是一种化合物，可以防止活性氧的破坏性影响，活性氧是由所有生物体从氧气中产生的），并且还需要作为生产胶原蛋白（在动物中）和激素（在动物中）的酶辅因子。动物和植物）。了解控制叶子中维生素 C 积累量的因素非常重要，原因有二。首先，它在人类饮食中提供维生素C。其次，维生素C含量低的植物容易受到各种环境胁迫的损害。研究发现，叶子维生素 C 含量与光强度密切相关，很可能是因为需要它来防止光合作用过程中不可避免地形成的潜在破坏性活性氧。该项目将确定控制叶子中维生素 C 浓度的生化机制。该研究的一部分将侧重于确定维生素 C 合成途径中每个步骤对增加暴露在强光下的叶子中维生素 C 的贡献。另一部分将详细研究两个基因（VTC2 和 VTC5），这两个基因都编码参与维生素 C 合成的酶（GDP-L-半乳糖磷酸化酶）。虽然对维生素 C 等产物的合成速率的控制通常由其合成途径中的许多步骤共享，但证据强烈表明 VTC2 和可能的 VTC5 是该途径中的主要控制点。在这个项目中，我们的目标是确定如何控制 VTC2 和 VTC5 的活性与光和光合作用的关系，以及它如何与该途径中的其他步骤一起有助于非常精确地控制叶子中的维生素 C 浓度。

项目成果

Evolution of alternative biosynthetic pathways for vitamin C following plastid acquisition in photosynthetic eukaryotes.

光合真核生物质体获取后维生素 C 替代生物合成途径的进化。

• 发表时间: 2015
• 作者: []

Expression analysis of the VTC2 and VTC5 genes encoding GDP-L-galactose phosphorylase, an enzyme involved in ascorbate biosynthesis, in Arabidopsis thaliana.

拟南芥中编码 GDP-L-半乳糖磷酸化酶（一种参与抗坏血酸生物合成的酶）的 VTC2 和 VTC5 基因的表达分析。

• DOI: http://dx.10.1271/bbb.110320
• 发表时间: 2011
• 期刊: Bioscience, biotechnology, and biochemistry
• 作者: Gao Y

The role of GDP-l-galactose phosphorylase in the control of ascorbate biosynthesis.

GDP-l-半乳糖磷酸化酶在控制抗坏血酸生物合成中的作用。

• DOI: http://dx.10.1093/plphys/kiab010
• 发表时间: 2021
• 期刊: Plant physiology
• 影响因子: 7.4
• 作者: Fenech M

The influence of ascorbate on anthocyanin accumulation during high light acclimation in Arabidopsis thaliana: further evidence for redox control of anthocyanin synthesis.

• DOI: 10.1111/j.1365-3040.2011.02369.x
• 发表时间: 2012-02-01
• 期刊: Plant, cell & environment
• 作者: M. Page;N. Sultana;Konrad H. Paszkiewicz;H. Florance;N. Smirnoff
• 通讯作者: N. Smirnoff

Ascorbic acid metabolism and functions: A comparison of plants and mammals.

抗坏血酸代谢和功能：植物和哺乳动物的比较。

• DOI: http://dx.10.1016/j.freeradbiomed.2018.03.033
• 发表时间: 2018
• 期刊: Free radical biology & medicine
• 影响因子: 7.4
• 作者: Smirnoff N