The twilight zone: the initiation of starch degradation in leaves

暮光区：叶子中淀粉降解的开始

• 批准号: BB/N001389/1
• 负责人: Alison Smith
• 金额: $ 67.88万
• 依托单位: John Innes Centre
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FN001389%2F1
• 关键词: twilight; zone; initiation; starch; degradation

Plants feed themselves by converting carbon dioxide from the air into sugars, in the process of photosynthesis. These sugars provide the energy and building blocks for plant growth. Although photosynthesis can only happen in the light, most plants continue to grow at night. They are able to do this because some of the sugars made during the day are stored in leaves as starch. At night, the starch is broken down to release sugars that can be used for growth. At the end of the day, as it gets dark, plants must switch from photosynthesis to starch breakdown as their source of sugars for growth. We know that this switch happens gradually during twilight. As the light fades and the supply of sugars from photosynthesis goes down, the supply of sugars from starch gradually increases. However, almost nothing is known about how plants bring about this transition from photosynthesis to starch breakdown as the source of sugars. We have discovered that starch breakdown is triggered by falling light levels at the end of the day. Surprisingly, however, the same fall in light levels does not trigger starch breakdown in the middle of the day. This discovery implies that plants have a sophisticated mechanism that anticipates when the night will come, and triggers starch breakdown in response to falling light levels only at that point. During this project, we will investigate how falling light levels trigger starch breakdown, and whether the timing of this process is controlled by the plant's internal clock (the circadian clock). The research will make use of mutant plants that have either a reduced ability to perceive light levels, or alterations in the functioning of their internal clock. The outcomes will be new information about how plants maintain their growth throughout the day night cycle, and insights into how different light regimes may affect plant productivity.

在光合作用过程中，植物通过将二氧化碳从空气转化为糖。这些糖为植物生长提供了能量和基础。尽管光合作用只能在光线下发生，但大多数植物在晚上继续生长。他们之所以能够这样做，是因为白天制造的某些糖作为淀粉存储在叶子中。到了晚上，淀粉被分解以释放可用于生长的糖。归根结底，随着植物的变化，植物必须从光合作用变为淀粉分解，作为其生长糖的来源。我们知道这种开关在暮光期间逐渐发生。随着光合作用的光和糖的供应下降，淀粉中糖的供应逐渐增加。但是，几乎一无所知，植物如何使这种从光合作用到淀粉分解作为糖来源的过渡。我们发现，淀粉故障是由一天结束时的光线下降引起的。但是，令人惊讶的是，在光线上同样的下降并不能触发一天中期的淀粉故障。这一发现意味着植物具有一种复杂的机制，可以预期何时夜晚到来，并且触发淀粉崩溃，以响应仅在这一点上下降的光水平下降。在此项目期间，我们将研究光线下降是如何触发淀粉分解的，以及该过程的时机是否受工厂的内部时钟（昼夜节律时钟）的控制。这项研究将利用突变植物的感知能力水平降低或内部时钟功能的改变。结果将是有关植物如何在整个夜间周期保持生长的新信息，以及有关不同光制制度如何影响植物生产力的见解。

项目成果

Leaf Starch Turnover Occurs in Long Days and in Falling Light at the End of the Day

• DOI: 10.1104/pp.17.00601
• 发表时间: 2017-08-01
• 期刊: PLANT PHYSIOLOGY
• 影响因子: 7.4
• 作者: Fernandez, Olivier;Ishihara, Hirofumi;Stitt, Mark
• 通讯作者: Stitt, Mark

The Arabidopsis Framework Model version 2 predicts the organism-level effects of circadian clock gene mis-regulation

拟南芥框架模型版本 2 预测生物钟基因失调的生物体水平影响

• DOI: 10.1101/105437
• 发表时间: 2017
• 作者: Chew Y

Rising rates of starch degradation during daytime and trehalose 6-phosphate optimize carbon availability.

• DOI: 10.1093/plphys/kiac162
• 发表时间: 2022-08-01
• 期刊: PLANT PHYSIOLOGY
• 影响因子: 7.4
• 作者: Ishihara, Hirofumi;Alseekh, Saleh;Feil, Regina;Perera, Pumi;George, Gavin M.;Niedzwiecki, Piotr;Arrivault, Stephanie;Zeeman, Samuel C.;Fernie, Alisdair R.;Lunn, John E.;Smith, Alison M.;Stitt, Mark
• 通讯作者: Stitt, Mark

Sucrose synthases are not involved in starch synthesis in Arabidopsis leaves.

• DOI: 10.1038/s41477-022-01140-y
• 发表时间: 2022-05
• 期刊: NATURE PLANTS
• 影响因子: 18
• 作者: Funfgeld, Maximilian M. F. F.;Wang, Wei;Ishihara, Hirofumi;Arrivault, Stephanie;Feil, Regina;Smith, Alison M.;Stitt, Mark;Lunn, John E.;Niittyla, Totte
• 通讯作者: Niittyla, Totte