Chlorophyll-f-containing Photosystem I

含叶绿素f的光系统I

• 批准号: BB/V002015/1
• 负责人: Alfred Rutherford
• 金额: $ 92.16万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FV002015%2F1
• 关键词: Chlorophyll; containing; Photosystem

In 2018 we discovered a new type of photosynthesis that does photochemistry using chlorophyll-f, which absorbs infra-red light. Photosynthesis uses sunlight to provide the energy for life on the planet and put the oxygen into the atmosphere. Since its appearance, the oxygen generated by photosynthesis formed the ozone layer that screens out the deadly UV and allowed respiration to occur, leading to the evolution of complex life. Photosynthesis also pulled down most of the CO2 from the atmosphere and converted it into living matter, resulting in conditions on the planet appropriate for the current inhabitants. Given the importance of photosynthesis, the discovery of a new kind did cause a stir. The new process is found in some bacteria that do normal, visible-light photosynthesis. However, when these bugs find themselves in darkness, shaded by other photosynthetic organisms that use the visible light but not the infra-red, they are able to switch-on a special suite of genes to make new photosynthetic enzymes that works with infra-red light. We showed that chlorophyll-f does the key light-driven chemical reactions at the heart of this type of photosynthesis.This discovery was a surprise as the standard type of photosynthesis shows little or no fundamental variation across all of the wide range of photosynthetic species, from cyanobacteria to oak trees. It had been assumed that the energy of visible light absorbed by chlorophyll-a was only just sufficient to do the demanding chemistry. The discovery that lower energy, longer wavelength light could be used to do exactly the same process, was thus highly unexpected. Photosynthesis is inefficient in energy terms and this makes agriculture inefficient too. This is why we put in enormous quantities of energy, in the form of fertilizers, pesticides, and processes, to get the yields we need. Unsurprisingly, for years scientists have been researching ways of improving photosynthesis. Recently there have been remarkable advances in which increased crop yields were obtained by modifying the regulation processes that optimize light use and protect plants under changing light conditions. A major intrinsic inefficiency in crops is that leaves in the lower canopy are shaded from the light by those in the upper canopy. The new infra-red photosynthesis could in principle be introduced into crops to function when needed in the shaded leaves. This could give a marked increase in photosynthetic yields. Extending the spectrum of photosynthesis to longer wavelengths has been talked about for years but it seemed a rather unrealistic task. The finding that evolution has already done it, makes the whole idea more feasible. The current project involves studies that are needed to learn what evolution has done to get the system to work with less energy. By comparing the new system with the standard one, we have already advanced rapidly in this area, but the present project is the first to deal specifically with the infra-red-driven Photosystem I, the enzyme that provides the energy boost needed to fix CO2 into living matter. To do this we will identify exactly which of the enzyme's chlorophylls are chlorophyll-f and how they are tweaked by the protein to make them do the job. We will combine molecular biology, biochemistry and biophysics to sort out the structural and mechanistic details required to understand how it works. In this way we can provide the knowledge needed to determine the feasibility of crop improvement and the best ways to implement it. The new Photosystem I also provides an opportunity to disentangle the individual chlorophyll contributions. Unlike the conventional chlorophyll-a systems, where all (95) pigments are the same color, these new systems have a small number of distinct chlorophylls-f in key positions. This undreamt-of decluttering of the color spectrum should allow old mysteries to be resolved. We hope to do that too in this project.

2018年，我们发现了一种新型的光合作用，它利用吸收红外光的叶绿素-f进行光化学。光合作用利用阳光为地球上的生命提供能量，并将氧气输送到大气中。自出现以来，光合作用产生的氧气形成了臭氧层，屏蔽了致命的紫外线，允许呼吸作用发生，导致了复杂生命的进化。光合作用还从大气中吸收了大部分二氧化碳，并将其转化为生物物质，导致地球上的条件适合目前的居民。鉴于光合作用的重要性，一种新的光合作用的发现确实引起了轰动。在一些进行正常可见光光合作用的细菌中发现了这一新过程。然而，当这些细菌发现自己处于黑暗中，被其他使用可见光但不使用红外线的光合作用有机体遮蔽时，它们能够启动一组特殊的基因，以制造新的光合酶，这种酶可以与红外光一起工作。我们证明了叶绿素-f在这类光合作用的核心进行关键的光驱动化学反应。这一发现令人惊讶，因为标准类型的光合作用在从蓝藻到橡树的所有广泛的光合作用物种中几乎没有根本的变化。人们一直认为，被叶绿素-a吸收的可见光的能量仅足以完成要求很高的化学物质。因此，更低能量、更长波长的光可以用来完成完全相同的过程的发现，是非常出人意料的。从能源角度讲，光合作用是低效的，这也使得农业低效。这就是为什么我们投入了大量的能源，以化肥、杀虫剂和加工的形式，以获得我们需要的产量。多年来，科学家们一直在研究改善光合作用的方法，这并不令人惊讶。近年来，通过改变调节过程来优化光的利用并在变化的光条件下保护植物，从而提高了作物的产量，取得了显着的进展。作物的一个主要内在低效是下层树冠的树叶被上层树冠的树叶遮蔽而不受光照。原则上，这种新的红外线光合作用可以被引入作物中，以便在遮荫的叶片中发挥作用。这可能会显著增加光合作用的产量。多年来，人们一直在讨论将光合作用的光谱扩展到更长的波长，但这似乎是一个相当不现实的任务。进化已经做到了这一点，这一发现使整个想法变得更加可行。目前的项目涉及到一些研究，这些研究需要了解进化是如何让系统以更少的能量工作的。通过将新系统与标准系统进行比较，我们已经在这一领域取得了快速进展，但本项目是第一个专门处理红外线驱动的光系统I的项目，这种酶提供将二氧化碳固定到生物体中所需的能量提升。为了做到这一点，我们将准确地确定哪些酶的叶绿素是叶绿素-f，以及它们是如何被蛋白质扭曲以完成这项工作的。我们将结合分子生物学、生物化学和生物物理学来理清理解它如何工作所需的结构和机制细节。通过这种方式，我们可以提供所需的知识，以确定作物改良的可行性和实施的最佳方式。新的光系统I也提供了一个解开个体叶绿素贡献的机会。与传统的叶绿素-a系统不同的是，所有(95)种色素都是相同的颜色，这些新系统在关键位置有少量不同的叶绿素-f。这种意想不到的光谱清理应该可以解开古老的谜团。我们希望在这个项目中也做到这一点。

项目成果

Changes in supramolecular organization of cyanobacterial thylakoid membrane complexes in response to far-red light photoacclimation.

• DOI: 10.1126/sciadv.abj4437
• 发表时间: 2022-02-11
• 期刊: Science advances
• 影响因子: 13.6
• 作者: MacGregor-Chatwin C;Nürnberg DJ;Jackson PJ;Vasilev C;Hitchcock A;Ho MY;Shen G;Gisriel CJ;Wood WHJ;Mahbub M;Selinger VM;Johnson MP;Dickman MJ;Rutherford AW;Bryant DA;Hunter CN
• 通讯作者: Hunter CN

Absorption changes in Photosystem II in the Soret band region upon the formation of the chlorophyll cation radical [PD1PD2].

叶绿素阳离子自由基 [PD1PD2] 形成后，Soret 带区域中光系统 II 的吸收变化。

• DOI: 10.1007/s11120-023-01049-3
• 发表时间: 2023
• 期刊: Photosynthesis research
• 影响因子: 3.7
• 作者: Boussac A

Impact of energy limitations on function and resilience in long-wavelength Photosystem II.

• DOI: 10.7554/elife.79890
• 发表时间: 2022-07-19
• 期刊: ELIFE
• 影响因子: 7.7
• 作者: Viola, Stefania;Roseby, William;Santabarbara, Stefano;Nurnberg, Dennis;Assuncao, Ricardo;Dau, Holger;Selles, Julien;Boussac, Alain;Fantuzzi, Andrea;Rutherford, A. William
• 通讯作者: Rutherford, A. William

Impact of energy limitations on function and resilience in long-wavelength Photosystem II

能量限制对长波长光系统 II 功能和弹性的影响

• DOI: 10.1101/2022.04.05.486971
• 发表时间: 2022
• 作者: Viola S

Absorption changes in Photosystem II in the Soret band region upon the formation of the chlorophyll cation radical [P D1 P D2 ] +

叶绿素阳离子自由基形成后索雷带区域光系统 II 的吸收变化 [P D1 P D2 ]

• DOI: 10.1101/2022.05.12.491653
• 发表时间: 2022
• 作者: Boussac A