An Early Step on the Long, Strange Road to Photosynthesis

E very second, trillions of watts of solar energy — more than 10,000 times the energy used by modern humans — blast the Earth’s surface.

紧接着，数万亿瓦的太阳能——超过现代人类使用能量的一万倍——席卷了地球表面。

Around 2.4 billion years ago, life took an evolutionary leap when bacteria learned to harness these photons to break apart water molecules and stitch carbon atoms into sugars.

大约 24 亿年前，当细菌学会利用这些光子来分解水分子并将碳原子缝合到糖中时，生命发生了进化的飞跃。

Along the way, they flooded Earth’s atmosphere with oxygen and rewrote the rules of life.

一路上，他们向地球大气层注入氧气，并改写了生命规则。

“The oxygen-evolving capability was a big innovation.

“释氧能力是一项重大创新。

I sometimes call that a singular event,” said Robert Blankenship , a retired biochemist from Washington University in St. Louis.

我有时称其为奇特事件，”圣路易斯华盛顿大学的退休生物化学家罗伯特·布兰肯希普 (Robert Blankenship) 说。

“By all accounts, it only happened once during the process of evolution, and that really set up the world for becoming oxygenated and the wholly aerobic world that we live in now.”

“从各方面来看，这种情况在进化过程中只发生过一次，这确实为含氧世界和我们现在生活的完全有氧世界奠定了基础。”

However, the set of chemical reactions we call photosynthesis has bewitched and befuddled scientists for generations.

然而，我们称之为光合作用的一系列化学反应已经让几代科学家着迷和困惑。

It requires the coordination of dozens of proteins and hundreds of pigments that harvest photons, all embedded in a cellular structure less than one-thousandth the width of a human hair.

它需要数十种蛋白质和数百种色素的协调来收集光子，所有这些都嵌入在小于人类头发宽度千分之一的细胞结构中。

Electrons pinball across membranes and between compounds to drive molecular turbines that rebuild air and water into sugars to provide the energy and raw materials that cells need to grow.

电子在膜和化合物之间弹球，驱动分子涡轮，将空气和水重建成糖，以提供细胞生长所需的能量和原材料。

We now know this process in fundamental detail; advances in microscopy and cell biology mean that researchers can essentially track a single electron through photosynthetic proteins to illuminate the full molecular mechanism.

我们现在已经了解了这个过程的基本细节；显微镜和细胞生物学的进步意味着研究人员基本上可以通过光合蛋白质追踪单个电子，以阐明完整的分子机制。

This level of detail dims, however, as scientists attempt to travel back in time to understand how photosynthesis could possibly have first evolved in single-celled organisms called cyanobacteria over 2 billion years ago.

然而，随着科学家试图回到过去，了解光合作用是如何在 20 亿多年前被称为蓝细菌的单细胞生物中首次进化出来的，这种细节水平就变得模糊了。

“It’s now pretty clear that all the photosynthetic [protein] complexes descend from a single common origin,” said Blankenship, who spent his career studying the molecular mechanisms of photosynthesis.

“现在很清楚，所有光合作用[蛋白质]复合物都来自一个共同的起源，”布兰肯希普说，他的职业生涯一直在研究光合作用的分子机制。

“But the nature of that very first organism is not very well understood.”

“但是第一个有机体的本质还不是很清楚。”

It’s not some weird one-off species.

它不是什么奇怪的一次性物种。

It has a real pattern of retaining these tools.

它有一个保留这些工具的真实模式。

Christen Grettenberger, University of California, Davis

克里斯汀·格雷滕伯格，加州大学戴维斯分校

To solve such riddles, biologists often turn to organisms that share many, but not all, of the traits they want to understand.

为了解决这些谜题，生物学家经常求助于具有许多（但不是全部）他们想要了解的特征的生物体。

But for years, they believed that nearly all modern cyanobacteria evolved in a single, closely related cluster, offering little variation that might reveal mechanisms of early photosynthesis.

但多年来，他们相信几乎所有现代蓝细菌都是在一个密切相关的单一簇中进化的，几乎没有提供可能揭示早期光合作用机制的变异。

The discovery of Gloeobacteria, a group of photosynthetic bacteria that branched off from other cyanobacteria over 2 billion years ago, changed this.

胶细菌（Gloeobacteria）是一群光合细菌，20亿多年前从其他蓝细菌中分支出来，它的发现改变了这一点。

Although Gloeobacteria haven’t remained at an evolutionary standstill — no organism has — they seem to have changed little over billions of years, making them a sort of genetic time capsule.

尽管胶细菌并没有处于进化停滞状态——任何有机体都没有——但它们似乎在数十亿年里几乎没有发生什么变化，这使它们成为一种基因时间胶囊。

“[Gloeobacteria] tell us a little bit about what the earliest cyanobacteria might have looked like,” said Christen Grettenberger , a geochemist and microbiologist at the University of California, Davis.

“[Gloeobacteria] 告诉我们一些关于最早的蓝藻可能是什么样子的信息，”加州大学戴维斯分校的地球化学家和微生物学家 Christen Gretenberger 说。

“It’s not some weird one-off species.

“这不是什么奇怪的一次性物种。

It has a real pattern of retaining these tools.”

它有保留这些工具的真实模式。”

The most recently identified Gloeobacteria species, Anthocerotibacter panamensis , harvests light using a different set of proteins than modern cyanobacteria — but converts sunlight into chemical energy within protein complexes that vary only slightly from those in other Gloeobacteria.

最近发现的胶杆菌属物种，Anthocerotibacter panamensis，使用与现代蓝细菌不同的一组蛋白质来收集光，但将阳光转化为蛋白质复合物内的化学能，该蛋白质复合物与其他胶杆菌中的化学能仅略有不同。

These traits add new color to the long, strange evolutionary story of photosynthesis.

这些特征为光合作用漫长而奇怪的进化故事增添了新的色彩。

Before striking a plant leaf, a solar photon travels 93 million miles through empty space.

在撞击植物叶子之前，太阳光子会在真空中行进 9300 万英里。

The most dynamic part of this journey happens in the last few billionths of a meter, as a Rube Goldberg machine of proteins and pigments converts the photon’s light energy into chemical energy.

这一旅程中最具活力的部分发生在最后几十亿分之一米，因为蛋白质和色素的鲁布·戈德堡机器将光子的光能转化为化学能。

The leaves of modern land plants are packed with chloroplasts, oblong organelles that are themselves stuffed with stacks of coin-shaped compartments known as thylakoids.

现代陆地植物的叶子充满了叶绿体，这是一种椭圆形的细胞器，它们本身充满了一堆被称为类囊体的硬币形隔室。

Thousands of proteins and pigments stud the thylakoid membrane, creating a sprawling biochemical circuit with a single purpose.

类囊体膜上布满了数以千计的蛋白质和色素，形成了一个具有单一目的的庞大生化回路。

A large protein complex there, named photosystem II, hosts light-harvesting “antenna” complexes on its outer ring that maximize the number of photons the plant can snag.

那里有一个名为光系统 II 的大型蛋白质复合物，在其外环上承载着光捕获“天线”复合物，可以最大限度地增加植物可以捕获的光子数量。

Chlorophyll and other pigments embedded within the antennae absorb the energy from captured photons.

嵌入天线内的叶绿素和其他色素吸收捕获的光子的能量。

Then, as in a game of hot potato, chlorophyll and other pigment molecules funnel this excess energy to the reaction center of the photosystem.

然后，就像在热土豆游戏中一样，叶绿素和其他色素分子将多余的能量输送到光系统的反应中心。

Energy is lost every time the photon hops between pigments, but it retains enough to jolt electrons loose from nearby water molecules, releasing oxygen as waste.

每次光子在颜料之间跳跃时都会损失能量，但它保留了足够的能量，可以使电子从附近的水分子中释放出来，释放出氧气作为废物。

These liberated electrons then flow through a series of membrane-bound proteins, known as an electron transport chain, where their energy pumps protons and spins molecular turbines.

然后，这些释放的电子流过一系列膜结合蛋白，称为电子传输链，其中它们的能量泵送质子并旋转分子涡轮。

This molecular assembly line generates life’s energy currency, a molecule known as adenosine triphosphate (ATP).

这条分子装配线产生生命的能量货币，一种称为三磷酸腺苷（ATP）的分子。

But photosynthesis isn’t complete at that stage.

但光合作用在那个阶段尚未完成。

Mostly depleted, the electrons then reach photosystem I, where another burst of sunshine kicks the flow back into high gear.

电子大部分耗尽后，到达光系统 I，在那里，另一束阳光将电子流踢回高速档。

Supercharged again, the electrons drive a separate set of reactions that build sugars from carbon dioxide.

再次增压后，电子驱动一组独立的反应，从二氧化碳中生成糖。

These sugars are themselves a form of energy, as the plant (as well as other organisms) can break them down to make more ATP.

这些糖本身就是一种能量形式，因为植物（以及其他生物体）可以分解它们以产生更多的 ATP。

Over billions of years, the reaction centers of the two photosystems have remained remarkably unchanged.

数十亿年来，两个光系统的反应中心一直保持明显的变化。

Evolutionary innovation has occurred, however, in the astonishing array of antenna complexes and accessory pigments seen across photosynthetic life.

然而，在光合作用生命中看到的一系列令人惊叹的天线复合体和辅助色素中，进化创新已经发生。

This juxtaposition of severe conservation with extreme diversity creates a challenge for scientists trying to understand how photosynthesis first evolved.

这种严格保护与极端多样性的并置，给试图了解光合作用最初是如何进化的科学家带来了挑战。

Even the earliest photosynthetic system must have already been a tiny solar-powered electrical circuit, capturing light and channeling electrons into metabolism, said Christopher Gisriel , a biochemist at the University of Wisconsin, Madison.

威斯康星大学麦迪逊分校的生物化学家克里斯托弗·吉斯里尔 (Christopher Gisriel) 表示，即使是最早的光合作用系统也一定是一个微型太阳能电路，用于捕获光并将电子引导至新陈代谢。

“At a minimum, we know that it would have all the features that we see in the diversity of reaction centers or photosystems today,” he said.

“至少，我们知道它将具有我们今天在反应中心或光系统多样性中看到的所有特征，”他说。

“It would have had the ability to somehow collect that light and perform charge separation and then move those electrons into metabolism.”

“它有能力以某种方式收集光线并进行电荷分离，然后将这些电子转移到新陈代谢中。”

Even the earliest photosynthetic system must have already been a tiny solar-powered electrical circuit.

即使是最早的光合作用系统也一定已经是一个微小的太阳能电路。

There is some photosynthetic diversity in living organisms that can provide insight into how this complex process could have evolved.

生物体存在一些光合作用多样性，可以帮助我们深入了解这一复杂过程是如何进化的。

For example, some bacteria use only photosystem I and avoid oxygen altogether in a form of anoxygenic photosynthesis.

例如，一些细菌仅使用光系统 I，并以无氧光合作用的形式完全避免氧气。

Many researchers therefore hypothesize that anoxygenic photosynthesis and its photosystem evolved first.

因此，许多研究人员假设缺氧光合作用及其光系统首先进化。

Then, at some point in the distant past, the system’s genes were duplicated.

然后，在遥远的过去的某个时刻，系统的基因被复制。

Over evolutionary time, this theory goes, one of those copies mutated and evolved to give rise to a second photosystem that uses oxygen to harvest energy more efficiently.

这一理论认为，随着进化时间的推移，其中一个副本发生突变并进化，产生了第二个光系统，该系统利用氧气更有效地收集能量。

Not all evolutionary biologists agree that photosystem I came first, but if it did, then how and when did it evolve?

并非所有进化生物学家都同意光系统“我”首先出现，但如果确实如此，那么它是如何以及何时进化的？

Even a primitive, stripped-down version would be an evolutionary marvel.

即使是一个原始的、精简的版本也将是一个进化奇迹。

The protein megacomplex boasts multiple subunits in a precise structure, where antenna proteins are decorated with chlorophylls and other pigments and surround a core reaction center where electrons twirl in an elaborate pas de deux.

这种蛋白质巨型复合物拥有精确结构中的多个亚基，其中天线蛋白用叶绿素和其他色素装饰，并围绕着一个核心反应中心，其中电子以复杂的双人舞旋转。

This is why researchers are flocking to an ancient lineage of single-celled cyanobacteria that could hold a more primal version of this process.

这就是为什么研究人员纷纷涌向古老的单细胞蓝藻谱系，它可能拥有这一过程的更原始版本。

The cells arrived as microscopic stowaways.

这些细胞以微小的偷渡者的形式到达。

They traveled on the leaf of a hornwort from Panama to the lab of the plant biologist Fay-Wei Li in Ithaca, New York.

他们沿着金鱼草的叶子从巴拿马来到纽约伊萨卡植物生物学家李菲维的实验室。

There, Li’s laboratory technician Duncan Hauser stripped microbial detritus from the hornwort’s leaves.

在那里，李的实验室技术员邓肯·豪瑟从金鱼草叶子上剥离了微生物碎屑。

He thought he had done a thorough job, but a chance glimpse of a small green speck under the microscope revealed he had missed something.

他以为自己已经完成了彻底的工作，但在显微镜下偶然瞥见了一个绿色的小斑点，这表明他错过了一些东西。

That Hauser had discovered a new species of bacterium wasn’t especially exciting; most microbial species have yet to be identified and described.

豪瑟发现了一种新的细菌，这并不是特别令人兴奋。大多数微生物物种尚未被识别和描述。

But as Hauser, Li, and then-postdoc Nasim Rahmatpour peered more intently at the interloper, they realized that its color and shape didn’t resemble those of most other cyanobacteria.

但当豪瑟、李和当时的博士后纳西姆·拉赫马普尔更仔细地观察这个闯入者时，他们意识到它的颜色和形状与大多数其他蓝藻细菌的颜色和形状并不相似。

An analysis of its DNA revealed their contaminant to be a type of Gloeobacterium, a lineage of photosynthetic microbes that branched off from cyanobacteria over 2 billion years ago.

对其 DNA 的分析显示，其污染物是一种球杆菌，这是一种光合微生物谱系，在 20 亿多年前从蓝细菌中分支出来。

They named it Anthocerotibacter panamensis in honor of its Central American birthplace and published their results in July 2021.

他们将其命名为 Anthocerotibacter panamensis，以纪念其中美洲的出生地，并于 2021 年 7 月发表了他们的研究结果。

Even among the little-known Gloeobacteria, A.

即使在鲜为人知的胶细菌中，A.

panamensis was unusual: It branched off from the rest of the group 1.4 billion years ago.

巴拿马树很不寻常：它在 14 亿年前就从该类群的其他物种中分离出来。

“This is an entirely different organism from the ones that we know of,” said Li, who is based at the plant-focused Boyce Thompson Institute.

“这是一种与我们所知的完全不同的生物体，”在以植物为重点的博伊斯汤普森研究所工作的李说。

“We know very little about them, and they’re completely different from other cyanobacteria.”

“我们对它们知之甚少，它们与其他蓝藻完全不同。”

Fay-Wei Li and his team characterized a new type of Gloeobacteria, a lineage that split from modern cyanobacteria more than 2 billion years ago, and cultured it in the lab.

Fay-Wei Li 和他的团队对一种新型胶细菌进行了鉴定，并在实验室中对其进行了培养，该细菌是 20 亿多年前从现代蓝细菌中分离出来的谱系。

Li’s team used cryo-electron microscopy to examine the bacterium’s subcellular structures and capture detailed images of its inner workings.

李的团队使用冷冻电子显微镜检查细菌的亚细胞结构并捕获其内部运作的详细图像。

A.

A.

panamensis had both photosystems — but no thylakoids.

巴拿马有两种光系统，但没有类囊体。

A sister species, Gloeobacter violaceus , discovered in 1974 , also lacked thylakoids, indicating that the now-familiar structures found throughout modern cyanobacteria likely hadn’t yet evolved when Gloeobacteria split from the group.

1974年发现的一个姊妹物种紫罗兰胶杆菌（Gloeobacter violaceus）也缺乏类囊体，这表明当胶杆菌从该群体中分裂出来时，在现代蓝细菌中发现的现在熟悉的结构可能尚未进化。

Instead, its photosystems stud the cell’s external plasma membrane rather than the thylakoid membrane found in plants and modern cyanobacteria.

相反，它的光系统分布在细胞的外部质膜上，而不是植物和现代蓝细菌中发现的类囊体膜上。

Among the most conspicuous anomalies were the structures A.

最显着的异常现象是结构 A.

panamensis used to harvest light.

巴拿马用于收集光。

Most modern cyanobacteria have large antenna complexes (or phycobilisomes), built from proteins infused with light-absorbing pigments, that fan out from the thylakoid membrane in a large semicircle.

大多数现代蓝藻都有大型天线复合体（或藻胆体），由注入光吸收色素的蛋白质构成，从类囊体膜呈扇形散开成一个大的半圆形。

The antenna complex in A.

天线复合体 A.

panamensis , however, looked nothing like a fan: It better resembled a canoe paddle.

然而，巴拿马扇子看起来一点也不像扇子：它更像是独木舟的桨。

In 2023, experiments showed that this paddle-shaped antenna strongly reduced the rate at which A.

2023年，实验表明这种桨状天线极大地降低了A.

panamensis could photosynthesize.

巴拿马草可以进行光合作用。

Li suspects that the paddle shape doesn’t collect as many photons as a fan shape.

李怀疑桨形收集的光子数量不如扇形。

But what about its core photosynthetic machinery?

但它的核心光合作用机制又如何呢？

A different team of scientists, including Gisriel, conducted a deep dive into photosystem I of A.

包括 Gisriel 在内的另一个科学家团队对 A. 的光系统 I 进行了深入研究。

panamensis to look for clues to how oxygen-producing photosynthesis might have evolved.

巴拿马树寻找产氧光合作用如何进化的线索。

The reaction center at the heart of the photosystem, where chlorophyll pigments absorb photons and produce sugar from carbon dioxide, showed only a few small changes when compared to the photosystems of other Gloeobacteria.

位于光系统核心的反应中心，叶绿素色素吸收光子并从二氧化碳中产生糖，与其他胶细菌的光系统相比，仅显示出一些微小的变化。

However, there was far more evolutionary change on the photosystem’s light-harvesting proteins that bind the pigments, such as the ones that make up the paddle-shaped antenna complex.

然而，光系统中与色素结合的光捕获蛋白（例如构成桨状天线复合体的蛋白）发生了更多的进化变化。

These results, published in May 2025 in the Proceedings of the National Academy of Sciences , suggest that the forces of natural selection have made limited changes to the photosystem’s core, but that other aspects of the photosynthetic machinery have proved more malleable.

这些结果发表在 2025 年 5 月的《美国国家科学院院刊》上，表明自然选择的力量对光系统核心的改变有限，但光合作用机制的其他方面已被证明更具可塑性。

“The photosynthetic system complexes are incredibly similar.

“光合作用系统复合体非常相似。

There’s not that much variation, even where there’s relatively significant changes [in other places],” said the chemist Gary Brudvig of Yale University, a co-author on the paper.

即使（在其他地方）发生了相对显着的变化，也没有那么大的变化，”该论文的合著者、耶鲁大学化学家加里·布鲁德维格（Gary Brudvig）说。

“Once nature came on with the solution, it didn’t change very much.

“一旦大自然提出了解决方案，它就没有发生太大变化。

It kept the basic framework.”

它保留了基本框架。”

The new findings in A.

A. 中的新发现

panamensis suggest that Gloeobacteria may indeed reflect a more ancient, basal form of photosynthesis.

巴拿马表明，胶细菌确实可能反映了一种更古老、基础的光合作用形式。

Over the past few billion years, most cyanobacteria and plants have evolved new features — more complex photosynthetic proteins as well as entirely new structures, such as thylakoids, to make the process more efficient.

在过去的数十亿年里，大多数蓝藻和植物都进化出了新的特征——更复杂的光合蛋白质以及全新的结构，例如类囊体，以使这个过程更加高效。

However, the photosystem I architecture of the Gloeobacteria has changed little over all that time.

然而，胶细菌的光系统 I 结构自始至终几乎没有变化。

Now researchers can inspect the core of the photosynthesis reaction center to understand how this ancient molecular machine might have evolved.

现在，研究人员可以检查光合作用反应中心的核心，以了解这种古老的分子机器可能是如何进化的。

“In my opinion, this makes it all that much more unlikely that oxygenic photosynthesis was at the root of the bacterial tree,” said Charles Delwiche at the University of Maryland, who studies the evolution of photosynthesis and was not involved in the study.

“在我看来，这使得含氧光合作用不太可能是细菌树的根部，”马里兰大学的查尔斯·德尔维奇说，他研究光合作用的进化，但没有参与这项研究。

That is assuming, however, that structures in Gloeobacteria are nearly identical to what they were billions of years ago.

然而，这是假设胶细菌的结构与数十亿年前几乎相同。

“[It] is not a snapshot in time.

“[它]不是时间的快照。

It’s not a fossil from 2.5 billion years ago,” said Patrick Shih , a plant synthetic biologist at the University of California, Berkeley who was not involved in the study.

它不是 25 亿年前的化石，”未参与这项研究的加州大学伯克利分校植物合成生物学家 Patrick Shih 说道。

“It’s undergone 2.5 billion years of evolution since that most recent common ancestor.” That’s why discovering more sister species to A.

“自最近的共同祖先以来，它已经经历了 25 亿年的进化。”这就是为什么发现了更多 A 的姐妹物种。

panamensis remains important, he said: More examples are needed to make a fully convincing case.

巴拿马仍然很重要，他说：需要更多的例子来提供完全令人信服的案例。

The evolutionary discoveries surrounding A.

围绕 A. 的进化发现

panamensis — its lack of thylakoids, unique antenna, and stable photosystem — have encouraged Grettenberger and Li to embark on a global quest for more Gloeobacteria.

巴拿马菌缺乏类囊体、独特的触角和稳定的光系统，这促使 Gretenberger 和 Li 开始在全球范围内寻找更多的胶杆菌。

Grettenberger wants not only more DNA evidence of this important group, but also species that, like A.

格雷滕伯格不仅想要更多关于这个重要群体的 DNA 证据，还想要像 A.

panamensis , can grow in the lab.

巴拿马，可以在实验室中生长。

“It would be really, really nice if we could get even earlier branching [species], so that we could see a stepwise evolution,” she said.

“如果我们能够获得更早的分支[物种]，那就真的非常好，这样我们就可以看到逐步的进化，”她说。

Only by enlarging the comparison group will biologists be able to determine whether some of the traits seen in A.

只有通过扩大比较组，生物学家才能确定 A.

panamensis are evolutionary oddities or more broadly representative of early life, she added.

她补充说，巴拿马人是进化上的怪人，或者更广泛地代表了早期生命。

The biochemist Christopher Gisriel (center) and his team found that the core photosynthetic machinery of A.

生物化学家 Christopher Gisriel（中）和他的团队发现 A.

panamensis remained remarkably similar to that of other Gloeobacteria despite 1.4 billion years of evolutionary distance between them.

尽管巴拿马菌与其他胶杆菌之间有 14 亿年的进化距离，但它们仍然非常相似。

More examples could also help address the mystery of which photosystem evolved first.

更多的例子也可以帮助解开哪个光系统首先进化的谜团。

While the hypothesis that the very first photosynthetic organisms were anoxygenic would be the most logical explanation, in several papers published in 2019 and 2021 , the evolutionary biologist Tanai Cardona at Queen Mary University of London argued that oxygenic photosynthesis may well have evolved first.

虽然最早的光合生物是缺氧的假设是最合乎逻辑的解释，但在 2019 年和 2021 年发表的几篇论文中，伦敦玛丽女王大学的进化生物学家塔奈·卡多纳 (Tanai Cardona) 认为，有氧光合作用很可能首先进化出来。

Scientists have so long assumed that anoxygenic photosynthesis — and photosystem I — came first that any new data is immediately interpreted through that lens, he said, even though the data remains incomplete.

他说，长期以来，科学家们一直认为无氧光合作用和光系统 I 首先出现，任何新数据都会立即通过这个镜头进行解释，尽管数据仍然不完整。

Both photosystems “go back to a single ancestor,” said Cardona, who co-authored the 2025 paper on A.

卡多纳说，这两种光系统“都可以追溯到同一个祖先”，他是 2025 年关于 A.

panamensis .

巴拿马。

“But at this stage, we have no sequence evidence to suggest that one gave rise to the other.” The gene duplication event that doubled the photosystems, allowing one copy to evolve a novel process, happened so long ago that any evidence of that first photosystem has been buried by extinction and billions of years of change.

“但现阶段，我们没有序列证据表明其中一个产生了另一个。”基因复制事件使光系统加倍，允许一个副本进化出一种新的过程，这一事件发生得太久远了，以至于第一个光系统的任何证据都被灭绝和数十亿年的变化所掩埋。

Still, clues are likely out there.

尽管如此，线索很可能就在那里。

For Shih, the implications of this work go far beyond basic science.

对施来说，这项工作的意义远远超出了基础科学的范畴。

The reality is that the chemical reactions that comprise photosynthesis and sugar production — the foundation of life’s diet, and thus humanity’s — are highly inefficient.

现实情况是，包括光合作用和糖生产在内的化学反应——生命饮食的基础，也是人类饮食的基础——效率非常低。

Shih and other scientists are working to engineer improvements in photosynthesis to boost crop production.

施和其他科学家正在努力改进光合作用，以提高作物产量。

Before scientists start experimenting, they need to know how the parts of the photosynthetic system fit together.

在科学家开始实验之前，他们需要知道光合作用系统的各个部分如何组合在一起。

That system, as we have it today, started some 2 billion years ago, when the emergence of oxygenic photosynthesis left an indelible green stain across Earth’s surface.

我们今天所拥有的这个系统大约开始于 20 亿年前，当时含氧光合作用的出现在地球表面留下了不可磨灭的绿色污点。

That was when microbes wrested energy from light and, in the process, breathed new life into the world.

那时，微生物从光中夺取能量，并在此过程中为世界注入了新的生命。

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辱骂、亵渎、自我推销、误导、语无伦次或偏离主题的评论将被拒绝。

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版主在正常工作时间（纽约时间）有工作人员，并且只能接受英文评论。