Creating a Better Leaf | The New Yorker

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Since its establishment in 2012, mature It expanded to include nearly a hundred researchers across four continents. Long hopes, in addition to NPQ modifications and bypassing, the project will come up with a half-dozen other ways to “improve” photosynthesis. A team in Australia is looking at how to speed up the CO2 journey to RuBisCo, and a team in England is studying what happens right after RuBisCo does its job. The next step will be to introduce these genetic modifications into plants of globally important crops – in addition to soybeans and potatoes, mature It works with corn, cowpea and cassava – then in local varieties. (Farmers in different parts of the world grow different strains of maize and cassava that have been bred for local conditions.)

Long is particularly keen on sourcing photo-enhanced seeds for farmers in sub-Saharan Africa, a region that has not benefited much from the yield gains from the original Green Revolution. Today, there are more than two hundred million people suffering from chronic undernourishment.

“If we can provide smallholder farmers in Africa with the technologies that will produce more food and provide them with better livelihoods, that is what really motivates the team,” said Li Long. One of the conditions of the Gates Foundation is that any breakthroughs result from matureThat the company’s work be made “affordable” to companies or government agencies that provide seeds to farmers in the world’s poorest countries.

before any of matureHis creations can be planted in sub-Saharan Africa, though, or anywhere else, for that matter, all kinds of licenses must be obtained. (The gene-editing techniques that Long and his colleagues use are often patented themselves.) Then the modified genes should be approved by the relevant agency in the respective country, and the modifications should be introduced into local varieties. So far, only a few African countries have approved GM crops, and most approvals have been on GM cotton. A recent study indicated that at least two dozen genetically modified food crops – some modified for insect resistance, others for salt tolerance – have been submitted to regulators in the region but are still largely forgotten.

The study noted that “a range of viable technologies remain on the shelves, often due to organizational paralysis.” (In the United States, virtually all GM soy and corn are genetically modified; other GM food crops include apples, potatoes, papayas, sugar beets, and canola. In Europe, by contrast, GM crops are generally banned.) To the extent that attitudes towards genetically modified foods in sub-Saharan Africa have been surveyed, the majority of people seem wary of them. A recent study in Zimbabwe, for example, found that nearly three-quarters of respondents think they are “extremely risky”. And smallholder farmers do not have enough land to leave the buffer zones, which means that if they grow GM crops that are pollinated, they can mix or contaminate their non-GM neighbours.

When I asked Long about the advisability of developing genetically modified varieties for use in countries that didn’t seem to particularly want them, he told me, in a meeting with mature Researchers, a similar question was asked to Bill Gates.

“His response was ‘Well, things might change if these predictions of food shortages come true,'” Long said.

About thirty million years ago, a plant – no one knows exactly which, but it may have been a herb – devised his own breakthrough to improve photosynthesis. The hack did not change the steps involved in the process; Instead, she added a new one. New steps focused carbon dioxide2 around RuBisCo, effectively eliminating the chance of the enzyme to make a mistake. (To extend the assembly line metaphor, imagine a worker surrounded by loads of the right parts and none of the wrong parts.) At the time, atmospheric carbon dioxide levels were dropping—a trend that would continue more or less until humans figured out how to burn fossil fuels—so on Although the hack cost the plant some energy, it was a net gain. In fact, it proved so beneficial that other plants quickly followed suit. What is now known as C4 photosynthesis has evolved independently at least forty-five times, in nineteen different plant families. (The term “C4” refers to a four-carbon compound produced in one of the complementary steps.) At present, many of the world’s major crop plants are C4, including maize, millet, and sorghum, as well as many of the world’s major weed plants, such as crabgrass and tumbleweed.

C4 photosynthesis is no more efficient than normal photosynthesis, which is known as C3. They also require less water, less nitrogen, and, therefore, less fertilizer. About twenty-five years ago, a plant physiologist named John Sheehy came up with what many plant physiologists considered a ridiculous idea. He decided that rice, which is a C3 plant, should convert to C4. Like Long, Sheehe was from England, but worked in the Philippines, at the research institute where, in the 1960s, breeders developed the rice varieties that helped spark the Green Revolution. In 1999, Shehhi hosted a meeting at the institute to discuss his idea. The general opinion of the participants was that this is impossible.

Shihee did not give up. In 2006, near retirement, he held a second meeting on the topic. Once again, the audience was skeptical. But this time they decided Shihei’s scheme was at least worth trying. Jane Langdale, a plant biologist from Oxford, was among the researchers at the second meeting. “There was a sense that it either happened now or never,” she said recently, when I spoke to her via Zoom. “We either had to get young people interested in this or lose the opportunity.” Thus was born the C4 Rice Project, which Langdale now heads. (Shehhi died in 2019).

C4 rice draft can be considered as matureEdger’s cousin. It is also funded by the Gates Foundation, and also aims to feed the world by re-engineering it from chloroplasts upwards. “Given that the C4 pathway is up to 50% more efficient than the C3 pathway, introducing C4 traits into a C3 crop would have a significant impact on crop yield,” the project’s website notes.

What makes the work so difficult is that C4 plants not only go through additional steps in photosynthesis; They have a different anatomy. Among other things, the veins in the leaves of C4 plants are more compact than those in C3 plants, and this spacing is important for the organization. The C4 Rice Project has thirty researchers in five countries. Some scientists focus on transforming plant leaves, others on changing the biochemistry.

“We’re working on trying to do those two things in parallel,” Langdale explained to me. “But in the end we have to do both.”

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The project faced many obstacles; However, it progressed slowly. Langdale’s lab has succeeded in producing rice plants with a size larger than the veins in their leaves, although the size is still not high enough. Other laboratories have developed rice plants that generate a basic four-carbon compound; However, these plants are not taking the next step, which is to give up one of the carbon atoms to be captured by RuBisCo.

“When we started, everyone thought we were crazy,” Langdale said. “And it hasn’t been an easy journey. But I think now people are looking and thinking, you know – they’re actually making progress.

“I don’t know if we will one day make rice with full C4 autopsy and biochemistry,” she continued. “But I think along the way we will find things that improve yield and improve efficiency, even if it’s not the whole thing.”

A few days after speaking to Langdale, three Punjab villagers were hit by a truck at the site of a demonstration near New Delhi. (All of the victims were women in their 50s and 60s.) Over the past year, hundreds of thousands of farmers in India have protested against Prime Minister Narendra Modi’s government, and for months tens of thousands have been camped out along roads leading into the capital.

In an immediate sense, the target of farmers’ wrath is a set of laws pushed by Parliament by Modi’s party. They fear that this will end the government’s price support. In a deeper sense, the tensions go back to the Green Revolution. To encourage farmers to grow higher yielding and thirstier rice and wheat varieties, the Indian government introduced price support system in the 1960s. Now the subsidies have produced a glut of these goods, even as their cultivation drains the country’s groundwater, and the government wants to urge farmers to stay away from the crops it once urged them to grow. For millions of farmers in the country, most of whom own less than five acres, it seems that changes to the status quo will only lead to more misery.

“Many people would argue that the price support currently offered is hardly enough to cover production costs,” Sudha Narayanan, a research fellow at the International Institute for Food Policy Research’s office in New Delhi, told me. But farmers rely on subsidies to establish at least a minimum income: “They are seen as a form of insurance.” In a surprising move last month, parliament voted to repeal the laws, but that did not end the protests. Farmers are now calling for price support to be extended to other crops.

How to produce a second Green Revolution without repeating or exacerbating the mistakes of the first is a question dogs seek to increase yields, particularly in the Global South. With climate change, the challenges are, in many ways, more acute than they were in the 1960s. The research institutes that helped drive the original Green Revolution, which include the International Center for Maize and Wheat Improvement, in Mexico, where Norman Borlaug was, and the International Rice Research Institute in the Philippines, where John Sheehe worked, are part of a consortium called CGIAR. (The name comes from the Consultative Group on International Agricultural Research). The CGIAR is in the midst of restructuring itself.


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