How CRISPR-edited rice gene could help tackle climate change

Can CRISPR gene-editing technology create new crops that help fight climate change as they grow? That’s what one group of researchers hopes to do with $11 million in funding from the Chan Zuckerberg Initiative. The funds will go toward efforts to improve plants, starting with rice, and soil to make them better at trapping carbon dioxide. The effort, which was announced last week, is being led by the Institute for Innovative Genomics, which was founded by Nobel laureate and CRISPR co-inventor Jennifer Doudna.

“[Jennifer] and I agreed with the weather and how big of a problem it is in the world. And we didn’t want to stand on the sidelines anymore,” says Brad Ringeisen, executive director of the Innovative Genomics Institute (IGI).

Climate experts overwhelmingly agree that the only way to truly address climate change is to reduce the amount of greenhouse gas emissions we put into the air when we burn fossil fuels to generate electricity or power trains, planes, and cars. But humans have already dumped so much planet-warming pollution into the atmosphere that we also need to find ways to clean up some of the existing mess and prevent even more catastrophic climate change. One way to achieve this is through plants. Plants naturally take up a common greenhouse gas, carbon dioxide, during photosynthesis. Eventually, they transfer that carbon to the soil.

CRISPR can be used to make precise changes to a plant’s genome to produce desired traits. There are three targets for gene editing in IGI’s carbon removal mission. It starts with trying to make photosynthesis more efficient in plants so that they become even better at capturing as much CO2 as possible. Second, IGI is interested in developing crops with longer roots. Plants transfer carbon to the soil through their roots (as well as the rest of their bodies when they die). Longer roots can deposit carbon deeper into the soil so it’s not as easily released back into the atmosphere. A similar effort to influence plant genes and develop crops with more robust roots is underway at the Salk Institute for Biological Studies, which received $30 million from the Bezos Earth Fund in 2020.

That brings us to the third arm of IGI’s research: increasing the soil’s ability to store, rather than release, greenhouse gases. Soil does not normally hold carbon for very long. It escapes into the atmosphere through the respiration of soil microbes as they break down plant matter. And techniques used in modern agriculture, such as tillage, speed up this process and allow the soil to lose more carbon. One potential outcome of IGI’s CRISPR research, according to Ringeisen, is a product that could be added to soil to nurture a soil microbiome that retains carbon longer.

All these are heavy jobs that are still a long way from being done. The $11 million from the Chan Zuckerberg Initiative funds three years of research, and Ringeisen expects a “real-world impact in seven to 10 years.” Even if they are successful in genetically engineering plants and soil microbes within that time frame, scaling up to have a significant impact on climate will remain a major challenge.

“Plants are already extremely efficient carbon sequestration machines, as a result of millions of years of evolution, so I am still not convinced that CRISPR can do much to improve carbon sequestration on the scale we need”, César Terrer , an MIT assistant professor who runs a lab focused on plant-soil interactions, writes to the edge in an email.

Terrer is not involved in the project, but was previously a member of one of the institutions involved, the Lawrence Livermore National Laboratory, “and if someone can do this [it’s] them,” he writes. Still, he warns that focusing on ways to engineer nature to help us with climate change can be a distraction from the more urgent need to reduce greenhouse gas pollution in the first place.

Agriculture is already responsible for its huge carbon footprint, much of which comes from livestock and fertilizers. Rice farming is also a big culprit in methane emissions, as soggy paddy fields are an ideal home for methane-producing microbes. IGI is also working on this problem, again looking at root disturbance and microbes in the soil.

The rice genome is easier to manipulate than other crops, according to Ringeisen, in part because it has already been studied extensively and is well understood. One of the scientists involved in the IGI initiative is Pamela Ronald, whose research is widely known for leading to the development of rice varieties that tolerate flooding much longer than other types using a different type of genetic engineering that is more like precision reproduction. That rice is now grown by more than 6 million farmers in India and Bangladesh, according to Ronald’s lab at the University of California, Davis.

IGI’s work will not stop with rice. Sorghum is another prime candidate for gene editing to drive carbon removal, according to Ringeisen. He is also hopeful that any new varieties they develop will come with additional incentives for farmers, such as bigger harvests resulting from more efficient photosynthesis. But that’s still a few years in the future. IGI hopes to begin international field tests with farmers about three years after its CRISPR rice research begins.

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