It is possible to dramatically increase the yield of rice and maize using CRISPR gene editing, field trials show
March 24, 2022
Turning off a particular gene in corn and rice could improve grain yields by 10% and 8% respectively, according to a new study. By exploring similar genes in other cereals, global agricultural production could be boosted.
Corn and rice are staple foods around the world, and each has a distinct history of being grown for large-scale consumption. Corn is believed to have originated in Mexico, while rice came from China. Despite the independent evolution of these species, plant biologists have noted that they possess very similar traits. This is called convergent evolution.
To study these similarities, Xiaohong Yang at the China Agricultural University in Beijing and his colleagues mapped the genomes of maize (Zea mays L. ssp. may) and rice (Oryza sativa).
They found 490 pairs of genes that appeared to perform similar functions in the two grains. From these pairs, the researchers identified two genes – known as KRN2 in maize and OsKRN2 in rice – that affected their grain yield. By using CRISPR gene editing to turn off these genes, they could increase grain yield by 10% for corn and 8% for rice. These figures come from tests in real conditions in agricultural fields.
“These are great results,” says Yang, who hopes to continue exploring the 490 gene pairs to further improve rice and maize production.
“These are two species that are the most important in terms of economics,” explains the co-author Alisdair Fernie at the Max Planck Institute for Molecular Plant Physiology in Potsdam, Germany. “They have such different domestication histories with different centers of origin and very different habitats to a large extent. The fact that convergent evolution has happened with so many genes is fascinating.
A better understanding of the genetic evolution of maize and rice could also lead to what are called de novo domestication events, Fernie says, that is, when domesticated genes are inserted into non-domesticated species. domesticated to create new crops. Wild crops are generally more resistant to extreme weather conditions and pathogens, but generally have a low yield.
“With CRISPR and gene editing, we could just take a handful of these domestication genes, such as KRN2, and reintroduce them into their wild species,” he says. “The idea is that you could grow high-yielding but resilient crops, which will be essential for us in the future.”
Journal reference: Science, DOI: 10.1126/science.abg7985
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