July 24, 2021. By Kolemann Lutz
On the left, rice plants without the RNA modification. On the right, a rice plant with the RNA modification that boosts yield.
Manipulating plant RNA by adding a gene encoding for a human protein called FTO to both rice and potato plants increased their yield by 50% and caused a more than threefold increase in grain yield under greenhouse conditions. The plants grew significantly larger, produced longer root systems and were better able to tolerate drought stress with an increased rate of photosynthesis.
University of Chicago Prof. Chuan He and Prof. Guifang Jia at Peking University, led the research with a group of scientists to investigate the effects of genetically engineering plant RNA.
Traditionally, we have believed that the RNA molecule reads DNA and creates proteins to carry out the instructions. In 2011, researchers discovered that the RNA does more than reading DNA blue print, the cell can also regular which parts of DNA blueprint are expressed by placing chemical markers onto RNA to module which and how many proteins are made. Professor He’s lab effectively opened an entire new field known as “epitranscriptomics”.
He and his colleagues immediately realized that this had major implications for biology and have started understanding how this affects animals, plants, and human diseases. He is a co-founder of a biotech cambridge-based startup called Accent Therapeutics now developing new anti-cancer medicines based on targeting RNA modification proteins that recently raised $63 million in a Series B round, led by EcoR1 Capital in 2017.
He and Guifang Jia, a former UChicago postdoctoral researcher who is now an associate professor at Peking University, began to wonder how it affected plant biology.
They focused on a protein called Fat mass and obesity-associated (FTO) protein, the first known protein or enzyme that erases chemical marks on RNA, which Jia discovered as a postdoctoral researcher in He's group at UChicago. After demonstrating the efficacy of FTO on RNA to affect cell growth in humans and animals, the scientists inserted the gene into rice plants.
The FTO controls a process known as RNA N6-methyladenosine (m6A), which is a key modification of RNA in plants. FTO erased the m6A RNA and muffled some of the signals that
plants use to slow down and reduce growth.
Under the presence of FTO, the rice plants grew three times more rice under laboratory conditions and produced significantly more RNA than control plants. When they tried it out in real field tests, the plants grew 50% more mass and yielded 50% more rice. They grew longer roots, photosynthesized more efficiently, and could better withstand stress from drought. The field tests exhibited no effect on mature cell size, shoot meristem cell proliferation, root diameter, plant height.
The scientists repeated the experiments with potato plants and received the results were the same. Further experiments showed that FTO started working early in the plant's development, boosting the total amount of biomass it produced.
"What's more, it worked with almost every type of plant we tried it with so far, and it's a very simple modification to make."
“This is a very exciting technology and could potentially help address problems of poverty and food insecurity at a global scale—and could also potentially be useful in responding to climate change,” said Michael Kremer, Professor in Economics at the University of Chicago.
Since the late 1900’s, scientists have been working to boost crop production in the face of an increasingly unstable climate and a growing global population. In California, the agriculture sector reported estimated losses of more than $3.8 billion from the 2012-2016 drought, considering that California produces more than a third of the vegetables and two-thirds of the fruits and nuts sold in the United States.
"This really provides the possibility of engineering plants to potentially improve the ecosystem as global warming proceeds,"
"Perhaps we could engineer grasses in threatened areas that can withstand drought. Perhaps we could teach a tree in the Midwest to grow longer roots, so that it's less likely to be toppled during strong storms. There are so many potential applications”, said He, who is the John T. Wilson Distinguished Service Professor of Chemistry, Biochemistry and Molecular Biology at the University of Chicago.
The next step is to learn how to use this in coherence with the plant’s existing genetics on Earth, in arid environments, simulant soils, and deserts, and later in space on the Moon and Mars.
More information: RNA demethylation increases the yield and biomass of rice and potato plants in field trials, Nature Biotechnology, DOI: 10.1038/s41587-021-00982-9 , www.nature.com/articles/s41587-021-00982-9