Scientists from Nanyang Technological University (NTU), Singapore have successfully genetically modified a plant protein that is responsible for oil accumulation in plant seeds and edible nuts.
Demonstrating their patent-pending method, the model plant Arabidopsis accumulated 15 to 18 per cent more oil in its seeds when it was grown with the modified protein under laboratory conditions.
Finding ways to make crops yield more oil in their seeds is a holy grail for the farming industry. However, most oil-producing crops - such as oil palm, soybean, sunflower, rapeseed, peanut - already have a high percentage of oil in their fruit or seed, and it is hard to increase their oil content through traditional crop crossbreeding methods.
Vegetable oils are commonly used in food processing, biofuels, soaps and perfumes, and the global market for them is estimated to be worth US$241.4 billion in 2021 and is expected to increase to US$324.1 billion by 2027.
Increasing the yield of oil from plants could also help the world in its quest for sustainability, helping to reduce the amount of arable land needed for oil-yielding crops.
The secret to helping plants store more oil in their seeds is one of their proteins called WRINKLED1 (WRI1). Scientists have known for over two decades that WRI1 plays an important role in controlling plant seed oil production.
Now for the first time, a high-resolution structure of WRI1 has been imaged and reported by the NTU team, jointly led by Associate Professor Gao Yonggui and Assistant Professor Ma Wei from the School of Biological Sciences.
Published in the scientific journal Science Advances, the team detailed the molecular structure of WRI1 and how it binds to plant DNA - which signals to the plant how much oil to accumulate in its seeds.
Based on the understanding that the atomic structure of the WRI1-DNA complex revealed, the team modified WRI1 to enhance its affinity for DNA in a bid to improve oil yield. In this approach, some portions in WRI1 were selected for modifications to improve its binding to DNA and several forms of WRI1 were produced.
These candidate WRI1s were then further tested to assess their ability to activate oil production in plant cells. As expected by the team, they showed that their modified versions of WRI1 increased DNA binding ten-fold compared to the original WRI1 - ultimately leading to more oil content in its seeds.
Assoc Prof Gao, a structural biologist said:
"Being able to see exactly what WRI1 looks like and how it binds to DNA that is responsible for oil production in the plant was the key to understanding the entire process. WRI1 is an essential regulator that informs the plant how much oil to store in its seeds. Once we were able to visualise the 'lock', we then engineered the 'key' that can unlock the potential of WRI1."