For the first time, researchers have shown that multigene bioengineering of photosynthesis increases the yield of an important food crop, namely soybeans, in field trials. After more than a decade of work to achieve this goal, a collaborative team from the University of Illinois (USA)-led RIPE (Realizing Enhanced Photosynthetic Efficiency) project transgenic soybean plants to increase productivity. photosynthesisAs published in ‘Science’ magazine, it results in higher performance without loss of quality.
The authors note that results of this magnitude may not come at a more important time. The UN’s most recent report, ‘The State of World Food Security and Nutrition 2022’, revealed that: Almost 10% of the world’s population is starving in 2021, it’s getting worse has increased steadily in recent years, dwarfing all other global health threats of scale.
According to UNICEF, more than 660 million people are expected to face food shortages and malnutrition by 2030. Two of the main reasons are the inefficiency of food supply chains (access to food) and harsher farming conditions due to climate change, thereby facilitating access to food and improve the sustainability of food crops in poor areas are the main objectives of this study and the RIPE project.
RIPE is an international research project. The aim is to increase global food production by increasing the photosynthetic efficiency of food crops for smallholder farmers in sub-Saharan Africa. With support from the Bill and Melinda Gates Foundation, the Food and Agricultural Research Foundation and the UK Foreign, Commonwealth and Development Office.
“The number of people affected by food shortages continues to increase, and estimates clearly show that a change in the level of food supply is needed to change the course,” warns Amanda De Souza, a research scientist with the RIPE project. an explanation. lead author.
“Our research shows an effective way to contribute to the food security of people who need it most., while preventing further land allotment to production –continues–. Improving photosynthesis is a great opportunity to get the needed jump in yield potential.”
Changing the mechanics of photosynthesis
Photosynthesis, the natural process that all plants use to convert sunlight into energy and yields, is a surprisingly inefficient process with more than 100 steps that RIPE researchers have been trying to develop for more than a decade. In this study, the group, which is the first of its kind, Enhanced VPZ structure inside the soybean plant to enhance photosynthesis and then conducted field trials to see if performance improved as a result.
The VPZ structure contains three genes that encode proteins from the xanthophyll cycle, a pigment cycle that helps photoprotect plants. After exposure to full sunlight, this cycle is activated in leaves to protect them from damage and allows the leaves to dissipate excess energy.
Again, this photoprotection should be turned off when leaves are shaded (by other leaves, clouds or the sun moving across the sky) so the leaves can continue the process of photosynthesis with a reserve of sunlight. It takes a few minutes for the plant to shut down its protection mechanism and wastes valuable time that could be used for photosynthesis.
Overexpression of three genes of the VPZ construct accelerates the process, so that each time a leaf moves from light to shade, photoprotection is deactivated more quickly. Leaves gain extra minutes of photosynthesis added during the growing season, which increases the overall rate of photosynthesis.. This study showed that the quality of the seeds was not affected, although the yield was increased by more than 20%.
“Despite the higher yield, the protein content of the seeds did not change. This suggests that some of the extra energy gained by enhanced photosynthesis was probably diverted to nitrogen-fixing bacteria in the plant nodules,” he explains. RIPE Director Stephen Long is Professor of Crop Sciences and Plant Biology at the Carl R. Woese Institute for Genomic Biology at Ikenberry University, Illinois.
First they tried the tobacco plant
The researchers first tested their idea on tobacco plants, due to the crop’s ease of genetic transformation and the number of seeds that could be produced from a single plant. These factors allow researchers to move from genetic transformation to field trial within a few months. After proving the concept in tobacco, they moved on to the more complex task of incorporating genetics into a food crop, soybeans.
“The fact that very significant yield increases have now been shown in both tobacco and soybeans, two very different crops, shows that it has universal applicability,” Long said. “Our work shows that making improvements in performance is highly dependent on the environment. It is crucial to determine the reproducibility of this result across environments and further improvement to ensure environmental stability of gain.”
Additional field testing of these GM soybean plants continues this year.Results are expected in early 2023.
“The biggest impact of this work is to open up ways to show that we can bioengineer photosynthesis and increase yields to increase food production in major crops. This is just the beginning of validation that the ideas are based on RIPE,” said De Souza. The project is a successful way to increase yields in major food crops.”
The project and its sponsors are committed to global reach. and making project technologies available to the farmers who need them most.
Reference work: https://www.igb.illinois.edu/article/ripe-researchers-prove-bioengineering-better-photosynthesis-increases-yields-food-crops
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