There is a simple genetic tweak in a single protein in crops that can result in plants needing 25% less water as revealed by scientists. It will still produce a regular yield. This breakthrough will lead to water-efficient crops and will help communities grow more food in areas where water is not in abundance.
The research was carried out by an international team of scientists led by the University of Illinois. They discovered that the protein called Photosystem II Subunit S (PsbS) when increased, force a plant to partially close the stomata (tiny pores in leaf, open and close to let oxygen in or CO2 out for photosynthesis).
Limiting the stomata opening would result in less water lost through transpiration and needing less water to grow. A 25% increase in atmospheric CO2 in the past century means the plants can get the desired CO2 with a smaller opening. “Evolution has not kept pace with this rapid change, so scientists have given it a helping hand,” says Stephen Long, director of Realizing Increased Photosynthetic Efficiency (RIPE), the international research project behind the study.
A tobacco crop was used to test the theory and showed remarkable results. Increasing PsbS reduced the stomatal openings and the ratio of carbon dioxide going into a plant to water escaping improved by 25%. This means the engineered crops required 25% less water to flourish. The experiment showed no significant difference in yield of modified and non-modified plants.
“This is a major breakthrough,” says Long. “Crop yields have steadily improved over the past 60 years, but the amount of water required to produce one ton of grain remains unchanged – which led most to assume that this factor could not change. Proving that our theory works in practice should open the door to much more research and development to achieve this all-important goal for the future.”
It might surprise you to know that 90% of the world’s fresh water supply is used by agriculture. Estimates say that a 70% increase in food production will become necessary 2050. This would prove to be a very difficult task with the current crops and the availability of water.
The tobacco crop was easy to test but we need engineered crops that can provide us food in water-limited conditions. Research suggests that PsbS in plants is relatively universal so this process should have a similar effect on common food crops as well.
“Making crop plants more water-use efficient is arguably the greatest challenge for current and future plant scientists,” said co-first author on the study Johannes Kromdijk. “Our results show that increased PsbS expression allows crop plants to be more conservative with water use, which we think will help to better distribute available water resources over the duration of the growing season and keep the crop more productive during dry spells.”
This really is a great development indeed.