Crops resistant to climate change
This adaptation of the plant can increase food security, especially for families whose survival largely depends on the availability of potatoes. The regions where this plant is grown are often already affected by climate change. Warming affects various crops and affects their yields – note the authors of the publication, scientists from the University of Illinois of Urbana-Champaign.
“If we are to meet the food needs of people living in regions most at risk of declining crop yields due to warming – we have toproduce crops that can withstand more frequent and intense heatwaves” – says Katherine Meacham-Hensold from the mentioned university. She heads the international research project Realizing Increased Photosynthetic Efficiency (RIPE), which aims to increase access to food in the world. The means to this end is to develop crops that more efficiently convert the energy of the sun into mass used as food.
This program is supported by the Bill & Melinda Gates Foundation, the Food and Agriculture Research Foundation and the UK Office of Foreign, Commonwealth & Development.
30 percent growth
According to Meacham-Hensold, “the 30 percent increase in tuber weight observed in field trials bodes well for improving the photosynthesis process and will lead to crops that are resistant to climate change.”
The biochemical process that the authors of the study focused on is photorespiration (photorespiration) – a process occurring in the presence of light in plant cells, manifested by the uptake of oxygen and the release of carbon dioxide in a way other than cellular respiration. Photorespiration takes place when the RuBisCo enzyme reacts with an oxygen molecule instead of carbon dioxide. Even in ideal conditions for photosynthesis, photorespiration takes place as much as 25%. cases. It occurs even more often at high temperatures. Plants must then devote a lot of energy to metabolizing toxic by-products of this process (glycolates).
Photorespiration has also previously been shown to reduce yields of soybeans, rice and vegetables by up to 40 percent.
Scientists assumed that under more favorable circumstances, the energy used for this process could be used for a slightly different process that would be more beneficial to humans: plant growth.
“Photorespiration is a high energy expenditure for the plant,” Meacham-Hensold points out. “It has a negative impact on food production because the energy is redirected to metabolizing the toxin. Our goal was to bypass the plant’s usual photorespiration pathway and reduce the energy wasted.”
Better photosynthetic efficiency
RIPE scientists have previously shown that by incorporating two new genes into a model plant: glycolate dehydrogenase and malate synthase – the efficiency of photosynthesis can be improved. The proteins, changed thanks to manipulation at the genome level, metabolize glycolate in the chloroplast (the structure present in the green parts of the plant where photosynthesis takes place) – instead of moving this compound to other parts of the cell, as is currently done.
When working on a crop model, the associated energy savings translated into greater growth. The authors of the study hope that this may translate into an increase in crop weight. Scientists didn’t just notice the difference. As they write in “Global Change Biology”, in conditions corresponding to heat waves, the benefits tripled.
They also remind us that as it progresses global warming heatwaves are becoming more frequent and intense.
Instead of wasting away, the potatoes were growing
In 2022, scientists conducted three-week field experiments on potatoes in the early growing season. At that time, there was a heatwave, which remained at least 35 degrees Celsius for four days, twice exceeding 38 degrees Celsius. After a few days of a slight decline, temperatures again reached almost 38 degrees.
What happened to the potatoes in this heat? Instead of wasting away – the modified plants produced 30 percent more. more tubers than potatoes from the control group, taking full advantage of the advantage associated with better photosynthetic efficiency and increased temperature tolerance.
“Modification of the photosynthesis process, which ensured higher yields, did not worsen the nutritional quality of potatoes,” reports Don Ort from the RIPE project. “Food safety is not only about the number of calories we obtain; quality must also be taken into account.” (PAP)
