ScienceMag by By Erik Stokstad Apr. 21, 2020
As plants convert sunlight into sugar, their cells are playing with fire. Photosynthesis generates chemical byproducts that can damage the light-converting machinery itself—and the hotter the weather, the more likely the process is to run amok as some chemical reactions accelerate and others slow. Now, a team of geneticists has engineered plants so they can better repair heat damage, an advance that could help preserve crop yields as global warming makes heat waves more common. And in a surprise, the change made plants more productive at normal temperatures.
“This is exciting news,†says Maria Ermakova of Australian National University, who works on improving photosynthesis. The genetic modification worked in three kinds of plants—a mustard that is the most common plant model, tobacco, and rice, suggesting any crop plant could be helped. The work bucked conventional wisdom among photosynthesis scientists, and some plant biologists wonder exactly how the added gene produces the benefits. Still, Peter Nixon, a plant biochemist at Imperial College London, predicts the study will “attract considerable attention.â€
When plants are exposed to light, a complex of proteins called photosystem II (PSII) energizes electrons that then help power photosynthesis. But heat or intense light can lead to damage in a key subunit, known as D1, halting PSII’s work until the plant makes and inserts a new one into the complex. Plants that make extra D1 should help speed those repairs. Chloroplasts, the organelles that host photosynthesis, have their own DNA, including a gene for D1, and most biologists assumed the protein had to be made there. But the chloroplast genome is much harder to tweak than genes in a plant cell’s nucleus.
More:
https://www.sciencemag.org/news/2020/04/rice-genetically-engineered-resist-heat-waves-can-also-produce-20-more-grain
