Researchers at the Netherlands-based Wageningen University and Research (WIR) have described a method that can completely replace the organelles (cell internal structures), of one plant with those of another, while the chromosomes remain unchanged. The organelles comprise chloroplasts, which are essential for photosynthesis, and mitochondria, which generate energy.
There is interest in whether the research, which was conducted using the thale cress plant, leading to improvements in photosynthesis, could be applied more widely to agricultural crops.
Researcher at the university, Erik Wijnker says: “Now that it is possible to replace the organelles of a plant using an efficient genetic trick, we can compare the original plants with plants that have the ‘new’ organelles. This makes it easy to determine which new combinations of organelles and chromosomes lead to the best plant properties. For example, for a certain type of chloroplast, we now know beforehand that, if we put them in thale cress, photosynthesis will be improved.”
Plants use only a fraction of absorbed sunlight for photosynthesis. Improving that process is seen as the key to more efficient plant growth, which can reduce the footprint of agriculture on the environment, and enable better feeding of the growing world population in the future, says the university. “For a long time it was thought that photosynthesis could not be improved.”
In recent years, various methods have been developed, including at WUR, to improve plant photosynthesis to such an extent that more of the captured sunlight can be used for biomass production. If this is successful, plants with improved photosynthesis can make an important new contribution to tackling the food problem without causing further damage to the climate, says WIR.
At the moment, virtually no use is made of the natural variation in chloroplasts and mitochondria in plant breeding. Researcher Pádraic Flood: “There is an enormous natural variation in chloroplasts, but researchers lacked simple methods to determine which chloroplasts possess the desired properties.”
PhD candidate Tom Theeuwen adds: “The trick we have used for thale cress is based on genetic modification, and its use for crops is subject to strict rules in Europe, but with the current modern breeding methods, it is fortunately very possible to make similar new combinations of organelles and chromosomes in a short period of time.
“Now that we have shown that this can lead to plants that perform better, a number of companies are interested to know whether this also applies to their crops. It offers us a new way of investigating whether we can better understand and improve plant photosynthesis, by creating and testing new combinations.”