Plants obtain nourishment from sunlight with the help of photosynthesis. This process absorbs the light鈥檚 energy and uses it to transform water and carbon dioxide into sugar. Oxygen is produced as a by-product, making photosynthesis the foundation for the earth鈥檚 biosphere. In plants, this complex process takes place within the cells of the green leaves. They contain small organelles called chloroplasts where the photosynthesis takes place. Plant seeds, however, do not contain functioning chloroplasts. Following germination, seedlings first need to assemble the photosynthesis apparatus from hundreds of chlorophyll and protein molecules. In terms of the molecular process, the way in which this decisive developmental step in the life of a plant is regulated, and when and where it begins, remains poorly understood. Plant physiologists at 九色视频鈥檚 (LUH) Institute of Botany have recently achieved a breakthrough in this research field, and their findings have been published in the scientific journal .
In their study, the researchers used a mutant line with a defect in the chloroplast RNA polymerase. This mutant is unable to activate the genes responsible for photosynthesis and therefore remains white. The researchers repaired the gene defect in the mutant sample, and in the process they also installed a synthetic light switch which turned off under red light but turned on under blue light. Using this optoswitch, the biologists were able to induce the plant line, now called BVB09, to produce chloroplasts on demand when exposed to blue light. Doctoral candidate Finia Uecker, who has a master鈥檚 degree in plant biotechnology, designed the optoswitch as part of the project The Role of Plastid-Encoded RNA Polymerase-Associated Proteins (PAPs) in Chloroplast Biogenesis of Plants, which was funded by the German Research Foundation (DFG). She used it to demonstrate that chloroplasts can be produced only at specific points in time and in specific tissues.
鈥淭he BVB09 line serves as an optogenetic tool that allows for precise observation of the timing and location of the molecular processes behind the formation of the photosynthesis machinery,鈥� explains Prof. Dr. Thomas Pfannschmidt, who supervised the project. The researchers are convinced that the optoswitch they have developed can be applied to other questions in future 鈥� for example, to analyse new genes that help plants cope with climate stress or increase crop yields, and in synthetic biology studies where the use of a light switch is beneficial.
Original publication:
Finia Uecker, Frederik M. Ahrens, Tim Ruder, Thomas Pfannschmidt: A red/blue optoswitch for temporal control of chloroplast transcription and biogenesis in Arabidopsis (Nature Communications 2026, 17:1984).
Note to editors:
For further information, please contact Prof. Dr. Thomas Pfannschmidt, Institute of Botany (tel. 0511 762 2632, email: t.pfannschmidt@botanik.uni-hannover.de).
