Scientists have discovered previously unexplored genetic variations in the DNA of Arabidopsis plants’ photosynthetic and energy centers, revealing key factors influencing photosynthesis efficiency.
Published Nov. 28 in Proceedings of the National Academy of Sciences (PNAS), these groundbreaking findings open new avenues for developing higher-yielding, climate-resilient crops, supporting sustainable global food security, according to a press release.
Plant cells, in addition to their chromosomes, house organelles within their nuclei. These specialized compartments perform distinct functions, such as chloroplasts, which drive photosynthesis by converting solar energy and CO₂ into sugars, and mitochondria, which generate energy by breaking down sugars. Each chloroplast and mitochondrion contains approximately 100–150 genes that encode proteins vital for their operations.
Optimal coordination between chromosomal, chloroplastic, and mitochondrial genes is essential for plants to function effectively. However, the impact of genetic variation in organelles on plant performance has remained largely unexplored — until now.
Researchers from Wageningen University & Research (WUR) and Michigan State University have shed new light on this topic. In a study published yesterday in the prestigious journal PNAS, they reveal that genetic variation in chloroplast and mitochondrial DNA significantly contributes to differences in photosynthesis efficiency among Arabidopsis thaliana (thale cress) plants.
“The role of variation in chloroplasts and mitochondria, particularly in energy production and photosynthesis, is something that could not be studied before—but now it can,” explains Mark Aarts, professor of Plant Genetics at WUR, who supervised the research.
Analysis of 240 ‘Cybrid’ Arabidopsis Lines
The release notes that for their research, the authors developed a new method for generating so-called cybrids on a large scale. In a cybrid, the original chloroplasts and mitochondria are all replaced by those from another plant.
“By combining the chromosomes of one of four different Arabidopsis plants with the chloroplasts and mitochondria of one of 60 other Arabidopsis plants, we were able to create 240 unique cybrids,” says Aarts.
The plants used in the study were sourced from diverse locations across Europe, Asia, and Africa, reflecting the natural range of Arabidopsis.
This marks the first instance of producing such an extensive set of cybrids. According to Aarts, this demonstrates that this approach could also be applied to agricultural crops, bringing a similar method within reach for plant breeding companies.
“In the past it was very complicated and time consuming to study the contribution of chloroplastic and mitochondrial variation to energy production and photosynthesis in plants—but now it is feasible.”
Advancing Photosynthesis Efficiency and Plant Growth
The efficiency of photosynthesis in crops is surprisingly low compared to solar panels, with plants utilizing only about 1% of the solar energy they receive. However, earlier studies suggest this efficiency could theoretically be 5 to 6 times higher. Unlocking this untapped potential is a key focus of ongoing research at the Jan IngenHousz Institute in Wageningen, where two of the study’s authors are based.
Historically, efforts to enhance photosynthesis have primarily targeted genetic variation in chromosomes. Aarts notes that this new discovery broadens opportunities for plant scientists and breeders to improve energy production and photosynthesis. These advancements could pave the way for future crop varieties better equipped to harness and convert energy, driving optimal growth.
“Enhancing the ability of crops to capture solar energy and produce reliable yields under varying environmental conditions is crucial for feeding a growing global population with climate-resilient, robust crops that are grown sustainably,” Aarts says.
