Scientists have just discovered that wheat seeds, not just the leaves, use photosynthesis. The type of photosynthesis used is a C4 pathway, which is more efficient and better adapted for hot, dry climates. The findings may help agriculturists grow better crops to meet future food demands. The details are in a paper just published in the journal Scientific Reports.
The standard photosynthesis process is called C3 photosynthesis and it’s the pathway used by most plants, including crops such as rice and wheat. There’s a second common photosynthesis pathway, however, known as C4. This method is more efficient and allows the plants to absorb more nutrients while using less water. It’s a common pathway for plants that live in warmer, drier climates. Corn is a C4 plant, along with many types of grass.
A research team from the Queensland Alliance for Agriculture and Food Innovation discovered something interesting about wheat: the seeds were using photosynthesis. Previously, it was believed that photosynthesis only took place in the leaves, never in the actual grains of the plant. Furthermore, the researchers found that the grains were using C4 photosynthesis even though wheat is a C3 plant. Genes specific to C4 photosynthesis were found in the genome of the wheat plants and the team initially thought their computer had made a mistake. Further analysis showed that wheat seeds do use C4 photosynthesis, an exciting discovery for agriculture. The team speculates that this was an adaptation during evolution as atmospheric carbon dioxide levels dropped. When the plant couldn’t get enough carbon dioxide, the seeds evolved the ability to use C4 photosynthesis to provide extra energy.
The findings show that wheat contains the necessary genes for C4 photosynthesis. Wheat grains photosynthesize, a process previously believed to only occur in leaves. This discovery will allow for the breeding of wheat varieties that utilize C4 photosynthesis pathways, making the plants more efficient and better adapted to hot climates. With a growing global demand for food and a changing environment due to global warming, developing heat-resistant crops has become critical.
Parimalan Rangan et al. New evidence for grain specific C4 photosynthesis in wheat. Scientific Reports (2016).