Genetic techniques used to improve plant photosynthesis and increase their growth

Unmodified plants (left) grow beside modified plants (right) (Photo courtesy Claire Benjamin/RIPE Project)
Unmodified plants (left) grow beside modified plants (right) (Photo courtesy Claire Benjamin/RIPE Project)

An article published in the journal “Science” reports the experimentation of the use of a genetic technique to increase the efficiency of plant photosynthesis. A team of researchers led by the molecular biologist Paul South of the US Agricultural Research Service carried out this experimentation within the Realizing Increased Photosynthetic Efficiency (RIPE) project, which has exactly this purpose to improve the sustainability of agricultural crops and increase land productivity. Modified plants increased their growth by 40%.

Photosynthesis allows plants to use solar energy but a concurrent process called photorespiration can inhibit it and stop it in the presence of high concentrations of oxygen. This process is useful to protect plants but uses a part of the energy obtained from photosynthesis reducing the efficiency of other metabolic processes. One of the consequences is a lower growth.

With an ever-growing human population and consequently a growing need for food, there’s research of various kinds on improving the productivity of food-producing plants. In many cases they work on the environment where plants grow, but there are projects that aim to exploit the new genetic techniques to improve the plants themselves. The RIPE research project is one of them and is supported by organizations such as the Bill & Melinda Gates Foundation, the US Foundation for Food and Agriculture Research (FFAR) and the British Department of International Development (DFID).

The researchers worked on the processes that follow what is produced by the enzyme known as Rubisco or with other abbreviations, used by photosynthesis. It ends up creating an oxygen-rich environment and tries to use that as well instead of carbon dioxide, triggering photorespiration.

Plants use complex adaptations to protect themselves from the potential damage deriving from reabsorbing the oxygen they emitted and the consequence is a considerable use of energy. However, those are useful adaptations therefore they were inherited in the natural selection with the passing of the generations. Some mechanisms are more efficient in bacteria of the Escherichia coli family, in the green alga of the species Chlamydomonas reinhardtii, in Arabidopsis thaliana and in the pumpkin, linked in particular to glycolate, a key molecule for photosynthesis.

Through genetic techniques, various modifications were made during the experimentation that was conducted on tobacco plants, chosen because they’re easier to modify and test than food crops. The researchers verified the impact of different genes by comparing the growth of modified and non modified plants. In the end, they produced a version whose growth increased by 40%.

The next step is experimentation in food crops, a goal that could take several years, also for the rules that regulate transgenic food crops. The RIPE project aims to offer royalty-free access to the products of its research to farmers, an important factor considering the strong controversies around transgenic plants commerce.

Leave a Reply

Your email address will not be published. Required fields are marked *