Although molecular farming is a promising method, its yield today is still insufficient and still requires laboratory research. Recently, Japanese researchers managed to increase this yield threefold by spraying the plants with vitamin C.
Molecular farming aims to make transgenic plants produce molecules of pharmaceutical interest in order to eventually manufacture drugs, or even vaccines. Molecular farming has several advantages over chemical or cellular synthesis. Among other things, it offers a lower cost and the possibility of cultivating on large plots. Nevertheless, its yield is still insufficient . The mass of dry plant cells obtained from plants is ten times less than that of bacteria. It is also three times lower than that of yeasts.
According to a publication in the journal Plant Physiology on February 26, 2021, researchers from the University of Tsukuba (Japan) believe they have found an effective and inexpensive solution. It involves spraying the leaves of plants with an antioxidant that everyone knows :ascorbic acid (or vitamin C). The scientists' work focused on the tobacco species Nicotiana benthamiana originally from Australia. It is often used in molecular farming because of its ability to produce exogenous genes . It is also easily cultivable in greenhouses.
Scientists used a particular technique:agro-infiltration. Concretely, it was a question of using the bacterium Agrobacterium in the plant. This same bacterium inserts a plasmid into the genome of the plant and expresses a gene producing the desired molecule. However, researchers face a major problem. Expressing a large amount of exogenous molecules can have undesirable consequences. This can cause leaf dehydration or premature cell death.
Ascorbic acid acts against these harmful effects , significantly increasing protein production. This antioxidant therefore prevents cell death, but can also reduce the degradation of newly formed proteins, leading to an increase in yield. Moreover, after verification, ascorbic acid does not interfere with the immunological properties of proteins. If the researchers obtained a yield three times higher than normal , it might be possible to go even further.
The ascorbic acid spray technique has been tested on different types of recombinant proteins. Some relate in particular to the production of functional antibodies . This technique therefore gives hope to players in the field as to the development of molecular farming in the near future.
