Biotechnologists from the National Institute for Plant Genome Research in New Delhi, India, have developed genetically modified potatoes that contain 60% more protein than regular tubers
The gene of the cereal plant amaranth helped them in this. According to scientists, their development will save not only vegetarians from protein starvation.
A significant part of the population of our planet (more than a billion people) does not have adequate nutrition and suffers most from protein deficiency. As has been repeatedly shown in animal experiments and in human observations, a lack of protein in the diet causes a delay in physical and mental development and can provoke serious illness. Protein malnutrition at an early age is especially dangerous. The human body, like other animals, can synthesize only 11 of the 21 amino acids required for the synthesis of body proteins. The remaining ten are essential amino acids that a person should receive from food.
Genetics are trying to increase the protein content in food crops all over the world. And for millions of people, especially in developing countries, potatoes are the basis of their daily diet. For all its advantages, there is little protein in tubers. Therefore, many scientific groups are creating protein-rich potatoes.
Gene selected from amaranth
To increase the protein content, scientists tried different genes, but they were not suitable for practical use. Indian geneticists from the National Institute of Plant Genome Research obtained and studied transgenic potatoes with an inserted AmA1 gene (Amaranth Albumin 1). This gene is obtained from the grain plant amaranth, where it performs an important function - it stores protein in the seeds. AmA1 protein is amino acid balanced and has been approved by the WHO for nutritional value.
Indian biologists led by Asis Datta have obtained transgenic potatoes from seven economically important varieties with different genotypes. To do this, a construct from the AmA1 gene in combination with the gene activating it was transferred into the plant genome. Agrobacteria have traditionally been used for transfer.
As the experiment showed, transgenic potato plants did not differ in any way from ordinary ones in morphological characteristics.
Essential amino acids added to potatoes
Scientists have found that the gene is expressed to a greater extent in tubers, to a lesser extent in the stem and very little in the leaves. In tubers, the amaranth gene stimulates protein storage. It was determined by the amount of nitrogen and by electrophoresis. In different transgenic cultivars, the protein content increased by 35-60% in comparison with conventional cultivars. The authors of the work note that previous attempts to increase the protein content in potatoes resulted in no more than 35% increase.
Promotional video:
Amino acid analysis showed that transgenic tubers have an increased content of several essential amino acids: lysine, tyrosine, and sulfur-containing amino acids, which are scarce in ordinary potatoes. The content of aspartic acid, glutamic acid, arginine, leucine and isoleucine also increased. All these changes are caused by the increased expression of the adamant gene for seed stocks.
Biologists looked to see if the protein enrichment of potatoes was accompanied by an increase in biomass. It turned out to be so: the dry weight of the terrestrial parts of the transgenic plants exceeded the weight of the control plants by 7–20%. This indicates an increase in the intensity of photosynthesis. The experiment confirmed that CO 2 utilization by transgenic plants increases by 27%. Scientists suggest that the following mechanism works here: increased protein synthesis in transgenic plants depletes the supply of free amino acids, and this, in turn, leads to enhanced photosynthesis. In two-year field experiments conducted in different climatic conditions, Indian geneticists found that the yield of transgenic potato tubers is 15-25% higher than usual.
Potatoes did not harm the rats
The transgenic potato was tested for safety on rats that ate it for three months. The biochemical blood test turned out to be normal, as well as the state of work of all body systems. The immune system also behaved calmly, no signs of allergy were observed in the animals. Postmortem histological analysis of various tissues showed no abnormalities. Scientists have made sure that the AmA1 protein is completely digested by enzymes in the gastric juice.
So the method for improving potatoes proposed by Indian scientists has been demonstrated to be effective and safe. The authors of the PNAS article believe that this gene can be used in other cultures.