Undernourishment and malnutrition are severe problems in the developing world. Many people—about a billion of them—eat primarily staple grain crops and do not get enough protein. Protein deficiency delays growth and development, can cause permanent brain impairments in babies and young children, and enhances susceptibility to disease. No single food crop exists that provides humans with all of the essential amino acids we need.

Researchers in India have made transgenic potatoes that contain more protein, are nonallergenic and nontoxic, and grow in different regions and climates. Just like regular potatoes, they taste better fried than boiled. (Seriously, they tested that.) They are called “protatoes,” for potatoes plus protein. Catchy, right?

Potatoes were chosen because they are an important food crop that is also used for animal feed and in industrial products. However, they don’t contain the amino acids lysine, tyrosine, cysteine, and methionine. The gene for amaranth albumin 1 (AmA1), a well-balanced protein in terms of amino acid composition, was inserted into potatoes under the control of a DNA sequence that drove tuber-specific expression. Transgenes were introduced into seven different potato strains, and the transgenic potato plants that developed looked the same as wild-type potatoes.

Transgenic tubers displayed a 35-60 percent increase in protein content, including a significant increase in the amino acids lacking in wild-type potatoes. When transgenic plants were moved from the greenhouse to the field, a moderate increase (15-25 percent) in tuber yield was observed. Since AmA1 is a seed storage protein, one of its normal roles is to deplete free amino acids, which causes an increase in photosynthesis. Ama1 performed the same role here; transgenic plants had an increased rate of photosynthesis, and therefore growth.

In contrast to other genes used to increase the protein content of crops, such as Brazil nut 2S albumin, soybean glycinin, and sunflower seed albumin, amaranth albumin 1 is nonallergenic. Moreover, the scientists note, “the samples of transgenic tubers were found to be nonirritating to the vaginal mucous membrane of rabbits.” (Thank goodness.)

These protatoes are more nutritious than wild-type potatoes, they grow better in a variety of conditions, and they deliver an increased yield, yet they look and taste the same. The developers hope that they "may prove to be more acceptable to the general public than currently used genetically modified crops because AmA1 is an edible crop-derived sequence." Acceptable or not, they should be a boon to the protein deficient multitudes who need them.

PNAS, 2010. DOI: 10.1073/pnas.1006265107 (About DOIs).