Potato glycoalkaloids: A burden or a blessing?

Steroidal glycoalkaloids (SGAs) are produced following the general steroid biosynthesis pathway, starting from acetyl-coenzyme A and followed by the intermediates mevalonic acid, squalene, cycloartenol, and cholesterol. alpha-Chaconine and alpha-solanine are the main SGAs of the cultivated potato (Solanum tuberosum), whereas many other SGAs are known in the wild potato species. Low concentrations of SGAs improve the taste of potato, but concentrations greater than 200 mg/kg can have toxic effects on animals and humans. SGAs have antimicrobial activity and confer resistance to some insects, but many such pests of potato are not greatly affected. Certain environmental conditions and wounding enhance SGA accumulation in tubers in the field and storage. Low production of SGAs is a dominant character inherited in a relatively simple manner and can be selected for in potato-breeding programs, whereas the use of wild potato germplasm tends to increase the SGA accumulation in the breeding lints. Further efforts are likely to be directed toward the reduction of the SGA content in the edible potato products through breeding and biotechnological methodologies, whereas potato genotypes with high SGA production may be developed for use in the pharmaceutical industry.