POTATO GLYCOALKALOIDS - A BURDEN OR A BLESSING

Steroidal glycoalkaloids (SGAs) are produced following the general ste roid biosynthesis pathway, starting from acetyl-coenzyme A and followe d by the intermediates mevalonic acid, squalene, cycloartenol, and cho lesterol. alpha-Chaconine and alpha-solanine are the main SGAs of the cultivated potato (Solanum tuberosum), whereas many other SGAs are kno wn in the wild potato species. Low concentrations of SGAs improve the taste of potato, but concentrations greater than 200 mg/kg can have to xic effects on animals and humans. SGAs have antimicrobial activity an d confer resistance to some insects, but many such pests of potato are not greatly affected. Certain environmental conditions and wounding e nhance SGA accumulation in tubers in the field and storage. Low produc tion of SGAs is a dominant character inherited in a relatively simple manner and can be selected for in potato-breeding programs, whereas th e use of wild potato germplasm tends to increase the SGA accumulation in the breeding lints. Further efforts are likely to be directed towar d the reduction of the SGA content in the edible potato products throu gh breeding and biotechnological methodologies, whereas potato genotyp es with high SGA production may be developed for use in the pharmaceut ical industry.