Abstract

Peanut is an affordable legume used in most households. It represents one of the most important protein supplies worldwide. However, peanut proteins are deficient in several essential amino acids (EAA), like most plant proteins; whereas plants are the main source of dietary proteins consumed by humans and livestock. This could lead to protein malnutrition in areas where people diet relies on one or two staple foods. Based on its high nutritional value, peanut is a good candidate for genetic biofortification. This study is aimed at expressing an EAA-rich artificial storage protein (ASPx) into peanut seeds for increased nutritive value. The ASPx derived gene was introduced into peanut via Agrobacterium-mediated transformation. Molecular analysis of regenerated kanamycin resistant plants using polymerase chain reaction (PCR) and Southern hybridization indicate the stable integration of one copy ASPx gene in transgenic plants. The expression of the ASPx in transgenic peanuts seeds was detected by mass spectrometry (multiple reaction monitoring). Amino acids analysis showed an increase of 12 to 19% of most EAA (Val, Tyr, Phe, Iso, Leu, Met) in a transgenic line. The results show that the nutritional quality of peanut could be improved.

Key words: Genetic biofortification, essential amino acid, storage protein, peanut.