Capsaicin formation in p-fluorophenylalanine resistant and normal cell cultures of Capsicum frutescens and activity of phenylalanine ammonia lyase.

ABSTRACT

Callus cultures of Capsicum frutescens capable of producing a maximum of 53 ~g capsaicin/g FW were exposed to various levels of p-fluorophenyialanine (PFP) at 100, 400, 1000 and 2000 ~M to develop a resistant cell line that over produces capsaicin. After 15 days of culturing on media lacking PFP, cell lines resistant to 100, 400 and 1000 ~M registered 18%, 34.5% and 45% increase in capsaicin content over normal cell line (cells not exposed to PFP). Capsaicin accumulation was inhibited in 2000 ~M PFP resistant cell line. The profile of phenylalanine ammonia lyase (PAL), the key enzyme in pheny1propanoid pathway in resistant cell cultures was studied and compared with normal cell cultures to understand its role in capsaicin formation. Importantly increased production of capsaicin was obtained using PFP resistant cell lines. The activity profile of PAL had no correlation with capsaicin content in both control and PFP resistant cells.