Transformation of chilli pepper (Capsicum frutescens) with a phenylalanine ammonia-lyase gene

Hypocotyl explants of chilli pepper (Capsicum frutescens) were inoculated with Agrobacterium rhizogenes strain A13 harbouring the binary vector pBI121, which contains the CaMV 35S promoter linked to the GUS reporter gene. After 4 weeks of culture, the hairy roots produced were transferred onto Schenk and Hildebrandt (SH) medium supplemented with 250mgl^-1 Cefotaxime. Subsequently they were selected in liquid SH medium containing 20mgl^-1 kanamycin. When treated with X-glucuronide, vascular and root tip tissues were predominantly stained. A phenylalanine ammonia-lyase (PAL) cDNA from parsley (Petroselinum) was subsequently linked to the 35S promoter and transferred into hairy roots using the same A. rhizogenes strain. Successful transformation was confirmed by Southern hybridisation. Hairy roots containing the PAL transgene showed different PAL activity, slow growth and altered morphology.