Identification, cloning and expression of a new GDSL lipase from Carica papaya

Abstract Plants are a very interesting and new source of lipases for a variety of applications. Carica papaya is a remarkable source of lipases, as its genome reveals several putative lipolytic genes whose expression, function and applications remain undefined. In this study, total RNA from papaya leaves was isolated and used as a template to amplify the open reading frame (ORF) of a putative GDSL lipase gene, CpLIP2 , by RT-PCR. It was found that CpLIP2 expression is induced by inoculation of papaya plants with the fungal pathogen Corynespora cassiicola . The CpLIP2 ORF was further cloned into a viral provector module for transient expression in Nicotiana benthamiana plants. The presence of CpLIP2 transcripts in CpLIP2 -transformed plants was demonstrated by RT-PCR. Importantly, lipase activity was only detected in extracts from plants transformed with the CpLIP2 gene and not in those from plants transformed with an irrelevant gene used as a negative control, confirming that the gene was successfully expressed and that its product retained activity. A characterization of substrate specificity showed that CpLIP2 has a preference for short-chain rather than medium- and long-chain triglycerides.