Enhanced production of podophyllotoxins by co-culture of transformed Linum album cells with plant growth-promoting fungi

Abstract

To investigate the plant growth-promoting effect and stimulation of lignan biosynthesis, the effect of culture filtrates/live co-culture of two arbuscular mycorrhizae-like fungi, Piriformospora indica and Sebacina vermifera, on growth of Linum album cells and on production of podophyllotoxin (PT) and 6-methoxypodophyllotoxin (6-MPT) was studied. For elicitation studies, different volumes of culture filtrates (autoclaved and membrane-filtered) of P. indica/S. vermifera were added to suspension cultures of L. album. The culture filtrates of both the fungi exhibited a positive effect on product formation. For co-culture experiments, both fungi were individually co-cultivated at different concentrations with L. album in suspension cultures for different time periods. This resulted in significant enhancement of PT and 6-MPT content in the plant cells. The activity of phenylalanine ammonia lyase (PAL) was observed to be related to the lignan accumulation, indicating its role as the key enzyme of the phenylpropanoid pathway. The study resulted in total lignan (PT and 6-MPT) production of 745.6 mg/l with a very high PT productivity of 52.4 mg/(l.d).