Polyamine effects on growth and endogenous hormones levels in Araucaria angustifolia embryogenic cultures

The aim of the present work was to determine the effects of exogenous polyamines (PAs) supplemented into a BM medium free of plant growth regulators (PGR), on the endogenous PAs, IAA and ABA contents and growth of A. angustifolia embryogenic cultures. The addition of PAs to the PGR-free BM medium, enhanced the growth of embryogenic cultures. PAs endogenous metabolism was significantly affected by exogenous PAs. PAs supplemented to a PGR-free BM medium, mainly Put and Spm, increased the endogenous IAA and ABA levels, showing a direct relationship -between PAs levels and ABA accumulation. These results direct new strategies to further improve A. angustifolia somatic embryogenesis, especially during the maturation phase, by culture medium manipulation using exogenous PAs.