Polyamine and amino acid profiles in immature Araucaria angustifolia seeds and their association with embryogenic culture establishment

Key message Analysis of polyamines and amino acid profiles in Araucaria angustifolia immature seeds from two mother tree genotypes in 2 consecutive years, and their association with the establishment of embryogenic cultures. Polyamines (PAs) and amino acids are an important source of nitrogen in plants. They are known to participate in plant development and their levels are associated with specific zygotic and somatic embryogenesis stages, which means that they may be useful as biochemical markers of developmental stages. The present study carried out an analysis of PA and amino acid profiles in immature Araucaria angustifolia seeds from two mother tree genotypes over 2 consecutive years, and their association with the initiation and maintenance of embryogenic cultures (ECs). The results showed that initiation of ECs in A. angustifolia, as observed in other conifers, depends on harvest year and mother tree genotype. PA and amino acid profiles showed that seeds from distinct mother trees and harvest years are different from one another. These differences were reflected in the initiation of ECs. The metabolic analysis indicates that conjugated Spd, ornithine, and asparagine profiles are candidates as biochemical markers for selection of mother trees. These results will allow for the testing of a large number of mother trees as explant sources and the selection of those with higher potential for somatic embryogenesis. (AU)