Polyamines in growth and differentiation of plant cell cultures: the effect of nitrogen nutrition, salt stress and embryogenic media.

Abstract

In vitro culture of plant cells and tissues has an increasingly important role in the advancement of both basic and applied aspects of plant growth and development. This includes the use of plant tissue cultures for the introduction of new traits by cell selection and genetic engineering, clonal micropropagation, pathogen elimination, as well as for elucidation of several molecular and metabolic events. Controlled organo-genesis and/or embryogenesis in cell and tissue cultures (i. e. regeneration of new plants) and selection of specific cell lines, are prerequisites for the practical utilization of the aspects mentioned above. Regeneration from tissue cultures is easily achieved in some plant species such as tobacco and carrot. Several agricultural crops and most woody plants are especially recalcitrant. In most cases growth of cell cultures and in vitro embryogenesis and organogenesis is manipulated by the use of known plant hormones only, in an empirical manner, and very little is known on the underlying mechanisms, and on the use of additional or alternative means which may regulate regeneration.