Specific polyamine ratios as indicators of Pinus caribaea microshoot rooting phases

Abstract

This study analysed the changes in the endogenous levels of total and individual polyamines (PAs) during the different rooting phases in Pinus caribaea microshoots: induction, induction-initiation and functional root system emergence. The analysis, performed using high-resolution liquid chromatography, demonstrated that during the inductive phase there is a drop in total PA content in all the fractions, with an increase in the degradation product diaminopropane. In the induction-initiation phase PAs are present in all the fractions. The microshoots with root nodules always presented higher Putrescine (Put) levels, whereas those that did not have them had similar spermidine and Put levels, while maintaining elevated spermine levels. The comparative analysis of microshoots with and without a rooting response indicates that high PA levels are maintained when root manifestation does not occur, coinciding with basal callus formation.

Keywords:

• Micropropagation
• putrescine
• rooting
• spermidine
• spermine

Acknowledgements

This research was supported by FAIR3-CT96-1445 Project and the Dirección de Investigación of the Universidad de Concepción. Matilde Uribe Moraga thanks ICI (Spain) for her doctoral fellowship.