Polyamine content during minimal growth storage of Thymus moroderi explants

Abstract

The polyamine (PA) content of in vitro-grown explants of Thymus moroderi Pau ex Martínez has been evaluated during minimal growth storage. The growth restriction was imposed by the combined action of osmotically-active compounds (15 g dm -3 sucrose and 15 g dm -3 mannitol) present in the Murashige and Skoog medium and the modification of the physical environment of the culture (4 °C and darkness). In these conditions, cultures were maintained up to 29 weeks without subculture. During this storage period, we analyzed contents of free, perchloric acid (PCA)-soluble and PCA-insoluble conjugated PA. Minimal growth storage brought about an increase in free putrescine (Put) coinciding with a reduction in PCA-soluble conjugated Put occurring during the first weeks of storage. PCA-insoluble conjugated spermidine (Spd) also accumulated in response to storage. © 2012 Springer Science+Business Media B.V.