Fluctuation in free and conjugated polyamines in Scots pine seedlings after changes in temperature and daylength

Abstract

Free, soluble and insoluble conjugated polyamines from the needles, roots and stem of five month old Scots pine (Pinus sylvestris L.) seedlings inoculated with Suillus variegatus (Fr.) O. Kuntze and seedlings without inoculation were analysed during decrease in daylength and temperature. Temporary changes in free, soluble and insoluble conjugated polyamine pools caused by a decrease in daylength or temperature were observed. Inoculation of pine seedlings affected significantly the polyamine levels of five month old pine seedlings. The roots of inoculated seedlings contained significantly higher levels of free and soluble conjugated purtrescine and free, soluble conjugated and insoluble conjugated spermidine than the roots of noninoculated seedlings. The needles of inoculated seedlings contained significatly higher concentrations of free putrescine and soluble conjugated spermidine but lower amount of free spermine than the needles of noninoculated seedlings. The stems of inoculated seedlings contained higher concentrations of free putrescine but lower amounts of insoluble conjugated spermine. Changes in polyamine levels in noninoculated seedlings were observed after shortening of the daylength, whereas in inoculated ones changes were induced mainly by the decrease in temperature. The possible role of polyamines in the initial stage of cold hardening process is discussed.