Plastids and glycolipids in the stemwood of Pinus sylvestris L.

Abstract

The ultrastructure of plastids in xylem ray parenchyma cells of Pinus sylvestris L. was studied and compared with the glycolipid composition of the stemwood. Seasonal changes of the ultrastructure were studied by taking samples regularly throughout the year. The plastids resemble amyloplasts. They usually have one large starch grain, and considerable variation in structure and starch content was observed, especially in the innermost sapwood and in the sapwood-heartwood transition zone. Electron-dense deposits were observed attached to the plastid membranes and envelopes, especially in the transition zone, from April to November. The plastids were aggregated near the nucleus and the starch disappeared during the winter (January-March). The glycolipids, monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), were present only in the sapwood, in trace amounts. The glycolipid content was slightly greater in the outer sapwood than in the sapwood-heartwood transition zone. DGDG was the dominant lipid of the two.

Novel perspectives in wood certification and forensics: dry wood as a source of DNA

“…All cells in the heartwood are dead, as are those found in the bark. The ultrastructure of ray parenchyma cells is gradually modified at increasing distances from cambium (Frey-Wyssling & Bosshard 1959;Saranpää 1988) and no organelles or nuclei are detectable in the heartwood (Bamber 1976). Thus, in heartwood, all cells are dead and empty, but short fragments of DNA may nevertheless have remained adsorbed on cell walls (Cano 1996), as indicated by the encouraging results obtained with DNA isolated from this part of the trunk.…”

Checking the geographical origin of oak wood: molecular and statistical tools

“…Markers from cpDNA nevertheless appear very promising and particularly suitable for geographical traceability purposes. First, cells may contain tens to hundreds of plastids, each comprising several copies of the cpDNA genome (amyloplast in the case of wood; Saranpää 1988). If the DNA is degraded, the chances of successful amplification increase if the target gene sequence is present in multiple copies in each cell (e.g.…”

The proliferation of amyloplasts in meristematic cells of developing stolons of potato and apple callus: Progenitors of proplastids

“…However, in the present study, formation of small precursors from amoeboid plastids was not detected. Plastidial organelles of similar ultrastructure to those shown in Figures 5, 13, 15 and 18 have infrequently been reported by other authors (Nepi et al, 1996;Pacini et al, 1992;Saranpää, 1988).…”