Additional file 4: of Repetitive somatic embryogenesis induced cytological and proteomic changes in embryogenic lines of Pseudotsuga menziesii [Mirb.]

Figure S3. Histology of non-embryogenic cells (NECs) clusters from 1ry and/or 2ry lines of genotypes TD17 and SD4. A / Histology of TD17 groups of loosely arranged NECs (arrow) in the vicinity of small somatic embryos (arrowhead); B / histology of TD17 compact NEC cluster accumulating phenolics (blue and brown cells, arrowheads) and starch (arrow); C / Lugol staining of TD17 NEC cluster showing starch (arrows) and phenolic compounds (small dark granules marked with arrowhead); D / TD17–1 NEC cluster with dividing cells (arrowheads); E /SD4–2 NEC cluster (arrow) within polyembryogenic center besides well-arranged embryonal heads (EH), note phenolic content (in dark blue-grey) of cells separating NEC from suspensor cells (in light blue); F / SD4–6 meristemoid-like NEC cluster; note phenolic content of cells between two meristemoid-like structures (in blue-grey). Scale bar: A, E = 200 μm; B, F = 100 μm; C, D = 50 μm. (DOCX 417 kb)