Metabolome and transcriptome profiling reveal new insights into somatic embryo germination in Norway spruce (Picea abies).

Dobrowolska I, Businge E, Abreu IN, Moritz T, Egertsdotter U

Tree Physiol 37 (12) 1752-1766 [2017-12-01; online 2017-10-07]

Transcriptome, metabolome and histological profiling were performed on normal and aberrant somatic embryo germinants of Norway spruce (Picea abies L. Karst) providing a simplistic systems biology description of conifer germination. Aberrant germinants (AGs) formed periderm-like tissue at the apical pole and lacked shoot growth above the cotyledons. Transcriptome profiling (RNA-Sequencing) revealed a total of 370 differentially expressed genes at ≥1 or ≤-1 log2-fold change, where 92% were down-regulated in AGs compared with normal germinants (NGs). Genes associated with shoot apical meristem formation were down-regulated in AGs, or not differentially expressed between AGs and NGs. Genes involved in hormone signaling and transport were also down-regulated. Metabolite profiling by gas chromatography-mass spectrometry (MS) and liquid chromatography-MS revealed biochemical difference between AGs and NGs, notably increased levels of sugars including glucose in AGs. Genes involved in glucose signaling were down-regulated and genes involved in starch biosynthesis were up-regulated, suggesting involvement of sugar signaling during late embryo development and germination. The overall results provide new data enabling further studies to confirm potential markers for a normal germination process in conifers.

Swedish Metabolomics Centre (SMC) [Service]

PubMed 28985382

DOI 10.1093/treephys/tpx078

Crossref 10.1093/treephys/tpx078

pii: 3896382