Identification and quantitative analysis of stage-specific organic acids in loblolly pine (Pinus taeda L.) zygotic embryo and female gametophyte

Stage-specific analyses of 32 organic acids were completed across the range of seed development for zygotic embryo and female gametophyte (FG) tissues of loblolly pine (Pinus taeda L.). Tissue was analyzed in triplicate from two open-pollinated families, grown in different locations and years, by gas chromatography/mass spectrometry (GC/MS). Significant changes in organic acids occurred over time, with both seed collections showing similar trends in change of organic acid content. Although concentrations were not always similar, embryo and female gametophyte tissues generally showed similar patterns of change in organic acid content over time. The major organic acids contributing to osmotic potential were malic early in seed development and oxalic late in seed development. This data provides suggestions for stage-specific media composition changes for each step in the somatic embryogenesis protocol.