Fig. 1

Relative mRNA level of PaWOX2. a Schematic representation of the developmental stages of embryo development. Proliferating proembryogenic masses (PEMs): PEM1, seven days after subculture to fresh proliferation medium in the presence of plant growth regulators (PGRs), PEM2 and PEM3, three and seven days after transfer to pre-maturation medium lacking PGRs; early embryo (EE), after one week on maturation medium; early late embryo (LE1) and late embryo before the formation of cotyledons (LE2) after one and two weeks on maturation medium, respectively; maturing embryo (ME1), characterized by the initiation of cotyledons after five weeks on maturation medium; ME2 (almost fully maturated embryo) and ME3 (fully maturated embryo) after about eight weeks on maturation medium. The majority of the embryos in each sample represented the designated specific developmental stage. However, since the development was not strictly synchronized, embryos from previous and subsequent stages could also be represented. b qRT-PCR analysis of the relative mRNA level of PaWOX2 in nine sequential developmental stages of embryo development. The mRNA level is relative to the mRNA level of PaWOX2 in LE1 and is normalized against three reference genes: CELL DIVISION CONTROL 2 (PaCDC2), ELONGATION FACTOR-1 (PaEF1) and PHOSPHOGLUCOMUTASE (PaPHOS). The mRNA level is the mean ± SE of three biological replicates. Different letters indicate significant differences in the mRNA levels among developmental stages (ANOVA, p < 0.05)