PMC

Figure 4. ACC, a precursor to ethylene, affects Arabidopsis SAM SE. Means and standard error of the mean are shown for two biological replicates of the experiment (n = 3–4 flasks scored per replicate). Different letters indicate significant difference at p < 0.001.

Figure 2. Ethylene production by cultivars of soybean from developing seeds containing 4–5 mm embryos without culture (A) or cotyledon explants from 4–5 mm embryos placed onto D40 medium for 3 or 7 d (B). Data shown are means and standard error of the mean for eight (A) or at least four (B) independent experiments. Asterisks indicate significant difference between the cultivars (A) or the timepoints within a cultivar (B) at *p < 0.05; **p < 0.01.

Figure 1. The soybean cultivar Defiance is less embryogenic than Jack. Immature cotyledon explants from 4–5 mm embryos were placed onto D40 SE initiation medium and the number of embryos scored at 30, 45 and 60 d. See the text for the scoring system. Means and standard error of the mean are shown for at least 11 plates of explants per genotype/timepoint. Significant differences between genotypes at a given timepoint at * p < 0.01; **p < 0.001.

Figure 3. Transcript accumulation in isolated developing seeds containing 4–5 mm embryos. Transcripts from genes involved in the control of embryogenesis accumulate to lower amounts in the poorly embryogenic soybean cultivar Defiance compared with Jack that is more competent for somatic embryogenesis. Developing seeds of the stage used for SE but without any culture were used in this experiment. Means and standard error of the mean for at least three biological replicates are shown. Asterisks indicate significant difference between the cultivars as follows: * p < 0.05; **p < 0.01; NS, not significant.