Figure 5

Transcript size and spatial and temporal expression. A Identification of transcript hybridized to a probe made from TaSSIVb EST. Northern analysis was performed with 0.5 μg poly (A+) RNA extracted from developing wheat caryopses. The cDNA probe utilised was a 550 bp fragment from a PstI and EcoRI digest of clone 1600-bp (Figure 1). A primary band of approximately 3.4 kb can be seen as a well as a faint band of around 3.7 kb. B Spatial and temporal expression of wheat SSs by comparative RT-PCR. RNA was extracted from embryos from caryopses at 25 DPA, endosperm (including the aleurone layer) from caryopses of approximately 4–7 DPA (13 mg), 5–10 DPA (17 mg), 10–16 DPA (22 mg), 16–20 DPA (28 mg), 20–25 DPA (35 mg), 26–32 DPA (43 mg) and leaves and roots from 14-day old seedlings. The mean mass in mgs of the caryopses used, i.e. 13, 17, 22, etc., is shown on the figure. The amounts of all products responded linearly to RNA input, number of PCR cycles and primer concentration.