Figure 4

Cell wall staining and CalS RT-PCR in Pinus taeda pollen tubes grown in vitro. A, Semi-quantitative RT-PCR of PtCalS13 from 0 to 72 h on growth medium. B, Ungerminated P. taeda pollen after 12 h on growth medium. Note the weak band stained by aniline blue in distal aperture area (at bottom) and strong staining of prothallial cell walls on proximal side of pollen grain (white arrows). C-E, Pollen tube after 48 h on growth medium (24 h after germination). In D, note strong aniline blue staining at the distal aperture area, and lack of stain in tube walls (compare with C). Calcofluor localizes to both intine and tube wall (E). Scale bars, 20 μm.