Fig. 3.

Analysis of sec1b single and sec1b keule double mutant. (A) Mutant phenotype. Note that the sec1b single mutant is indistinguishable from wild-type (WT), unlike the keule single mutant, which is fully rescued with a KNOLLE(KN)::mRFP-SEC1B transgene (T) (see SI Appendix, Table S1 for genetic analysis). (B and C) Mature pollen of sec1b keule double mutant. Pollen were stained with DAPI (B) or with fluorescein diacetate (FDA) (green) and propidium iodide (PI) (red) (C). Note that sec1b keule double-mutant pollen are collapsed and not labeled with DAPI or FDA (arrows in B and C; see SI Appendix, Fig. S5B for images in separate channels; SI Appendix, Table S2C for quantification). (D) SYP132::GFP-SYP132 expression in developing pollen of sec1b keule/+ plants. Note the aggregates of GFP-SYP132 in the sec1b keule double mutant (asterisk, Right) compared with the accumulation of GFP-SYP132 in a sec1b single mutant at the plasma membrane (arrowhead, Right) as in wild type (Left). See also SI Appendix, Fig. S7 for overview and line intensity profiles and SI Appendix, Table S3 for quantitative measurement. (Scale bars: 2 mm in A and 10 µm in B–D.)