Figure 7.

The Pollen Tube Growth Promotive Effect of STIG1 Depends on Its Interaction with LePRK2 and on Its Phospholipid Binding Capacity.

(A) Phospholipid binding assay of recombinant GST-ΔSP STIG1 and its mutants. The data shown are representative of at least two independent experiments.

(B) Representative pollen tubes expressing STIG1-mRFP and its mutants. At least 10 pollen tubes were observed for each bombardment experiment. Bars = 10 μm.

(C) Pollen tube growth promotion effect of STIG1 and its mutants. Equal amounts of recombinant protein (250 nM each) were used. n = 3 independent experiments. Asterisks indicate significant differences from wild-type STIG1 (P < 0.05, Student’s t test). Error bars indicate se.

(D) Summary of the abilities of STIG1variants for LePRK2 interaction, phosphoinositide binding, and pollen tube growth promotive activities compared with wild-type STIG1. Yes, similar activity to LeSTIG1; No, no activity detected; blank, not tested; Y2H, yeast two-hybrid assay.