Additional file 13: Figure S8. of Quantitative proteomics of the tobacco pollen tube secretome identifies novel pollen tube guidance proteins important for fertilization

Pairwise alignment of Arabidopsis and tobacco TCTP proteins and expression profile of LAT52 and PRK2/4 receptor kinases. a Amino acid conservation between the Arabidopsis and N. tabacum TCTP protein. Blue highlighting indicates mismatches. b A hydropathy plot of NtTCTP hydrophobicity prediction based on the Kyte Doolitle method showing GRAVY score (red line) and overall hydrophobic nature of NtTCTP. c In vitro pollen tube growth assay of +/Attctp-1 tetrad pollen showing normal pollen tube germination. d Aniline blue staining of self-fertilized +/Attctp-1 pistils 18 h after pollination, independently verifying normal pollen tube growth in planta. e Pairwise alignment of pollen tube-secreted L. barbarum LAT52-like and S. lycopersicum LAT52 proteins. Alignment showing the predicted 23 amino acid N-terminal signal peptide (blue highlighting), the conserved eight cysteine residues (boxed), and N-glycosylation sites (grey highlighting). f Expression profiles of pollen receptor kinase 2 (PRK2) and pollen receptor kinase 4 (PRK4) derived from Agilent 44 K Tobacco Genome Array [19] and Arabidopsis Affymetrix ATH1 microarray [53] data. g Semi-RT-PCR verification of PRK2 and PRK4 expression in tobacco mature pollen (MP), 4 h (PT4) and 24 h (PT24) in vitro pollen tubes, leaves (LF), roots (RT), SIV pollen tubes, and unfertilized ovules. h Topology of the receptor modules, PRK2 and PRK4, and the ligand module LAT52. We speculate that detection of both modules after 24 h of pollen tube growth implies a later function of the complex leading to successful fertilization. (TIF 953 kb)