Molecular Cloning and Characterization of Rice Pollen Profilin

Profilin is a low molecular weight protein and is identified as an actin-binding protein in higher plants. Two pollen-specific cDNA clones of rice, RproA and RproB, were isolated from a cDNA library of rice mature pollen. The two cDNA clones was 821 bp and 805 bp long and contained an open reading frame of 131 amino acids, 5' and 3' untranslated regions and a long poly(A) tail. The comparison of deduced amino acid sequences from RproA and RproB cDNA and other plant profilin cDNA indicated that the two rice profilin are high homologous to each other, showed that 89% similarity to maize (ZmPRO3), 87% to C. dactylon, 83% to H.brasiliensis and 89% to P. pratense. Genomic southernblot analysis suggested the existence of two genes at least. Northern blot and reverse transcriptase polymerase chain reaction analysis demonstrated that the two rice profilin cDNA are anther or pollen specific.