Abstract: The present disclosure describes a novel calmodulin-binding protein, termed NPG1 (No Pollen Germination1) of plants that is specifically expressed in pollen, and the nucleic acid coding sequence, and genomic DNA fragments containing pollen-specific transcriptional and translational regulatory elements. Genetic, histological, and pollen germination studies with the Arabidopsis mutant line for the NPG1 gene indicate that NPG1 is essential for pollen germination. Therefore, this invention provides new means to generate a transgenic plant that is male sterile by modulating expression of the NPG1 gene or interfering with the function of the NPG1 polypeptide. The availability of the tissue specific regulatory elements of the NPG1 gene makes it possible for the pollen-specific expression of various genes of interest.