Cloning and expression analysis of CaPEX3 in pepper

Abstract [Objective] PEX (pollen extensin-like) gene is involved in controlling pollen development, which plays a crucial role in embryogenesis of pollen microspores and haploid culture. In this study, the authors isolated the CaPEX3 gene from pepper and analyzed its protein structure and expression pattern, which provides a theoretical foundation for further investigation into the function of the CaPEX3 gene. [Methods] CaPEX3 was cloned by PCR, and its protein structure, evolution, and gene regulation were analyzed by bioinformatics. Expression of CaPEX3 in different tissues and pollen of different varieties were detected by qRT-PCR. Pollen viability of different pepper varieties was detected by staining method and their relationship with CaPEX3 expression was analyzed. [Results] The coding region of CaPEX3 was 1 581 bp in length, encoding 526 amino acids, which belongs to the LRX (leucine-rich repeats/extensins) gene family. The protein had phosphorylation and glycosylation sites, signaling peptides, and transmembrane domains. The expression level of CaPEX3 was the highest in flowers, and the gene expression was higher in tissues with high pollen vitality. The regulatory network predicted that CaPEX3 might be involved in the regulation of pollen development through the action of genes related to flower development. [Conclusion] CaPEX3 was specifically expressed in flowers, and a correlation was observed between its expression level and the activity of pollen grains. The analysis of gene expression and the construction of related vectors provided a theoretical foundation and technical support for the subsequent investigation of gene function and mechanism of CaPEX3