Characterization of a pollen-specific agp1-like protein in Arabidopsis thaliana

Article history: Received on: 16/05/2016 Revised on: 10/06/2016 Accepted on: 20/06/2016 Available online: 05/11/2016 In plants, pollen tube germination occurs widely in flowering plants. In Arabidopsis thaliana, it has been reported ARABINOGALACTAN PROTEIN 1 (AGP1) plays an important role in pollen tube germination. The expression of arabinogalactan protein in Arabidopsis pollen tubes has been extensively studied. Herein, we characterized an Arabidopsis AGP1-LIKE PROTEIN (ALP), which is shown to have 47% homology at the amino acid level to At1g24520.1 (BCP1), POLLEN PROTEIN1 in Brassica campestris. BCP1, which is highly expressed in both tapetum and microspores, is essential for pollen fertility. Transgenic Arabidopsis transformed with an ALP promoter-driven β-glucuronidase (GUS) construct exhibited strong GUS activity in the pollen and young siliques, in good agreement with the RT-qPCR analysis. To further understand the function of ALP, the ALP-RNAi lines were generated for further investigations. Phenotypic deficiency of siliques was observed in the ALP-RNAi line, in comparison to the wild type. Furthermore, scanning electron microscopy suggested defects in the ALP-RNAi line and in vivo pollen germination showed reduced ability in the ALP-RNAi line. Taken together, our results suggested the important role of ALP in pollen and seed development.