A pollen-specific calmodulin-binding protein from rice is essential to pollen development

摘要

A pollen-expressed gene of rice that encodes a novel calmodulin (CaM)-binding protein named OsPCBP was previously identified. The role of QsPCBP in pollen germination and tube growth has been determined. To further investigate the function of OsPCBP in pollen development, we generated transgenic plants using RNA interference (RNAi) approach. Analysis of the OsPCBP–RNAi plants found that each produced approximately equal amounts of normal and aborted pollen. Microscopic examination of the microspores at different stages of anther development revealed that microspores of the OsPCBP–RNAi plants developed normally until the binucleate stage. However, about half of the microspores were aborted at subsequent stages. RT-PCR and protein gel blot analysis of the aborted pollen grains showed that the deletion of OsPCBP was correlated with pollen abortion phenotype. Our experimental results provide convincing evidence that OsPCBP plays an important role in pollen development, especially for the later stage of pollen development.