Blocked pollen release prevents fruit formation in the halophyte Elaeagnus angustifolia in non-saline habitats

•Halophyte Elaeagnus angustifolia can’t bear fruits in non-saline soils.•Pollen viability and stigma receptivity were also high in non-saline soils.•No pollen tubes presented in styles after nature pollination in non-saline soils.•Pollen tubes formed in styles after hand pollination in non-saline soils.•No fruits in non-saline soils due to expressional level changes of related genes. Anther development affects the reproduction of flowering plants. Halophyte Elaeagnus angustifolia can bear fruits when grown in saline soils. However, no fruits are born in non-saline soils. The possible reasons and differences in E. angustifolia under two growing conditions were elucidated. We examined features including pollen viability and germination, in situ pollen germination after natural and hand pollination, anthers after pollen release, and the transcriptome in anthers. No significant difference was observed in pollen viability or stigma receptivity in E. angustifolia in non-saline vs. saline habitats. However, no pollen tubes were present in styles, and pollen grains were abundant in E. angustifolia anthers under non-saline conditions. Notably, many pollen tubes formed in styles of E. angustifolia after hand pollination in the non-saline habitat. The differentially expressed genes in anthers from saline vs. non-saline habitats were mainly related to phytohormone, cell wall secondary thickening, transcription factors and ion transport. E. angustifolia fail to form fruits in non-saline habitats due to poor anther pollen release. The induction and coordinated upregulation of genes related to anther cell wall formation and JA biosynthesis likely contribute to anther dehiscence in E. angustifolia in saline habitats, whereas anther dehiscence is blocked in plants grown in non-saline habitats.