Overexpressing rice lesion simulating disease 1-like gene (OsLOL1) in Gossypium hirsutum promotes somatic embryogenesis and plant regeneration

Abstract

Background: Cotton somatic embryogenesis is difficult or rarely frequent to present, which has limited gene function identification and biotechnological utility. Here, we employed a rice key somatic embryogenesis-related gene, rice lesion simulating disease 1-like gene (OsLOL1), to develop transgenic cotton callus for evaluating its function in ectopic plants. Results: Overexpressing OsLOL1 can promote cotton callus to form embryogenic callus, not only shortening time but also increasing transition of somatic callus cells to embryogenic callus cells. And the regenerating plantlets per transgenic OsLOL1 embryogenic callus were significantly higher than those in the control transformed with empty vector. Analysis of physiological and biochemical showed that OsLOL1 can repress cotton superoxide dismutase 1 gene (GhSOD1) expression, possibly resulting in reactive oxidant species (ROS) accumulation in transgenic callus cells. And OsLOL1-overexpressed embryogenic callus exhibited higher α-amylase activity compared with the control, resulting from the promotion of OsLOL1 to cotton amylase 7 gene (GhAmy7) and GhAmy8 expression. Conclusion: The data showed that OsLOL1 could be used as a candidate gene to transform cotton to increase its somatic embryogenesis capacity, facilitating gene function analysis and molecular breeding in cotton.