A functional characterization of TaMs1 orthologs in Poaceae plants

TaMs1 encodes a non-specific lipid transfer protein (nsLTP) and is required for pollen development in wheat. Although MS1 is a Poaceae-specific gene, the roles of MS1 genes in other Poaceae plants are unknown, especially in rice and maize. Here, we identified one ortholog in rice (OsLTPg29) and two orthologs in maize (ZmLTPg11 and ZmLTPx2). Similar to TaMs1, both OsLTPg29 and ZmLTPg11 genes are specifically expressed in the microsporocytes, and both OsLTPg29 and ZmLTPg11 proteins showed lipid-binding ability to phosphatidic acid and several phosphoinositides. To determine their roles in pollen development, we created osltpg29 mutants and zmItpg11zmltpx2 double mutants by CRISPR/Cas9. osltpg29, not zmltpg11zmltpx2, is defective in pollen development, and only OsLTPg29, not ZmLTPg11, can rescue the male sterility of tams] mutant. Our results demonstrate that the biological function of MS1 in pollen development differs in the evolution of Poaceae plants. (C) 2021 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.

Automated summary

TaMs1 encodes a non-specific lipid transfer protein essential for pollen development in wheat. Orthologs of TaMs1 in rice and maize, OsLTPg29 and ZmLTPg11, play similar roles in microsporocytes, but only OsLTPg29 can rescue male sterility in wheat mutants.