摘要
Phosphatidylserine （PS）, a quantitatively minor membrane phospholipid, is involved in many biological processes besides its role in membrane structure. One PS synthesis gene, PHOSPHATIDYLSERINE SYNTHASE1 （PSSl）, has been discovered to be required for microspore development in Arabidopsis thaliana L. but how PSS1 affects postembryonic development is still largely unknown. Here, we show that PSSl is also required for inflorescence meristem and organ development in Arabidopsis. Disruption of PSSI causes severe dwarfism, smaller lateral organs and reduced size of inflorescence meristem. Morphological and molecular studies suggest that both cell division and cell elongation are affected in the pssl-1 mutant. RNA in situ hybridization and promoter GUS analysis show that expression of both WUSCHEL （WUS） and CLA VA TA3 （CL V3） depend on PSS1. Moreover, the defect in meristem maintenance is recovered and the expression of WUS and CLV3 are restored in the pssl-1 clvl-1 double mutant. Both SHOOTSTEMLESS （STM） and BREVIPEDICELLUS （BP） are upregulated, and auxin distribution is disrupted in rosette leaves of pssl-1. However, expression of BP, which is also a regulator of internode development, is lost in the pssl-1 inflorescence stem. Our data suggest that PSS1 plays essential roles in inflorescence meristem maintenance through the WUS-CLV pathway, and in leaf and internode development by differentially regulating the class I KNOX genes.
Phosphatidylserine （PS）, a quantitatively minor membrane phospholipid, is involved in many biological processes besides its role in membrane structure. One PS synthesis gene, PHOSPHATIDYLSERINE SYNTHASE1 （PSSl）, has been discovered to be required for microspore development in Arabidopsis thaliana L. but how PSS1 affects postembryonic development is still largely unknown. Here, we show that PSSl is also required for inflorescence meristem and organ development in Arabidopsis. Disruption of PSSI causes severe dwarfism, smaller lateral organs and reduced size of inflorescence meristem. Morphological and molecular studies suggest that both cell division and cell elongation are affected in the pssl-1 mutant. RNA in situ hybridization and promoter GUS analysis show that expression of both WUSCHEL （WUS） and CLA VA TA3 （CL V3） depend on PSS1. Moreover, the defect in meristem maintenance is recovered and the expression of WUS and CLV3 are restored in the pssl-1 clvl-1 double mutant. Both SHOOTSTEMLESS （STM） and BREVIPEDICELLUS （BP） are upregulated, and auxin distribution is disrupted in rosette leaves of pssl-1. However, expression of BP, which is also a regulator of internode development, is lost in the pssl-1 inflorescence stem. Our data suggest that PSS1 plays essential roles in inflorescence meristem maintenance through the WUS-CLV pathway, and in leaf and internode development by differentially regulating the class I KNOX genes.
基金
supported by the National Natural Science Foundation of China(Grant numbers 90717106 and 30821004 to D.L.
