ABSTRACT
Arabidopsis trichomes are large branched single cells that protrude from the epidermis. The first morphological indication of trichome development is an increase in nuclear content resulting from an initial cycle of endoreduplication. Our previous study has shown that the C2H2 zinc finger protein GLABROUS INFLORESCENCE STEMS (GIS) is required for trichome initiation in the inflorescence organ and for trichome branching in response to gibberellic acid signaling, although GIS gene does not play a direct role in regulating trichome cell division. Here, we describe a novel role of GIS, controlling trichome cell division indirectly by interacting genetically with a key endoreduplication regulator SIAMESE (SIM). Our molecular and genetic studies have shown that GIS might indireclty control cell division and trichome branching by acting downstream of SIM. A loss of function mutation of SIM signficantly reduced the expression of GIS. Futhermore, the overexpression of GIS rescued the trichome cluster cell phenotypes of sim mutant. The gain or loss of function of GIS had no significant effect on the expression of SIM. These results suggest that GIS may play an indirect role in regulating trichome cell division by genetically interacting with SIM.
Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Cell Cycle Proteins/metabolism , Transcription Factors/metabolism , Trichomes/growth & development , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Cell Division , Cloning, Molecular , Gene Expression Regulation, Plant , Genotype , Gibberellins/metabolism , Inflorescence/genetics , Microscopy, Electron, Scanning , Mutation , Phenotype , RNA, Plant/metabolism , Real-Time Polymerase Chain Reaction , Signal Transduction , Transcription Factors/genetics , Zinc FingersABSTRACT
OBJECTIVE: To observe the effect on energy metabolism of rats with cold property Chinese medicine Radix Scutellariae. METHODS: The body weight gain, temperature, hydroposia content were determined before administration and every five days after administration. The activities of Na4(+)-K(+)-ATPase, Ca(2+)-ATPase and SDH, LPL, HP, the contents of NEAF, T3, T4, TSH were measured after having been administrated with water extracts of Radix Scutullaxiae at the dose of 6.0, 3.0 g/kg for 43 days. RESULTS: The body weight gains were raised and the hydroposia contents have been decreased. The activities of SDH were increased significantly while Na(+)-K(+)-ATPase, Ca(2+)-ATPase of liver had little change. The content of NEAF, the activity of LPL, HP were decreased significantly, and the contents of T3, T4, TSH and the body weight, temperature had no significant change. CONCLUSION: Radix Scutellariae can inhibit the energy metabolism of rat. The mechanism may not be related to thyroxine pathway.
