Cloning And Functional Analysis Of Transcription Factor Genes ABS5, ABS7and GTPase Family Gene SVR10in Aarabiodpsis Thaliana

Leaf blade is the chief organ in the plant, which is the key factor for plant photosynthesis.Here, we screen two curly leaf mutant abs5-1D and abs7-1D for studying leaf shapedevelopment. Otherwise, for research the chloroplast devlopment, we get another the leafvirescent mutant svr10-1.The main results are as follows:（1）abs5-1D and abs7-1D was isolated through activation tagging method, and thetargeted genes were identified by plasmid rescue. We constructed the overexpression line ofABS5and ABS7to confirm the function of ABS5and ABS7respectively, in which increasedexpression of ABS5or ABS7result in the leaf curl.（2）ABS5was annotated to encode the bHLH transcription factor bHLH30. ABS7encode MYB transcription factor MYB101. RT-PCR test indicated that ABS5mainly wasexpressed in root and stem. The subcellular localization analysis showed that ABS5andABS7was targeted to the nucleus. Otherwise, ABS7protein has ranscriptional activationactivity in yeast, while ABS5has not.（3）The cotyledon vein was more active in abs5-1D background than WT. Meantimes,the signal of auxin response element DR5::GUS in ABS5overexpression line is present in themargin of leaf.（4）There was no phenotype discrepancy between abs5-1or abs7-1(loss of functionmutant) and WT.（5）Under the control of epidermis specifical promoter pML1, the expresssion of ABS5or ABS7resulted in curling leaf. This result indicated the epidermis cell played importantrole in leaf morphology development（6）we isoalted the another leaf virescent mutant svr10-1from the mutant pool, the geneSVR10had been cloned by map based clone.（7）Genetic analysis proved that the svr10-1was epistasis to the variegated phenotypeof var2（8）Sequence analysis shows the SVR10belongs to the GTPase family which contains5GTP binding domains. （9）After the isolation of the svr10-1/P35S::SVR10-Flag chloroplast, western blotmanifested in the anti-flag signal in the plastid stroma. BN-PAGE gel showed thechloroplast protein supercomplex is changed in svr10-1.（10）The number of0areoles cotyledon vein in svr10-1or bpg2-2was significantlyincreased. This result showed that the development of svr10-1and bpg2-2cotyledon vein wasdelayed.