Submitted to: Plant Molecular Biology Reporter
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/9/2011
Publication Date: 5/31/2011
Citation: Dinkins, R.D., Tavva, V.S., Palli, S.R., Collins, G.B. 2011. Mutant and overexpression analysis of a C2H2 single zinc finger gene of Arabidopsis. Plant Molecular Biology Reporter. 30:99-110. Interpretive Summary: The zinc finger protein gene family is one of the largest groups of transcription factors in eukaryotes, and its members play a wide and important role in growth and development. Plants contain a large number of unique single zinc finger proteins that have no known function. Two of the best characterized single zinc finger proteins are SUPERMAN (SUP) and RABBIT EARS (RBE) that display a range of abnormalities during flowering, although the molecular basis for the mutant phenotypes remains unknowns. The goal of this work was to characterize additional single zinc finger genes in Arabidopsis that are the most similar to SUP and RBE, and one, labeled as AtZFP11 was selected for further analysis. Several lines containing mutations in this gene were isolated, however no differences from wild type plants were observed in any of the lines analyzed. This result suggests that AtZFP11 may function redundantly with other proteins or factors that mask the effects of these mutations. Transgenic plants over-expressing these single zinc finger proteins display severe abnormalities, are sterile, suggesting that over expression of this proteins is detrimental. In order to isolate viable plants over-expressing the AtZFP11 gene, AtZFP11 was placed under control of an inducible promoter. This allowed for the recovery of normal plants that displayed the abnormal phenotype when induced. Utilizing these inducible AtZFP11 plants a whole genome expression analysis was conducted allowing for the identification of a number of genes that are induced or repressed when AtZFP11 is over-expressed.
Technical Abstract: The goal of this work was to characterize an Arabidopsis C2H2 single zinc finger gene, named AtZFP11, that is similar to SUPERMAN (SUP) and RABBIT EARS (RBE). No altered phenotype was observed in mutants analyzed that were derived through TILLING, nor a T-DNA insertion into the exon of AtZFP11. Plants derived by intercrossing AtZFP11 to SUP and RBE alleles did not display any phenotype that could be attributed to AtZFP11. Transgenic plants constitutively over-expressing the AtZFP11 protein displayed severe abnormalities. Phenotypically normal transgenic plants that contained an ecdysone inducible promoter system fused to the AtZFP11 gene were recovered. These transgenic plants displayed similar abnormalities once induced with methoxyfenozide. Microarray and RT-PCR analysis of gene expression in plants over-expressing AtZFP11 after induction revealed changes in gene expression of a number of genes involved in auxin, jasmonic acid and stress responses. These results suggest that AtZFP11 plays a role in regulation of gene expression and may be functionally redundant, or that conditions needed to observe phenotypic differences in the mutant plants was not provided in the course of these experiments.