Plant & Animal Genomes XIII Conference Plant & Animal Genomes XIII ConferenceJanuary 15-19, 2005
Town & Country Convention Center
San Diego, CA
Plant-specific zinc finger homeodomain proteins (ZF-HD) were recently recognized (Windhovel et al., 2001). They possess a putative zinc finger for protein-protein interaction at N termini and a C-terminal homeodomain distantly related to classic homeodomains. The evolutionary history and function of this family remain largely unknown. Our study shows that ZF-HD proteins widely exist in all major plant groups. The origin of this family can be traced back to non-vascular plant Physcomitrella, but not found in unicellular green algae Chlamydomonas. Complete genomes of Arabidopsis, rice and popular indicate that one species could have 10~20 genes of this family. Depending on the presence or not of homeodomain, this family can be divided into ZF-HD subfamily and zinc-finger-only (ZFO) subfamily. ZF-HD subfamily can be further divided into 2 subgroups based on the amino acid sequences within the zinc finger domain. We have initiated functional studies of ZF-HD family in the model plant Arabidopsis. Sequence analysis and expression pattern suggest functional redundancy/overlapping among homologs, which is partially supported by the fact that no obvious phenotypes have been found from single T-DNA mutants examined. However, overexpression of one of the three ZFO genes in Arabidopsis genome resulted in severe defects of plant growth and development. Phenotypic analyses and whole-genome microarray profiling suggested that multiple pathways of phytohormone signaling were blocked or inhibited in the transgenic plants. We have more and more evidence to believe that ZFO genes play important regulatory roles. We will present recent results in the meeting.