Mechanism for target specificity in transcriptional regulation during Arabidopsis anther development
Transcriptional regulation is essential for plant development and other processes; many genetically identified developmental genes are known or thought to encode transcription factors. However, the mechanisms that allow these transcription factors to regulate their target genes with high degrees of specificity are largely unclear. Molecular genetic studies in our lab and by others have identified a number of key regulators for proper anther and pollen development, including receptor-like protein kinases (EMS1, BAM1/2 and others) and transcription factors (e.g., DYT1, AMS, MYB35 and MS1). In addition, transcriptomic analyses revealed that ~1500 genes are preferentially expressed in early anthers near the time of meiosis, when anther cell layers are formed. The specific gene expression patterns suggest that normal anther development requires the function of transcriptional regulators, including those identified by genetic studies. However, little is known about the molecular mechanisms by which the transcriptional factors regulate their targets, including target specificity. Our analyses of DYT1 and other functionally related factors provide strong support for multiple mechanisms that contribute to target specificity, including feed-back and feed-forward molecular genetic interactions, protein-protein physical interactions that affect temporally regulated nuclear localization, and combinatorial binding to promoter sequences. These mechanisms allow DYT1 and its interacting proteins to regulate different targets at different stages of anther/taputem development, contributing to complex transcriptional networks that ensure normal anther transcriptome and development. These results provide new insights into the control of male fertility, and the presence of their homologs in many other plants suggest that they are generally important for plant fitness and crop yield.
Host: Zhiyong Wang
zwang@carnegiescience.edu
Please join us for a reception following the seminar