Dirigent (DIR) proteins were found to mediate regio- and stereoselectivity of bimolecular phenoxy radical coupling during lignan biosynthesis. Here we summarize the current knowledge of the importance of DIR proteins in lignan and lignin biosynthesis and highlight their possible importance in plant development. We focus on the still rather enigmatic Arabidopsis DIR gene family, discussing the few members with known functional importance. We comment on recent discoveries describing the detailed structure of two DIR proteins with implications in the mechanism of DIR-mediated catalysis. Further, we summarize the ample evidence for stress-induced dirigent gene expression, suggesting the role of DIRs in adaptive responses. In the second part of our work, we present a preliminary bioinformatics-based characterization of the AtDIR family. The phylogenetic analysis of AtDIRs complemented by comparison with DIR proteins of mostly known function from other species allowed us to suggest possible roles for several members of this family and identify interesting AtDIR targets for further study. Finally, based on the available metadata and our in silico analysis of AtDIR promoters, we hypothesize about the existence of specific transcriptional controls for individual AtDIR genes and implicate them in various stress responses, hormonal regulations, and developmental processes.

Department of Biology Norwegian University of Science and Technology 5 Hogskoleringen N 7491 Trondheim Norway

Glycobiochemistry CEITEC Central European Institute of Technology and National Centre for Biomolecular Research Masaryk University Kamenice 5 CZ 625 00 Brno Czech Republic

Laboratory of Molecular Plant Physiology and Functional Genomics and Proteomics of Plants CEITEC Central European Institute of Technology and National Centre for Biomolecular Research Masaryk University Kamenice 5 CZ 625 00 Brno Czech Republic

Laboratory of Molecular Plant Physiology and Functional Genomics and Proteomics of Plants CEITEC Central European Institute of Technology and National Centre for Biomolecular Research Masaryk University Kamenice 5 CZ 625 00 Brno Czech Republic Research Centre for Toxic Compounds in the Environment Masaryk University Kamenice 5 CZ 625 00 Brno Czech Republic

Research Centre for Toxic Compounds in the Environment Masaryk University Kamenice 5 CZ 625 00 Brno Czech Republic

Citace poskytuje Crossref.org