Basic leucine zipper (bZIP) transcription factors involved in abiotic stresses: A molecular model of a wheat bZIP factor and implications of its structure in function

Abstract

Background: Basic leucine zipper (bZIP) genes encode transcription factors (TFs) that control important biochemical and physiological processes in plants and all other eukaryotic organisms.

Scope of review: Here we present (i) the homo-dimeric structural model of bZIP consisting of basic leucine zipper and DNA binding regions, in complex with the synthetic Abscisic Acid-Responsive Element (ABREsyn); (ii) discuss homo- and hetero-dimerisation patterns of bZIP TFs; (iii) summarise the current progress in understanding the molecular mechanisms of function of bZIP TFs, including features determining the specificity of their binding to DNA cis-elements, and (iv) review information on interaction partners of bZIPs during plant development and stress response, as well as on types and roles of post-translational modifications, and regulatory aspects of protein-degradation mediated turn-over. Finally, we (v) recapitulate on the recent advances regarding functional roles of bZIP factors in major agricultural crops, and discuss the potential significance of bZIP-based genetic engineering in improving crop yield and tolerance to abiotic stresses.

Major conclusions: An accurate analysis and understanding of roles of plant bZIP TFs in different biological processes requires the knowledge of interacting partners, time and location of expression in plant organs, and the information on mechanisms of homo- and hetero-dimerisation of bZIP TFs.

General significance: Studies on molecular mechanisms of plant bZIP TFs at the atomic levels will provide novel insights into the regulatory processes during plant development, and responses to abiotic and biotic stresses.

Keywords: 14–3-3 proteins; Abiotic stress; DNA binding; Genetic engineering; Homo- and hetero-dimerisation; Kinases; Phytohormones; Plant development; Protein-protein interactions.