Evolutionary Pattern of Angiosperm bZIP Factors Homologous to the Maize Opaque2 Regulatory Protein

Abstract

Opaque2 (O2) is a bZIP transcriptional regulatory factor involved in the control of seed storage proteins synthesis as well as carbon and nitrogen metabolism during maize seed development. Phylogenetic analysis of a possible complete and nonredundant collection of angiosperm bZIP factors resulted in the identification of 20 angiosperm O2-homologues that defined what we call the O2 gene family. Members of the family share a highly conserved bZIP DNA binding domain and several other motifs which define important functional features. The O2 family was enriched by the identification of 25 new putative angiosperm O2 homologous genes in EST databases and in the rice genome. Based on parsimony analysis, the collection of O2 homologues was organized into one eudicot-monocot and three monocot groups of orthologous genes and two groups of eudicot genes. These results support a model of the evolution of the O2 family that involves two O2 homologous gene duplications before the separation of monocots and eudicots. Further expansion of O2 homologues resulted in at least three and one gene duplications in the monocot and eudicot lineages, respectively. O2 appears to have been the result of a monocot-specific gene duplication event, and the possibility that O2 represents a functional specialization restricted to monocots is suggested.

Green Transcription Factors: A Chlamydomonas Overview

“…A PoGO is defined by the following criteria: (i) members of a PoGO have a monophyletic origin, indicated by a bootstrap support of .50%; (ii) a PoGO conserved in all green plants possesses at least one representative gene of each of the main lineages analyzed here, including algae, bryophytes, and angiosperms, assuming that the putative complete sets of TF genes of these organisms were identified and no selective gene loss had occurred; (iii) the inferred phylogeny is consistent with the known phylogeny of plant species (Vincentz et al 2003).…”

Redox-mediated Mechanisms Regulate DNA Binding Activity of the G-group of Basic Region Leucine Zipper (bZIP) Transcription Factors in Arabidopsis

“…The A. thaliana genome encodes at least 75 predicted bZIP transcription factors (36,45,46), which are clustered into 10 subgroups (A-I and S) (36). Plant bZIP transcription factors have been shown to bind the G-box, C-box, and A-box elements, all containing the functional ACGT core (47).…”

bZIP transcription factor OsbZIP52/RISBZ5: a potential negative regulator of cold and drought stress response in rice

“…The distinguishing structural feature of Group C bZIPs present in maize Opaque2 and its orthologs (e.g., OHP1, OHP2, BLZ2, SPA, and others) is a sequence that recognizes the GCN4 motif and is also involved in the coordinated regulation of protein synthesis and nitrogen and sugar metabolism of seeds during seed development and maturation (Schmidt et al 1992;Pysh and Schmidt 1996;Onate et al 1999;Vincentz et al 2003;Locatelli et al 2009). Group C bZIP genes also participate in abiotic stress signaling, including G/HBF1 (Glycine max), which plays a putative role in the activation of early transcription-dependent defenses (Droge-Laser et al 1997).…”