Evolutionary and Expression Analyses of the Apple Basic Leucine Zipper Transcription Factor Family

Abstract

Transcription factors (TFs) play essential roles in the regulatory networks controlling many developmental processes in plants. Members of the basic leucine (Leu) zipper (bZIP) TF family, which is unique to eukaryotes, are involved in regulating diverse processes, including flower and vascular development, seed maturation, stress signaling, and defense responses to pathogens. The bZIP proteins have a characteristic bZIP domain composed of a DNA-binding basic region and a Leu zipper dimerization region. In this study, we identified 112 apple (Malus domestica Borkh) bZIP TF-encoding genes, termed MdbZIP genes. Synteny analysis indicated that segmental and tandem duplication events, as well as whole genome duplication, have contributed to the expansion of the apple bZIP family. The family could be divided into 11 groups based on structural features of the encoded proteins, as well as on the phylogenetic relationship of the apple bZIP proteins to those of the model plant Arabidopsis thaliana (AtbZIP genes). Synteny analysis revealed that several paired MdbZIP genes and AtbZIP gene homologs were located in syntenic genomic regions. Furthermore, expression analyses of group A MdbZIP genes showed distinct expression levels in 10 different organs. Moreover, changes in these expression profiles in response to abiotic stress conditions and various hormone treatments identified MdbZIP genes that were responsive to high salinity and drought, as well as to different phytohormones.

Genome-Wide Identification ofbZIPFamily Genes Involved in Drought and Heat Stresses in Strawberry (Fragaria vesca)

“…However, mrna14556 expression was not detected in any organ, even in response to drought or heat. A similar observation was made in grape, apple, and sorghum with some bZIP genes [65, 68, 69], and we speculate that those genes may be degenerated into a nonfunctional gene, or it is involved in other processes that were not investigated here, such as other abiotic and biotic stresses [68, 69], or they may be expressed at other organs and time points after treatment [65]. This can be supported by the fact that the bZIP ABF genes, ABF1 and ABF4 , are induced by cold as well as ABF2 and ABF3 expression are induced by high salt in vegetative tissues [26, 53].…”

“…MdbZIP26 was abundantly expressed in roots, stems, and apical buds [65]. OsABF2 showed expression in different tissues of rice and induction of drought, salinity, cold, and ABA.…”

Bioinformatic Analyses of Subgroup-A Members of the Wheat bZIP Transcription Factor Family and Functional Identification of TabZIP174 Involved in Drought Stress Response

“…Members of the bZIP transcription factor family were comprehensively identified or predicted in some plant genomes, such as Arabidopsis , rice, soybean, sorghum, maize, cucumber, grapevine, castor bean, Brachypodium distachyon , tomato, wheat, Triticum urartu, Aegilops tauschii , barley, and apple (Jakoby et al, 2002; Liao et al, 2008; Nijhawan et al, 2008; Wang et al, 2011; Wei et al, 2012; Baloglu et al, 2014; Jin et al, 2014; Liu et al, 2014; Li D. et al, 2015; Li X. et al, 2015; Liu and Chu, 2015; Zhao et al, 2016). bZIP family members were classified into 14 subgroups (Jakoby et al, 2002; Li X. et al, 2015).…”

Stress-Mediated cis-Element Transcription Factor Interactions Interconnecting Primary and Specialized Metabolism in planta

“…The bZIP family (basic leucine zipper) is one of the largest TF families in plants, which is involved in diverse regulatory functions, like abiotic and biotic stress tolerance, hormone signaled gene regulation, sugar signaling, nitrogen, carbon and energy metabolism, light responsiveness and developmental regulation (like cell elongation, differentiation, flowering, senescence and maturation of seedlings, Chuang et al, 1999; Wei et al, 2012; Bastías et al, 2014; Llorca et al, 2014; Zhao et al, 2016). The bZIP TFs have a widespread presence among eukaryotes (17 in S. cerevisiae , 27 in Drosophila, 75 in A. thaliana , 89 in rice, 125 in maize, 131 in soybean, 69 in tomato and 585 among six leguminous plants: G. max, M. truncatula, P. vulgaris, C. arietinum, C. cajan , and L. japonicus , Fassler et al, 2002; Wei et al, 2012; Llorca et al, 2014; Li D. et al, 2015; Wang et al, 2015).…”