Cloning and characterization of a maize bZIP transcription factor, ZmbZIP72, confers drought and salt tolerance in transgenic Arabidopsis. Planta
ABSTRACT In plants, the bZIP (basic leucine zipper) transcription factors regulate diverse functions, including processes such as plant development and stress response. However, few have been functionally characterized in maize (Zea mays). In this study, we cloned ZmbZIP72, a bZIP transcription factor gene from maize, which had only one copy in the maize genome and harbored three introns. Analysis of the amino acid sequence of ZmbZIP72 revealed a highly conserved bZIP DNA-binding domain in its C-terminal region, and four conserved sequences distributed in N- or C-terminal region. The ZmbZIP72 gene expressed differentially in various organs of maize plants and was induced by abscisic acid, high salinity, and drought treatment in seedlings. Subcellular localization analysis in onion epidermal cells indicated that ZmbZIP72 was a nuclear protein. Transactivation assay in yeast demonstrated that ZmbZIP72 functioned as a transcriptional activator and its N terminus (amino acids 23-63) was necessary for the transactivation activity. Heterologous overexpression of ZmbZIP72 improved drought and partial salt tolerance of transgenic Arabidopsis plants, as determined by physiological analyses of leaf water loss, electrolyte leakage, proline content, and survival rate under stress. In addition, the seeds of ZmbZIP72-overexpressing transgenic plants were hypersensitive to ABA and osmotic stress. Moreover, overexpression of ZmbZIP72 enhanced the expression of ABA-inducible genes such as RD29B, RAB18, and HIS1-3. These results suggest that the ZmbZIP72 protein functions as an ABA-dependent transcription factor in positive modulation of abiotic stress tolerance and may be a candidate gene with potential application in molecular breeding to enhance stress tolerance in crops.
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- "The basic region leucine zipper (bZIP) family of TFs is exclusively present in eukaryotes and regulates diverse functions such as plant development and stress responses (Deppmann et al., 2004; Ying et al., 2012). This family of TFs is characterized by a 40–80 amino acid long conserved bZIP domain, hence its name (Correa et al., 2008; Nijhawan et al., 2008). "
ABSTRACT: Drought is one of the major constraints in crop production and has an effect on a global scale. In order to improve crop production, it is necessary to understand how plants respond to stress. A good understanding of regulatory mechanisms involved in plant responses during drought will enable researchers to explore and manipulate key regulatory points in order to enhance stress tolerance in crops. Transcription factors (TFs) have played an important role in crop improvement from the dawn of agriculture. TFs are, therefore, good candidates for genetic engineering to improve crop tolerance to drought because of their role as master regulators. TFs are major components in regulatory pathways and may control clusters of genes that make them ideal candidates to regulate traits that were controlled by multiple genes such as drought. Many families of TFs, such as CCAAT, homeodomain, bHLH, NAC, AP2/ERF, bZIP and WRKY have members that may have the potential to be tools for improving crop tolerance to drought. In this review, the roles of TFs as tools to improve drought tolerance in crops are discussed. The review also focuses on current strategies in the use of TFs with emphasis on several major TF families in improving drought tolerance of major crops. Finally, many promising transgenic lines that may have improved drought responses have been poorly characterized, and consequently their usefulness in the field is uncertain. New advances in high-throughput phenotyping, both greenhouse and field based, should facilitate improved phenomics of transgenic lines. Systems biology approaches should then define the underlying changes that result in higher yields under water stress conditions. These new technologies should help show whether manipulating TFs can have effects on yield under field conditions.Omics A Journal of Integrative Biology 07/2014; 18(10). DOI:10.1089/omi.2013.0177 · 2.73 Impact Factor
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- "To adapt to abiotic stresses, plants must modulate various physiological and metabolic responses, such as stomatal closure, repression of cell growth and photosynthesis, and activation of respiration (Hull et al. 1990; Miedema 1982; Zorb et al. 2004). Various abiotic stresses have been shown to induce many different functional genes, including the bZIP transcription factors (Jia et al. 2009; Ying et al. 2012), dehydration-responsive element binding (DREB) factors (Qin et al. 2004; Wang et al. 2011), mitogen-activated protein kinase (MAPK) cascades (Pan et al. 2012; Wang et al. 2010; Yang et al. 2011a), and CBLinteracting protein kinases (CIPKs) (Chen et al. 2011; Zhao et al. 2009). The identification of these genes has demonstrated that there are interacting mechanisms that respond to different abiotic stresses in maize. "
ABSTRACT: To identify the crosstalk between gene expression and metabolism in response to cold, drought and salt stresses, digital gene expression (DGE) analysis was performed on maize (Zea mays L.) seedlings subjected to these stresses. A total of 103,953 (70.79 %), 111,130 (68.62 %), 94,435 (69.33 %) and 94,577 (68.92 %) tags were matched to reference genes. The most differentially regulated tags, with a log2 ratio ≥1 or ≤−1 (P < 0.01 and FDR ≤0.001), were further analysed. Many genes and biological pathways were affected by multiple abiotic stresses. In particular, expression changes for the gibberellin (GA) metabolic genes could improve understanding of the molecular basis of the response of the GA pathway to stress conditions. In addition, a large dataset of tag-mapped transcripts was obtained that provide a strong basis for future research on the response to abiotic stress in maize. And a new list of candidate targets for functional studies on genes involved in cold, drought and salt stresses has been generated. In this study, we revealed complex changes at the transcriptional level in maize seedlings under different abiotic stresses. Such studies could lead to a better understanding of the genetic basis of the maize response to different environmental stimuli and would be essential for improving the abiotic stress tolerance of maize.Plant Molecular Biology Reporter 12/2013; 31(6). DOI:10.1007/s11105-013-0622-z · 2.37 Impact Factor
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- "Transcription factors are found in a wide range of organisms from bacteria to plants and animals (Haake et al. 2002; Tong et al. 2009; Zou et al. 2008). Overexpression of transcription factors in cultured plant cell cultures resulted in improvement of plant salt tolerance (Hu et al. 2006; Xiang et al. 2008; Ying et al. 2012). Transcription factors were reported to play a role in the protection of cell cultures from stresses, and this protection was mainly related to the avoidance of lipid peroxidation reactions, preventing the formation of oxidative damage (Gao et al. 2011; Su et al. 2011; Tang et al. 2007; Wakasa et al. 2011; Zhang et al. 2011a and b). "
ABSTRACT: The Arabidopsis thaliana bZIP60 (AtbZIP60) transcription factor regulates stress signaling. However, its involvement in plant salt tolerance is not fully understood. In this investigation, cell suspension cultures of three different plant species: tobacco (Nicotiana tabacum), rice (Oryza sativa L.), and slash pine (Pinus elliottii Engelm.) were transformed via Agrobacterium tumefaciens LBA4404 harboring pBI-AtbZIP60deltaC. Integration of AtbZIP60deltaC into the genome of tobacco, rice, or slash pine has been confirmed by polymerase chain reaction, Southern blotting, and Northern blotting analyses. Six transgenic cell lines from each of three species were used to analyze the salt tolerance conferred by the overexpression of AtbZIP60deltaC. Our results demonstrated that expression of AtbZIP60deltaC enhanced salt tolerance of transgenic cells in all transgenic lines and that improved salt tolerance was associated with increased activities of both ascorbate peroxidase and superoxide dismutase, and decreased lipid peroxidation (thiobarbituric acid reactive substances). This investigation has demonstrated that the expression of AtbZIP60deltaC gene in transgenic cell lines attenuated salt-induced oxidative damage by increasing the activities of antioxidant enzymes and the overexpression of AtbZIP60deltaC gene could be an alternative choice for engineering plant salt tolerance.Plant Molecular Biology Reporter 10/2012; 30(5). DOI:10.1007/s11105-012-0437-3 · 2.37 Impact Factor