Isolation and characterization of two ABRE-binding proteins: EABF and EABF1 from the oil palm

Abstract

Abscisic acid (ABA) is an important phytohormone involved in the abiotic stress resistance in plants. The ABA-responsive element (ABRE) binding factors play significant roles in the plant development and response to abiotic stresses, but none so far have been isolated and characterized from the oil palm. Two ABA-responsive cDNA clones, named EABF and EABF1, were isolated from the oil palm fruits using yeast one-hybrid system. The EABF had a conserved AP2/EREBP DNA-binding domain (DNA-BD) and a potential nuclear localization sequence (NLS). No previously known DNA-BD was identified from the EABF1 sequence. The EABF and EABF1 proteins were classified as DREB/CBF and bZIP family members based on the multiple sequence alignment and phylogenetic analysis. Both proteins showed ABRE-binding and transcriptional activation properties in yeast. Furthermore, both proteins were able to trans-activate the down-stream expression of the LacZ reporter gene in yeast. An electrophoretic mobility shift assay revealed that in addition to the ABRE sequence, both proteins could bind to the DRE sequence as well. Transcriptional analysis revealed that the expression of EABF was induced in response to the ABA in the oil palm fruits and leaves, but not in roots, while the EABF1 was constitutively induced in all tissues. The expressions of both genes were strongly induced in fruits in response to the ABA, ethylene, methyl jasmonate, drought, cold and high-salinity treatments, indicating that the EABF and EABF1 might act as connectors among different stress signal transduction pathways. Our results indicate that the EABF and EABF1 are novel stress-responsive transcription factors, which are involved in the abiotic stress response and ABA signaling in the oil palm and could be used for production of stress-tolerant transgenic crops.

Drought Resilience in Oil Palm Cultivars: A Multidimensional Analysis of Diagnostic Variables

“…Additionally, the accumulation of abscisic acid (ABA) seen in the 11 cultivars, especially in the low-moisture soil treatments, may be considered a response to the stressful event since ABA plays a vital role in the adaptive responses to environmental stress such as drought [ 40 ] since its function has been seen in the signal transduction pathways between the perceived water stress signal and gene expression [ 41 ]. This was seen in palm oil, where two ABA-sensitive regulatory proteins and their role in the ABRE- and DRE/CRT-mediated expression were reported, finding the involvement of the EABF and EABF1 proteins in the stress response and the ABA signaling pathway [ 42 ].…”

OsABF1 Represses Gibberellin Biosynthesis to Regulate Plant Height and Seed Germination in Rice (Oryza sativa L.)

“…Its mutants became more sensitive to drought and salinity treatments, which are closely related to the functions of ABA. Additionally, its closest Arabidopsis orthologs, OsABF1, 2, 3, and 4, are also ABA-inducible and functionally involved in abiotic stress responses [62]. Combining the roles of OsABF1 in ABA signaling and GA biosynthesis suppression, it is rational to propose that OsABF1 is a key player in mediating the antagonistic relationship of ABA and GA.…”

Cloning and stress response analysis of the PeDREB2A and PeDREB1A genes in moso bamboo (Phyllostachys edulis)

“…For example, expression of CiDREB1A and CiDREB1B was found to be induced during low temperature adverse conditions but not in response to other abiotic stresses (Liang et al, 2014), and the BdDREB2 gene was significantly expressed in response to drought and salt stress (Zhang et al, 2014). In previous studies, a number of DREB TFs have been isolated from many plant species, including Physcomitrella patens (PpDBF1) (Liu et al, 2007), Hordeum vulgare (HvDREB1-a) (Xu et al, 2009), Medicago falcate (MfDREB1 and MfDREB1s) (Niu et al, 2010), Glycine soja (GsTIFY11b) (Zhu et al, 2012), oil palm (EABF and EABF1) (Omidvar et al, 2012), Avicennia marina (AmCBF1, 2, and 3) (Peng et al, 2013a), and Malus sieversii Roem (MsDREB2C) (Zhao et al, 2013). Interestingly, it has been found that over-expression of stress inducible DREB TFs may regulate the expression of all target genes that contain a DRE element within their promoters, resulting in transgenic plants with improved stress tolerance.…”