Characterization of the promoter region of the glycerol-3-phosphate-O-acyltransferase gene in Lilium pensylvanicum

Abstract

Yadav et al., 2014), while associations between the promoters of these genes and resistance have not yet been reported. Plant promoters play an important role in the regulation of gene expression in plants ( Kim et al., 2013;Reynolds et al., 2013). Promoters are located on the 5'-flanking region of structural genes, recognized by RNA polymerase and combined with template DNA, ensuring that transcription starts effectively and accurately. The promoter consists of two parts: the core region and upstream regulator region (Zhu and Li, 2002). There are abundant cis-acting elements that participate in gene regulation in the promoter (Razdan et al., 2013;Sarvestani et al., 2013). Transient transformation and histochemical staining can contribute to promoter functional analysis (Koia et al., 2013). Cloning and functional studies related to the promoters of the key genes in improving resistance of plants will aid us in understanding its signal transduction pathways and gene expression patterns.According to gene expression, promoters can be divided into two categories: constitutive promoters and specific Abstract: Cold environmental conditions influence the growth and development of plants, causing crop reduction or even plant death. Under stress conditions, cold-inducible promoters regulate cold-related gene expression as a molecular switch. Recent studies have shown that the chloroplast-expressed GPAT gene plays an important role in determining cold sensitivity. However, the mechanism of the transcriptional regulation of GPAT is ambiguous. The 5'-flanking region of GPAT with length of 1494 bp was successfully obtained by chromosome walking from Lilium pensylvanicum. The cis-elements of GPAT promoters were predicted and analyzed by a plant cisacting regulatory DNA element database. There exist core promoter regions including TATA-box and CAAT-box and transcription regulation regions, which involve some regulatory elements such as I-box, W-box, MYB, MYC, and DREB. Full-length and four 5'-deletion fragments linked with GUS vectors were constructed and transformed into Nicotiana tabacum by Agrobacterium-mediated transformation. Transient transformation and histochemical staining of leaves indicated that the activity of the GPAT promoter was strong and induced by low-temperature stress. The deletion of a -294 bp region suggested that the DRE-motif was functionally an essential element for cold induction, and the deletion of -1494 bp and -1194 bp regions suggested that negative regulation exists in the promoter. Our results show that the GPAT gene promoter is a key regulator under cold stress and we think that this study will have significant impact on lily molecular breeding and improving the resistance of plants.