Plant Promoters: Their Identification, Characterization, and Role in Gene Regulation

Abstract

One of the strategies to overcome diseases or abiotic stress in crops is the use of improved varieties. Genetic improvement could be accomplished through different methods, including conventional breeding, induced mutation, genetic transformation, or gene editing. The gene function and regulated expression through promoters are necessary for transgenic crops to improve specific traits. The variety of promoter sequences has increased in the generation of genetically modified crops because they could lead to the expression of the gene responsible for the improved trait in a specific manner. Therefore, the characterization of the promoter activity is necessary for the generation of biotechnological crops. That is why several analyses have focused on identifying and isolating promoters using techniques such as reverse transcriptase-polymerase chain reaction (RT-PCR), genetic libraries, cloning, and sequencing. Promoter analysis involves the plant genetic transformation method, a potent tool for determining the promoter activity and function of genes in plants, contributing to understanding gene regulation and plant development. Furthermore, the study of promoters that play a fundamental role in gene regulation is highly relevant. The study of regulation and development in transgenic organisms has made it possible to understand the benefits of directing gene expression in a temporal, spatial, and even controlled manner, confirming the great diversity of promoters discovered and developed. Therefore, promoters are a crucial tool in biotechnological processes to ensure the correct expression of a gene. This review highlights various types of promoters and their functionality in the generation of genetically modified crops.

Genome-wide analysis of FRF gene family and functional identification of HvFRF9 under drought stress in barley

“…Promoters are gene switches located in the upstream of the coding region of genes, which turn on and off the functional activity of genes and contain specific cis -elements. These elements are the binding targets of upstream regulatory genes, and they regulate the expression of target genes by binding to upstream genes ( Hernandez-Garcia and Finer, 2014 ; Villao-Uzho et al., 2023 ). The analysis of cis -elements in the promoter region of HvFRFs revealed that the promoter region of HvFRFs contains a large number of hormone- and abiotic-stress-response elements.…”

Nicotiana benthamiana Methanol-Inducible Gene (MIG) 21 Encodes a Nucleolus-Localized Protein That Stimulates Viral Intercellular Transport and Downregulates Nuclear Import

“…Various regulatory elements, such as enhancers, promoters, and transcription factor binding sites, modulate the expression of these genes. Inducible promoters are often found in genes that need to be turned on or off rapidly in response to changes in the cellular environment [ 51 ]. Inducible promoters allow for the dynamic control of gene expression, enabling cells to adapt to various internal and external cues, including stress, developmental signals, or environmental changes.…”

Genome-Wide Identification of Members of the Soybean CBL Gene Family and Characterization of the Functional Role of GmCBL1 in Responses to Saline and Alkaline Stress

“…The structures and functions of plant gene promoters are inextricably linked with one another [54]. The promoters of GmCBLs were found to harbor a wide range of cis-acting elements, emphasizing the ability of these genes to respond to diverse internal and external factors (Figure 3).…”