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

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.

ITS1 Barcode and Phytochemical Analysis by Gas Chromatography-Mass Spectrometry of Corynaea crassa Hook. f (Balanophoraceae) from Ecuador and Peru.

The use of medicinal plants is the basis of traditional healthcare. Recently, the use of herbal medicine has been increasing among consumers due to availability, economy, and less side effect. For instance, the hemiparasite plant Corynaea crassa has medicinal properties and could be found in some regions of America, from Costa Rica to Bolivia. Phytochemical and genetic characterization of medicinal plants is needed for proper identification of metabolites responsible for medicinal properties and for genotyping, respectively. Moreover, characterization of medicinal plants through the use of DNA barcodes is an important tool for phylogenetic analysis and identification of species; furthermore, complemented with phytochemical analysis, both are useful for identification of plant species and quality control of medicinal products. The objective of this study was to analyze the species of C. crassa collected in Ecuador and Peru from the phylogenetic and phytochemical point of view. Polymerase chain reaction (PCR) was performed for amplification of the internal transcribed spacer 1 (ITS1) region after DNA extraction of samples of C. crassa. Blast analysis was performed in the GenBank database with the ITS1 sequences obtained from two accessions of C. crassa from Ecuador (GenBank accession numbers OM471920 and OM471919 for isolates CIBE-17 and CIBE-18, respectively) and three from Peru (GenBank accession numbers OM471921, OM471922, and OM471923 for isolates CIBE-13, CIBE-14, and CIBE-15, respectively). The accessions available in the GenBank were used for phylogenetic analysis. For the phytochemical analysis, hydroalcoholic extracts were obtained by maceration using 80% ethanol as solvent, followed by a derivatization process and analysis by gas chromatography-mass spectrometry. Based on the phylogenetic analysis of the C. crassa samples, the ITS1 sequence could be used to differentiate C. crassa of different locations. The samples of C. crassa from Ecuador and Peru are more similar between them than with other clades including Helosis spp. The phytochemical study revealed differences in the presence and relative abundance of some metabolites; mainly eugenol, 1,4-lactone arabinonic acid, dimethoxyrabelomycin and azelaic acid, which are reported for the first time for the species under study and the genus Corynaea. These results are the first findings on the combined analysis using genetic and phytochemical analysis for C. crassa, which could be used as a useful tool for quality control of the C. crassa species in medicinal products.