عنوان مقاله [English]
Introduction: Climate changes and increased severity and duration of abiotic stresses have considerably affected the crops’ productivity, e.g., wheat. Accordingly, evaluating the influences of environmental stresses at the cellular and molecular levels to distinguish regulatory and tolerance mechanisms in plants has become a priority worldwide. In response to stress conditions, plants employ altered mechanisms, including a rapid induction in producing reactive oxygen species (ROS) known as oxidative burst. ROS are helpful in a small amount and they are primarily used in cell signaling and as secondary messengers, but excessive accumulation of ROS under environmental stress disturbs the oxidation-reduction balance in the plant and causes oxidative stress. ROSs are usually produced in chloroplasts, mitochondria, peroxisomes in the cytoplasm, peroxidase and amine-oxidase in the plants’ cell walls along with NADP(H) oxidase (NOX) family enzymes available in plants’ cell membrane. NAD(P)H oxidase genes play a vital role in plant response to environmental changes by regulating the transportation of electrons from NAD(P)H molecules to molecular oxygen and producing superoxide ions, which further leads to the creation of various types of ROS. This research aimed to investigate the promoter region of the gene encoding NAD(P)H oxidase enzyme in the wheat genome in order to find the effect of important regulatory elements on expression.
Materials and methods: The promoter region of genes and regulatory elements located within this region play an important role in regulating gene expression in plants under different conditions. In order to recognize the regulation of gene expression for the NAD(P)H oxidase gene, the promoter region of the gene was investigated by using online tools. First, the sequence of the gene encoding this enzyme in wheat was downloaded using the NCBI site. Then, 1500 base pairs upstream from the transcription start point were assessed by using online tools on the PlantEnsemble site. The promoter sequence was finally analyzed by the PlantCare website to identify important regulatory elements with specific roles in gene expression.
Results: The results showed that a diverse set of regulatory elements involved in different biochemical pathways can affect the expression level of the NAD(P)H oxidase gene in wheat. The most effective elements identified by promoter analysis were ABRE, TCA motif, TGACG motif, ARE, CCAAT-Box, skn-1-motif, and circadian, whose activities are regulated by specific hormones and transcription factors.
Conclusion: The analysis showed that changes in environmental conditions could change NAD(P)H oxidase gene expression. Hormones and transcription factors each target specific regulatory elements in the gene promoter, leading to changes in the level of enzyme expression. NADPH oxidase enzyme manages the production of superoxide ions, leading to the production of other types of ROS in the plant. ABRE, TCA motif, TGACG motif, ARE, CCAAT-Box, skn-1-motif, and circadian can be mentioned among the regulatory elements that were identified by promoter analysis. They are involved in the response pathways to abscisic acid, salicylic acid, and jasmonic acid hormones, anaerobic reaction pathways, response to drought through MYB transcription factors, plant endosperm pathway, and light reactions, respectively. According to scientific contexts, the expression of these elements can improve the plant's response to harsh conditions and environmental stresses in different growth stages and play an important role in plants' adaptation to changed environments.