Plants encounter a wide range of biotic and abiotic environmental stresses throughout their lifespan. To adapt and survive, they have evolved complex defense mechanisms that involve the production of secondary metabolites (SMs), which play critical roles in enhancing plant resilience. These bioactive compounds function as deterrents to herbivores, barriers against pathogens, and protectants against oxidative stress. Plants regulate the synthesis and accumulation of secondary metabolites (SMs) in response to various environmental factors such as drought, salinity, cold, heat, heavy metals, and UV-B radiation. These stress conditions can significantly alter SM levels as part of the plant's adaptive response. Transcription factors (TFs) are essential mediators in this process, regulating gene expression involved in SM biosynthesis. By interacting with various signaling pathways, TFs fine-tune the plant's defense mechanisms, ensuring the timely accumulation of specific SMs that mitigate stress impacts. This review provides a comprehensive examination of the influence of environmental factors on SM accumulation in plants under both biotic and abiotic stress conditions. Additionally, we thoroughly discuss the roles of key TFs—including AP2/ERF, WRKY, bHLH, bZIP, MYB, and NAC—in regulating SM biosynthesis, highlighting their contributions to the plant's ability to withstand and adapt to stress.

Salt stress is one of the major abiotic stresses that negatively affect crops worldwide. Plants have evolved a series of mechanisms to cope with the limitations imposed by salinity. Molecular mechanisms, including the upregulation of cation transporters such as the Na+/H+ antiporters, are one of the processes adopted by plants to survive in saline environments. NHX antiporters are involved in salt tolerance, development, cell expansion, growth performance and disease resistance of plants. They are integral membrane proteins belonging to the widely distributed CPA1 sub-group of monovalent cation/H+ antiporters and provide an important strategy for ionic homeostasis in plants under saline conditions. These antiporters are known to regulate the exchange of sodium and hydrogen ions across the membrane and are ubiquitous to all eukaryotic organisms. With the genomic approach, previous studies reported that a large number of proteins encoding Na+/H+ antiporter genes have been identified in many plant species and successfully introduced into desired species to create transgenic crops with enhanced tolerance to multiple stresses. In this review, we focus on plant antiporters and all the aspects from their structure, classification, function to their in silico analysis. On the other hand, we performed a genome-wide search to identify the predicted NHX genes in Argania spinosa L. We highlighted for the first time the presence of four putative NHX (AsNHX1-4) from the Argan tree genome, whose phylogenetic analysis revealed their classification in one distinct vacuolar cluster. The essential information of the four putative NHXs, such as gene structure, subcellular localization and transmembrane domains was analyzed.