Drought limits plant growth, development and productivity, leading to more than 50% crop loss globally. Drought-induced oxidative stress disturbs the plant’s metabolism; however, plants activate signaling pathways to respond and adapt to drought stress. Although drought response mechanisms are well reported in several crops, these mechanisms are poorly understood in Amaranthus. As a highly nutritious crop, rich in antioxidants with the ability to survive in extreme agro-climatic environments, Amaranthus has the potential to serve as a climate-smart future crop. This review provides evidence of some drought response traits in grain and vegetable Amaranthus species. Grain amaranths are the most tolerant species, mainly through improved osmoregulation, antioxidant capacity, and gene expression. While biomass partitioning, efficient water use, and membrane stability have been reported in both grain and vegetable amaranth, the molecular response of vegetable amaranth remains limited. Thus, future research must focus on integrated biochemical, molecular, and multi-omics applications to screen and identify resilient Amaranthus genotypes under drought for sustainable agriculture.

Tylosema esculentum (Burch.) A. Schreib. (also known as marama) is a perennial legume native to the arid and semi-arid regions of southern Africa, where it thrives under extreme climatic conditions, particularly in hot and water-limited environments and nutrient-poor soils. This review outlines current knowledge on marama’s nutritional and medicinal potential, as well as genomic insights and drought adaptation mechanisms, to ensure sustainable food systems. Marama has added advantages since the entire crop, including grains/beans, stems and tubers, can be used as a source of food for animals and humans. However, the nutritional value and safe consumption of different tissues are dependent on developmental stages and appropriate processing to reduce anti-nutritional compounds and improve digestibility. Marama beans possess exceptional nutritional value, being rich in protein; unsaturated lipids; essential micronutrients; and health-promoting phytochemicals including phenolics, flavonoids, saponins and phytosterols. To date, the chloroplast and mitochondrial genomes of Tylosema esculentum (marama) have been sequenced and assembled, while its nuclear genome size has been estimated at approximately 1 gigabyte, providing valuable genomic resources for further research. Marama exhibits a predominantly drought-avoidance strategy characterized by the development of deep tubers for water and nutrient storage, reduction in transpiration through leaf senescence and stomatal regulation, and maintenance of plant water status during prolonged dry periods. Marama also exhibits osmotic adjustment, which further enhances cellular protection and stress tolerance under water-deficit conditions. Despite these promising attributes, marama remains largely underutilized due to limited agronomic data to support its cultivation and insufficient data on its metabolic and genetic architecture that drives drought adaptation and socio-economic potential. Thus, there is an urgent need for integrated research efforts that will facilitate the transition of this crop from a wild-harvested resource to a sustainable, climate-resilient crop suited to arid and semi-arid agroecosystems.