Drought stress is a multidimensional abiotic stress that negatively affects plant growth and yield. Therefore, identifying useful, low-cost, and low-risk solutions to deal with drought along with identifying tolerant plants is crucial for sustainable agriculture and crop production worldwide. In some cases, due to a lack of nutrients, even if there is enough moisture, the plants are still unable to absorb water. Increasing essential macro- and micronutrients may reduce the harmful effects of abiotic stresses, among which drought, while increasing yield. The essential element molybdenum (Mo) has a role in many processes such as photosynthesis, nitrogen (N) metabolism, hormone signaling and tolerance of abiotic stresses. Plants absorb Mo as molybdate anion (MoO42−), which is the main common soluble form of Mo present in neutral to alkaline soils. Mo has a unique effect on the synthesis of hormones and enzymes, and thus affecting plant water relationships and response to environmental stresses. On the other hand, limited water resources and lack of access to adequate water for agricultural production in terms of quantity and quality risk compromising the uptake of Mo which is already critical in soils acidic and/or poor in this essential micronutrient. This study systematically investigated the response to Mo stress and provided valuable evidence for the efficacy of Mo as a candidate to temper the adverse effects of drought stress on crops. Further, this review article also explains the mechanistic actions exerted by Mo in alleviating the drastic effects of drought on crops.
