Drought stress, which is one of the most critical environmental constraints affecting global crop productivity, is exacerbated by climate change and increased atmospheric water demand. This review comprehensively examines plant responses to drought, integrating physiological, morphological, biochemical, and genetic adaptations that contribute to water‐use efficiency and stress tolerance. Key mechanisms such as osmotic adjustment, stomatal regulation, antioxidant defense, and hormonal signaling are analyzed, highlighting their role in mitigating drought‐induced cellular damage. Advances in plant breeding and biotechnological approaches, including transgenic strategies, genome editing, and marker‐assisted selection, are discussed in the context of improving drought resilience. The importance of root system architecture, leaf anatomical modifications, and stress‐responsive transcription factors is underscored as essential components of drought adaptation. Additionally, agronomic innovations such as precision irrigation, soil management techniques, and plant‐microbe interactions are reviewed due to their potential to enhance sustainable water use in agriculture. The role of epigenetic modifications and long‐distance signaling mechanisms in drought acclimation is explored, shedding light on emerging strategies for engineering multi‐stress tolerant crops. Furthermore, we assess the impact of drought on crop nutritional quality, the trade‐offs between drought tolerance and pest resistance, and the socio‐economic implications of water scarcity on global food security. This review provides a roadmap for integrating cutting‐edge scientific knowledge with practical agricultural applications, aiming to develop resilient cropping systems capable of sustaining productivity under increasingly unpredictable climatic conditions.

Grafting is a widely utilized agronomical technique to improve yield, disease resistance, and quality of fruit and vegetables. This work aims to assess the effect of grafting and fruit ripening on the production, physico-chemical characteristics, and nutritional quality of fruit from Spanish local pepper landraces. Landraces “Cuerno,” “Sueca,” and “Valencia” were used as scions, and “NIBER^®” as the rootstock. Two ripening stages of the fruits were sampled: green and red. Grafting improved the yield and marketable quality and did not negatively influence the physico-chemical and nutritional characteristics of the fruit. It was noteworthy that the bioactive compound contents and antioxidant capacity were more related to maturity stage and genotype, and red fruit had a higher antioxidant capacity than green fruit. However, in all the scions, grafting significantly enhanced lycopene content in both red and green fruit. Another important effect of grafting was the volatile compound composition evidenced by discriminant analyses, which was characterized for the first time in the fruit of these landraces. The rootstock and scion combination could be a way to improve not only the production, but also the fruit quality of peppers.

Currently, limited water supply is a major problem in many parts of the world. Grafting peppers onto adequate rootstocks is a sustainable technique used to cope with water scarcity in plants. For 1 month, this work compared grafted peppers by employing two rootstocks (H92 and H90), with different sensitivities to water stress, and ungrafted plants in biomass, photosynthesis, and antioxidant response terms to identify physiological–antioxidant pathways of water stress tolerance. Water stress significantly stunted growth in all the plant types, although tolerant grafted plants (variety grafted onto H92, Var/H92) had higher leaf area and fresh weight values. Var/H92 showed photosynthesis and stomata conductance maintenance, compared to sensitive grafted plants (Var/H90) and ungrafted plants under water stress, linked with greater instantaneous water use efficiency. The antioxidant system was effective in removing reactive oxygen species (ROS) that could damage photosynthesis; a significant positive and negative linear correlation was observed between the rate of CO₂ uptake and ascorbic acid (AsA)/total AsA (AsA_t) and proline, respectively. Moreover, in Var/H92 under water stress, both higher proline and ascorbate concentration were observed. Consequently, less membrane lipid peroxidation was quantified in Var/H92.

The use of rootstocks tolerant to water stress in pepper crops is a complementary technique for saving irrigation water without affecting yields by means of particular rootstock physiological traits, which changes the scion’s perception stress. The present study aimed to analyze the morphological and physiological adaptation of the ‘Cuerno’ pepper cultivar grafted onto tolerant rootstock NIBER^® subjected to capacitance sensor-based deficit irrigation. The stomatal conductance, relative water content and leaf water potential parameters were used to confirm the degree of crop stress. Leaf dry weight and root volume were higher in the grafted plants under the control irrigation and stress treatment conditions. Total fresh root biomass and root volume percentage of grafted plants under water stress were 24% and 33% higher, respectively, than the ungrafted plants. The grafted plants subjected to both water stress and control conditions had a higher marketable production than the ungrafted plants. The higher yields obtained using tolerant rootstocks were explained by the reduced blossom-end rot incidence.

In this study, hybrid pepper rootstock NIBER^® is tested for its ability to overcome water stress situations under soil conditions. The impact of deficit irrigation (DI) on yield and fruit quality, irrigation water use efficiency is evaluated, and consequently, the agronomic impact of employing water-stress tolerant rootstock is compared to ungrafted pepper plants. For this purpose, plants of the California-type sweet pepper ‘Maestral F1’ grafted onto NIBER^® underwent a sustained DI regime during seasons 2018 and 2019 and were compared to their respective controls. Plants were drip-fertirrigated, and volumetric soil water content was continuously monitored by capacitance sensors. Gas exchange and leaf water potential measurements were taken early in the morning and midday 58, 79, and 114 days after transplanting. Plant and fruit dry biomass, marketable quality, blossom-end rot incidence and harvest index were also determined. For consecutive years, our results confirmed that grafting a pepper cultivar onto an appropriate rootstock (NIBER^® in this case) as part of a DI strategy can overcome the negative effects of sustained water stress conditions. The plant biomass production and fruit yields of grafted plants were less affected by DI due to less sensitivity to water stress. This can be attributed to a less marked reduction in shoot dry weight in the grafted plants, which allowed greater whole photosynthesis by maintaining sink activity compared to ungrafted plants.