Our agriculture is threatened by climate change and the depletion of resources and biodiversity. A new agriculture revolution is needed in order to increase the production of crops and ensure the quality and safety of food, in a sustainable way. Nanotechnology can contribute to the sustainability of agriculture. Seed nano-priming is an efficient process that can change seed metabolism and signaling pathways, affecting not only germination and seedling establishment but also the entire plant lifecycle. Studies have shown various benefits of using seed nano-priming, such as improved plant growth and development, increased productivity, and a better nutritional quality of food. Nano-priming modulates biochemical pathways and the balance between reactive oxygen species and plant growth hormones, resulting in the promotion of stress and diseases resistance outcoming in the reduction of pesticides and fertilizers. The present review provides an overview of advances in the field, showing the challenges and possibilities concerning the use of nanotechnology in seed nano-priming, as a contribution to sustainable agricultural practices.

Water deficit (WD) promotes great losses in agriculture, and the development of new sustainable technologies to mitigate the effects of this stress on plants is essential. This study aimed to evaluate the morphophysiological and biochemical alterations induced by the priming of tomato seeds with different formulations in plants under field capacity and WD conditions. In the first experiment, the treatments consisted of nanoparticles of alginate/chitosan and chitosan/tripolyphosphate containing gibberellic acid (GA₃) in different concentrations (0.5, 5, and 50 µg mL⁻¹ GA₃), in addition to control with deionized water. The alginate/chitosan (5 µg mL⁻¹ GA₃) provided the greatest gains in plant growth under field capacity. In addition, under WD this treatment reduced damage to photosystem II (−14%), stomatal conductance (−13%), and water loss (−38%) and increased the instantaneous carboxylation efficiency (+24%) and intrinsic water use efficiency (+12%). In the second experiment, the treatments were alginate/chitosan nanoparticles containing GA₃ (NPGA₃ 5 µg mL⁻¹), free GA₃ (GA₃ 5 µg mL⁻¹), nanoparticles without GA₃ (NP), deionized water (WATER), and non-primed seeds (CONT). Under WD, GA₃ and CONT maintained plant growth and lost water rapidly, reducing stomatal conductance (−87%) and net photosynthesis (−69%). In contrast, NPGA₃ decreased leaf area (−44%) and increased root-to-shoot ratio (+39%) when compared to GA₃, reducing water loss (−28%). Activation of protective mechanisms (e.g., superoxide dismutase and catalase activities) by WATER, NPGA₃, and NP treatments also resulted in lower susceptibility to WD compared to CONT and GA₃. The results highlight the positive effect of seed priming on plant response to WD, which was enhanced by the use of nanoencapsulated GA₃.

Caryocar brasiliense Cambess is a plant species typical of the Cerrado, a Brazilian biome. The fruit of this species is popularly known as pequi, and its oil is used in traditional medicine. However, an important factor hindering the use of pequi oil is its low yield when extracted from the pulp of this fruit. Therefore, in this study, with aim of developing a new herbal medicine, we an-alyzed the toxicity and anti-inflammatory activity of an extract of pequi pulp residue (EPPR), fol-lowing the mechanical extraction of the oil from its pulp. For this purpose, EPPR was prepared and encapsulated in chitosan. The nanoparticles were analyzed, and the cytotoxicity of the encapsu-lated EPPR was evaluated in vitro. After confirming the cytotoxicity of the encapsulated EPPR, the following evaluations were performed with non-encapsulated EPPR: in vitro anti-inflammatory activity, quantification of cytokines, and acute toxicity in vivo. Once the anti-inflammatory activity and absence of toxicity of EPPR were verified, a gel formulation of EPPR was developed for topical use and analyzed for its in vivo anti-inflammatory potential, ocular toxicity, and previous stability assessment. EPPR and the gel containing EPPR showed effective anti-inflammatory activity and lack of toxicity. The formulation was stable. Thus, a new herbal medicine with anti-inflammatory activity can be developed from discarded pequi residue.