Plant stress is one of the most significant factors affecting plant fitness and, consequently, food production. However, plant stress may also be profitable since it behaves hormetically; at low doses, it stimulates positive traits in crops, such as the synthesis of specialized metabolites and additional stress tolerance. The controlled exposure of crops to low doses of stressors is therefore called hormesis management, and it is a promising method to increase crop productivity and quality. Nevertheless, hormesis management has severe limitations derived from the complexity of plant physiological responses to stress. Many technological advances assist plant stress science in overcoming such limitations, which results in extensive datasets originating from the multiple layers of the plant defensive response. For that reason, artificial intelligence tools, particularly Machine Learning (ML) and Deep Learning (DL), have become crucial for processing and interpreting data to accurately model plant stress responses such as genomic variation, gene and protein expression, and metabolite biosynthesis. In this review, we discuss the most recent ML and DL applications in plant stress science, focusing on their potential for improving the development of hormesis management protocols.

Agriculture in the current century is seeking sustainable tools in order to generate plant production systems with minimal negative environmental impact. In recent years it has been shown that the use of insect frass is an option to be used for this purpose. The present work studied the effect of low doses (0.1, 0.5, and 1.0% w/w) of cricket frass (Acheta domesticus) in the substrate during the cultivation of tomatos under greenhouse conditions. Plant performance and antioxidant enzymatic activities were measured in the study as explicative variables related to plant stress responses in order to determine possible biostimulant or elicitor effects of cricket frass treatments during tomato cultivation under greenhouse conditions. The main findings of this study indicated that tomato plants responded in a dose dependent manner to cricket frass treatments, recalling the hormesis phenomenon. On the one hand, a 0.1% (w/w) cricket frass treatment showed typical biostimulant features, while on the other hand, 0.5 and 1.0% treatments displayed elicitor effects in tomato plants under evaluated conditions in the present study. These results support the possibility that low doses of cricket frass might be used in tomato cultivation (and perhaps in other crops) for biostimulant/elicitor input into sustainable production systems.

Aquaculture waters can be associated with the modification of the phytochemical profile in plants when they are used for irrigation; thus, Integrated Agri-Aquaculture Systems such as aquaponics represent a strategy to improve the bioactive content of medicinal plants. This study aimed to analyze the effect caused by cultivation using aquaponics on the modification of the content of bioactive compounds such as phenols, flavonoids, and apigenin in Cuphea hyssopifolia and Cuphea cyanea irrigated with Cyprinus carpio waters. The results of each culture method showed unique differences (p ≤ 0.05) in the concentrations of bioactive compounds and antioxidant activity in Cuphea spp. For C. hyssopifolia in aquaponics, 76% (61.08 ± 7.2 mg g⁻¹ GAEq) of phenols and 50% (5.62 ± 0.5 mg g⁻¹ CAEq) of flavonoids were maintained compared to 20% (16.99 ± 0.4 mg g⁻¹ GAEq) of phenols and 76.5% (8.19 ± 1.6 mg g⁻¹ CAEq) of flavonoids in conventional culture. For C. cyanea in aquaponics, 91% (15.36 ± 0.8 mg g⁻¹ GAEq) of phenols and 47% (3.52 ± 0.6 mg g⁻¹ CAEq) of flavonoids were maintained compared to 24% (14.11 ± 1.3 mg g⁻¹ GAEq) of phenols and 82% (1.79 ± 0.1 mg g⁻¹ CAEq) of flavonoids in conventional culture. An increase of more than 60% in the apigenin content of C. hyssopifolia in aquaponics confirms a eustress effect related to the use of organically enriched waters. The results indicate that aquaponics can promote the biostimulation/elicitation of medicinal plants and increase their bioactive compounds, but this effect does not occur in the same way between species.

Background/Objectives: Timbe (Acaciella angustissima) is a legume recognized for its environmental benefits, such as soil restoration, wildlife nutrition, and the presence of biologically active compounds. This study investigates the antioxidant, pharmacological, and antimicrobial properties of Timbe. Methods: The total phenolic content, flavonoids, and condensed tannins from Timbe flowers, seeds, and pods were quantified, and their antioxidant activity was evaluated using the DPPH and ABTS assays. Enzymatic activities were assessed through α-amylase, α-glucosidase, and ACE-I inhibition, and antimicrobial properties were tested against various bacterial strains. Results: The pods and flowers exhibited higher antioxidant capacities compared to seeds, effectively neutralizing free radicals. Flavonoids and condensed tannins showed positive correlations with antioxidant activity and the inhibition of α-amylase and α-glucosidase, suggesting the potential benefits of these metabolites in blood glucose control. Timbe also demonstrated ACE-I inhibition, particularly the flowers. Regarding antimicrobial activity, the pods displayed moderate inhibition against E. coli, K. pneumoniae, and S. aureus. Conclusions: The results indicate that different parts of Timbe (flowers, seeds, and pods) possess significant therapeutic potential for preventing and treating metabolic disorders and bacterial infections.

Tenebrio molitor is a common stored grains pest. The conventional way for its management involves the use of synthetic fumigants. Despite their effectiveness, these can cause environmental damage. The use of essential oils has emerged as an alternative for its management. Therefore, the aim of this study was to assess Lantana camara essential oil (EO) and endo-borneol biological activities against T. molitor. Insecticidal activity and weight gain were evaluated through the impregnated paper method against larvae and adults, while repellency was conducted with a Y-tube olfactometer; L. camara EO showed higher mortality for T. molitor adults (LC₅₀ = 7.2 μL EO L⁻¹ air) than for larvae (LC₅₀ = 13.7 μL EO L⁻¹ air) after 30 d. Furthermore, L. camara EO was found to be repellent for T. molitor adults (RC₅₀ = 0.08 μL EO cm⁻²). Regarding the EO composition, endo-borneol was identified by GC-MS as a major compound with 14.24% abundance. Larvae exhibited higher susceptibility (LC₅₀ = 7.8 μL L⁻¹ air) to endo-borneol than adults (LC₅₀ = 46 μL L⁻¹ air) after 72 h. Notably, endo-borneol demonstrated significantly higher repellent activity (RC₅₀ = 0.03 μL cm⁻²) than L. camara EO (RC₅₀ = 0.08 μL EO cm⁻²). These findings suggest that endo-borneol has potential as a natural source alternative for T. molitor management.

<!----> <!----> Worldwide, plants are exposed to different biotic and abiotic stress factors that may limit their yield, growth, quality, and performance. Plant production practices aim at plant cultivation trying to minimize their stress using different production systems either under protected or open field conditions. Notwithstanding, it is known that controlling plant stress during cultivation, a strategy called as “controlled elicitation,” might be a useful tool to enhance vegetables production. To conceive this idea, it is necessary to recall the theory of stress that indicates a dose–response relationship between the strength and length of the stress factor (stressor) and the plant response. Plant responses to cope stress are triggered after recognition of biological, chemical, or physical stressors. Slight doses of stressors might cause positive effects on plant performance (“positive stress” or eustress), whereas high doses cause negative effects (“negative stress” or distress). Managed as eustress dose a stressor is called “eustressor,” and it might stimulate the plant response in such a way that plant production and quality could be improved. Current literature has been reported showing beneficial effects for the applications of eustressors in crop production. This chapter aims at presenting an overview of the current status of case studies and applications of some biological, chemical, and physical eustressors in plant production. Some specific examples are also mentioned regarding the possibilities of controlled elicitation to increase crop production and quality. <!----> <!---->