Iodine is a non-essential element for land plants, but is considered as a beneficial element, related to antioxidant capacity, environmental adaptations and improvement of plant growth. Salinity is one of the more recurrent abiotic stresses worldwide, seriously affecting vegetal production. The aim of this work was to evaluate iodine application (Q products® and KIO3, Quimcasa de México, Naucalpan, Mexico) in strawberry plants under normal and salt stress conditions. Growth, antioxidant content, essential minerals, iodine accumulation and fruit quality were evaluated. The results showed that, under stress conditions, the application of Q products increased ascorbate peroxidase (APX) and catalase (CAT) activity as well as glutathione (GSH) content and yield in fruit, without avoiding biomass loss; with the application of KIO3 an increase in GSH and APX activity as well as P and K concentrations were obtained. In leaves an increase in P, Ca, Mn and iodine accumulation was evidenced with the application of Q products, and an increased concentration of ascorbic acid and iodine with KIO3 treatments. Under normal conditions in fruits, the application of Q products increased phenolic compounds synthesis; additionally, an increase in Ca and Mn concentrations was shown. KIO3 application increased the firmness and Mn. In leaves, the application of Q products increased chlorophyll a, b and calcium. In conclusion, the application of iodine improves the quality value of strawberries under normal conditions and provides an enhancement of salt stress tolerance.

Selenium (Se) is an essential element in mammals; however, there is frequently an insufficient intake due to several factors. Different techniques have been used to deal with this problem, such as plant biofortification with Se in its ionic forms and, more recently, at the nanoscale. Additionally, despite the fact that Se is not considered an essential element in plants, it has been shown to stimulate (through still unknown mechanisms) plant metabolism, causing an increase in the synthesis of molecules with reducing power, including enzymes such as glutathione peroxidase, catalase and ascorbate peroxidase as well as non-enzymatic antioxidants such as phenolic compounds, glucosinolates, vitamins and chlorophylls. A positive correlation has also been shown with other essential elements, achieving an increase in tolerance to environmental adversities. This article describes the advances made in the field of the biofortification of horticultural crops with ionic Se and nanoselenium (nSe) from 2009 to 2019. The aspects covered include various concentrations used, the findings made regarding the impact these chemical forms have on plant metabolism, and indications of its participation in the synthesis of primary and secondary metabolites that increase stress tolerance.

A new, rapid and efficient reverse phase Liquid Chromatography (RP-LC) method was developed for determination of Gibberellin A4 (GA4) in samples of flower stalk of Dasylirion cedrosanum and vegetative tissue of Epithelantha micromeris. Purification of GA4 was carried out by solid phase extraction (SPE), in Epithelantha micromeris. In the chromatography method was obtaining a retention time of 2.1 min, using Hypersil GOLD C-18 column (100 × 4.6 mm dim and size particle 5 µ), mobile phase 50/50 acetonitrile/water and a flow 1.0 ml/min. Detection was carried out by a UV detector set at 205 nm, and a quantization limit of 0.4 mg/L. The obtained correlation coefficient was 0.995.

Plant biostimulants have been used to reduce the damage caused by different types of biotic and abiotic stresses. Iodine (I) is a non-essential element in plants. Still, it is considered beneficial and a biostimulant, since exogenous application can enhance the redox metabolism, which improves antioxidants, synergies with essential minerals and increases tolerance to adverse factors. However, little is known about the mechanism of action of iodine; so, it is advantageous to undertake research that elucidates the impact of this element on plant physiology, which is expected to encourage the productive agricultural sector to use this element with additional biofortification benefit. The objective of this research was to evaluate the effect of foliar KIO3 applications every 15 days at 100 μM, on growth, mineral content and antioxidants in tomato plants grown under greenhouse conditions subjected to salinity stress (100 mM NaCl). The results showed that iodine did not mitigate the adverse impact of salinity on fresh or dry biomass but increased fruit production by 23%. A greater amount of N and Fe was also found in the leaves but not in the fruits; the same happened with the iodine concentration, which was high in the leaves of the treated plants but not in tomato fruits. The content of Ca and Mg in fruits was decreased in plants treated with iodine, as well as the activity of the GPX, lycopene and the antioxidant potential. None of the fruit quality variables were affected by salinity with or without application of iodine.

The availability of water and nutrients are determining factors for the growth and productivity of the cucumber crop. The implementation of the grafting techniques increases the efficiency in the absorption of resources such as water and nutrients, improving the quality, mineral content, and enzymatic activity of the fruit. The objective of this research work was to evaluate the effect of the anchor point (soil and substrate), graft (with and without graft), and irrigation volume (100 and 75%) on fruit quality, macro and microelement content, and enzymatic antioxidant activity. A total of eight treatments was established in a completely randomized experiment with a factorial design with a 2 × 2 × 2 arrangement. The results showed an increase in the fruit weight by 10% in grafted plants under 100% irrigation in the substrate, no significant differences between treatments were found in firmness or total soluble solids (TSS). Additionally, while there was a higher accumulation of potassium because of the graft, there was no difference for calcium. It was observed that the enzymatic activity was inhibited using the graft. The graft represents a viable option for the efficient use of water, both in the soil and substrate, being the substrate with the best environment for development, mitigating stress by decreasing enzymatic activity.

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Raspberry has acquired great interest in human health due to its content of bioactive compounds that provide protection against diseases caused by non-communicable diseases. Bioactive compounds are mainly represented by secondary metabolites such as phenols, anthocyanins, and flavonoids. Biostimulants and elicitors are substances or microorganisms that provide protection and defence to the physiological processes of plants. The present study evaluated the effect of two elicitors (hydrogen peroxide, salicylic acid) and three biostimulants (humic and fulvic acids, glutamic acid, seaweed extracts) on the content of bioactive compounds in raspberry fruits, agronomic and fruit yield parameters in plants. Hydrogen peroxide increased the content of bioactive compounds such as flavonoids, anthocyanins, omega 3 and oleic acid. Salicylic acid increased the content of flavonoids, anthocyanins, and citric acid in raspberry fruits; the number of fruit loaders and fruits per plant was also increased. Humic and fulvic acids, glutamic acid, and glutamic acid combined with seaweed extracts increased the content of flavonoids and anthocyanins, without affecting growth parameters and fruit yield. Glutamic acid and seaweed extracts were the only treatments that increased the content of palmitic acid, while seaweed extracts increased °Brix content in fruits.