Soil Selenium (Se) Biofortification Changes the Physiological, Biochemical and Epigenetic Responses to Water Stress in Zea mays L. by Inducing a Higher Drought Tolerance

Abstract

Requiring water and minerals to grow and to develop its organs, Maize (Zea mays L.) production and distribution is highly rainfall-dependent. Current global climatic changes reveal irregular rainfall patterns and this could represent for maize a stressing condition resulting in yield and productivity loss around the world. It is well known that low water availability leads the plant to adopt a number of metabolic alterations to overcome stress or reduce its effects. In this regard, selenium (Se), a trace element, can help reduce water damage caused by the overproduction of reactive oxygen species (ROS). Here we report the effects of exogenous Se supply on physiological and biochemical processes that may influence yield and quality of maize under drought stress conditions. Plants were grown in soil fertilized by adding 150 mg of Se (sodium selenite). We verified the effects of drought stress and Se treatment. Selenium biofortification proved more beneficial for maize plants when supplied at higher Se concentrations. The increase in proline, K concentrations and nitrogen metabolism in aerial parts of plants grown in Se-rich substrates, seems to prove that Se-biofortification increased plant resistance to water shortage conditions. Moreover, the increase of SeMeSeCys and SeCys2 forms in roots and aerial parts of Se-treated plants suggest resistance strategies to Se similar to those existing in Se-hyperaccumulator species. In addition, epigenetic changes in DNA methylation due to water stress and Se treatment were also investigated using methylation sensitive amplified polymorphism (MSAP). Results suggest that Se may be an activator of particular classes of genes that are involved in tolerance to abiotic stresses. In particular, PSY (phytoene synthase) gene, essential for maintaining leaf carotenoid contents, SDH (sorbitol dehydrogenase), whose activity regulates the level of important osmolytes during drought stress and ADH (alcohol dehydrogenase), whose activity plays a central role in biochemical adaptation to environmental stress. In conclusion, Se-biofortification could help maize plants to cope with drought stress conditions, by inducing a higher drought tolerance.

Effect of selenium enrichment on metabolism of tomato (Solanum lycopersicum) fruit during postharvest ripening

“…The lower weight loss that occurred in Se‐fortified fruit compared to control may be ascribed to the increase in water retention due to the increased Se content, as observed in olive trees and in Zea mays . This effect can be attributable not only to an increase in cuticle thickness but also to a gene expression regulation …”

Effect of Feed Supplemented with Selenium-Enriched Olive Leaves on Plasma Oxidative Status, Mineral Profile, and Leukocyte DNA Damage in Growing Rabbits

“…Diet samples were treated as reported by Mattioli et al [18]. Quantification of organic and inorganic Se species was performed via HPLC (Agilent 1100, Agilent Technologies, Santa Clara, CA, United States) using an anion exchange column (Hamilton, PRP-X100, 250 × 4.6 mm, 5 µm particle size) with analytical method and instrument parameters described by Bocchini et al [32]. Results are expressed as ng/mL of plasma.…”

Plant Biostimulant Effects of Baker’s Yeast Vinasse and Selenium on Tomatoes through Foliar Fertilization

“…Several pieces of evidence related to such Se effects were presented already in the beginning of the introduction. The interconnected biochemical mechanisms involved in such effects are related to epigenetic effects [60], including gene activation and enzyme induction [61], regulation of reactive oxygen (and nitrogen) species [62], and recovery of the cell and organelle membrane integrity [10].…”

“…The sterilized seeds were germinated in aseptic conditions, in sterile Petri dishes ∅ 9 cm, which contained a sterile cotton wool bed, moistened with sterile pure water. The germinated seeds were transferred to small pots containing growing substrate (Canna Terra Professional, Canna), sterilized by 60 Co γ-radiation. The plants were maintained for 30 days in the climatic chamber.…”