Phytic Acid and Mineral Biofortification Strategies: From Plant Science to Breeding and Biotechnological Approaches

Abstract

Mineral deficiencies, particularly for iron and zinc, affect over two billion people worldwide, mainly in developing countries where diets are based on the consumption of staple crops. Mineral biofortification includes different approaches aimed to increase mineral concentration and to improve mineral bioavailability in the edible parts of plants, particularly the seeds. A multidisciplinary approach, including agronomic, genetic, physiological, and molecular expertise, is necessary to obtain detailed knowledge of the complex homeostatic mechanisms that tightly regulate seed mineral concentrations and the molecules and mechanisms that determine mineral bioavailability, necessary to reach the biofortification objectives. To increase bioavailability, one strategy is to decrease seed content of phytic acid, a highly electronegative molecule present in the cell that chelates positively charged metal ions, many of which are important for human nutrition. All the contributions of the current Special Issue aim at describing new results, reviewing the literature, and also commenting on some of the economic and sociological aspects concerning biofortification research. A number of contributions are related to the study of mineral transport, seed accumulation, and approaches to increase seed micronutrient concentration. The remaining ones are mainly focused on the study of low phytic acid mutants.

Genetic Variability of Mineral Content in Different Grain Structures of Bean Cultivars from Mesoamerican and Andean Gene Pools

“…These observations are consistent with those reported by Ariza-Nietoetal et al [ 21 ], who evaluated the mineral contents of these three grain tissues in eight bean genotypes of Andean and Mesoamerican origin. Within grains, P is stored predominantly in the form of phytic acid, which is considered one of the main anti-nutritional factors in plants, owing to its tendency to bind to other minerals and nutrients, thereby altering their digestibility and absorption by the human body [ 22 ]. Phytic acid accounts for between 65% and 85% of total P content in grains and is differentially distributed among cotyledons (95–98%), embryonic axis (1–3%), and seed coat (0.5–4%) [ 17 , 23 ], with that stored in the cotyledons and embryonic axis serving as a source of P for germination and development during the early stages of plant growth [ 24 ].…”

Improving nutrition through biofortification–A systematic review

“…Generally, there are four interventions that have been adopted in curbing malnutrition and hidden hunger. These include dietary diversification, food supplementation, food fortification and biofortification (1,63).…”

Subcellular dynamics studies of iron reveal how tissue‐specific distribution patterns are established in developing wheat grains

“…Second, most of the iron and zinc in the embryo and aleurone layer is bound to phytic acid, forming insoluble complexes that have poor bioavailability. Attempts to biofortify cereal grains are focussing on increasing the total amounts of iron and zinc, changing their distribution and reducing phytic acid levels (Vasconcelos et al ., 2017; Cominelli et al ., 2020).…”