Phytic acid or myo-inositol hexakisphosphate (IP6) is the predominant storage form of phosphorus in cereal grains. It is considered a major anti-nutritional factor as it chelates essential nutrients such as iron, zinc, calcium and magnesium, thereby reducing their bioavailability in the human diet. This reduction in mineral uptake contributes to micronutrient deficiencies, commonly referred to as “hidden hunger”, which has become a major concern in many developing countries, despite significant efforts to enhance the nutritional quality of cereals. Elevated levels of phytic acid can exacerbate micronutrient malnutrition in populations heavily dependent on cereal-based diet. Traditionally, post-harvest processing techniques, such as soaking, fermentation, milling and conventional breeding approaches such as germplasm screening and the use of low phytate mutants were used to develop low phytic acid levels cereal varieties. Nevertheless, the agronomic and economic trade-offs of these methods created an urgent need to shift to genetically safe approaches. Genomic manipulation techniques, including marker-assisted breeding and genome editing tools such as CRISPR/Cas systems, offer significant potential to precisely target genes involved in phytic acid biosynthesis and transport. These techniques enable the development of low-phytic-acid cereal varieties with improved mineral bioavailability and enhanced nutritional quality. Recent studies have demonstrated the efficiency of these techniques in manipulation of MRP and IPK gene family resulting up to 85 % and 60 % phytic acid reduction in wheat and rice respectively. Since cereals play a significant role in food system transformation, this review emphasises the scope of these techniques in breeding low-phytic-acid cereals for global nutritional sustainability.
Navya et al. (Wed,) studied this question.