Triumphing over hidden hunger: Redesigning rice (Oryza sativa L.) for enhanced nutraceutical grain composition...

Rice, a staple food crop, is consumed by most of the world's population. Micronutrient malnutrition is a severe health issue, leading to diseases such as cancer, anemia, diabetes, heart disease, and disorders in physical and psychological development. We aimed to create rice with low cadmium in the grain but having high cadmium in shoots, safe biofortified protein, high iron, and zinc using CRISPR/Cas9 and breeding technologies instead of adding drugs. The triple gene Knockout rice lines for two iron sensors and one negative regulator gene for cadmium were created to offer high Fe/Zn and low Cd content for breeders. Multiplexed gene editing mediated biolistic transformation of rice callus, and genotyping was used to check the genetic stability of the edited rice lines. Rice lines were found to have enhanced iron, zinc, and protein content, with concentrations varying based on growth conditions. These lines can be used as phytoremediators for cadmium by storing Cd on plant shoots. The rice-edited plants possessed excellent agro-morphological traits, photosynthetic, and physiological performance. The developed edited indica rice lines have crucial agronomic traits with more nutritional value. Compared to the other lines and the wild wildtype, the genome-edited free Cas9 line 2 showed better traits: 13.48 μg/g (iron), 22.9 μg/g (zinc), and a high protein content, which depends on how bioavailable metals and nutrients are in the soil. The line also had 20.60 g of seeds per 1000 g of plant, a total plant yield of 102.76 g, and 101 days of 50 % flowering. This work offers efficient and precise multiple gene-editing in rice with an effective, sustainable strategy for multi-trait enhancement. The developed lines could be used in breeding programs for sustainable solutions for malnutrition worldwide. The experimental results can provide reference and support for the safe use of edited crops as a diet.