Breeding Strategies and Biotechnological Approaches to Reduce Nitrate Levels in Vegetables: A Comprehensive Review

Abstract

Nitrate is a natural chemical compound found in soil and water, which plants absorb and convert into essential nutrients. Elevated concentrations of nitrate in vegetables can pose health risks, particularly when consumed in substantial amounts. Green leafy vegetables, while crucial for human nutrition, unfortunately belong to the category of foods that have the highest impact on nitrate absorption in living organisms. Overuse of nitrogen fertiliser can lead to the accumulation of high levels of nitrate in these plants. Therefore, it is crucial to make efforts to reduce the nitrate levels in leafy vegetables and restrict their use by humans. Plant breeders employ several techniques, such as traditional breeding and genetic modification, to selectively produce plants with lower nitrate levels. The process frequently involves intentionally choosing and crossbreeding plants that naturally have lower levels of nitrates, so transmitting this trait to their offspring. This method is frequently conducted over multiple generations to ensure stable and uniform results. In addition, modern biotechnological techniques, such as genetic engineering or gene editing, can be employed to directly modify the genes responsible for nitrate metabolism in plants. Advanced techniques such as integrated multi-omics, RNAi, gene editing, and genomics-assisted breeding are applied to create crops with fewer undesirable traits and to develop new strategies for regulating these traits in crop improvement projects.