Root System Architecture (RSA) and Drought Tolerance in Rice: Exploring Genetic Mechanisms and Genomic Approaches for Enhancing RSA

Rice is a staple food crop for half of the world's population. Its production and productivity are significantly affected by various abiotic and biotic factors. In recent years, drought has become a critical environmental challenge exacerbated by climate change. Rice is highly vulnerable to water scarcity and leading to substantial reduction in crop yield during drought conditions. However, it has various adaptive mechanisms to cope with adverse environmental conditions. The main objective of this study the mechanisms underlying rice adaptations to water scarcity through Root System Architecture (RSA) and explore novel genomic approaches utilized to enhance RSA. It explores morphological, physiological, biochemical, and molecular mechanisms influencing RSA traits, underscoring the significance of deeper and well-distributed roots in alleviating water stress. Moreover, we discussed the role of key hormones, genes, Transcription Factors (TFs), metabolites, and key regulatory pathways governing RSA in rice. Genomics approaches such as multi-omics, genome-wide association studies (GWAS), Single nucleotide polymorphisms (SNPs), and CRISPR-Cas9 are being leveraged to improve RSA traits. Additionally, we attempt to presents some promising rice genotypes and cultivars from major rice-growing countries, which have enhanced RSA, significant drought tolerance and yield potential under water stress. Moreover, utilization of these knowledge offers wider understanding for breeding rice cultivars with improved RSA that are well adapted to water-scarce environments, thereby contributing to global food security amid climate challenges.