Rice (Oryza sativa) is a crucial staple crop worldwide, providing nutrition to more than half of the global population. Nonetheless, the sustainability of grain production is increasingly jeopardized by both biotic and abiotic stressors exacerbated by climate change, which increases the crop’s rvulnerability to pests and diseases. Genome-editing by clustered regularly interspaced short palindromic repeats and CRISPR-associated Protein 9 (CRISPR-Cas9) presents a potential solution for enhancing rice productivity and resilience under climatic stress. This technology can alter a plant’s genetic components without the introduction of foreign DNA or genes. It has become one of the most extensively used approaches for discovering new gene functions and creating novel varieties that exhibit a higher tolerance to both abiotic and biotic stresses, herbicide resistance, and improved yield production. This study examines numerous CRISPR-Cas9-based genome-editing techniques for gene knockout, gene knock-in, multiplexing for simultaneous disruption of multiple genes, base-editing, and prime-editing. This review elucidates the application of genome-editing technologies to enhance rice production by directly targeting yield-related genes or indirectly modulating numerous abiotic and biotic stress-responsive genes. We highlight the need to integrate genetic advancements with conventional and advanced agricultural methods to create rice varieties that are resilient to stresses, thereby safeguarding food security and promoting agricultural sustainability amid climatic concerns.
Rice (Oryza sativa) is an important staple food crop worldwide, especially in east and southeast Asia. About one-third of rice cultivated area is under saline soil, either natural saline soils or irrigation with brackish water. Salinity stress is among the devastating abiotic stresses that not only affect rice growth and crop productivity but also limit its cultivation area globally. Plants adopt multiple tolerance mechanisms at the morphological, physiological, and biochemical levels to tackle salinity stress. To identify these tolerance mechanisms, this study was carried out under both a controlled glass house as well as natural saline field conditions using 22 green super rice (GSR) lines along with two local varieties (“IRRI 6 and Kissan Basmati”). Several morpho-physiological and biochemical parameters along with stress-responsive genes were used as evaluation criteria under normal and salinity stress conditions. Correlation and Principal Component Analysis (PCA) suggested that shoot-related parameters and the salt susceptible index (SSI) can be used for the identification of salt-tolerant genotypes. Based on Agglomerative Hierarchical Cluster (AHC) analysis, two saline-tolerant (“S19 and S20”) and saline-susceptible (“S3 and S24”) lines were selected for further molecular evaluation. Quantitative RT-PCR was performed, and results showed that expression of 1-5-phosphoribosyl -5-5-phosphoribosyl amino methylidene amino imidazole-4-carboxamide isomerase, DNA repair protein recA, and peptide transporter PTR2 related genes were upregulated in salt-tolerant genotypes, suggesting their potential role in salinity tolerance. However, additional validation using reverse genetics approaches will further confirm their specific role in salt tolerance. Identified saline-tolerant lines in this study will be useful genetic resources for future salinity breeding programs.
The wheat plant requires elevated phosphorus levels for its normal growth and yield, but continuously depleting non-renewable phosphorus reserves in the soil is one of the biggest challenges in agricultural production worldwide. The Phosphorus Starvation Tolerance 1 (PSTOL1) gene has been reported to play a key role in efficient P uptake, deeper rooting, and high yield in rice. However, the function of the PSTOL1 gene in wheat is still unclear. In this study, a total of 22 PSTOL1 orthologs were identified in the wheat genome, and found that wheat PSTOL1 orthologs are unevenly distributed on chromosomes, and these genes were under strong purifying selection. Under different phosphorus regimes, wheat PSTOL1 genes showed differential expression patterns in different tissues. These results strengthen the classification of Pakistan-13 as a P-efficient cultivar and Shafaq-06 as a P-inefficient cultivar. Phenotypic characterization demonstrated that Pakistan-13 wheat cultivar has significantly increased P uptake, root length, root volume, and root surface area compared to Shafaq-06. Some wheat PSTOL1 orthologs are co-localized with phosphorus starvation’s related quantitative trait loci (QTLs), suggesting their potential role in phosphorus use efficiency. Altogether, these results highlight the role of the wheat PSTOL1 genes in wheat P uptake, root architecture, and efficient plant growth. This comprehensive study will be helpful for devising sustainable strategies for wheat crop production and adaptation to phosphorus insufficiency.