Strategies to enhance rice productivity in response to global demand have been the paramount focus of breeders worldwide. Multiple factors, including agronomical traits such as plant architecture and grain formation and physiological traits such as photosynthetic efficiency and NUE (nitrogen use efficiency), as well as factors such as phytohormone perception and homeostasis and transcriptional regulation, indirectly influence rice grain yield. Advances in genetic analysis methodologies and functional genomics, numerous genes, QTLs (Quantitative Trait Loci), and SNPs (Single-Nucleotide Polymorphisms), linked to yield traits, have been identified and analyzed in rice. Genome editing allows for the targeted modification of identified genes to create novel mutations in rice, avoiding the unintended mutations often caused by random mutagenesis. Genome editing technologies, notably the CRISPR/Cas9 system, present a promising tool to generate precise and rapid modifications in the plant genome. Advancements in CRISPR have further enabled researchers to modify a larger number of genes with higher efficiency. This paper reviews recent research on genome editing of yield-related genes in rice, discusses available gene editing tools, and highlights their potential to expedite rice breeding programs.

Rice production faces severe challenges from abiotic stresses, including drought, salinity, heat, cold and nutrient imbalance, causing yield losses of 30-70 % depending on stress severity and developmental stage. SQUAMOSA promoter binding protein-LIKE (SPL) genes, regulated primarily by miR156 and miR529, have emerged as key transcriptional regulators of abiotic stress tolerance in rice. This review synthesizes current research on SPL gene functions in stress adaptation, examining their roles in hormone signalling, ion homeostasis and developmental regulation during both vegetative and reproductive stages. We analyse functional genomics and reverse genetics studies demonstrating SPL contributions to yield improvement and stress tolerance and evaluate recent advances in CRISPR/Cas9 and base editing technologies for precise SPL gene modulation. The findings reveal distinct tissue specific and developmental stage specific functions of miR156/miR529-SPL regulatory modules, with miR156 predominantly controlling vegetative development while miR529 regulates reproductive processes. This review provides a framework for leveraging SPL gene networks in developing climate-resilient rice varieties through targeted genome editing approaches.

Rice is a staple food grain and its yield has undergone two major leaps, first during the 1960’s through improving the harvest index by introducing semi-dwarf trait and secondly through the introduction of hybrids during the 1980’s. However, yields have plateaued in the past decade, even as the growing population necessitates doubling rice production by 2050. Hence, genetic enhancement of yield potential in rice has become mandatory in rice-breeding programs, which can be achieved by mining novel yield genes from wild species, manipulating photosynthetic traits (e.g., C4 rice), or creating novel alleles through targeted mutagenesis. The available genome of the Nipponbare rice genome and the 3K Rice Genome Project have identified beneficial alleles and valuable accessions for breeding. Progress towards C4 rice highlights the need for photosynthetic trait manipulation to improve yields. However, the labor and time required stimulate breeders towards new technologies like genome editing. The CRISPR system offers a simpler, faster method to alter desired traits, with numerous candidate genes for grain yield. Rice, with its relatively small genome and strong synteny with other cereals, serves as an ideal model for the development of novel gene editing technologies. This review unveils an up-to-date investigation of rice genome editing for yield-related traits, with a focus on recent advancements, emerging trends and future directions to address the key challenges and opportunities in enhancing rice productivity. Future advancements in CRISPR-based multiplex editing, epigenome engineering and AI-driven predictive breeding will accelerate rice yield improvements, ensuring sustainable production to meet global food security demands by 2050.

The increasing global population, combined with escalating climate change, has necessitated the adoption of innovative agricultural practices to ensure sustainable food production. Traditional crop cultivation system relies on conventional weed management practices that are labour and resource intensive. To address this challenge, the development of herbicide-resistant (HR) crops has emerged as a critical solution. CRISPR/Cas-based genome editing has revolutionized HR crop development, offering precision and efficiency over conventional breeding and transgenic approaches. The acetolactate synthase (ALS) gene, which is essential for biosynthesis of branched-chain amino acids (BCAAs) such as leucine, isoleucine and valine, serves as a key target for ALS-inhibiting herbicides to control broad spectrum of weed species. Notably, several weed species were identified with natural mutations in ALS gene that confers strong level of resistance to different ALS-inhibiting herbicides. Advanced genome editing technologies like CRISPR/Cas9, CRISPR/Cas mediated base editing (BE) and prime editing (PE) have been successfully utilized to mimic these natural mutations or introduce novel mutations in ALS gene, thereby creating heritable herbicide resistance in various crops. In this review, we summarize the remarkable achievements reported so far in the development of herbicide-resistant crops specifically by targeting the ALS gene using CRISPR/Cas genome editing approach. Furthermore, we propose forward-looking perspectives on integrating multiplex gene editing and gene stacking. The synergy between CRISPR (Clustered Regularly Interspaced Palindromic Repeat) technology and advanced phenotyping platforms holds significant promise for next generation of climate-resilient herbicide resistance crop varieties. These insights offer a valuable roadmap for researchers to design tailored, sustainable weed management strategies and accelerate the global transition towards precision agriculture.