The SPL gene family in rice: Master regulators of abiotic stress tolerance and prospects for crop resilience

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.