Plant growth regulator applications and mechanisms for boosting rice productivity

Plant growth regulators (PGRs) have emerged as an important tool for improving crop productivity and adaptation to intensifying environmental challenges, especially in rice. This review summarizes 209 publications (2000–2025) on the current developments in exogenous PGR applications across major growth phases from germination to grain filling. It reveals the principal findings on hormonal crosstalk, including abscisic acid-gibberellin (ABA-GA) antagonism, stress balancing, and genotype-specific multi-hormonal strategies. It outlines 10–40% yield improvements in conjunction with precision agronomy. We elucidate how PGRs regulate growth, development, stress tolerance, and yield through molecular and physiological pathways. Nano-formulations and genome-editing methods offer revolutionary potential, combining hormonal modification with genetic improvement and digital technologies for sustainable intensification. While emphasizing the important role PGRs play, this review also highlights context-specific effects and application risks, and emphasizes variety-specific, evidence-based protocols. Ultimately, this work charts a course for future research and precision application, and it marks a shift in paradigm to create a stronger, more sustainable rice production system.