MicroRNAs-mediated heat stress regulations in plants: Mechanisms and targets

Heat stress, exacerbated by global warming, can cause significant challenges to agriculture, adversely impacting plant growth, reproduction, and yield. This review examines the crucial role of microRNAs (miRNAs) in mediating plant responses to heat stress across various key crops, including Arabidopsis (Arabidopsis thaliana), rice (Oryza sativa), wheat (Triticum aestivum), and other significant species. Under high temperatures, miRNAs regulate gene expression by targeting transcription factors (e.g., SPL, NF-YA, and Apetala 2 [AP2]), heat shock proteins, and antioxidant enzymes (e.g., copper/zinc superoxide dismutase), thereby modulating pathways involved in hormone signaling, oxidative stress mitigation, and developmental transitions. Advanced high-throughput sequencing technologies have identified heat-responsive miRNAs (e.g., miR156, miR398, miR172) and their functional networks, including crosstalk with small interfering RNAs, long noncoding RNAs, and circular RNAs via competing endogenous RNA (ceRNA) mechanisms. These findings highlight miRNAs as promising targets for engineering heat-resilient crops. However, gaps remain in understanding tissue-specific miRNA dynamics and their integration with epigenetic and multi-omics networks. Future research should employ integrative approaches to optimize miRNA-based strategies for sustainable agriculture in the context of climate change.