Epigenetic Memory and Hormonal Crosstalk in Plant Drought Adaptation: Mechanisms, miRNAs, and Technological Advances

Abstract

Drought poses a major threat to global food security, making it critical to understand the molecular mechanisms underlying plant responses to water scarcity. Epigenetic modifications, including DNA methylation and histone alterations, play central roles in regulating genes and hormonal pathways essential for drought adaptation. MicroRNAs, while primarily functioning as post-transcriptional regulators, can also influence epigenetic pathways and contribute to chromatin remodelling, suggesting a role in modulating epigenetic memory. Investigating these interactions is essential for understanding how plants integrate epigenetic and post-transcriptional regulation during stress. Epigenetic memory in drought-adapted plants provides insights into the transgenerational inheritance of adaptive traits and reveals how plants balance genome stability with flexibility. The crosstalk between epigenetic mechanisms and hormonal signalling is crucial for fine-tuning gene expression, promoting drought resilience. This review proposes a conceptual framework integrating epigenetic, hormonal, and miRNA-mediated regulation of drought responses. It emphasizes the impact of advanced technologies, such as bisulfite sequencing and CRISPR-Cas9, in dissecting plant epigenetic responses to drought. These approaches improve our understanding of drought tolerance mechanisms and offer promising strategies for developing resilient crops for sustainable agriculture. However, direct evidence linking epitranscriptomic modifications to long-term drought memory remains limited, and this emerging regulatory layer requires further experimental validation.