Transcriptional Regulation, Epigenetic Memory, and CRISPR-Based Engineering of Combined Abiotic Stress Tolerance in Cereal Crops

Abstract

Simple Summary Wheat, rice, maize, barley, and sorghum feed most of the world, but their harvests are increasingly damaged by weather extremes that arrive together, such as drought combined with heat, or salty soil combined with cold. When two stresses hit at once, crop damage is worse than either stress alone would cause, and plants respond in ways that differ from how they respond to a single stress. Most studies still test crops against only one stress at a time, leaving a poor understanding of how plants cope with combinations. This review brings together three areas of plant science that are usually studied separately. These are the internal switches, called regulatory proteins, that turn stress defence genes on and off, the chemical markers on plant genetic material that can remember past stress and help the plant respond faster next time, and modern gene editing tools that can fine tune these systems in crop plants. By connecting these three areas into one framework, the review shows which mechanisms are well understood, which remain unknown, and which crops need further study, particularly barley and sorghum. This work offers a roadmap for researchers and plant breeders aiming to develop cereal varieties that can withstand multiple weather stresses at once, supporting global food security as climate conditions become more unpredictable and severe.