Unraveling grain quality in cereals: development, heat stress, and molecular mechanisms

Over the past half-century, maize, rice, and wheat have been crucial for global food security. Today, escalating demand for high-quality grain coincides with the mounting challenge of balancing quality with yield under climate change. Grain quality, governed by complex molecular mechanisms, is more intricate than yield. This review synthesizes recent advances in understanding these mechanisms, focusing on genes and pathways controlling appearance (e.g., size via ubiquitination, color via anthocyanins) and nutritional value (e.g., starch and storage protein composition). We also explore how high temperatures compromise these traits. Furthermore, we discuss integrative breeding strategies that leverage shared molecular pathways across cereals to develop high-yielding cultivars with superior quality, aiming to enhance both human nutrition and agricultural sustainability.