The aleurone layer of cereal grains: Development, genetic regulation, and breeding applications

Cereal aleurone cells are differentiated from triploid endosperm cells and exhibit distinct cytological, physiological, and biochemical characteristics that distinguish them from the starchy endosperm cells of cereals. Aleurone cells maintain viability throughout seed development, whereas starchy endosperm cells undergo programmed cell death during maturation. Despite variations in aleurone-related traits among cereal species, the aleurone layer plays a crucial role in regulating many aspects of seed development, including the accumulation of storage reserves, the acquisition of dormancy, and germination. Given that many nutrients-such as lipids, dietary fibers, vitamins, and minerals like iron and zinc-are predominantly accumulated in the aleurone cells of cereal grains, this layer has attracted considerable attention aimed at improving the nutritional value of cereals. This review provides a comprehensive overview of the developmental, genetic, and molecular basis of aleurone cell differentiation and proliferation. It focuses on the improvement of aleurone-related traits informed by knowledge of the molecular networks governing aleurone development and presents a detailed discussion on the challenges and potential solutions associated with cereal improvement through the manipulation of aleurone-related traits.