description
- As the primary source of calories, cereals are the cornerstone species of our food security. To sustainably meet food demands, we need to increase cereal grain yields without increasing inputs or using more land, all the while facing accelerating and more extreme temperature and drought events. Plants faced severe climate challenges millions of years ago when they expanded to living on land. To survive, land plants evolved a highly adaptive outer surface lined with epidermal cells that secrete a protective lipid-rich cuticle to prevent water loss and reflect incoming radiation, interspersed with adjustable air pores called stomata allowing plants to breathe and transpire. In this way, the outer epidermis balances protection and exchange with the above-ground environment. Fine-tuning this balance helps plants respond to changing and challenging environments. For example, grasses, including staple cereal crops develop extremely efficient stomatal complexes and thick waxy cuticles, key elaborations which help grasses save water and maintain temperature on hot, high light plains. Epidermal surfaces can also develop other types of specialised cells, including defensive structures such as hairs and silica-accumulating cells which can also influence epidermal water loss, cooling and stomatal function. We propose that these adaptive features of the cereal epidermis can be mobilised to engineer cereal crops which need less irrigation and maintain yield in future climates. To do this, we need to understand how plants coordinate the cuticle and specialised cell types on the epidermis and the relevance of each component and their combinations to epidermal function. In a major advance in this effort, our research group recently revealed that deeply conserved, interacting genes control both epidermal cell patterning as well as cuticle properties in barley, thus identifying a shared upstream network controlling multiple epidermal features linked to cereal performance. This proposal exploits these findings as a platform to determine the crucial steps in epidermal development and how they influence each other, respond to environmental conditions and impact epidermal functions and whole plant productivity. We will deploy cutting edge approaches to profile cuticle and cell patterning in the epidermis at an unprecedented resolution and explore the interdepenc(ies) between these events. We will also exploit our genetic knowledge to evaluate genetic determinants in wheat, a closely related cereal which along with barley dominate temperate agriculture. Finally, we will use state-of-the-art controlled environments and specialist physiological methods to assess the impact of altered epidermal features on physiological function both at the tissue and whole plant level and future climate scenarios. Taken together, our research will deliver a step-change in our ability to design suites of epidermal features to future-proof our crops.