From photoreceptor signalling to organ morphogenesis: How light regulates leaf shape

Objective

Leaves are one of the defining features of plants and are essential for their survival because they perform key functions such photosynthesis. Like for many plant organs, the growth of leaves is tremendously sensitive to the surrounding environment, including to the presence of light, which is necessary for photosynthesis. Light perception by plant photoreceptors can cause changes in leaf shape that help the plant adapt to its environment. Despite the agricultural importance of leaves, the mechanisms underlying these responses are poorly understood. The project will address this, using as a model the leaf flattening that is induced when plants detect blue light from above, a response that enables maximised light capture. A change in organ shape upon photoreceptor signalling requires coordinated regulation at the molecular, cellular, and tissue scales. The project will uncover the mechanisms underpinning regulation at each of these scales during blue-light-induced leaf flattening. The relationship between biological scales is often non-intuitive due to feedbacks and emergent properties. In these cases, mathematical models are particularly useful to generate and test hypotheses, and hence will be used for this project in combination with experiments. This work will generate a predictive understanding of how leaf shape is regulated by light, thereby answering a fundamental question about photobiology and plant development.