All cereal crops are grasses, meaning that the grass family provides more than 50% of global calories. The grass leaf underpins this crucial productivity and yet we do not understand the gene regulatory networks that control its development. In part this is because the grass leaf has a distinct shape from other flowering plants. Unlike many flowering plants which have a narrow base (called a petiole) and a wide, flat lamina, grasses have a leaf base that wraps around the stem (called a sheath), a middle hinge like region (ligule and auricles), and a narrow, elongated lamina (called a blade). Despite these stark shape differences, our lab’s recent work has shown that it is possible that a common underlying genetic mechanism underpins the development of both leaf shapes (Richardson, et. al, Science 2021). Through analysis of mutant phenotypes we hypothesise that this network may also underpin the development of other grass-specific organs that have a key role in cereal grain quality (Richardson, et. al, Current Opinion in Plant Biology, 2024). However, to date we only know a handful of the genes that may contribute to this fundamental gene regulatory network. To address this major gap in our understanding, during this PhD you will investigate the genetic network underpinning grass leaf development and how it may differ in other grass organs. To do this you will learn to use 3D imaging, computational modelling, and gene expression analyses to test hypotheses and characterise gene functions. This work will identify new genes involved in the gene network that defines the shape of the grass leaf and how these genes interact to modulate growth patterns to generate different organ shape. Through a better understanding of the gene regulatory networks that control grass growth and development, in the future we will be able to identify approaches for precision engineering of cereal development for optimal yields and quality, under different environments and agronomic practices.

During this PhD you will gain experience in a range of different experimental and analytical techniques, including confocal microscopy, molecular biology, high-throughput sequencing, gene editing, and statistics. Through joining the inclusive and supportive environment of the Plant Shape Lab you will also have opportunities to develop independence as a researcher as well as team research skills, work with both national and international collaborators, and to present your work to a wide audience through scientific outreach events and attendance of conferences.