Reproduction is central to the life cycle of most organisms, with the reproduction of plants critical for the production of crops and food security. Despite the importance of plant reproduction for agriculture and life on the planet, there are still many steps in the process that are not fully understood. We use molecular genetics, developmental biology and cell biology to study how plants reproduce. We examine the function of proteins involved in this developmental process, with a particular focus on receptor kinases linked to signalling during pollen tube reception at the ovule and kinesins that are implicated in cell division and reproduction.
Receptors on the cell surface detect diverse signals to monitor the environment surrounding each cell, with over 400 receptor kinases present in the model plant, Arabidopsis. During reproduction these receptor kinases mediate the interaction of the pollen tube and ovule via secreted signals to coordinate pollen tube growth, reception upon arrival at the ovule, and delivery of the sperm nuclei to the egg and central cells. We are interested in the functions of a subset of these proteins, the malectin domain receptor kinases, during fertilisation having identified two malectin domain receptor kinases that act in the synergid cells during pollen tube reception (Galindo Trigo et al. 2020). This family of malectin domain receptor kinases has been implicated in cell wall integrity monitoring and peptide binding. Plant reproduction is a fabulous system in which to study cell-to-cell communication during normal plant development. This work is currently supported by a BBSRC responsive mode grant.
Further information on our work on receptor kinases in reproduction and signalling
Our bioinformatic analysis of the kinases led to the recognition that malectin domains in plants occasionally also exist in proteins other than receptor kinases. Specifically, the malectin domain can also been found joined to a kinesin domain, with kinesins acting as molecular motors that move along the cytoskeleton. For one of the malectin domain kinesins, we have identified a function in pollen and seed development, probably through a role in cell division (Galindo Trigo et al. 2020). Despite the discovery of cells in plants 350 years ago and the importance of plant cell division to life on Earth, many aspects of cell division are still not understood in plants. This includes details of how new cell membranes and walls are assembled to split a mother cell into two daughter cells. The existence of malectin domain kinesins raises the conundrum of what a carbohydrate-binding domain, usually associated with cell wall monitoring, does in the cytoplasm during cell division .
The function of malectin domain proteins in plant development
We are also involved in other research projects via collaborations. Plants not only respond to their immediate environmental conditions from surrounding cells and from biotic and abiotic factors, but can also ‘remember’ past conditions, and even the environment in which their parent(s) grew. As the DNA sequencing of a plant changes only very slowly, the memory of the recent past is via chemical changes to the DNA that affect its function (epigenetics).
These epigenetic mechanisms can regulate gene expression and also keep immobile the transposable elements (otherwise known as jumping genes for their ability to move within a genome). Together with collaborators in Sheffield and Germany, we are now investigating how these epigenetic mechanisms elements contribute to plant adaptation to stress and the evolution of plant genomes.
The lab is part of the Plants, Photosynthesis and Soils research cluster in the School of Biosciences at the University of Sheffield.
We believe everyone is welcome in science, regardless of gender, sexuality, nationality, race, disability or any other characteristic. Together with the other occupants of the D59 lab (Andrew Fleming and Sam Amsbury's groups), we hope we are creating an environment where everyone feels safe and able to be themselves.