Charles Melnyk, Department of Plant Biology, SLU.
For thousands of years, people have cut and joined together different plants to combine desirable characteristics through a process known as grafting. Plant tissues fuse, vasculature connects and a chimeric organism forms that has higher yields or enhanced disease resistance. Plant grafting is commonly used in horticulture, for instance in orchards and vineyards, to increase yields. However, grafting is limited to closely related species and grafts to unrelated species are not normally successfully. This failure is known as graft incompatibility and it limits which plants can be grafted.
Interestingly, plant pathogens known as parasitic plants undergo a conceptually related process to grafting by connecting elements of their vascular tissue to withdraw nutrients from the plants they infect, causing massive agricultural losses. Often, parasitic plants overcome recognition barriers to infect completely unrelated hosts, a process that is not possible during traditional grafting. Despite the huge agricultural importance of grafting and parasitic plant infection, we know little about these processes and how the vasculature regenerates or connects.
My research focuses on understanding how plants graft and how parasitic plants infect their hosts. Through my work with grafting, I am focusing on identifying the genes and mechanisms behind successful graft formation, and understanding why some plants fail to graft.
I will describe work my lab is doing with Arabidopsis thaliana and conifer trees, and extend these findings to a group of plants that were previously thought to be ungraftable: the monocots. I will also talk about our work in wound healing and regeneration, and how these processes help us better understand successful graft formation. I will extend the analysis to parasitic plants where we have identified a signal that regulates the number of parasitic plants infections.
Taken together, this work will improve our understanding of vascular biology and provide fundamental information that can be used to broaden the range of grafted plants and combat parasitic plant infections.