第1111回生物科学セミナー
When Two Make One: Understanding How Plants Graft
Dr. Charles Melnyk（The Sainsbury Laboratory, University of Cambridge）
2016年09月20日(火) 16:30-18:00 理学部2号館 講堂
Plant grafting is a biologically important phenomenon involving the physical joining of two plants to generate a chimeric organism. It is widely practiced in horticulture and used in science to study the long-distance movement of molecules. Despite its widespread use, the mechanism of graft formation and vascular reconnection is not well understood. Here, I present the dynamics and mechanisms of vascular regeneration in Arabidopsis thaliana during graft formation. I demonstrate a temporal separation between phloem and xylem reconnection, and show an asymmetry in cell division, gene expression and cell differentiation that is resolved by grafting. Thousands of genes are differentially expressed at the graft junction including genes that are only upregulated by grafting. Grafted plants initially show a transcriptional response that is similar to cutting, but after several days, a unique transcriptional response appears in grafted plants. I propose that an inter-tissue communication process occurs at the graft junction to promote vascular connection. Altogether, this research has implications for phenomena where forming vascular connections are important including plant grafting, parasitic plant infection and wound healing.
