Plants are constantly exposed to mechanical forces: roots must penetrate soil and navigate around rocks to take up water and nutrients. Aboveground organs are exposed to wind, which can damage and even uproot plants. Plants must also accommodate the effects of gravity, which provides directional information for plant growth but also increases the mechanical self-load of plants as they grow in size and mass. Mechanical forces are also generated internally in all turgescent plant cells and drive cellular expansion. While plant morphological responses to mechanical forces have been described in great detail, at the molecular level, the mechanisms of plant mechanical signaling remain poorly understood.
Research in my lab is focused on understanding how mechanical forces are sensed, how stimulus perception is transduced into cellular Ca2+ and pH signaling and how these physiological signals are translated into growth and developmental responses. Using a combination of live cell fluorescence microscopy, automated phenotyping and molecular biology/genomic approaches, we have identified the receptor-like kinase FERONIA as a candidate sensor of cell stretching in Arabidopsis. Loss of FER function results in compromised mechanical Ca2+ signaling, reduced mechanical strength of root tissues and impaired control of cell expansion. Our current work is addressing the role of cyclic nucleotide-gated ion channels (CNGC) in FER-dependent Ca2+ signaling. Such Ca2+ signaling appears to serve as part of a conserved ion-signaling module to rapidly suppress cell expansion in growing tissues in response to a stressful environment.