University of Amsterdam amsterdam, Noord-Holland, Netherlands
Body of Abstract: Phosphorus (P) plays a critical role in plants. It is present in soils in various forms with usually low availability and poor mobility. Hence, plants have evolved various strategies to absorb sufficient amounts of P, which include modification of the root system architecture, and changes in carbon metabolism and the composition of cellular membranes. To investigate how roots respond to phosphate availability, we discovered that increasing concentrations of KH2PO4 triggered a dose-dependent root skewing response in Arabidopsis. Evidence is provided that this response is Pi-specific and involves rearrangement of the microtubule cytoskeleton in cells in the elongation zone. Higher P<sub>i levels cause a stronger left-handed cell-file rotation which causes a right-handed root skewing response. These results indicate that P<sub>i plays a key role in controlling root circumnutation, knowledge that may help with the challenge of breeding crops for low-input agriculture and compacted soils.