Speaker
Description
Understanding the uptake and localization of micronutrients in plant-soil systems is essential for improving crop nutrient efficiency and agricultural production. Copper (Cu) is an essential micronutrient required for fertility and grain production in grasses; however, its limited solubility in soils restricts plant acquisition and complicates efforts to understand Cu bioavailability in the rhizosphere. We investigated matrix-dependent Cu uptake in the model grass species Brachypodium distachyon by combining synchrotron-based imaging with physiological assays.
Synchrotron μXRF analyses of root and shoot tissues from plants grown in CuO-amended soil demonstrated that Brachypodium acquires and redistributes Cu from sparingly soluble mineral sources. Complementary μXRF and μXRD measurements of intact roots growing in CuO-amended field soil further demonstrated the utility of simultaneously mapping elemental distributions and mineral phases to investigate Cu localization at the soil-root interface.
To investigate the physiological basis of mineral-associated Cu uptake, we performed time-resolved spectrophotometric analyses of Cu(II) reduction by intact Brachypodium roots using CuO and Cu-citrate. These assays revealed matrix-dependent differences in Cu reduction kinetics, with reduction activity enhanced under Cu deficiency and exhibiting saturation behavior consistent with a finite, enzyme-like reduction capacity. Together, these complementary approaches link Cu distribution in complex soil environments with a candidate physiological mechanism for Cu acquisition, providing new insight into matrix-dependent Cu uptake in grasses and demonstrating the value of multimodal synchrotron imaging for investigating plant-soil interactions.