Iron availability modulates the root calcium signature evoked by exogenous ATP.

Plants use changes in cytosolic free Ca ("signatures") to encode information from the specific signals generated in development, immunity and stress perception. Phosphate availability has a significant impact on the root calcium signatures generated in response to abiotic stress stimuli and exogenous purine nucleotides. In the case of the response to exogenous ATP, the effect of low phosphate availability is linked to abnormal iron and reactive oxygen species accumulation with iron deprivation's restoring normal signature dynamics. Here, the effect of iron deprivation with normal phosphate availability has been examined. Iron deprivation significantly alters the root calcium signature evoked by exogenous ATP and may link to levels of reactive oxygen species and callose deposition.