Abstract Background Nitrogen (N) and phosphorus (P) are macronutrients essential for crop growth and productivity.In cultivated fields, N and P levels are rarely sufficient, contributing to the gap between realized and potential production.Fertilizer application increases nutrient availability, but is Ball - Field Equipment - Training Aids Team not available to all farmers, nor are current rates of application sustainable or environmentally desirable.Transcriptomic studies of cereal crops have revealed dramatic responses to either low N or low P single stress treatments.In the field, however, levels of both N and P may be suboptimal.
The interaction between N and P starvation responses remains to be fully characterized.Results We characterized growth and root and leaf transcriptomes of young maize plants under nutrient replete, low N, low P or combined low NP conditions.We identified 1555 genes to respond to our nutrient treatments, in one or both tissues.A large group of genes, including many classical P starvation response genes, were regulated antagonistically between low N and P conditions.An additional experiment over a range of N availability indicated that a mild reduction in N levels was barcoo Bridles -Stock bridles sufficient to repress the low P induction of P starvation genes.
Although expression of P transporter genes was repressed under low N or low NP, we confirmed earlier reports of P hyper accumulation under N limitation.Conclusions Transcriptional responses to low N or P were distinct, with few genes responding in a similar way to the two single stress treatments.In combined NP stress, the low N response dominated, and the P starvation response was largely suppressed.A mild reduction in N availability was sufficient to repress the induction of P starvation associated genes.We conclude that activation of the transcriptional response to P starvation in maize is contingent on N availability.