NPK-N application limits grain cadmium concentration of wheat via promoting Cd export during grain filling

https://link.springer.com/article/10.1007/s11104-025-07277-x

Plant and Soil，11 February 2025

Yiran Cheng,Yuanjiang He,Jia Chen,Weiping Li,Wenhui Xiang,Xing Chen,Dan Long,Jian Zeng,Yang Liu,Dongwei Wang,Dandan Wu,Lina Sha,Xing Fan,Haiqin Zhang,Houyang Kang,Yonghong Zhou,Yong Ren&Yi Wang

Aims

Wheat easily absorbs Cadmium (Cd) from soils and accumulates in its grains. Nitrogen (N) fertilizer management has been used to limit grain Cd concentrations in wheat, but the effects of compound fertilizers (NPK-N) are unclear.

Methods

Here, three years’ of field experiments were conducted to evaluate the effects of NPK-N on grain Cd concentration and yield of 50 wheat cultivars. A high-Cd accumulating cultivar Chuanmai 68 (CM68) and a low-Cd accumulating Mianmai 902 (MM902) were further used to reveal the physiological and molecular mechanisms of the Cd transport pathway.

Results

The results showed that NPK-N application significantly reduced grain Cd accumulation in all 50 wheat cultivars compared to amide N fertilize (urea-N) application. MM902 showed lower Cd uptake before anthesis, higher Cd export from plant during grain filling, and lower grain Cd concentration than CM68. Meanwhile, NPK-N application significantly reduced grain Cd concentration in CM68 (39.70%) and MM902 (35.12%), as well as Cd uptake, but promoted Cd export compared to urea-N. Besides, the expression levels ofTaIRT1(Iron Regulated Transporter 1) andTaCCX2(Cation/Ca Exchanger 2) were associated with Cd uptake and export, respectively. Overexpression ofTaIRT1increased Cd uptake and grain Cd concentration in rice.

Conclusions

Our study showed that NPK-N application can limit grain Cd concentration and increase grain yield of wheat. The different grain Cd concentrations between CM68 and MM902 are mainly results from the different Cd uptake before anthesis and Cd export during grain filling. The results provide a theoretical basis for safe and high-quality wheat production by NPK-N application.