Molybdenum-induced effects on nitrogen absorption and utilization under different nitrogen sources in Vitis vinifera

ABSTRACT Nitrogen (N) in different forms has been demonstrated to play significant roles in plants. However, little is known about molybdenum (Mo) effects on N absorption and utilization in grapevine seedlings grown under different N sources. The present study used a sand culture system to analyze the impact of Mo application (0 μM; 1 μM) on N absorption and utilization in grapevine (Vitislabrusca × V. vinifera ‘Shine Muscat’ (rootstock 3309 m)) young potted seedlings under different N sources (NO3 −, NH4NO3 and NH4 +). The different N forms and Mo application significantly influenced dry matter accumulation, and root architecture and activity. The effects of Mo on total N content followed the order of (NH4NO3 > NO3 − > NH4 +). Moreover, Mo and N induced VvMOT1 and VvNRT1.1 expression synergistically. Mo supply altered the utilization of NO3 −, NO2 −, and NH4 + in grapevines under different N sources. NH4NO3 showed the highest effect while NH4 + the least. Furthermore, the 15N-labeling experiment showed that the 15N content in shoot and root and the 15N-use efficiency were the highest after Mo application under NH4NO3 source, indicating the synergistic effects of Mo with the co-application of NO3 − and NH4 + sources. The study’s findings provide insights on Mo and N fertilizer utilization for cultivation and production practices in fruits.