Nitrogen Modulates the Effects of Short-Term Heat, Drought and Combined Stresses after Anthesis on Photosynthesis, Nitrogen Metabolism, Yield, and Water and Nitrogen Use Efficiency of Wheat

More frequent and more intense heat waves greater drought stress will occur in the future climate environment. Short-term extreme often simultaneously after winter wheat anthesis, which has become major constraint threatening yield. In this study, short-term heat, their combination were applied to plants all restored outdoor normal temperature full watering treatment. The aim of current study was evaluate role nitrogen (N) modulating effects post-anthesis on photosynthesis, N metabolism-related enzymes, accumulation protein growth, as well yield water (WUE) use efficiency (NUE) results showed that compared with low application (N1), medium (N2) enhanced activities nitrate reductase (NR) glutamine synthase (GS) grains under alone, provided a basis for at later stage growth. Under individual stresses, N2 or high (N3) increased leaf photosynthetic rate (An), PSII photochemical instantaneous WUE N1, whereas these parameters usually significantly improved by N1 combined stress. positive effect An growth represented higher green area, aboveground dry mass plant height, variation can be explained accurately content per unit area. anthesis resulted pronounced decrease reducing grain number spike thousand kernel weight. reduction NUE than Compared N3 prevented caused alone. However, conducive improving productivity, when exposed data indicated appropriately increasing effectively physiological activity alleviating yield, NUE. conditions, (N1) may suitable strategy compensate