Recently, a paper named Nitrogen Metabolism in Adaptation of Photosynthesis to Water Stress in Rice Grown under Different Nitrogen Levels reported by Jin Qianyu's research team from China National Rice Research Institute (CNRRI) of Chinese Academy of Agricultural Sciences (CAAS) was published on the Frontiers in Plant Sciences. The roles of N metabolism in the adaptation of photosynthesis to water stress in rice were investigated in this paper.

Photosynthesis is one of the physiological processes that is easily impacted by water stress. The majority of assimilated N in plants is also invested in photosynthetic machinery, but there is ongoing debate concerning the role of N metabolism in the adaptation of photosynthesis to water stress in rice.

Our results reveal that higher N increases adaptability of rice photosynthesis to water stress via the pathways including: (i) mitigation of stomatal limitation to photosynthesis and maintenance of higher Rubisco activity and higher excessive energy dissipation capacity; (ii) maintained or increased antioxidant enzymes activities and key enzymes involved in N metabolism (Glutamate synthase, GOGAT; Glutamate dehydrogenase, GDH; Glycolate oxidase, GO); and (iii) increased nitrate and ammonium assimilation and synthesis of proline. Nitrogen metabolism plays a central role in these pathways. The results suggest that the resistance of rice photosynthesis to water stress could be improved by manipulation of key enzymes involving in N metabolism, which provides new insights for improving rice N use efficiency and drought tolerance via the nutrient resource management in certain drought-prone regions.

This study was supported by National Science Foundation of China (Grant No.: 31270035), Agricultural Science and Technology Innovation Program (ASTIP) of CAAS (Grant No.: CAAS-ASTIP-2013-CNRRI) and Natural Science Foundation of Zhejiang Province (Grant No.: LY18C130005, LQ15C130004). More details are available on the link below: https://www.frontiersin.org/articles/10.3389/fpls.2017.01079/full