Nitrate has been reported to improve tolerance of plants under flooding by modulating carbon and nitrogen metabolism of root cells; however, the extent to which nitrate modulates the photosynthetic process is not well understood. This work aimed to evaluate the photosynthetic process by nitrate-mediated modulation of hypoxic metabolism in the root of common bean plants (Phaseolus vulgaris L.) under flooding and recovery conditions. Three groups of common beans [N₂-fixing (N₂)], N₂-fixing pre-hypoxic nitrate-treated (N₂ + NO₃⁻), and nitrate (NO₃⁻)-supplied plants] were grown in vermiculite and the root system was subjected to flooding for 48 h at the early reproductive stage. After flooding, plants returned to normoxic conditions per 24 and 72 h for recovery. Plants from N₂ + NO₃⁻ and mainly NO₃⁻ groups maintained transpiration rate (E) and CO₂ assimilation under root-flooding, which was not shown by N₂-fixing plants. No changes in the dynamic dissipation of photosynthetic energy were evidenced in leaves of NO₃⁻ plants upon flooding, besides an increase in nitrate reductase (NR) activity and a decrease in fermentative enzymes in roots. Reactive oxygen species (ROS) and antioxidative enzymes increased in leaves and decreased in roots. Nitrate-mediated maintenance of the photosynthetic process may be related to induction in NR activity in roots to alleviate the toxic effects of fermentation through a decrease of fermentative enzyme activity.

据报道，硝酸盐可通过调节根细胞的碳和氮代谢来提高植物在淹水条件下的耐性。但是，硝酸盐调节光合作用的程度尚不十分清楚。这项工作旨在通过淹水和恢复条件下硝酸盐介导的普通豆类植物（菜豆（Phaseolus vulgaris L.））根部缺氧代谢的调节来评估光合作用过程。三组共同豆[N ₂ -定影（N ₂）]，N ₂ -定影预缺氧硝酸盐处理过的（N ₂  + NO ₃ ^- ）和硝酸（NO ₃ ^-（）提供的植物]在ver石中生长，并且在生殖初期将根系浸没48 h。淹水后，植物每24和72小时恢复到常氧条件以恢复。选自N植物₂  + NO ₃ ^-和主要NO ₃ ^-基团保持蒸腾速率（ë）和CO ₂下根溢流同化，这是不被N示出₂ -定影植物。光合能量的耗散动态没有更改证明在无叶₃ ^-水淹后植物除根部的硝酸还原酶（NR）活性增加和发酵酶减少外。叶片中的活性氧（ROS）和抗氧化酶增加，而根部减少。硝酸盐介导的光合作用过程的维持可能与根部NR活性的诱导有关，以通过降低发酵酶的活性来减轻发酵的毒性作用。