Systemic regulation of nodule structure and assimilated carbon distribution by nitrate in soybean

• DOI: 10.3389/fpls.2023.1101074
• Publication Date: 2023-02-06T06:11:12Z
• Authors: Sha Li; Chengbin Wu; Hao Liu; Xiaochen Lyu; Fengsheng Xiao; Shuhong Zhao; Chunmei Ma; Chao Yan; Zhilei Liu; Hongyu Li; Xuelai Wang; Zhenping Gong
• Keywords: Nodule (geology); Carbon fibers

Background The nitrate regulates soybean nodulation and nitrogen fixation systemically, mainly in inhibiting nodule growth reducing nitrogenase activity, but the reason for its inhibition is still inconclusive. Methods systemic effect of on structure, function, carbon distribution ( Glycine max (L.) Merr.) was studied a dual-root system, with both sides inoculated rhizobia only one side subjected to treatment four days. non-nodulating genetically devoid ability form nodules. Nutrient solutions concentrations 0, 100, 200 mg L -1 were applied as KNO 3 side, while nodulating received nitrogen-free nutrient solution. Carbon partitioning roots nodules monitored using 13 C-labelled CO 2 . Other responses measured via estimation activity microscopic observation ultrastructure. Results Elevated caused decrease number bacteroids, fusion symbiosomes, enlargement peribacteroid spaces, onset degradation poly-β-hydroxybutyrate granules, which storage bacteroids. These observations associated strong Furthermore, our data demonstrate that assimilated more likely be allocated roots, follows from competition between symbiotic non-symbiotic system. Conclusion We propose there no when they are indirectly supplied nitrate, reduction fluxes mechanism by plant systemically suppresses under nitrogen-replete conditions.