Oxygen and the Regulation of N2 Fixation in Legume Nodules Under P Scarcity

Kleinert, Aleysia; Roux, Marcellous Le; Kang, Yun Hwan; Valentine, Alex J.

doi:10.1007/978-3-319-55729-8_5

Cited by 2 publications

(2 citation statements)

References 61 publications

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“…But quite remarkably, the more rhizosphere ventilation is not a better strategy, because the plant rhizosphere has both aerobic azotobacter and amphitropic anaerobic bacteria, and a diffusion barrier in legume root nodules restricts O 2 flux into the nodule and thereby protects nitrogenase from inactivation by O 2 [ 55 , 56 ]. This study was consistent with the results from previous studies [ 56 , 57 ] considering root morphology and nodule development under soil ventilation.…”

Section: Discussionsupporting

confidence: 93%

Rhizosphere Ventilation Effects on Root Development and Bacterial Diversity of Peanut in Compacted Soil

Liang,

Yang,

et al. 2024

Plants

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Soil compaction is one of the crucial factors that restrains the root respiration, energy metabolism and growth of peanut (Arachis hypogaea L.) due to hypoxia, which can be alleviated by ventilation. We therefore carried out a pot experiment with three treatments: no ventilation control (CK), (2) ventilation volumes at 1.2 (T1), and 1.5 (T2) times of the standard ventilation volume (2.02 L/pot). Compared to no-ventilation in compacted soil, ventilation T1 significantly increased total root length, root surface area, root volume and tips at the peanut anthesis stage (62 days after sowing), while T2 showed a negative impact on the above-mentioned root morphological characteristics. At the podding stage (S2, 95 days after sowing), both ventilation treatments improved root morphology, especially under T1. Compared to CK, both ventilation T1 and T2 decreased the activities of enzymes involving the anaerobic respiration, including root lactate dehydrogenase, pyruvate decarboxylase and alcohol dehydrogenase. The activities of antioxidant enzymes of root superoxide dismutase, peroxidase and catalase also decreased at S1, while superoxide dismutase and peroxidase significantly increased under T1 at S2. The ventilation of compacted soil changed soil nitrogen-fixing bacterial communities, with highest bacterial alpha diversity indices under T1. The Pearson correlation analyses indicated a positive relationship between the relative abundance of Bradyrhizobiaceae and root activity, and between unclassified_family of Rhizobiales and the root surface area, while Enterobacteriaceae had a negative impact on the root nodule number. The Pearson correlation test showed that the root surface, tips and activity positively correlated with root superoxide dismutase and peroxidase activities. These results demonstrate that soil ventilation could enhance plant root growth, the diversity and function of soil nitrogen-fixing bacterial communities. The generated results from this present study could serve as important evidence in alleviating soil hypoxia caused by compaction.

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Section: Discussionsupporting

confidence: 93%

Rhizosphere Ventilation Effects on Root Development and Bacterial Diversity of Peanut in Compacted Soil

Liang,

Yang,

et al. 2024

Plants

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“…Overall, several experimental works have shown that the ODB plays an important role in regulating O 2 diffusion, especially when plant growth is restricted (i.e., mineral nutrient deficiencies). In this case, a down-regulation of N 2 fixation is required to meet the N demand of the legume plant [96].…”

Section: Nodule Oxygen Supplymentioning

confidence: 99%

Regulation of Symbiotic Nitrogen Fixation in Legume Root Nodules

Schwember

Schulze

Pozo

et al. 2019

Plants

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In most legume nodules, the di-nitrogen (N2)-fixing rhizobia are present as organelle-like structures inside their root host cells. Many processes operate and interact within the symbiotic relationship between plants and nodules, including nitrogen (N)/carbon (C) metabolisms, oxygen flow through nodules, oxidative stress, and phosphorous (P) levels. These processes, which influence the regulation of N2 fixation and are finely tuned on a whole-plant basis, are extensively reviewed in this paper. The carbonic anhydrase (CA)-phosphoenolpyruvate carboxylase (PEPC)-malate dehydrogenase (MDH) is a key pathway inside nodules involved in this regulation, and malate seems to play a crucial role in many aspects of symbiotic N2 fixation control. How legumes specifically sense N-status and how this stimulates all of the regulatory factors are key issues for understanding N2 fixation regulation on a whole-plant basis. This must be thoroughly studied in the future since there is no unifying theory that explains all of the aspects involved in regulating N2 fixation rates to date. Finally, high-throughput functional genomics and molecular tools (i.e., miRNAs) are currently very valuable for the identification of many regulatory elements that are good candidates for accurately dissecting the particular N2 fixation control mechanisms associated with physiological responses to abiotic stresses. In combination with existing information, utilizing these abundant genetic molecular tools will enable us to identify the specific mechanisms underlying the regulation of N2 fixation.

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Oxygen and the Regulation of N2 Fixation in Legume Nodules Under P Scarcity

Cited by 2 publications

References 61 publications

Rhizosphere Ventilation Effects on Root Development and Bacterial Diversity of Peanut in Compacted Soil

Rhizosphere Ventilation Effects on Root Development and Bacterial Diversity of Peanut in Compacted Soil

Regulation of Symbiotic Nitrogen Fixation in Legume Root Nodules

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