Nitrogen fixation in the rhizosphere of rice

Hirota, Yukinori; Fujii, Takayoshi; Sano, Yoshio; Iyama, S.

doi:10.1038/276416a0

Cited by 63 publications

(34 citation statements)

References 15 publications

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“…Although nitrogen can be depleted from rice paddy soil to the atmosphere by the nitrification-denitrification process, atmospheric N2 can also be incorporated into soil and rhizosphere under rice paddy field conditions by biological nitrogen fixation (BNF) (37,145,146,150). In addition, cyanobacteria and phototrophic bacteria grown on the surface water of rice paddies can also fix N2 (21,132).…”

Section: Nitrogen Fixationmentioning

confidence: 99%

Nitrogen Cycling in Rice Paddy Environments: Past Achievements and Future Challenges

et al. 2011

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Nitrogen is generally the most limiting nutrient for rice production. In rice paddy soils, various biochemical processes can occur regarding N cycling, including nitrification, denitrification, and nitrogen fixation. Since its discovery in the 1930s, the nitrification-denitrification process has been extensively studied in Japan. It may cause N loss from rice paddy soils, while it can also reduce environmental pollutions such as nitrate leaching and emission of nitrous oxide (N 2 O). In this review article, we first summarize the early and important findings regarding nitrification-denitrification in rice paddy soils, and then update recent findings regarding key players in denitrification and N 2 O reduction. In addition, we also discuss the potential occurrence of other newly found reactions in the N cycle, such as archaeal ammonia oxidization, fungal denitrification, anaerobic methane oxidation coupled with denitrification, and anaerobic ammonium oxidation.

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Section: Nitrogen Fixationmentioning

confidence: 99%

Nitrogen Cycling in Rice Paddy Environments: Past Achievements and Future Challenges

et al. 2011

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“…Anoxic microsites existing in soil particles (19) and litter (21) often provide a habitat for clostridia because they have been isolated from nonsubmerged soil and litter (13). Interestingly, early works suggested the presence of N 2 fixation by strictly anaerobic organisms and clostridia in the rice rhizosphere (10) and by the soil microbial community in aerobic cultures (14). Therefore, it is not surprising that clostridia reside in the aerial parts of plant tissues, which are exposed to the air and to O 2 produced by photosynthesis.…”

Section: Vol 70 2004 Anaerobic Nitrogen-fixing Consortia 3097mentioning

confidence: 99%

Anaerobic Nitrogen-Fixing Consortia Consisting of Clostridia Isolated from Gramineous Plants

Minamisawa

Nishioka

Miyaki

et al. 2004

Appl Environ Microbiol

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We report here the existence of anaerobic nitrogen-fixing consortia (ANFICOs) consisting of N 2 -fixing clostridia and diverse nondiazotrophic bacteria in nonleguminous plants; we found these ANFICOs while attempting to overcome a problem with culturing nitrogen-fixing microbes from various gramineous plants. A major feature of ANFICOs is that N 2 fixation by the anaerobic clostridia is supported by the elimination of oxygen by the accompanying bacteria in the culture. In a few ANFICOs, nondiazotrophic bacteria specifically induced nitrogen fixation of the clostridia in culture. ANFICOs are widespread in wild rice species and pioneer plants, which are able to grow in unfavorable locations. These results indicate that clostridia are naturally occurring endophytes in gramineous plants and that clostridial N 2 fixation arises in association with nondiazotrophic endophytes.Microbes are not always culturable even though their biological activities may be detectable (1,15,20). This is true for some N 2 -fixing bacteria associated with plants, such as Azoarcus endophytes (16) and rhizobial bacteroids (22). Although the functional significance of microbial consortia in biofilms, for example (1, 3), has been emphasized, there are few concrete examples of their specific functions.The availability of fixed nitrogen limits primary productivity in plant ecosystems. During their evolution, legumes have acquired a symbiotic relationship with rhizobia that fix atmospheric nitrogen. Among nonleguminous plants, several diazotrophs have been isolated and characterized as nitrogenfixing endophytes, including Acetobacter (18), Azoarcus (11,16), and Herbaspirillum (6,8). Endophytes are microorganisms that spend most of their life cycles inside plant tissues without causing symptoms of plant damage (16). We still do not know whether these diazotrophic endophytes contribute substantially to the nitrogen economy of grasses (11,12). It is possible that we have overlooked the real contributors to nitrogen fixation in nonleguminous plants. Indeed, nitrogenase transcript analysis has indicated that endophytes, such as Azoarcus sp. and others in an apparently unculturable state, fix nitrogen in plants (11).Wild grasses can often grow in nitrogen-deficient soils, suggesting that functioning diazotrophic bacteria are associated with them. We therefore tried to isolate and characterize diazotrophic bacteria associated with wild rice species in situ and pioneer plants growing on a devastated lahar area with volcanic eruptions. For this work, we used mainly the aerial parts of plants as isolation materials to avoid bacterial contamination from soils. During efforts to isolate endophytic diazotrophs from these plants, we faced problems with unculturable diazotrophic bacteria and found an anaerobic nitrogen-fixing consortium (ANFICO) consisting of N 2 -fixing clostridia and diverse nondiazotrophic bacteria. The objective of this work was to clarify the members of ANFICOs and their interactions. MATERIALS AND METHODSIsolation of nitrogen-fixing bact...

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“…Most of these studies in the field and in the laboratory have used the acetylene reduction assay, and activity has been found in the lower portion of the stem, the roots, the rhizosphere soil, and in the bulk of the anaerobic soil (8,15,17,19). There have also been several studies which demonstrated incorporation of 15N2 into flooded rice soils without plants (5,11,14,19).…”

mentioning

confidence: 99%

Heterotrophic ¹⁵N₂ Fixation and Distribution of Newly Fixed Nitrogen in a Rice-Flooded Soil System

Eskew

Eaglesham²,

App³

1981

Plant Physiol.

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Rice (Oryza sativa L.) plants growing in pots of flooded soil were exposed to a "'Nrenriched atmosphere for 3 to 13 days in a gas-tight chamber. The floodwater and soil surface were shaded with a black cloth to reduce the activity of phototrophic N2-fLXing micro-organisms. The highest 1"N enrichments were consistently observed in the roots, although the total quantity of 16N incorporated into the soil was much greater. The rate of 1"N incorporation into roots was much higher at the heading than at the tillering stage of growth. Definite enrichments were also found in the basal node and in the lower outer leaf sheath fractions after 3 days of exposure at the heading stage. Thirteen days was the shortest time period in which definite 16N enrichment was observed in the leaves and panicle. When plants were exposed to 1N2 for 13 days just before heading and then allowed to mature in a normal atmosphere, 11.3% of the total 16N in the system was found in the panicles, 2.3% in the roots, and 80.7% in the subsurface soil. These results provide direct evidence of heterotrophic N2 fixation associated with rice roots and the flooded soil and demonstrate that part of the newly fixed N is available to the plant.Nitrogen fixation by heterotrophic bacteria associated with rice (Oryza sativa L.) growing in flooded soil has been extensively studied, and this work has been summarized in a series of reviews (7,12,16). Most of these studies in the field and in the laboratory have used the acetylene reduction assay, and activity has been found in the lower portion of the stem, the roots, the rhizosphere soil, and in the bulk of the anaerobic soil (8,15,17,19). There have also been several studies which demonstrated incorporation of 15N2 into flooded rice soils without plants (5,11,14,19). Recently, Ito et al. (9) demonstrated incorporation of '5N2 into the roots, basal node, and decaying outer leaf sheaths of rice plants which had been transferred from the field and exposed to 1 N2 in N-free nutrient solution. These studies do not allow direct comparison of the activity in the soil versus that in the roots, and there is also no information on the fate of the fixed N. There have been few experiments done in which undisturbed grass soil systems were exposed to '5N2 and none with rice. De-Polli et al. (6) showed that the roots and rhizomes of Digitania decumbens and Paspalum notatum became enriched when soil cores containing these plants were exposed to '6N2 and presented some evidence for transport of the newly fixed nitrogen to the leaves of P. notatum. In the present study, rice plants growing in pots of flooded soil were exposed to

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Nitrogen fixation in the rhizosphere of rice

Cited by 63 publications

References 15 publications

Nitrogen Cycling in Rice Paddy Environments: Past Achievements and Future Challenges

Nitrogen Cycling in Rice Paddy Environments: Past Achievements and Future Challenges

Anaerobic Nitrogen-Fixing Consortia Consisting of Clostridia Isolated from Gramineous Plants

Heterotrophic ¹⁵N₂ Fixation and Distribution of Newly Fixed Nitrogen in a Rice-Flooded Soil System

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Nitrogen fixation in the rhizosphere of rice

Cited by 63 publications

References 15 publications

Nitrogen Cycling in Rice Paddy Environments: Past Achievements and Future Challenges

Nitrogen Cycling in Rice Paddy Environments: Past Achievements and Future Challenges

Anaerobic Nitrogen-Fixing Consortia Consisting of Clostridia Isolated from Gramineous Plants

Heterotrophic 15N2 Fixation and Distribution of Newly Fixed Nitrogen in a Rice-Flooded Soil System

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Heterotrophic ¹⁵N₂ Fixation and Distribution of Newly Fixed Nitrogen in a Rice-Flooded Soil System