Plant nutritional and soil factors in relation to microbial activity in the rhizosphere, with particular emphasis on denitrification

Trolldenier, G.

doi:10.1002/jpln.19891520214

Cited by 26 publications

(13 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In plant‐free systems, different C substrates increase N 2 O production to varying extents that depend on the oxygen status (Morley & Baggs, ), and the ratio of molecular N (N 2 ):N 2 O depends on the source of C (Henry et al, ; Morley, Richardson, & Baggs, ). Moreover, plant‐induced emissions of N 2 O from the root zone have been shown to depend on plant species (Abalos, De Deyn, Kuyper, & van Groenigen, ; Ishikawa, Subbarao, Ito, & Okada, ), nutrient availability (Trolldenier, ) and the developmental stage of plants (Sey, Manceur, Whalen, Gregorich, & Rochette, ). The relevance of root exudation still remains unclear, as other potential effects of roots were not controlled for (e.g., N or water uptake, root growth), or experimental conditions were highly artificial (e.g., application of artificial root exudates, in vitro experiments), so that transferability to real in situ situations is highly questionable.…”

Section: Introductionmentioning

confidence: 99%

Carbon sink reduction by fruit removal triggers respiration but not nitrous oxide emissions from the root zone of cucumber

Nett

Hauschild

Kläring

2019

Annals of Applied Biology

View full text Add to dashboard Cite

Root exudation of organic carbon (C) is generally believed to be the cause of positive effects of root activity on nitrous oxide (N 2 O) emissions. We tested the effects of root exudation in an actual soil-plant system on N 2 O emissions while excluding most other potential factors. The C source/sink ratio in cucumber was changed by removing fruits to increase root exudation. Root-zone emissions of carbon dioxide (CO 2 ) and N 2 O were monitored in complete stands of adult plants in a greenhouse.Whereas CO 2 emissions rapidly increased as a result of fruit removal the N 2 O emissions were completely unaffected. After cutting the shoots CO 2 emissions decreased within 2 weeks in both the fruit removal treatment and the control to a value significantly lower than that before the start of the treatments. However, N 2 O emissions immediately exhibited a short peak, which was significantly higher in the fruit removal treatment compared to the control. Thereafter N 2 O emissions in both treatments remained on the same level but considerably higher than before shoot cutting.We concluded that in a well-aerated root zone, a root exudation pulse does not necessarily increase N 2 O emissions, because C substrates are quickly respired by microorganisms before they can support heterotrophic denitrification. The results further indicate the significance of dying/dead roots for the creation of denitrificaton hotspots, which likely result from providing C substrates as well as poorly aerated habitats. K E Y W O R D Sanaerobic microorganisms, Cucumis sativus L., denitrification hot-spots, dry matter, root exudation

show abstract

Section: Introductionmentioning

confidence: 99%

Carbon sink reduction by fruit removal triggers respiration but not nitrous oxide emissions from the root zone of cucumber

Nett

Hauschild

Kläring

2019

Annals of Applied Biology

View full text Add to dashboard Cite

show abstract

“…The impact of the rhizosphere on microbial activities such as denitrification has been previously reported (14,23,28,31). However, little is known about the influence of the rhizosphere on the structure of the nitrate-reducing community and previous studies on this community were performed mainly in the rhizosphere of aerenchymatous plant by using cultivation-based approaches (4, 17).…”

mentioning

confidence: 99%

Molecular Analysis of the Nitrate-Reducing Community from Unplanted and Maize-Planted Soils

Philippot

Piutti

Martin-Laurent

et al. 2002

Appl Environ Microbiol

183

137

View full text Add to dashboard Cite

Microorganisms that use nitrate as an alternative terminal electron acceptor play an important role in the global nitrogen cycle. The diversity of the nitrate-reducing community in soil and the influence of the maize roots on the structure of this community were studied. The narG gene encoding the membrane bound nitrate reductase was selected as a functional marker for the nitrate-reducing community. The use of narG is of special interest because the phylogeny of the narG gene closely reflects the 16S ribosomal DNA phylogeny. Therefore, targeting the narG gene provided for the first time a unique insight into the taxonomic composition of the nitrate-reducing community in planted and unplanted soils. The PCR-amplified narG fragments were cloned and analyzed by restriction fragment length polymorphism (RFLP). In all, 60 RFLP types represented by two or more clones were identified in addition to the 58 RFLP types represented by only one clone. At least one clone belonging to each RFLP type was then sequenced. Several of the obtained sequences were not related to the narG genes from cultivated bacteria, suggesting the existence of unidentified nitrate-reducing bacteria in the studied soil. However, environmental sequences were also related to NarG from many bacterial divisions, i.e., Actinobacteria and ␣, ␤, and ␥ Proteobacteria. The presence of the plant roots resulted in a shift in the structure of the nitrate-reducing community between the unplanted and planted soils. Sequencing of RFLP types dominant in the rhizosphere or present only in the rhizosphere revealed that they are related to NarG from the Actinobacteria in an astonishingly high proportion.Nitrate-reducing prokaryotes constitute a wide group with members among the ␣, ␤, and ␥ Proteobacteria, gram-positive Bacteria, and even Archea, sharing the ability to obtain energy from dissimilatory reduction of nitrate into nitrite. The nitrite can then be reduced into gaseous nitrogen compounds by denitrification or into NH 4 by dissimilatory nitrate reduction into ammonia. Denitrification is the dominant process in soils and lake sediment, whereas dissimilatory nitrate reduction into ammonia occurs mainly in the rumen and in digested sludge (30). Due to nitrogen losses in agricultural soils and production of the greenhouse gases NO and N 2 O, denitrification has received a lot of attention over the last 20 years (7). There are two distinct forms of dissimilatory nitrate reductase; a periplasmic nitrate reductase and a membrane-bound nitrate reductase (reviewed in references 16 and 22). Only the nitrate reductase is found universally in prokaryotes and can therefore be used as a functional marker for these microorganisms. In addition, many microorganisms can contain both nitrate reductases (22). The membrane-bound nitrate reductase is composed of a soluble ␤ subunit containing four [Fe-S] clusters and the ␥ subunit containing two b-type hemes. The last subunit, encoded by the narG gene, contains a [4Fe-4S] cluster and a molybdopterin guanine dinucleotide cofact...

show abstract

“…Temporal and spatial variability in the quantity and quality of available resources is generally thought to be responsible for this pattern of variability in microorganism numbers (15,32). Resources to which microbial populations have been shown to respond include organic matter (1, 7, 8, 12, 13, 18, 32), nitrogen (1,8,31,32), and soil moisture or water potential (2, 8, 23,30,32).…”

mentioning

confidence: 99%

Seasonal and spatial population dynamics of the nitrogen-efficient guild in a desert bajada grassland

Herman

Provencio

Torrez

et al. 1994

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

Plant nutritional and soil factors in relation to microbial activity in the rhizosphere, with particular emphasis on denitrification

Cited by 26 publications

References 30 publications

Carbon sink reduction by fruit removal triggers respiration but not nitrous oxide emissions from the root zone of cucumber

Carbon sink reduction by fruit removal triggers respiration but not nitrous oxide emissions from the root zone of cucumber

Molecular Analysis of the Nitrate-Reducing Community from Unplanted and Maize-Planted Soils

Seasonal and spatial population dynamics of the nitrogen-efficient guild in a desert bajada grassland

Contact Info

Product

Resources

About