Expression of Maize and Fungal Nitrate Reductase Genes in Arbuscular Mycorrhiza

Kaldorf, Michael; Schmelzer, Elmon; Bothe, Hermann

doi:10.1094/mpmi.1998.11.6.439

Cited by 107 publications

(71 citation statements)

References 46 publications

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“…3 and 4). Moreover, several studies have demonstrated that after the establishment of ectomycorrhizal symbioses, the fungal NR is increased and the plant enzyme down-regulated (4,38,39). Apparently in mycorrhizal symbioses, amino acids represent the major compounds that serve to transfer nitrogen to the host plant (38).…”

Section: Discussionmentioning

confidence: 99%

The Endophytic Fungus Piriformospora indica Stimulates the Expression of Nitrate Reductase and the Starch-degrading Enzyme Glucan-water Dikinase in Tobacco and Arabidopsis Roots through a Homeodomain Transcription Factor That Binds to a Conserved Motif in Their Promoters

Sherameti

Shahollari

Venus

et al. 2005

Journal of Biological Chemistry

246

155

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Piriformospora indica, an endophytic fungus of the Sebacinaceae family, promotes growth of Arabidopsis and tobacco seedlings and stimulates nitrogen accumulation and the expression of the genes for nitrate reductase and the starch-degrading enzyme glucan-water dikinase (SEX1) in roots. Neither growth promotion nor stimulation of the two enzymes requires heterotrimeric G proteins. P. indica also stimulates the expression of the uidA gene under the control of the Arabidopsis nitrate reductase (Nia2) promoter in transgenic tobacco seedlings. At least two regions (؊470/؊439 and ؊103/ ؊89) are important for Nia2 promoter activity in tobacco roots. One of the regions contains an element, ATGATAGATAAT, that binds to a homeodomain transcription factor in vitro. The message for this transcription factor is up-regulated by P. indica. The transcription factor also binds to a CTGATAGATCT segment in the SEX1 promoter in vitro. We propose that the growthpromoting effect initiated by P. indica is accompanied by a co-regulated stimulation of enzymes involved in nitrate and starch metabolisms.Often nitrogen is the limiting source for plant growth and development. It is recruited by plants either as nitrate or ammonium or for a few species by nitrogen fixation with the help of rhizobia (1, 2). Mycorrhizal fungi also play an important role in delivering either nitrate or ammonium to the root cells. It is believed that mycorrhizal fungi preferentially recruit ammonium rather than nitrate from the soil and that amino acids represent the major compounds that serve to transfer nitrogen to the host plant (cf. Refs. 3 and 4). We studied Piriformospora indica, an endophytic fungus of the Sebacinaceae family, which colonizes the roots of a wide variety of plant species and promotes their growth (5-10). The interaction of the endophytic fungus with plant roots is accompanied by an enormous requisition of nitrogen from the environment. By analyzing the interaction of P. indica with Arabidopsis and tobacco roots we found that in contrast to mycorrhizal associations, nitrate reduction in the roots is stimulated by P. indica. A homeodomain transcription factor responds to the fungus and binds to promoter regions of the P. indica-responsive Nia2, SEX1, and 2-nitropropane dioxygenase genes. These results suggest that the expression of P. indica-responsive target genes may be controlled by common regulatory elements and trans-factors. MATERIALS AND METHODSTransgenic Tobacco-Transgenic seeds of Nicotiana tabacum L., var. Samsun NN were obtained from greenhouse-grown plants (6). They were sterilized and germinated on Murashige-Skoog medium (11) supplemented with 2% (w/v) sucrose and 0.8% (w/v) agar in temperaturecontrolled (25°C) growth chambers under a 16-h light/8-h dark cycle. 80 g of ml Ϫ1 (w/v) kanamycin was added to the medium. Four-week-old plantlets were transferred to soil to obtain seeds for the physiological experiments. The antisense lines for the heterotrimeric G protein subunit ␤ were described previously (12).Growth Conditions of Pla...

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Section: Discussionmentioning

confidence: 99%

The Endophytic Fungus Piriformospora indica Stimulates the Expression of Nitrate Reductase and the Starch-degrading Enzyme Glucan-water Dikinase in Tobacco and Arabidopsis Roots through a Homeodomain Transcription Factor That Binds to a Conserved Motif in Their Promoters

Sherameti

Shahollari

Venus

et al. 2005

Journal of Biological Chemistry

246

155

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“…Both NADH and NADPH can act as reductant for nitrite formation [52], but, in AM fungi, nitrate reductase activity is mainly driven by NADPH [90]. Nitrate reductase activity in both roots [44,83,84,87] and shoots [83,87,95] of AM plants is generally higher than in non-mycorrhizal control plants (for more information, see also [72].…”

Section: After No3mentioning

confidence: 99%

Role of Arbuscular Mycorrhizal Fungi in the Nitrogen Uptake of Plants: Current Knowledge and Research Gaps

2015

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Arbuscular mycorrhizal (AM) fungi play an essential role for the nutrient uptake of the majority of land plants, including many important crop species. The extraradical mycelium of the fungus takes up nutrients from the soil, transfers these nutrients to the intraradical mycelium within the host root, and exchanges the nutrients against carbon from the host across a specialized plant-fungal interface. The contribution of the AM symbiosis to the phosphate nutrition has long been known, but whether AM fungi contribute similarly to the nitrogen nutrition of their host is still controversially discussed. However, there is a growing body of evidence that demonstrates that AM fungi can actively transfer nitrogen to their host, and that the host plant with its carbon supply stimulates this transport, and that the periarbuscular membrane of the host is able to facilitate the active uptake of nitrogen from the mycorrhizal interface. In this review, our current knowledge about nitrogen transport through the fungal hyphae and across the mycorrhizal interface is summarized, and we discuss the regulation of these pathways and major research gaps.

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“…After its uptake from the soil, NO3 -is converted into NH4 + via nitrate and nitrite reductases in AM [103,114] and ECM fungi [109]. In AM fungi and most ECM fungi, NH4 + is assimilated via the glutamine synthase/glutamine oxoglutarate aminotransferase (GS/GOGAT) pathway into amino acids [103,112].…”

Section: Fungal Nitrogen Metabolismmentioning

confidence: 99%

The Role of the Mycorrhizal Symbiosis in Nutrient Uptake of Plants and the Regulatory Mechanisms Underlying These Transport Processes

Bücking¹,

Liepold²,

Ambilwade³

2012

Plant Science

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Expression of Maize and Fungal Nitrate Reductase Genes in Arbuscular Mycorrhiza

Cited by 107 publications

References 46 publications

The Endophytic Fungus Piriformospora indica Stimulates the Expression of Nitrate Reductase and the Starch-degrading Enzyme Glucan-water Dikinase in Tobacco and Arabidopsis Roots through a Homeodomain Transcription Factor That Binds to a Conserved Motif in Their Promoters

The Endophytic Fungus Piriformospora indica Stimulates the Expression of Nitrate Reductase and the Starch-degrading Enzyme Glucan-water Dikinase in Tobacco and Arabidopsis Roots through a Homeodomain Transcription Factor That Binds to a Conserved Motif in Their Promoters

Role of Arbuscular Mycorrhizal Fungi in the Nitrogen Uptake of Plants: Current Knowledge and Research Gaps

The Role of the Mycorrhizal Symbiosis in Nutrient Uptake of Plants and the Regulatory Mechanisms Underlying These Transport Processes

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