Systemic Signaling of the Plant Nitrogen Status Triggers Specific Transcriptome Responses Depending on the Nitrogen Source in Medicago truncatula

In recent years, the application of nanotechnology for the development of new “smart fertilizers” is regarded as one of the most promising solutions for boosting a more sustainable and modern grapevine cultivation. Despite showing interesting potential benefits over conventional fertilization practices, the use of nanofertilizers in viticulture is still underexplored. In this work, we investigated the effectiveness of non-toxic calcium phosphate nanoparticles (Ca3(PO4)2∙nH2O) doped with urea (U-ACP) as a nitrogen source for grapevine fertilization. Plant tests were performed for two years (2019–2020) on potted adult Pinot gris cv. vines grown under semi-controlled conditions. Four fertilization treatments were compared: N1: commercial granular fertilization (45 kg N ha−1); N2: U-ACP applied in fertigation (36 kg N ha−1); N3: foliar application of U-ACP (36 kg N ha−1); C: control, receiving no N fertilization. Plant nitrogen status (SPAD), yield parameters as well as those of berry quality were analyzed. Results here presented clearly show the capability of vine plants to recognize and use the nitrogen supplied with U-ACP nanoparticles either when applied foliarly or to the soil. Moreover, all of the quali–quantitative parameters measured in vine plants fed with nanoparticles were perfectly comparable to those of plants grown in conventional condition, despite the restrained dosage of nitrogen applied with the nanoparticles. Therefore, these results provide both clear evidence of the efficacy of U-ACP nanoparticles as a nitrogen source and the basis for the development of alternative nitrogen fertilization strategies, optimizing the dosage/benefit ratio and being particularly interesting in a context of a more sustainable and modern viticulture.

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Systemic control of nodule formation by the plant N demand requires autoregulation dependent and independent mechanisms

Journal of Experimental Botany ◽

10.1093/jxb/erab374 ◽

2021 ◽

Author(s):

Marjorie Pervent ◽

Ilana Lambert ◽

Marc Tauzin ◽

Alicia Karouani ◽

Martha Nigg ◽

...

Keyword(s):

Nitrogen Fixation ◽

Nodule Formation ◽

Atmospheric Nitrogen ◽

Plant Nitrogen ◽

Systemic Signaling ◽

Systemic Control ◽

Whole Plant ◽

Strong Control ◽

Mutant Genes ◽

N Demand

Abstract In legumes interacting with rhizobia the formation of symbiotic organs involved in the acquisition of atmospheric nitrogen is depending of the plant nitrogen (N) demand. We used Medicago truncatula plants cultivated in split-root systems to discriminate between responses to local and systemic N signalings. We evidenced a strong control of nodule formation by systemic N-signaling but obtained no clear evidence of a local control by mineral nitrogen. Systemic signaling of the plant N demand controls numerous transcripts involved in the root transcriptome reprogramming associated to early rhizobia interaction and nodule formation. SUNN has an important role in this control but major systemic N signaling responses remained active in the sunn mutant. Genes involved in the activation of nitrogen fixation are regulated by systemic N signaling in the mutant, explaining why the hypernodulation phenotype is not associated to a higher nitrogen fixation of the whole plant. The control of the transcriptome reprogramming of nodule formation by systemic N signaling requires other pathway(s) that parallel the SUNN/CLE pathway.

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Loci controlling partial resistance to rice blast do not show marked QTL × environment interaction when plant nitrogen status alters disease severity

New Phytologist ◽

10.1111/j.1469-8137.2005.01507.x ◽

2005 ◽

Vol 168 (2) ◽

pp. 455-464 ◽

Cited By ~ 30

Author(s):

Zahirul I. Talukder ◽

A James S. McDonald ◽

Adam H. Price

Keyword(s):

Disease Severity ◽

Partial Resistance ◽

Rice Blast ◽

Environment Interaction ◽

Nitrogen Status ◽

Plant Nitrogen

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Effect of plant nitrogen status on the contribution of arbuscular mycorrhizal hyphae to plant nitrogen uptake

Physiologia Plantarum ◽

10.1034/j.1399-3054.1999.105414.x ◽

1999 ◽

Vol 105 (4) ◽

pp. 694-700 ◽

Cited By ~ 41

Author(s):

Heidi-Jayne Hawkins ◽

Eckhard George

Keyword(s):

Nitrogen Uptake ◽

Arbuscular Mycorrhizal ◽

Nitrogen Status ◽

Plant Nitrogen ◽

Plant Nitrogen Uptake ◽

Mycorrhizal Hyphae

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Aphid infestation differently affects the defences of nitrate-fed and nitrogen-fixing Medicago truncatula and alters symbiotic nitrogen fixation

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.1493 ◽

2020 ◽

Vol 287 (1934) ◽

pp. 20201493

Author(s):

Gaurav Pandharikar ◽

Jean-Luc Gatti ◽

Jean-Christophe Simon ◽

Pierre Frendo ◽

Marylène Poirié

Keyword(s):

Nitrogen Fixation ◽

Medicago Truncatula ◽

Sinorhizobium Meliloti ◽

Acyrthosiphon Pisum ◽

Symbiotic Nitrogen Fixation ◽

Pea Aphid ◽

Systemic Resistance ◽

Aphid Infestation ◽

Plant Nitrogen ◽

Pathogenesis Related Protein

Legumes can meet their nitrogen requirements through root nodule symbiosis, which could also trigger plant systemic resistance against pests. The pea aphid Acyrthosiphon pisum , a legume pest, can harbour different facultative symbionts (FS) influencing various traits of their hosts. It is therefore worth determining if and how the symbionts of the plant and the aphid modulate their interaction. We used different pea aphid lines without FS or with a single one ( Hamiltonella defensa , Regiella insecticola, Serratia symbiotica ) to infest Medicago truncatula plants inoculated with Sinorhizobium meliloti (symbiotic nitrogen fixation, SNF) or supplemented with nitrate (non-inoculated, NI). The growth of SNF and NI plants was reduced by aphid infestation, while aphid weight (but not survival) was lowered on SNF compared to NI plants. Aphids strongly affected the plant nitrogen fixation depending on their symbiotic status, suggesting indirect relationships between aphid- and plant-associated microbes. Finally, all aphid lines triggered expression of Pathogenesis-Related Protein 1 ( PR1 ) and Proteinase Inhibitor (PI) , respective markers for salicylic and jasmonic pathways, in SNF plants, compared to only PR1 in NI plants. We demonstrate that the plant symbiotic status influences plant–aphid interactions while that of the aphid can modulate the amplitude of the plant's defence response.

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