Revistas
Revista:
FRONTIERS IN PLANT SCIENCE
ISSN:
1664-462X
Año:
2023
Vol.:
14
Págs.:
1180688
Many studies have shown the capacity of soil humic substances (HS) to improve plant growth in natural ecosystems. This effect involves the activation of different processes within the plant at different coordinated molecular, biochemical, and physiological levels. However, the first event triggered by plant root-HS interaction remains unclear. Some studies suggest the hypothesis that the interaction of HS with root exudates involves relevant modification of the molecular conformation of humic self-assembled aggregates, including disaggregation, which might be directly involved in the activation of root responses. To investigate this hypothesis, we have prepared two humic acids. A natural humic acid (HA) and a transformed humic acid obtained from the treatment of HA with fungal laccase (HA enz). We have tested the capacity of the two humic acids to affect plant growth (cucumber and Arabidopsis) and complex Cu. Laccase-treatment did not change the molecular size but increased hydrophobicity, molecular compactness and stability, and rigidity of HA enz. Laccase-treatment avoided the ability of HA to promote shoot- and root-growth in cucumber and Arabidopsis. However, it does not modify Cu complexation features. There is no molecular disaggregation upon the interaction of HA and HA enz with plant roots. The results indicate that the interaction with plant roots induced in both HA and laccase-treated HA (HA enz), changes in their structural features that showed higher compactness and rigidity. These events might result from the interaction of HA and HA enz with specific root exudates that can promote intermolecular crosslinking. In summary, the results indicate that the weakly bond stabilized aggregated conformation (supramolecular-like) of HA plays a crucial role in its ability to promote root and shoot growth. The results also indicate the presence of two main types of HS in the rhizosphere corresponding to those non-interacting with plant roots (forming aggregated molecular assemblies) and those produced after interacting with plant root exudates (forming stable macromolecules).
Revista:
FRONTIERS IN PLANT SCIENCE
ISSN:
1664-462X
Año:
2022
Vol.:
13
Págs.:
803013
Many studies have shown the close relationship between the beneficial action of soil and sedimentary humic acids on the growth of plants cultivated in calcareous soils and their ability to improve Fe plant nutrition. These results have been ascribed to the humic acid (HA) capability to improve Fe solubility and bioavailability. However, other effects more related to a humic acid action on the specific mechanisms activated in roots of plants under Fe deficiency cannot be ruled out. Although this question has been studied in dicotyledonous plants, in graminaceous plants there are no specific studies. Here we investigate the ability of a humic acid extracted from peat (HA) to improve Fe nutrition in wheat plants cultivated under Fe deficient and sufficient conditions. The results show that HA can improve the physiological status of Fe deficient wheat plants by alleviating some of the deleterious consequences of Fe deficiency on plant development and increasing the plant ability to secrete phytosiderophores to the nutrient solution. This action of HA is associated with increases in the Fe-active pool in leaves that might be related to the mobilization of the Fe complexed by HA resulting from the interaction of HA with the phytosiderophores in the nutrient solution. The Fe translocation from the root to the shoot may be favored by the action of trans-Zeatin Riboside (tZR) since the leaf concentration of this phytohormone was enhanced by HA in Fe deficient plants.
Revista:
PLANT DIRECT
ISSN:
2475-4455
Año:
2019
Vol.:
3
N°:
10
Págs.:
1 - 12
Although the ability of humic (HA) and fulvic acids (FA) to improve plant growth has been demonstrated, knowledge about the mechanisms responsible for the direct effects of HA and FA on the promotion of plant growth is scarce and fragmentary. Our study investigated the causal role of both root PM H+-ATPase activity and ABA in the SHA-promoting action on both root and shoot growth. The involvement of these processes in the regulation of shoot cytokinin concentration and activity was also studied. Our aim was to integrate such plant responses for providing new insights to the current model on the mode of action of HA for promoting root and shoot growth. Experiments employing specific inhibitors and using Cucumis sativus L. plants show that both the root PM H+-ATPase activity and root ABA play a crucial role in the root growth-promoting action of SHA. With regard to the HA-promoting effects on shoot growth, two pathways of events triggered by the interaction of SHA with plant roots are essential for the increase in root PM H+-ATPase activity-which also mediates an increase in cytokinin concentration and action in the shoot-and the ABA-mediated increase in hydraulic conductivity (Lp(r)).
Revista:
APPLIED SOIL ECOLOGY
ISSN:
0929-1393
Año:
2018
Vol.:
123
Págs.:
521 - 537
The ability of rhizospheric humic substances to improve plant growth has been well established by many studies carried out using diverse plant species cultivated under many different conditions. These beneficial effects of humic substances on plant development are expressed in both root and shoot. However, the mechanisms responsible for this action of humic substances are only partially known and poorly integrated. In fact, although the studies focused on plant root development are numerous, those dealing with plant shoot development are scarce. Likewise, studies integrating humic effects on root and shoot are also few. In this context, the main goal of this work is to summarize some of the results regarding the effects of humic substances on plant development within a hypothetical holistic framework that will allow us to interconnect these findings and disclose some features of the functional crosstalk between the effects on soil, root and shoot. Furthermore, the significance of all these mechanisms in plants growing in the field is also discussed.
Revista:
BMC PLANT BIOLOGY
ISSN:
1471-2229
Año:
2018
Vol.:
18
N°:
105
Págs.:
14
Background: The release of phytosiderephores (PS) to the rhizosphere is the main root response to iron (Fe) deficiency in graminaceous plants. We have investigated the role of the Fe status in the shoot as well as of the signaling pathways controlled by three relevant phytoregulators-indolacetic acid (IAA), ethylene and nitric oxide (NO) - in the regulation of this root response in Fe-starved wheat plants. To this end, the PS accumulation in the nutrient solution and the root expression of the genes encoding the nicotianamine aminotransferase (TaNAAT) and ferritin (TaFER) have been evaluated in plants subjected to different treatments. Results: The application of Fe to leaves of Fe-deficient plants prevented the increase in both PS root release and TaNAAT gene expression thus showing the relevant role of the shoot to root communication in the regulation of PS root release and some steps of PS biosynthesis. Experiments with specific hormone inhibitors showed that while ethylene and NO did not positively regulate Fe deficiency induced PS root release, auxin plays an essential role in the regulation of this process. Moreover, the application of IM to Fe-sufficient plants promoted both PS root release and TaNAAT gene expression thus indicating that auxin might be involved in the shoot to root signaling network regulating Fe-deficiency root responses in wheat Conclusions: These results therefore indicate that PS root release in Fe-deficient wheat plants is directly modulated by the shoot Fe status through signaling pathways involving, among other possible effectors, auxin.
Revista:
PLANT PHYSIOLOGY
ISSN:
0032-0889
Año:
2015
Vol.:
169
N°:
4
Págs.:
2587 - 2596
The physiological and metabolic mechanisms behind the humic acid-mediated plant growth enhancement are discussed in detail. Experiments using cucumber (Cucumis sativus) plants show that the shoot growth enhancement caused by a structurally well-characterized humic acid with sedimentary origin is functionally associated with significant increases in abscisic acid (ABA) root concentration and root hydraulic conductivity. Complementary experiments involving a blocking agent of cell wall pores and water root transport (polyethylenglycol) show that increases in root hydraulic conductivity are essential in the shoot growth-promoting action of the model humic acid. Further experiments involving an inhibitor of ABA biosynthesis in root and shoot (fluridone) show that the humic acid-mediated enhancement of both root hydraulic conductivity and shoot growth depended on ABA signaling pathways. These experiments also show that a significant increase in the gene expression of the main root plasma membrane aquaporins is associated with the increase of root hydraulic conductivity caused by the model humic acid. Finally, experimental data suggest that all of these actions of model humic acid on root functionality, which are linked to its beneficial action on plant shoot growth, are likely related to the conformational structure of humic acid in solution and its interaction with the cell wall at the root surface.
Autores:
A.; S.; V; et al.
Revista:
FRONTIERS IN PLANT SCIENCE
ISSN:
1664-462X
Año:
2015
Vol.:
6
N°:
317
Higher plants have to cope with fluctuating mineral resource availability. However, strategies such as stimulation of root growth, increased transporter activities, and nutrient storage and remobilization have been mostly studied for only a few macronutrients. Leaves of cultivated crops (Zea mays, Brassica napus, Pisum sativum, Triticum aestivum, Hordeum vulgare) and tree species (Quercus robur, Populus nigra, Alnus glutinosa) grown under field conditions were harvested regularly during their life span and analyzed to evaluate the net mobilization of 13 nutrients during leaf senescence. While N was remobilized in all plant species with different efficiencies ranging from 40% (maize) to 90% (wheat), other macronutrients (K-P-S-Mg) were mobilized in most species. Ca and Mn, usually considered as having low phloem mobility were remobilized from leaves in wheat and barley. Leaf content of Cu-Mo-Ni-B-Fe-Zn decreased in some species, as a result of remobilization. Overall, wheat, barley and oak appeared to be the most efficient at remobilization while poplar and maize were the least efficient. Further experiments were performed with rapeseed plants subjected to individual nutrient deficiencies. Compared to field conditions, remobilization from leaves was similar (N-S-Cu) or increased by nutrient deficiency (K-P-Mg) while nutrient deficiency had no effect on Mo-Zn-B-Ca-Mn, which seemed to be non-mobile during leaf senescence under field conditions.
Revista:
PHYSIOLOGIA PLANTARUM
ISSN:
1399-3054
Año:
2015
Vol.:
155
N°:
3
Págs.:
338 - 354
Although climate scenarios have predicted an increase in [CO2] and temperature conditions, to date few experiments have focused on the interaction of [CO2] and temperature effects in wheat development. Recent evidence suggests that photosynthetic acclimation is linked to the photorespiration and N assimilation inhibition of plants exposed to elevated CO2. The main goal of this study was to analyze the effect of interacting [CO2] and temperature on leaf photorespiration, C/N metabolism and N transport in wheat plants exposed to elevated [CO2] and temperature conditions. For this purpose, wheat plants were exposed to elevated [CO2] (400 vs 700 mu molmol(-1)) and temperature (ambient vs ambient+4 degrees C) in CO2 gradient greenhouses during the entire life cycle. Although at the agronomic level, elevated temperature had no effect on plant biomass, physiological analyses revealed that combined elevated [CO2] and temperature negatively affected photosynthetic performance. The limited energy levels resulting from the reduced respiratory and photorespiration rates of such plants were apparently inadequate to sustain nitrate reductase activity. Inhibited N assimilation was associated with a strong reduction in amino acid content, conditioned leaf soluble protein content and constrained leaf N status. Therefore, the plant response to elevated [CO2] and elevated temperature resulted in photosynthetic acclimation. The reduction in transpiration rates induced limitations in nutrient ...
Revista:
PLANT PHYSIOLOGY AND BIOCHEMISTRY
ISSN:
0981-9428
Año:
2015
Vol.:
86
Págs.:
66 - 71
The importance of zinc (Zn) has been of little concern in human nutrition despite a strong decrease of this element in crops since the rise of high yielding varieties. For better food quality, Zn biofortification can be used, but will be optimal only if mechanisms governing Zn management are better known. Using Zn deficiency, we are able to demonstrate that Zn is not remobilized in Brassica napus (B. napus). Thus, remobilization processes should not be targeted by biofortification strategies. This study also complemented previous work by investigating leaf responses to Zn deficiency, especially from proteomic and ionomic points of view, showing for example, an increase in Manganese (Mn) content and of the Mn-dependent protein, Oxygen Evolving Enhancer.
Autores:
V.; A.; A.; et al.
Revista:
PLOS ONE
ISSN:
1932-6203
During the last 40 years, crop breeding has strongly increased yields but has had adverse effects on the content of micronutrients, such as Fe, Mg, Zn and Cu, in edible products despite their sufficient supply in most soils. This suggests that micronutrient remobilization to edible tissues has been negatively selected. As a consequence, the aim of this work was to quantify the remobilization of Cu in leaves of Brassica napus L. during Cu deficiency and to identify the main metabolic processes that were affected so that improvements can be achieved in the future. While Cu deficiency reduced oilseed rape growth by less than 19% compared to control plants, Cu content in old leaves decreased by 61.4%, thus demonstrating a remobilization process between leaves. Cu deficiency also triggered an increase in Cu transporter expression in roots (COPT2) and leaves (HMA1), and more surprisingly, the induction of the MOT1 gene encoding a molybdenum transporter associated with a strong increase in molybdenum (Mo) uptake. Proteomic analysis of leaves revealed 33 proteins differentially regulated by Cu deficiency, among which more than half were located in chloroplasts. Eleven differentially expressed proteins are known to require Cu for their synthesis and/or activity. Enzymes that were located directly upstream or downstream of Cu-dependent enzymes were also differentially expressed.
Revista:
PHYSIOLOGIA PLANTARUM
ISSN:
0031-9317
Año:
2014
Vol.:
151
N°:
4
Págs.:
375 - 389
This study examines the extent to which the predicted CO2 -protective effects on the inhibition of growth, impairment of photosynthesis and nutrient imbalance caused by saline stress are mediated by an effective adaptation of the endogenous plant hormonal balance. Therefore, sweet pepper plants (Capsicum annuum, cv. Ciclón) were grown at ambient or elevated [CO2] (400 or 800 µmol mol(-1)) with a nutrient solution containing 0 or 80 mM NaCl. The results show that, under saline conditions, elevated [CO2] increased plant dry weight, leaf area, leaf relative water content and net photosynthesis compared with ambient [CO2], whilst the maximum potential quantum efficiency of photosystem II was not modified. In salt-stressed plants, elevated [CO2 ] increased leaf NO3(-) concentration and reduced Cl(-) concentration. Salinity stress induced ABA accumulation in the leaves but it was reduced in the roots at high [CO2], being correlated with the stomatal response. Under non-stressed conditions, IAA was dramatically reduced in the roots when high [CO2] was applied, which resulted in greater root DW and root respiration. Additionally, the observed high CK concentration in the roots (especially tZR) could prevent downregulation of photosynthesis at high [CO2], as the N level in the leaves was increased compared with the ambient [CO2], under salt-stress conditions. These results demonstrate that the hormonal balance was altered by the [CO2], which resulted in significant changes at the grow
Autores:
V.; P.; L.; et al.
Revista:
JOURNAL OF PLANT GROWTH REGULATION
ISSN:
0721-7595
Año:
2014
Vol.:
33
N°:
2
Págs.:
305 - 316
Different strategies, known as crop biofortification, can be used to increase micronutrient concentrations in harvested parts to reduce nutrient deficiencies in the human diet. Apart from fertilization and genetic selection, a more environmentally friendly, less expensive, and more immediate solution could rely on the use of biostimulants derived from natural materials. Two biostimulants, AZAL5 and HA7, which are derived from seaweed and black peat, respectively, have been previously described as promoting growth of Brassica napus and having a substantial effect on gene expression. They were further studied to evaluate their effects on N and S and a wide range of other nutrients (that is, K, Ca, P, Mg, Fe, Na, Mn, B, Si, Cu, and Zn). Providing these two biostimulants in the nutrient solution did not change the mineral supply significantly, but they mostly stimulated root growth and macronutrient uptake (N, S, K, and P) at a level similar to growth. Both biostimulants also stimulate chloroplast division. More surprisingly, they also increased Mg, Mn, Na, and Cu plant concentrations and root-to-shoot translocation of Fe and Zn. These observations were associated with an increased expression of a Cu transporter (COPT2) and NRAMP3, a gene putatively involved in Fe and Zn translocation. Overall, this study showed that specific nutrient balance and transport were stimulated by both biostimulants more significantly than growth, offering new perspectives for biofortification strateg.
Autores:
Arkoun, M.; Jannin, L.; Laîné, P.; et al.
Revista:
PLANT AND SOIL
ISSN:
0032-079X
Año:
2013
Vol.:
362
N°:
1 - 2
Págs.:
79 - 92
Background and aims: Urea is the major nitrogen (N) form supplied as fertilizer in agriculture. However, urease, a nickel-dependent enzyme, allows plants to use external or internally generated urea as a nitrogen source. Since a urease inhibitor is frequently applied in conjunction with urea fertilizer, the N-metabolism of plants may be affected. The aim of this study was to determine physiological and molecular effects of nickel deficiency and a urease inhibitor on urea uptake and assimilation in oilseed rape.
Methods: Plants were grown on hydroponic solution with urea as the sole N source under three treatments: plants treated with nickel (+Ni) as a control, without nickel (¿Ni) and with nickel and phenylphosphorodiamidate (+Ni+PPD). Urea transport and assimilation were investigated.
Results: The results show that Ni-deficiency or PPD supply led to reduced growth and reduced 15N-uptake from urea. This effect was more pronounced in PPD-treated plants, which accumulated high amounts of urea and ammonium. Thus, Ni-deficiency or addition of PPD, limit the availability of N and decreased shoot and root amino acid content. The up-regulation of BnDUR3 in roots indicated that this gene is a component of the stress response to nitrogen-deficiency. A general decline of glutamine synthetase (GS) activity and activation of glutamate dehydrogenase (GDH) and increases in its expression level were observed in control plants.
Autores:
Jannin, L.; Arkoun, M.; Etienne, P.; et al.
Revista:
JOURNAL OF PLANT GROWTH REGULATION
ISSN:
0721-7595
Año:
2013
Vol.:
32
N°:
1
Págs.:
31 - 52
Despite its high capacity to take up nitrate from soil, winter rapeseed (Brassica napus) is characterized by a low N recovery in seeds. Thus, to maintain yield, rapeseed requires a high fertilization rate. Increasing nutrient use efficiency in rapeseed by addition of a biostimulant could help improve its agroenvironmental balance. The effects of marine brown seaweed Ascophyllum nodosum on plant growth have been well described physiologically. However, to our knowledge, no study has focused on transcriptomic analyses to determine metabolic targets of these extracts. A preliminary screening of different extracts revealed a significant effect of one of them (AZAL5) on rapeseed root (+102 %) and shoot (+23 %) growth. Microarray analysis was then used on AZAL5-treated or nontreated plants to characterize changes in gene expression that were further supported by physiological evidence. Stimulation of nitrogen uptake (+21 and +115 % in shoots and roots, respectively) and assimilation was increased in a similar manner to growth, whereas sulfate content (+63 and +133 % in shoots and roots, respectively) was more strongly stimulated leading to sulfate accumulation. Among the identified genes whose expression was affected by AZAL5, MinE, a plastid division regulator, was the most strongly affected. Its effect was supported by microscopic analysis showing an enhancement of chloroplast number per cell and starch content but without a significant difference in net photosynthetic rate.
Revista:
AGROCIENCIA (MEXICO)
ISSN:
1405-3195
Año:
2012
Vol.:
16
N°:
3
Págs.:
188 - 190
A number of studies have shown the ability of natural organic matter (NOM) in general and humic substances (HS) in particular, to affect the development of plants and microorganisms in many different natural ecosystems and agroecosystems. Regarding plants, these NOM and HS effects were expressed in both root growth and architecture, and shoot growth. However, these effects were different in intensity and quality depending on several intrinsic and extrinsic factors associated with HS structure and concentration, plant species and soil properties. Two main mechanisms have been proposed to explain the beneficial action of NOM and HS on plant growth. An indirect effect expressed through the improvement of plant nutrition by increasing soil nutrient availability, principally some micronutrients (mostly P and Fe); and a possible direct action affecting the transcriptional and post-transcriptional regulation of several enzymes and molecular transporters in the root. These biological effects within the plant seem to be associated with both nutrient root uptake ability and the efficient use of the nutrient in plant leaves. In this communication, the relationships between the effects of HS on root development, shoot development, plant nutrition, and soil properties; are discussed. This study is developed in the context of the links existing between the signal role of some nutrients and the hormonal balance in both root and shoot.
Autores:
Jannin, L. (Autor de correspondencia); Arkoun, M.; Ourry, A.; et al.
Revista:
PLANT AND SOIL
ISSN:
0032-079X
Año:
2012
Vol.:
359
N°:
1 - 2
Págs.:
297 - 319
Background & aims: Winter rapeseed (Brassica napus) is characterized by a low N recovery in seeds and requires high rates of fertilization to maintain yield. Its nutrient use efficiency could be improved by addition of a biostimulant such as humic acids whose physiological effects have been described previously in some plant species. However, to our knowledge, no study has focused on transcriptomic analyses to determine metabolic targets of this extract.
Methods: A preliminary screening of ten humic acids revealed a significant effect of one of them (HA7) on rapeseed root growth. Microarray analysis was then used on HA7-treated or non-treated plants to characterize changes in gene expression that were further supported by physiological evidence.
Results: Stimulation of nitrogen uptake (+15% in shoots and +108% in roots) and assimilation was found to be increased in a similar manner to growth while sulfate content (+76% in shoots and +137% in roots) was more strongly stimulated leading to higher sulfate accumulation. In parallel, microscopic analysis showed an enhancement of chloroplast number per cell.
Conclusion: It is therefore suggested that HA7, which promotes plant growth and nutrient uptake, could be used as a supplementary tool to improve rapeseed nitrogen use efficiency.
Revista:
PLANT GROWTH REGULATION
ISSN:
0167-6903
Año:
2011
Vol.:
63
N°:
1
Págs.:
73 - 79
The use of urea as an N fertilizer has increased to such an extent that it is now the most widely used fertilizer in the world. However, N losses as a result of ammonia volatilization lead to a decrease in its efficiency, therefore different methods have been developed over the years to reduce these losses. One of the most recent involves the use of urea combined with urease inhibitors, such as N-(n-butyl) thiophosphoric triamide (NBPT), in an attempt to delay the hydrolysis of urea in the soil. The aim of this study was to perform an in-depth analysis of the effect that NBPT use has on plant growth and N metabolism. Wheat plants were cultivated in a greenhouse experiment lasting 4 weeks and fertilized with urea and NBPT at different concentrations (0, 0.012, 0.062, 0.125%). Each treatment was replicated six times. A non-fertilized control was also cultivated. Several parameters related with N metabolism were analysed at the end of growth period. NBPT use was found to have visible effects, such as a transitory yellowing of the leaf tips, at the end of the first week of treatment. At a metabolic level, plants treated with the inhibitor were found to have more urea in their tissues and a lower amino acid content, lower glutamine synthetase activity, and lower urease and glutamine synthetase content at the end of the study period, whereas their urease activity seemed to have recovered by this stage.
Revista:
JOURNAL OF PLANT PHYSIOLOGY
ISSN:
0176-1617
Año:
2010
Vol.:
167
N°:
8
Págs.:
633 - 642
Numerous studies have reported the ability of humic substances to increase shoot growth in different plant species cultivated under diverse growth conditions. However, the mechanism responsible for this effect of humic substances is poorly understood. It is possible that the shoot promoting effect of humic substances involves a primary effect on root H(+)-ATPase activity and nitrate root-shoot distribution that, in turn, causes changes in the root-shoot distribution of certain cytokinins, polyamines and abscisic acid, thus affecting shoot growth. We investigated this hypothesis in the present study.
The results showed that the root application of a purified humic acid causes a significant increase in shoot growth that is associated with an enhancement in root H(+)-ATPase activity, an increase in nitrate shoot concentration, and a decrease in roots. These effects were associated with significant increases in the shoot concentration of several cytokinins and polyamines (principally putrescine), concomitant with decreases in roots. Likewise, these changes in the root-shoot distribution of diverse active cytokinins correlated well to significant changes in the root-shoot distribution of several mineral nutrients.
These results, taken together, indicate that the beneficial effects of humic substances on shoot development in cucumber could be directly associated with nitrate-related effects on the shoot concentration of several active cytokinins and polyamines (principally putrescine).
Revista:
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
ISSN:
0022-5142
Año:
2010
Vol.:
90
N°:
3
Págs.:
357 - 369
BACKGROUND: In certain plant species, ammonium or urea nutrition can cause negative effects on plant development which can result in toxic symptoms. Some authors suggest that the presence of nitrate can alleviate these symptoms by increasing ammonium and urea assimilation, avoiding its accumulation. In order to study this hypothesis, wheat (Triticum aestivum L.) seedlings were grown with various nitrogen supplies containing the main nitrogen forms (ammonium, nitrate and urea). Amino acids content and the activity of the three main enzymes involved in nitrogen assimilation (nitrate reductase, glutamine synthetase and urease) were studied.
RESULTS: The application of nitrate along with urea and/or ammonium was not associated with a time¿sustained increase in the activity of glutamine synthetase and urease. Amino acid analysis revealed that nitrate induced changes in amino acid metabolism enhancing its concentration. Likewise the content of protein was also higher in nitrate¿treated plants.
CONCLUSION: These results suggest that the effect of nitrate is compatible with a rapid and transient increase in the activity of glutamine synthetase and urease during the first hour after the onset of treatments. Nevertheless, a possible effect of nitrate reducing ammonium accumulation through the activation of alternative metabolic pathways different from that involving glutamine synthetase cannot be ruled out.
Revista:
JOURNAL OF PLANT PHYSIOLOGY
ISSN:
0176-1617
Año:
2010
Vol.:
167
N°:
15
Págs.:
1264 - 1272
Ammonium can result in toxicity symptoms in many plants when supplied as a sole nitrogen source. Nitrate reduces the negative effects caused by ammonium and promotes plant growth. In order to explore the mechanism responsible of this beneficial effect, we investigated whether nitrate application causes significant changes in the indoleacetic acid (IAA)- and cytokinin-plant distribution and abscisic acid (ABA) accumulation in wheat (Triticum aestivum L.) plants grown with ammonium. Two differentdoses of nitrate were supplied to ammonium-fed plants (100 mu M and 5 mM), to determine whether the effects of nitrate require significant doses (nutritional character), or can be promoted by very low doses (signal effect).
The results showed that the presence of NO(3)(-) was associated with clear increases in the active forms of cytokinins (zeatine (Z), trans-zeatine riboside (tZR), isopentenyl adenosine (IPR)) and reduction of the levels of the lower active forms (cis-zeatine riboside (cZR)), independently of the dose applied. Likewise. the presence of nitrate also enhanced IAA shoot content, which correlated with higher cytokinin levels and a tendency toward lower ABA concentration. This study presents further evidence that the possible signal effect of NO(3)(-) involved in its beneficial effect on the growth of wheat plants fed with NH(4)(+) could be mediated by a coordinated action of the levels of cytokinins, IAA and ABA in the shoot.
Nacionales y Regionales
Título:
Diseño y estudio del uso de nuevos bioestimulantes naturales de origen metabólico o microbiano para mejorar la eficiencia en el uso del nitrógeno en especies vegetales de interés agronómico.
Código de expediente:
0011-1383-2022-000015 PC018-019 BioestimulaN
Investigador principal:
María Garnica Ochoa
Financiador:
GOBIERNO DE NAVARRA
Convocatoria:
2022 GN Proyectos Colaborativos
Fecha de inicio:
01/12/2021
Fecha fin:
30/11/2024
Importe concedido:
191.017,31€
Otros fondos:
-
Título:
Diseño y manejo de moduladores del metabolismo nitrogenado vegetal para la reducción del contenido de nitrato en hortalizas. HORTA 0.0
Código de expediente:
0011-1383-2020-000010 PC107 UNAV HORTA 0,0
Investigador principal:
Maria Movila Movila
Financiador:
GOBIERNO DE NAVARRA
Convocatoria:
2020 GN Proyectos Colaborativos
Fecha de inicio:
01/12/2019
Fecha fin:
31/12/2022
Importe concedido:
160.450,00€
Otros fondos:
-
Título:
Alternativas de fertilización nitrogenada en hortalizas para minimizar su contenido en nitratos y mejorar su calidad alimentaria
Código de expediente:
0011-1383-2019-000005 PC068-069 Nitrohealthy 2
Investigador principal:
Idoia Ariz Arnedo
Financiador:
GOBIERNO DE NAVARRA
Convocatoria:
2019 GN Centros
Fecha de inicio:
01/12/2018
Fecha fin:
30/11/2019
Importe concedido:
80.948,51€
Otros fondos:
-
Título:
Desarrollo de aplicaciones optimizadas de sustancias húmicas para mejorar el crecimiento vegetal de plantas sometidas a estrés salino (HUMIESTRÉS 2)
Código de expediente:
0011-1383-2019-000005 PT009 HUMIESTRES 2
Investigador principal:
Marta Fuentes Ramírez
Financiador:
GOBIERNO DE NAVARRA
Convocatoria:
2019 GN Centros
Fecha de inicio:
01/12/2018
Fecha fin:
30/11/2019
Importe concedido:
65.293,21€
Otros fondos:
-
Título:
Sistema circular para la recuperación y valoración agronómica del fósforo
Código de expediente:
RTC-2017-6049-2
Financiador:
MINISTERIO DE CIENCIA, INNOVACIÓN Y UNIVERSIDADES
Convocatoria:
2017 MINECO RETOS COLABORACIÓN
Fecha de inicio:
01/07/2018
Fecha fin:
31/05/2022
Importe concedido:
173.781,60€
Otros fondos:
Fondos FEDER
Título:
Descontaminantes polivalentes (metales pesados y contaminantes orgánicos) para la regeneración y/o protección de suelos y del medio ambiente
Código de expediente:
0011-1365-2016-000163
Investigador principal:
Javier Erro Garcés
Financiador:
GOBIERNO DE NAVARRA
Convocatoria:
2016 GN I+D
Fecha de inicio:
01/07/2016
Fecha fin:
30/04/2018
Importe concedido:
152.910,51€
Otros fondos:
-
Título:
Fuentes M 0011-1365-2016-000065 QUELATOS NATURALES DE MICROELEMENTOS PARA FERTILIZACIÓN AGRÍCOLA SOSTENIBLE
Código de expediente:
0011-1365-2016-000065
Investigador principal:
Marta Fuentes Ramírez
Financiador:
GOBIERNO DE NAVARRA
Convocatoria:
2016 GN I+D
Fecha de inicio:
01/07/2016
Fecha fin:
30/04/2018
Importe concedido:
167.371,19€
Otros fondos:
-
Título:
Evaluación de biochar como aditivo técnico para la obtención de nuevas formas de liberación y protección de nutrientes en fertilizantes especiales de alto valor (FERTCHAR)
Código de expediente:
0011-1365-2018-000187
Investigador principal:
Óscar Urrutia Sagardia
Financiador:
GOBIERNO DE NAVARRA
Convocatoria:
2018 GN I+D
Fecha de inicio:
01/03/2018
Fecha fin:
31/12/2019
Importe concedido:
163.052,70€
Otros fondos:
Fondos FEDER
Título:
Alternativas de fertilización nitrogenada en hortalizas para minimizar su contenido en nitratos y mejorar su calidad alimentaria
Código de expediente:
0011-1383-2018-000005 PC061-062 NITROHEALTHY
Investigador principal:
Idoia Ariz Arnedo
Financiador:
GOBIERNO DE NAVARRA
Convocatoria:
2018 GN Centros
Fecha de inicio:
01/02/2018
Fecha fin:
30/11/2018
Importe concedido:
82.657,44€
Otros fondos:
-