TY  - JOUR
AU  - Nikolic, Miroslav
AU  - Cesco, Stefano
AU  - Monte, Rossella
AU  - Tomasi, Nicola
AU  - Gottardi, Stefano
AU  - Zamboni, Anita
AU  - Pinton, Roberto
AU  - Varanini, Zeno
PY  - 2012
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/569
AB  - Background: The mechanisms by which nitrate is transported into the roots have been characterized both at physiological and molecular levels. It has been demonstrated that nitrate is taken up in an energy-dependent way by a four-component uptake machinery involving high-and low-affinity transport systems. In contrast very little is known about the physiology of nitrate transport towards different plant tissues and in particular at the leaf level. Results: The mechanism of nitrate uptake in leaves of cucumber (Cucumis sativus L. cv. Chinese long) plants was studied and compared with that of the root. Net nitrate uptake by roots of nitrate-depleted cucumber plants proved to be substrate-inducible and biphasic showing a saturable kinetics with a clear linear non saturable component at an anion concentration higher than 2 mM. Nitrate uptake by leaf discs of cucumber plants showed some similarities with that operating in the roots (e. g. electrogenic H+ dependence via involvement of proton pump, a certain degree of induction). However, it did not exhibit typical biphasic kinetics and was characterized by a higher Km with values out of the range usually recorded in roots of several different plant species. The quantity and activity of plasma membrane (PM) H+-ATPase of the vesicles isolated from leaf tissues of nitrate-treated plants for 12 h (peak of nitrate foliar uptake rate) increased with respect to that observed in the vesicles isolated from N-deprived control plants, thus suggesting an involvement of this enzyme in the leaf nitrate uptake process similar to that described in roots. Molecular analyses suggest the involvement of a specific isoform of PM H+-ATPase (CsHA1) and NRT2 transporter (CsNRT2) in root nitrate uptake. At the leaf level, nitrate treatment modulated the expression of CsHA2, highlighting a main putative role of this isogene in the process. Conclusions: Obtained results provide for the first time evidence that a saturable and substrate-inducible nitrate uptake mechanism operates in cucumber leaves. Its activity appears to be related to that of PM H+-ATPase activity and in particular to the induction of CsHA2 isoform. However the question about the molecular entity responsible for the transport of nitrate into leaf cells therefore still remains unresolved.
PB  - Bmc, London
T2  - Bmc Plant Biology
T1  - Nitrate transport in cucumber leaves is an inducible process involving an increase in plasma membrane H+-ATPase activity and abundance
VL  - 12
DO  - 10.1186/1471-2229-12-66
ER  - 

@article{
author = "Nikolic, Miroslav and Cesco, Stefano and Monte, Rossella and Tomasi, Nicola and Gottardi, Stefano and Zamboni, Anita and Pinton, Roberto and Varanini, Zeno",
year = "2012",
abstract = "Background: The mechanisms by which nitrate is transported into the roots have been characterized both at physiological and molecular levels. It has been demonstrated that nitrate is taken up in an energy-dependent way by a four-component uptake machinery involving high-and low-affinity transport systems. In contrast very little is known about the physiology of nitrate transport towards different plant tissues and in particular at the leaf level. Results: The mechanism of nitrate uptake in leaves of cucumber (Cucumis sativus L. cv. Chinese long) plants was studied and compared with that of the root. Net nitrate uptake by roots of nitrate-depleted cucumber plants proved to be substrate-inducible and biphasic showing a saturable kinetics with a clear linear non saturable component at an anion concentration higher than 2 mM. Nitrate uptake by leaf discs of cucumber plants showed some similarities with that operating in the roots (e. g. electrogenic H+ dependence via involvement of proton pump, a certain degree of induction). However, it did not exhibit typical biphasic kinetics and was characterized by a higher Km with values out of the range usually recorded in roots of several different plant species. The quantity and activity of plasma membrane (PM) H+-ATPase of the vesicles isolated from leaf tissues of nitrate-treated plants for 12 h (peak of nitrate foliar uptake rate) increased with respect to that observed in the vesicles isolated from N-deprived control plants, thus suggesting an involvement of this enzyme in the leaf nitrate uptake process similar to that described in roots. Molecular analyses suggest the involvement of a specific isoform of PM H+-ATPase (CsHA1) and NRT2 transporter (CsNRT2) in root nitrate uptake. At the leaf level, nitrate treatment modulated the expression of CsHA2, highlighting a main putative role of this isogene in the process. Conclusions: Obtained results provide for the first time evidence that a saturable and substrate-inducible nitrate uptake mechanism operates in cucumber leaves. Its activity appears to be related to that of PM H+-ATPase activity and in particular to the induction of CsHA2 isoform. However the question about the molecular entity responsible for the transport of nitrate into leaf cells therefore still remains unresolved.",
publisher = "Bmc, London",
journal = "Bmc Plant Biology",
title = "Nitrate transport in cucumber leaves is an inducible process involving an increase in plasma membrane H+-ATPase activity and abundance",
volume = "12",
doi = "10.1186/1471-2229-12-66"
}

Nikolic, M., Cesco, S., Monte, R., Tomasi, N., Gottardi, S., Zamboni, A., Pinton, R.,& Varanini, Z.. (2012). Nitrate transport in cucumber leaves is an inducible process involving an increase in plasma membrane H+-ATPase activity and abundance. in Bmc Plant Biology
Bmc, London., 12.
https://doi.org/10.1186/1471-2229-12-66

Nikolic M, Cesco S, Monte R, Tomasi N, Gottardi S, Zamboni A, Pinton R, Varanini Z. Nitrate transport in cucumber leaves is an inducible process involving an increase in plasma membrane H+-ATPase activity and abundance. in Bmc Plant Biology. 2012;12.
doi:10.1186/1471-2229-12-66 .

Nikolic, Miroslav, Cesco, Stefano, Monte, Rossella, Tomasi, Nicola, Gottardi, Stefano, Zamboni, Anita, Pinton, Roberto, Varanini, Zeno, "Nitrate transport in cucumber leaves is an inducible process involving an increase in plasma membrane H+-ATPase activity and abundance" in Bmc Plant Biology, 12 (2012),
https://doi.org/10.1186/1471-2229-12-66 . .

TY  - JOUR
AU  - Nikolic, Miroslav
AU  - Cesco, Stefano
AU  - Roemheld, Volker
AU  - Varanini, Zeno
AU  - Pinton, Roberto
PY  - 2007
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/187
AB  - Cucumber (Cucumis sativus L.) plants were precultured for 7 days in either optimal (10 mu M) or low (0.5 mu M) Fe conditions and then grown for further 5 days in a N-free nutrient solution with (+Fe) or without (-Fe) 10 mu M Fe. Thereafter NO(3)(-) (4mM) was added to the nutrient solution for 24 h and, concomitantly, half of the -Fe plants were treated with 1 mu M Fe complexed to water extractable humic substances (WEHS). Supply of NO(3)(-) to + Fe-N-deprived plants caused a large induction in the capacity to take up the anion by roots, which was accompanied by a rise in root-shoot NO(3)(-) concentration. The -Fe plants showed a lower level of induction of NO(3)(-) uptake and hence a lower accumulation of the anion in the tissues, these effects being reversed by supply of Fe-WEHS. Supply of either NO(3)(-) - or NH(4)(+) -N (+/-Fe-WEHS) to -Fe plants promoted the development of the root Fe(III)-chelate reductase activity, but the capacity of roots to take up the Fe(2+) remained unaffected. Results show that an inadequate Fe supply can limit the acquisition of NO(3)(-), whereas NO(3)(-) supply can affect Fe uptake by influencing the development and maintenance of a high Fe(III)-chelate reducing capacity.
PB  - Csiro Publishing, Collingwood
T2  - Functional Plant Biology
T1  - Short-term interactions between nitrate and iron nutrition in cucumber
EP  - 408
IS  - 5
SP  - 402
VL  - 34
DO  - 10.1071/FP07022
ER  - 

@article{
author = "Nikolic, Miroslav and Cesco, Stefano and Roemheld, Volker and Varanini, Zeno and Pinton, Roberto",
year = "2007",
abstract = "Cucumber (Cucumis sativus L.) plants were precultured for 7 days in either optimal (10 mu M) or low (0.5 mu M) Fe conditions and then grown for further 5 days in a N-free nutrient solution with (+Fe) or without (-Fe) 10 mu M Fe. Thereafter NO(3)(-) (4mM) was added to the nutrient solution for 24 h and, concomitantly, half of the -Fe plants were treated with 1 mu M Fe complexed to water extractable humic substances (WEHS). Supply of NO(3)(-) to + Fe-N-deprived plants caused a large induction in the capacity to take up the anion by roots, which was accompanied by a rise in root-shoot NO(3)(-) concentration. The -Fe plants showed a lower level of induction of NO(3)(-) uptake and hence a lower accumulation of the anion in the tissues, these effects being reversed by supply of Fe-WEHS. Supply of either NO(3)(-) - or NH(4)(+) -N (+/-Fe-WEHS) to -Fe plants promoted the development of the root Fe(III)-chelate reductase activity, but the capacity of roots to take up the Fe(2+) remained unaffected. Results show that an inadequate Fe supply can limit the acquisition of NO(3)(-), whereas NO(3)(-) supply can affect Fe uptake by influencing the development and maintenance of a high Fe(III)-chelate reducing capacity.",
publisher = "Csiro Publishing, Collingwood",
journal = "Functional Plant Biology",
title = "Short-term interactions between nitrate and iron nutrition in cucumber",
pages = "408-402",
number = "5",
volume = "34",
doi = "10.1071/FP07022"
}

Nikolic, M., Cesco, S., Roemheld, V., Varanini, Z.,& Pinton, R.. (2007). Short-term interactions between nitrate and iron nutrition in cucumber. in Functional Plant Biology
Csiro Publishing, Collingwood., 34(5), 402-408.
https://doi.org/10.1071/FP07022

Nikolic M, Cesco S, Roemheld V, Varanini Z, Pinton R. Short-term interactions between nitrate and iron nutrition in cucumber. in Functional Plant Biology. 2007;34(5):402-408.
doi:10.1071/FP07022 .

Nikolic, Miroslav, Cesco, Stefano, Roemheld, Volker, Varanini, Zeno, Pinton, Roberto, "Short-term interactions between nitrate and iron nutrition in cucumber" in Functional Plant Biology, 34, no. 5 (2007):402-408,
https://doi.org/10.1071/FP07022 . .

TY  - JOUR
AU  - Nikolic, Miroslav
AU  - Cesco, Stefano
AU  - Romheld, V
AU  - Varanini, Zeno
AU  - Pinton, Roberto
PY  - 2003
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/83
AB  - A research was carried out to evaluate the leaves' ability to utilize Fe supplied as a complex with water-extractable humic substances (WEHS) and the long-distance transport of Fe-59 applied to sections of fully expanded leaves of intact sunflower (Helianthus annuus L.) plants. Plants were grown in a nutrient solution containing 10 muM Fe(III)-EDDHA (Fe-sufficient plants), with the addition of 10 mM NaHCO3 to induce iron chlorosis (Fe-deficient plants). Fe(III)-WEHS could be reduced by sunflower leaf discs at levels comparable to those observed using Fe(III)-EDTA, regardless of the Fe status. On the other hand, Fe-59 uptake rate by leaf discs of green and chlorotic plants was significantly lower in Fe-WEHS-treated plants, possibly suggesting the effect of light on photochemical reduction of Fe-EDTA. In the experiments with intact plants, Fe-59-labeled Fe-WEHS or Fe-EDTA were applied onto a section of fully expanded leaves. Irrespective of Fe nutritional status, Fe-59 uptake was significantly higher when the treatment was carried out with Fe-EDTA. A significant difference was found in the amount of Fe-59 translocated from treated leaf area between green and chlorotic plants. However, irrespective of the Fe nutritional status, no significant difference was observed in the absolute amount of Fe-59 translocated to other plant parts when the micronutrient was supplied either as Fe-EDTA or Fe-WEHS. Results show that the utilization of Fe complexed to WEHS by sunflower leaves involves an Fe(III) reduction step in the apoplast prior to its uptake by the symplast of leaf cells and that Fe taken up from the Fe-WEHS complexes can be translocated from fully expanded leaves towards the roots and other parts of the shoot.
PB  - Taylor & Francis Inc, Philadelphia
T2  - Journal of Plant Nutrition
T1  - Uptake of iron (Fe-59) complexed to water-extractable humic substances by sunflower leaves
EP  - 2252
IS  - 10-11
SP  - 2243
VL  - 26
DO  - 10.1081/PLN-120024278
ER  - 

@article{
author = "Nikolic, Miroslav and Cesco, Stefano and Romheld, V and Varanini, Zeno and Pinton, Roberto",
year = "2003",
abstract = "A research was carried out to evaluate the leaves' ability to utilize Fe supplied as a complex with water-extractable humic substances (WEHS) and the long-distance transport of Fe-59 applied to sections of fully expanded leaves of intact sunflower (Helianthus annuus L.) plants. Plants were grown in a nutrient solution containing 10 muM Fe(III)-EDDHA (Fe-sufficient plants), with the addition of 10 mM NaHCO3 to induce iron chlorosis (Fe-deficient plants). Fe(III)-WEHS could be reduced by sunflower leaf discs at levels comparable to those observed using Fe(III)-EDTA, regardless of the Fe status. On the other hand, Fe-59 uptake rate by leaf discs of green and chlorotic plants was significantly lower in Fe-WEHS-treated plants, possibly suggesting the effect of light on photochemical reduction of Fe-EDTA. In the experiments with intact plants, Fe-59-labeled Fe-WEHS or Fe-EDTA were applied onto a section of fully expanded leaves. Irrespective of Fe nutritional status, Fe-59 uptake was significantly higher when the treatment was carried out with Fe-EDTA. A significant difference was found in the amount of Fe-59 translocated from treated leaf area between green and chlorotic plants. However, irrespective of the Fe nutritional status, no significant difference was observed in the absolute amount of Fe-59 translocated to other plant parts when the micronutrient was supplied either as Fe-EDTA or Fe-WEHS. Results show that the utilization of Fe complexed to WEHS by sunflower leaves involves an Fe(III) reduction step in the apoplast prior to its uptake by the symplast of leaf cells and that Fe taken up from the Fe-WEHS complexes can be translocated from fully expanded leaves towards the roots and other parts of the shoot.",
publisher = "Taylor & Francis Inc, Philadelphia",
journal = "Journal of Plant Nutrition",
title = "Uptake of iron (Fe-59) complexed to water-extractable humic substances by sunflower leaves",
pages = "2252-2243",
number = "10-11",
volume = "26",
doi = "10.1081/PLN-120024278"
}

Nikolic, M., Cesco, S., Romheld, V., Varanini, Z.,& Pinton, R.. (2003). Uptake of iron (Fe-59) complexed to water-extractable humic substances by sunflower leaves. in Journal of Plant Nutrition
Taylor & Francis Inc, Philadelphia., 26(10-11), 2243-2252.
https://doi.org/10.1081/PLN-120024278

Nikolic M, Cesco S, Romheld V, Varanini Z, Pinton R. Uptake of iron (Fe-59) complexed to water-extractable humic substances by sunflower leaves. in Journal of Plant Nutrition. 2003;26(10-11):2243-2252.
doi:10.1081/PLN-120024278 .

Nikolic, Miroslav, Cesco, Stefano, Romheld, V, Varanini, Zeno, Pinton, Roberto, "Uptake of iron (Fe-59) complexed to water-extractable humic substances by sunflower leaves" in Journal of Plant Nutrition, 26, no. 10-11 (2003):2243-2252,
https://doi.org/10.1081/PLN-120024278 . .

TY  - JOUR
AU  - Cesco, Stefano
AU  - Nikolic, Miroslav
AU  - Romheld, V
AU  - Varanini, Zeno
AU  - Pinton, Roberto
PY  - 2002
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/79
AB  - The capability of cucumber (Cucumis sativus L., cv. Serpente cinese), a Strategy I plant and barley (Hordeum vulgaris L., cv. Europa), a Strategy II plant to use Fe complexed by a water-soluble humic fraction (WEHS) extracted from a peat, was studied. Uptake of Fe-59 from Fe-59-WEHS by cucumber plants was higher at pH 6.0 than at pH 7.5. Roots of intact cucumber plants were able to reduce the Fe III-WEHS complex either at pH 6.0 or 7.5, rates being higher in the assay medium buffered at pH 6.0. After supply of Fe-59-WEHS, a large pool of root extraplasmatic Fe-59 was formed, which could be used to a large extent by Fe-deficient plants, particularly under acidic conditions. Uptake of Fe-59 from Fe-59-WEHS by Fe-sufficient and Fe-deficient barley plants was examined during periods of high (morning) and low (evening) PS release. Uptake paralleled the diurnal rhythm of PS release. Furthermore, Fe-59 uptake was strongly enhanced by addition of PS to the uptake solution in both Fe-sufficient and Fe-deficient plants. High amount of root extraplasmatic Fe-59 was formed upon supply of Fe-WEHS, particularly in the evening experiment. Fe-deficient barley plants were able to utilize Fe from the root extraplasmatic pool, conceivably as a result of high rates of PS release. The results of the present work together with previous observations indicate that cucumber plants (Strategy I) utilize Fe complexed to WEHS, presumably via reduction of Fe III-WEHS by the plasma membrane-bound reductase, while barley plants (Strategy II) use an indirect mechanism involving ligand exchange between WEHS and PS.
PB  - Springer, Dordrecht
T2  - Plant and Soil
T1  - Uptake of Fe-59 from soluble Fe-59-humate complexes by cucumber and barley plants
EP  - 128
IS  - 1
SP  - 121
VL  - 241
DO  - 10.1023/A:1016061003397
ER  - 

@article{
author = "Cesco, Stefano and Nikolic, Miroslav and Romheld, V and Varanini, Zeno and Pinton, Roberto",
year = "2002",
abstract = "The capability of cucumber (Cucumis sativus L., cv. Serpente cinese), a Strategy I plant and barley (Hordeum vulgaris L., cv. Europa), a Strategy II plant to use Fe complexed by a water-soluble humic fraction (WEHS) extracted from a peat, was studied. Uptake of Fe-59 from Fe-59-WEHS by cucumber plants was higher at pH 6.0 than at pH 7.5. Roots of intact cucumber plants were able to reduce the Fe III-WEHS complex either at pH 6.0 or 7.5, rates being higher in the assay medium buffered at pH 6.0. After supply of Fe-59-WEHS, a large pool of root extraplasmatic Fe-59 was formed, which could be used to a large extent by Fe-deficient plants, particularly under acidic conditions. Uptake of Fe-59 from Fe-59-WEHS by Fe-sufficient and Fe-deficient barley plants was examined during periods of high (morning) and low (evening) PS release. Uptake paralleled the diurnal rhythm of PS release. Furthermore, Fe-59 uptake was strongly enhanced by addition of PS to the uptake solution in both Fe-sufficient and Fe-deficient plants. High amount of root extraplasmatic Fe-59 was formed upon supply of Fe-WEHS, particularly in the evening experiment. Fe-deficient barley plants were able to utilize Fe from the root extraplasmatic pool, conceivably as a result of high rates of PS release. The results of the present work together with previous observations indicate that cucumber plants (Strategy I) utilize Fe complexed to WEHS, presumably via reduction of Fe III-WEHS by the plasma membrane-bound reductase, while barley plants (Strategy II) use an indirect mechanism involving ligand exchange between WEHS and PS.",
publisher = "Springer, Dordrecht",
journal = "Plant and Soil",
title = "Uptake of Fe-59 from soluble Fe-59-humate complexes by cucumber and barley plants",
pages = "128-121",
number = "1",
volume = "241",
doi = "10.1023/A:1016061003397"
}

Cesco, S., Nikolic, M., Romheld, V., Varanini, Z.,& Pinton, R.. (2002). Uptake of Fe-59 from soluble Fe-59-humate complexes by cucumber and barley plants. in Plant and Soil
Springer, Dordrecht., 241(1), 121-128.
https://doi.org/10.1023/A:1016061003397

Cesco S, Nikolic M, Romheld V, Varanini Z, Pinton R. Uptake of Fe-59 from soluble Fe-59-humate complexes by cucumber and barley plants. in Plant and Soil. 2002;241(1):121-128.
doi:10.1023/A:1016061003397 .

Cesco, Stefano, Nikolic, Miroslav, Romheld, V, Varanini, Zeno, Pinton, Roberto, "Uptake of Fe-59 from soluble Fe-59-humate complexes by cucumber and barley plants" in Plant and Soil, 241, no. 1 (2002):121-128,
https://doi.org/10.1023/A:1016061003397 . .