TY  - JOUR
AU  - Nikolic, Miroslav
AU  - Nikolić, Nina
AU  - Liang, Yongchao
AU  - Kirkby, Ernest A.
AU  - Romheld, V
PY  - 2007
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/176
AB  - A basic problem in silicon (Si) uptake studies in biology is the lack of an appropriate radioactive isotope. Radioactive germanium-68 (Ge-68) has been used previously as a Si tracer in biological materials, but its suitability for the study of Si transport in higher plants is still untested. In this study, we investigated Ge-68-traced Si uptake by four crop species differing widely in uptake capacity for Si, including rice (Oryza sativa), barley (Hordeum vulgare), cucumber (Cucumis sativus), and tomato (Lycopersicon esculentum). Maintenance of a Ge-68:Si molar ratio that was similar in the plant tissues of all four plant species to that supplied in the nutrient solution over a wide range of Si concentrations demonstrated the absence of discrimination between Ge-68 and Si. Further, using the Ge-68 tracer, a typical Michaelis-Menten uptake kinetics for Si was found in rice, barley, and cucumber. Compared to rice, the relative proportion of root-to-shoot translocated Si was lower in barley and cucumber and especially in tomato (only 30%). Uptake and translocation of Si in rice, barley, and cucumber (Si accumulators) were strongly inhibited by 2,4-dinitrophenol and HgCl2, but in tomato, as a Si-excluding species, both inhibitors produced the opposite effect. In conclusion, our results suggest the use of the Ge-68 tracer method as an appropriate choice for future studies of Si transport in plants. Our findings also indicate that the restriction of Si from symplast to apoplast in the cortex of Si excluders is a metabolically active process.
PB  - Amer Soc Plant Biologists, Rockville
T2  - Plant Physiology
T1  - Germanium-68 as an Adequate Tracer for Silicon Transport in Plants. Characterization of Silicon Uptake in Different Crop Species
EP  - 503
IS  - 1
SP  - 495
VL  - 143
DO  - 10.1104/pp.106.090845
ER  - 

@article{
author = "Nikolic, Miroslav and Nikolić, Nina and Liang, Yongchao and Kirkby, Ernest A. and Romheld, V",
year = "2007",
abstract = "A basic problem in silicon (Si) uptake studies in biology is the lack of an appropriate radioactive isotope. Radioactive germanium-68 (Ge-68) has been used previously as a Si tracer in biological materials, but its suitability for the study of Si transport in higher plants is still untested. In this study, we investigated Ge-68-traced Si uptake by four crop species differing widely in uptake capacity for Si, including rice (Oryza sativa), barley (Hordeum vulgare), cucumber (Cucumis sativus), and tomato (Lycopersicon esculentum). Maintenance of a Ge-68:Si molar ratio that was similar in the plant tissues of all four plant species to that supplied in the nutrient solution over a wide range of Si concentrations demonstrated the absence of discrimination between Ge-68 and Si. Further, using the Ge-68 tracer, a typical Michaelis-Menten uptake kinetics for Si was found in rice, barley, and cucumber. Compared to rice, the relative proportion of root-to-shoot translocated Si was lower in barley and cucumber and especially in tomato (only 30%). Uptake and translocation of Si in rice, barley, and cucumber (Si accumulators) were strongly inhibited by 2,4-dinitrophenol and HgCl2, but in tomato, as a Si-excluding species, both inhibitors produced the opposite effect. In conclusion, our results suggest the use of the Ge-68 tracer method as an appropriate choice for future studies of Si transport in plants. Our findings also indicate that the restriction of Si from symplast to apoplast in the cortex of Si excluders is a metabolically active process.",
publisher = "Amer Soc Plant Biologists, Rockville",
journal = "Plant Physiology",
title = "Germanium-68 as an Adequate Tracer for Silicon Transport in Plants. Characterization of Silicon Uptake in Different Crop Species",
pages = "503-495",
number = "1",
volume = "143",
doi = "10.1104/pp.106.090845"
}

Nikolic, M., Nikolić, N., Liang, Y., Kirkby, E. A.,& Romheld, V.. (2007). Germanium-68 as an Adequate Tracer for Silicon Transport in Plants. Characterization of Silicon Uptake in Different Crop Species. in Plant Physiology
Amer Soc Plant Biologists, Rockville., 143(1), 495-503.
https://doi.org/10.1104/pp.106.090845

Nikolic M, Nikolić N, Liang Y, Kirkby EA, Romheld V. Germanium-68 as an Adequate Tracer for Silicon Transport in Plants. Characterization of Silicon Uptake in Different Crop Species. in Plant Physiology. 2007;143(1):495-503.
doi:10.1104/pp.106.090845 .

Nikolic, Miroslav, Nikolić, Nina, Liang, Yongchao, Kirkby, Ernest A., Romheld, V, "Germanium-68 as an Adequate Tracer for Silicon Transport in Plants. Characterization of Silicon Uptake in Different Crop Species" in Plant Physiology, 143, no. 1 (2007):495-503,
https://doi.org/10.1104/pp.106.090845 . .

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  - Nikolic, Miroslav
AU  - Romheld, V
PY  - 2003
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/80
AB  - It has been hypothesized that nitrate (NO3-) nutrition might induce iron (Fe) deficiency chlorosis by inactivation of Fe in the leaf apoplast (H.U. Kosegarten, B. Hoffmann, K. Mengel [1999] Plant Physiol 121: 1069-1079). To test this hypothesis, sunflower (Helianthus annuus L. cv Farnkasol) plants were grown in nutrient solutions supplied with various nitrogen (N) forms (NO3-, NH4+ and NH4NO3), with or without pH control by using pH buffers [2-(N-morpholino)ethanesulfonic acid or 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid]. It was shown that high pH in the nutrient solution restricted uptake and shoot translocation of Fe independently of N form and, therefore, induced Fe deficiency chlorosis at low Fe supply [1 mum ferric ethylenediaminedi(O-hydroxyphenylacetic acid)]. Root NO3- supply (up to 40 mM) did not affect the relative distribution of Fe between leaf apoplast and symplast at constant low external pH of the root medium. Although perfusion of high pH-buffered solution (7.0) into the leaf apoplast restricted Fe-59 uptake rate as compared with low apoplastic solution pH (5.0 and 6.0, respectively), loading of NO3- (6 mM) showed no effect on Fe-59 uptake by the symplast of leaf cells. However, high light intensity strongly increased Fe-59 uptake, independently of apoplastic pH or of the presence of NO3- in the apoplastic solution. Finally, there are no indications in the present study that NO3- supply to roots results in the postulated inactivation of Fe in the leaf apoplast. It is concluded that NO3- nutrition results in Fe deficiency chlorosis exclusively by inhibited Fe acquisition by roots due to high pH at the root surface.
PB  - Amer Soc Plant Biologists, Rockville
T2  - Plant Physiology
T1  - Nitrate does not result in iron inactivation in the apoplast of sunflower leaves
EP  - 1314
IS  - 3
SP  - 1303
VL  - 132
DO  - 10.1104/pp.102.017889
ER  - 

@article{
author = "Nikolic, Miroslav and Romheld, V",
year = "2003",
abstract = "It has been hypothesized that nitrate (NO3-) nutrition might induce iron (Fe) deficiency chlorosis by inactivation of Fe in the leaf apoplast (H.U. Kosegarten, B. Hoffmann, K. Mengel [1999] Plant Physiol 121: 1069-1079). To test this hypothesis, sunflower (Helianthus annuus L. cv Farnkasol) plants were grown in nutrient solutions supplied with various nitrogen (N) forms (NO3-, NH4+ and NH4NO3), with or without pH control by using pH buffers [2-(N-morpholino)ethanesulfonic acid or 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid]. It was shown that high pH in the nutrient solution restricted uptake and shoot translocation of Fe independently of N form and, therefore, induced Fe deficiency chlorosis at low Fe supply [1 mum ferric ethylenediaminedi(O-hydroxyphenylacetic acid)]. Root NO3- supply (up to 40 mM) did not affect the relative distribution of Fe between leaf apoplast and symplast at constant low external pH of the root medium. Although perfusion of high pH-buffered solution (7.0) into the leaf apoplast restricted Fe-59 uptake rate as compared with low apoplastic solution pH (5.0 and 6.0, respectively), loading of NO3- (6 mM) showed no effect on Fe-59 uptake by the symplast of leaf cells. However, high light intensity strongly increased Fe-59 uptake, independently of apoplastic pH or of the presence of NO3- in the apoplastic solution. Finally, there are no indications in the present study that NO3- supply to roots results in the postulated inactivation of Fe in the leaf apoplast. It is concluded that NO3- nutrition results in Fe deficiency chlorosis exclusively by inhibited Fe acquisition by roots due to high pH at the root surface.",
publisher = "Amer Soc Plant Biologists, Rockville",
journal = "Plant Physiology",
title = "Nitrate does not result in iron inactivation in the apoplast of sunflower leaves",
pages = "1314-1303",
number = "3",
volume = "132",
doi = "10.1104/pp.102.017889"
}

Nikolic, M.,& Romheld, V.. (2003). Nitrate does not result in iron inactivation in the apoplast of sunflower leaves. in Plant Physiology
Amer Soc Plant Biologists, Rockville., 132(3), 1303-1314.
https://doi.org/10.1104/pp.102.017889

Nikolic M, Romheld V. Nitrate does not result in iron inactivation in the apoplast of sunflower leaves. in Plant Physiology. 2003;132(3):1303-1314.
doi:10.1104/pp.102.017889 .

Nikolic, Miroslav, Romheld, V, "Nitrate does not result in iron inactivation in the apoplast of sunflower leaves" in Plant Physiology, 132, no. 3 (2003):1303-1314,
https://doi.org/10.1104/pp.102.017889 . .

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 . .

TY  - JOUR
AU  - Erenoglu, B
AU  - Nikolic, Miroslav
AU  - Romheld, V
AU  - Cakmak, I
PY  - 2002
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/75
AB  - Using two bread wheat (Triticum aestivum) and two durum wheat (Triticum durum) cultivars differing in zinc (Zn) efficiency, uptake and translocation of foliar-applied Zn-65 were studied to characterize the role of Zn nutritional status of plants on the extent of phloem mobility of Zn and to determine the relationship between phloem mobility of Zn and Zn efficiency of the used wheat cultivars. Irrespective of leaf age and Zn nutritional status of plants, all cultivars showed similar Zn uptake rates with application of (ZnSO4)-Zn-65 to leaf strips in a short-term experiment. Also with supply of (ZnSO4)-Zn-65 by immersing the tip (3 cm) of the oldest leaf of intact plants, no differences in Zn uptake were observed among and within both wheat species. Further, Zn nutritional status did not affect total uptake of foliar applied Zn. However, Zn-deficient plants translocated more Zn-65 from the treated leaf to the roots and remainder parts of shoots. In Zn-deficient plants about 40% of the total absorbed Zn-65 was translocated from the treated leaf to the roots and remainder parts of shoots within 8 days while in Zn-sufficient plants the proportion of the translocated Zn-65 of the total absorbed Zn-65 was about 25%. Although differences in Zn efficiency existed between the cultivars did not affect the translocation and distribution of Zn-65 between roots and shoots. Bread wheats compared to durum wheats, tended to accumulate more Zn-65 in shoots and less Zn-65 in roots, particularly under Zn-deficient conditions. The results indicate that differences in expression of Zn efficiency between and within durum and bread wheats are not related to translocation or distribution of foliar-applied Zn-65 within plants. Differential compartementation of Zn at the cellular levels is discussed as a possible factor determining genotypic variation in Zn efficiency within wheat.
PB  - Springer, Dordrecht
T2  - Plant and Soil
T1  - Uptake and transport of foliar applied zinc (Zn-65) in bread and durum wheat cultivars differing in zinc efficiency
EP  - 257
IS  - 2
SP  - 251
VL  - 241
DO  - 10.1023/A:1016148925918
ER  - 

@article{
author = "Erenoglu, B and Nikolic, Miroslav and Romheld, V and Cakmak, I",
year = "2002",
abstract = "Using two bread wheat (Triticum aestivum) and two durum wheat (Triticum durum) cultivars differing in zinc (Zn) efficiency, uptake and translocation of foliar-applied Zn-65 were studied to characterize the role of Zn nutritional status of plants on the extent of phloem mobility of Zn and to determine the relationship between phloem mobility of Zn and Zn efficiency of the used wheat cultivars. Irrespective of leaf age and Zn nutritional status of plants, all cultivars showed similar Zn uptake rates with application of (ZnSO4)-Zn-65 to leaf strips in a short-term experiment. Also with supply of (ZnSO4)-Zn-65 by immersing the tip (3 cm) of the oldest leaf of intact plants, no differences in Zn uptake were observed among and within both wheat species. Further, Zn nutritional status did not affect total uptake of foliar applied Zn. However, Zn-deficient plants translocated more Zn-65 from the treated leaf to the roots and remainder parts of shoots. In Zn-deficient plants about 40% of the total absorbed Zn-65 was translocated from the treated leaf to the roots and remainder parts of shoots within 8 days while in Zn-sufficient plants the proportion of the translocated Zn-65 of the total absorbed Zn-65 was about 25%. Although differences in Zn efficiency existed between the cultivars did not affect the translocation and distribution of Zn-65 between roots and shoots. Bread wheats compared to durum wheats, tended to accumulate more Zn-65 in shoots and less Zn-65 in roots, particularly under Zn-deficient conditions. The results indicate that differences in expression of Zn efficiency between and within durum and bread wheats are not related to translocation or distribution of foliar-applied Zn-65 within plants. Differential compartementation of Zn at the cellular levels is discussed as a possible factor determining genotypic variation in Zn efficiency within wheat.",
publisher = "Springer, Dordrecht",
journal = "Plant and Soil",
title = "Uptake and transport of foliar applied zinc (Zn-65) in bread and durum wheat cultivars differing in zinc efficiency",
pages = "257-251",
number = "2",
volume = "241",
doi = "10.1023/A:1016148925918"
}

Erenoglu, B., Nikolic, M., Romheld, V.,& Cakmak, I.. (2002). Uptake and transport of foliar applied zinc (Zn-65) in bread and durum wheat cultivars differing in zinc efficiency. in Plant and Soil
Springer, Dordrecht., 241(2), 251-257.
https://doi.org/10.1023/A:1016148925918

Erenoglu B, Nikolic M, Romheld V, Cakmak I. Uptake and transport of foliar applied zinc (Zn-65) in bread and durum wheat cultivars differing in zinc efficiency. in Plant and Soil. 2002;241(2):251-257.
doi:10.1023/A:1016148925918 .

Erenoglu, B, Nikolic, Miroslav, Romheld, V, Cakmak, I, "Uptake and transport of foliar applied zinc (Zn-65) in bread and durum wheat cultivars differing in zinc efficiency" in Plant and Soil, 241, no. 2 (2002):251-257,
https://doi.org/10.1023/A:1016148925918 . .

TY  - JOUR
AU  - Nikolic, Miroslav
AU  - Romheld, V
PY  - 2002
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/70
AB  - The role of the leaf apoplast in iron (Fe) uptake into the leaf symplast is insufficiently understood, particularly in relation to the supposed inactivation of Fe in leaves caused by elevated bicarbonate in calcareous soils. It has been supposed that high bicarbonate supply to roots increases the pH of the leaf apoplast which decreases the physiological availability of Fe in leaf tissues. The study reported here has been carried out with sunflower plants grown in nutrient solution and with grapevine plants grown on calcareous soil under field conditions. The data obtained clearly show that the pH of the leaf apoplastic fluid was not affected by high bicarbonate supply in the root medium (nutrient solution and field experiments). The concentrations of total, symplastic and apoplastic Fe were decreased in chlorotic leaves of both sunflower (nutrient solution experiment) and grapevine plants in which leaf expansion was slightly inhibited (field experiment). However, in grapevine showing severe inhibition of leaf growth, total Fe concentration in chlorotic leaves was the same or even higher than in green ones, indicative to the so-called `chlorosis paradox'. The findings do not support the hypothesis of Fe inactivation in the leaf apoplast as the cause of Fe deficiency chlorosis since no increase was found in the relative amount of apoplastic Fe (% of total leaf Fe) either in the leaves of sunflower or grapevine plants. It is concluded that high bicarbonate concentration in the soil solution does not decrease Fe availability in the leaf apoplast.
PB  - Springer, Dordrecht
T2  - Plant and Soil
T1  - Does high bicarbonate supply to roots change availability of iron in the leaf apoplast?
EP  - 74
IS  - 1
SP  - 67
VL  - 241
DO  - 10.1023/A:1016029024374
ER  - 

@article{
author = "Nikolic, Miroslav and Romheld, V",
year = "2002",
abstract = "The role of the leaf apoplast in iron (Fe) uptake into the leaf symplast is insufficiently understood, particularly in relation to the supposed inactivation of Fe in leaves caused by elevated bicarbonate in calcareous soils. It has been supposed that high bicarbonate supply to roots increases the pH of the leaf apoplast which decreases the physiological availability of Fe in leaf tissues. The study reported here has been carried out with sunflower plants grown in nutrient solution and with grapevine plants grown on calcareous soil under field conditions. The data obtained clearly show that the pH of the leaf apoplastic fluid was not affected by high bicarbonate supply in the root medium (nutrient solution and field experiments). The concentrations of total, symplastic and apoplastic Fe were decreased in chlorotic leaves of both sunflower (nutrient solution experiment) and grapevine plants in which leaf expansion was slightly inhibited (field experiment). However, in grapevine showing severe inhibition of leaf growth, total Fe concentration in chlorotic leaves was the same or even higher than in green ones, indicative to the so-called `chlorosis paradox'. The findings do not support the hypothesis of Fe inactivation in the leaf apoplast as the cause of Fe deficiency chlorosis since no increase was found in the relative amount of apoplastic Fe (% of total leaf Fe) either in the leaves of sunflower or grapevine plants. It is concluded that high bicarbonate concentration in the soil solution does not decrease Fe availability in the leaf apoplast.",
publisher = "Springer, Dordrecht",
journal = "Plant and Soil",
title = "Does high bicarbonate supply to roots change availability of iron in the leaf apoplast?",
pages = "74-67",
number = "1",
volume = "241",
doi = "10.1023/A:1016029024374"
}

Nikolic, M.,& Romheld, V.. (2002). Does high bicarbonate supply to roots change availability of iron in the leaf apoplast?. in Plant and Soil
Springer, Dordrecht., 241(1), 67-74.
https://doi.org/10.1023/A:1016029024374

Nikolic M, Romheld V. Does high bicarbonate supply to roots change availability of iron in the leaf apoplast?. in Plant and Soil. 2002;241(1):67-74.
doi:10.1023/A:1016029024374 .

Nikolic, Miroslav, Romheld, V, "Does high bicarbonate supply to roots change availability of iron in the leaf apoplast?" in Plant and Soil, 241, no. 1 (2002):67-74,
https://doi.org/10.1023/A:1016029024374 . .

TY  - JOUR
AU  - Nikolic, Miroslav
AU  - Romheld, V
AU  - Merkt, N
PY  - 2000
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/49
AB  - In order to study the effect of high bicarbonate concentration in the root medium on root Fe-III reduction, Fe uptake and its translocation to the leaves, two rootstocks (Vitis riparia Michx., susceptible, and 41 B (Vitis vinifera L. cv. Chasselas x Vitis berlandieri Planch.), resistant to Fe deficiency chlorosis) were pre-cultivated in nutrient solutions with high and low Fe supply. After three weeks of preculture at low Fe, chlorosis symptoms occurred in both, Fe-resistant and Fe-susceptible genotypes. The Fe-III reducing capacity by roots was enhanced at Fe deficiency in both genotypes, which was consistent with the increase of subsequent root uptake and translocation rates of Fe-59. In the presence of bicarbonate in the solutions the Fe-III reducing capacity, Fe-59 uptake and translocation rate decreased in both genotypes precultured with low re supply. The Fe-59 uptake and translocation rate, however, were significantly higher in the Fe chlorosis-resistant rootstock 41 B. These results clearly indicate that bicarbonate-induced Fe chlorosis in grapevine rootstocks is obviously caused by an inhibition of Fe uptake and translocation due to an inhibition of Fe-III reduction by root cells. The fact that these processes were less inhibited in the chlorosis-resistant rootstock hints to genotypical differences in Fe acquisition by roots at high bicarbonate levels. These differences might be used in breeding programs to identify Fe chlorosis-resistant rootstocks.
PB  - Bundesanstalt Zuchtungs Forschung Kulturpflanzen, Siebeldingen
T2  - VITIS
T1  - Effect of bicarbonate on uptake and translocation of Fe-59 in two grapevine rootstocks differing in their resistance to Fe deficiency chlorosis
EP  - 149
IS  - 4
SP  - 145
VL  - 39
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_49
ER  - 

@article{
author = "Nikolic, Miroslav and Romheld, V and Merkt, N",
year = "2000",
abstract = "In order to study the effect of high bicarbonate concentration in the root medium on root Fe-III reduction, Fe uptake and its translocation to the leaves, two rootstocks (Vitis riparia Michx., susceptible, and 41 B (Vitis vinifera L. cv. Chasselas x Vitis berlandieri Planch.), resistant to Fe deficiency chlorosis) were pre-cultivated in nutrient solutions with high and low Fe supply. After three weeks of preculture at low Fe, chlorosis symptoms occurred in both, Fe-resistant and Fe-susceptible genotypes. The Fe-III reducing capacity by roots was enhanced at Fe deficiency in both genotypes, which was consistent with the increase of subsequent root uptake and translocation rates of Fe-59. In the presence of bicarbonate in the solutions the Fe-III reducing capacity, Fe-59 uptake and translocation rate decreased in both genotypes precultured with low re supply. The Fe-59 uptake and translocation rate, however, were significantly higher in the Fe chlorosis-resistant rootstock 41 B. These results clearly indicate that bicarbonate-induced Fe chlorosis in grapevine rootstocks is obviously caused by an inhibition of Fe uptake and translocation due to an inhibition of Fe-III reduction by root cells. The fact that these processes were less inhibited in the chlorosis-resistant rootstock hints to genotypical differences in Fe acquisition by roots at high bicarbonate levels. These differences might be used in breeding programs to identify Fe chlorosis-resistant rootstocks.",
publisher = "Bundesanstalt Zuchtungs Forschung Kulturpflanzen, Siebeldingen",
journal = "VITIS",
title = "Effect of bicarbonate on uptake and translocation of Fe-59 in two grapevine rootstocks differing in their resistance to Fe deficiency chlorosis",
pages = "149-145",
number = "4",
volume = "39",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_49"
}

Nikolic, M., Romheld, V.,& Merkt, N.. (2000). Effect of bicarbonate on uptake and translocation of Fe-59 in two grapevine rootstocks differing in their resistance to Fe deficiency chlorosis. in VITIS
Bundesanstalt Zuchtungs Forschung Kulturpflanzen, Siebeldingen., 39(4), 145-149.
https://hdl.handle.net/21.15107/rcub_rimsi_49

Nikolic M, Romheld V, Merkt N. Effect of bicarbonate on uptake and translocation of Fe-59 in two grapevine rootstocks differing in their resistance to Fe deficiency chlorosis. in VITIS. 2000;39(4):145-149.
https://hdl.handle.net/21.15107/rcub_rimsi_49 .

Nikolic, Miroslav, Romheld, V, Merkt, N, "Effect of bicarbonate on uptake and translocation of Fe-59 in two grapevine rootstocks differing in their resistance to Fe deficiency chlorosis" in VITIS, 39, no. 4 (2000):145-149,
https://hdl.handle.net/21.15107/rcub_rimsi_49 .

TY  - JOUR
AU  - Nikolic, Miroslav
AU  - Romheld, V
PY  - 1999
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/47
AB  - The mechanism of iron (Fe) uptake from the leaf apoplast into leaf mesophyll cells was studied to evaluate the putative Fe inactivation as a possible cause of Fe deficiency chlorosis. For this purpose, sunflower (Helianthus annuus L.) and faba bean plants (Vicia faba L.) were precultured with varied Fe and bicarbonate (HCO3-) supply in nutrient solution. After 2-3 weeks preculture, Fe-III reduction and Fe-59 uptake by leaf discs were measured in solutions with Fe supplied as citrate or synthetic chelates in darkness. The data clearly indicate that Fe-III reduction is a prerequisite for Fe uptake into leaf cells and that the Fe nutritional status of plants does not affect either process. In addition, varied supply of Fe and HCO3- to the root medium during preculture had no effect on pH of the xylem sap and leaf apoplastic fluid. A varied pH of the incubation solution had no significant effect on Fe-III reduction and Fe uptake by leaf discs in the physiologically relevant pH range of 5.0-6.0 as measured in the apoplastic leaf fluid. It is concluded that Fe inactivation in the leaf apoplast is not a primary cause of Fe deficiency chlorosis induced by bicarbonate.
PB  - Springer, Dordrecht
T2  - Plant and Soil
T1  - Mechanism of Fe uptake by the leaf symplast: Is Fe inactivation in leaf a cause of Fe deficiency chlorosis?
EP  - 237
IS  - 2
SP  - 229
VL  - 215
DO  - 10.1023/A:1004786211779
ER  - 

@article{
author = "Nikolic, Miroslav and Romheld, V",
year = "1999",
abstract = "The mechanism of iron (Fe) uptake from the leaf apoplast into leaf mesophyll cells was studied to evaluate the putative Fe inactivation as a possible cause of Fe deficiency chlorosis. For this purpose, sunflower (Helianthus annuus L.) and faba bean plants (Vicia faba L.) were precultured with varied Fe and bicarbonate (HCO3-) supply in nutrient solution. After 2-3 weeks preculture, Fe-III reduction and Fe-59 uptake by leaf discs were measured in solutions with Fe supplied as citrate or synthetic chelates in darkness. The data clearly indicate that Fe-III reduction is a prerequisite for Fe uptake into leaf cells and that the Fe nutritional status of plants does not affect either process. In addition, varied supply of Fe and HCO3- to the root medium during preculture had no effect on pH of the xylem sap and leaf apoplastic fluid. A varied pH of the incubation solution had no significant effect on Fe-III reduction and Fe uptake by leaf discs in the physiologically relevant pH range of 5.0-6.0 as measured in the apoplastic leaf fluid. It is concluded that Fe inactivation in the leaf apoplast is not a primary cause of Fe deficiency chlorosis induced by bicarbonate.",
publisher = "Springer, Dordrecht",
journal = "Plant and Soil",
title = "Mechanism of Fe uptake by the leaf symplast: Is Fe inactivation in leaf a cause of Fe deficiency chlorosis?",
pages = "237-229",
number = "2",
volume = "215",
doi = "10.1023/A:1004786211779"
}

Nikolic, M.,& Romheld, V.. (1999). Mechanism of Fe uptake by the leaf symplast: Is Fe inactivation in leaf a cause of Fe deficiency chlorosis?. in Plant and Soil
Springer, Dordrecht., 215(2), 229-237.
https://doi.org/10.1023/A:1004786211779

Nikolic M, Romheld V. Mechanism of Fe uptake by the leaf symplast: Is Fe inactivation in leaf a cause of Fe deficiency chlorosis?. in Plant and Soil. 1999;215(2):229-237.
doi:10.1023/A:1004786211779 .

Nikolic, Miroslav, Romheld, V, "Mechanism of Fe uptake by the leaf symplast: Is Fe inactivation in leaf a cause of Fe deficiency chlorosis?" in Plant and Soil, 215, no. 2 (1999):229-237,
https://doi.org/10.1023/A:1004786211779 . .