Uptake of iron (Fe-59) complexed to water-extractable humic substances by sunflower leaves
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 signifi...cantly 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.
Keywords:
iron / humic substances / Helianthus annuus L. / foliar uptake / chlorosisSource:
Journal of Plant Nutrition, 2003, 26, 10-11, 2243-2252Publisher:
- Taylor & Francis Inc, Philadelphia
DOI: 10.1081/PLN-120024278
ISSN: 0190-4167
WoS: 000185604600028
Scopus: 2-s2.0-0141788075
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Institut za multidisciplinarna istraživanjaTY - 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 . .