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Nicotianamine Increases the Uptake of FeEDDHA by Plants at Micromolar Iron Concentration
Biochem. Physiol. Pflanzen 180,397- 400 (1985)
Short Communication
Nicotianamine Increases the Uptake of FeEDDHA by Plants at Micromolar Iron Concentration GUNTER SCHOLZ1) , KARLHEINZ SEIFERT2) and KLAUS SCHREIBER2) Forschungsbereich Biowissenschaften und Medizin der Akademie der Wissenschaften der DDR
1) Zentralinstitut fiir Genetik und Kulturpflanzenforschung, Gatersleben 2) Institut fiir Biochemie der Pfla.nzen, Halle, DDR Key T e r mIn d ex: phytosiderophore, nicotianamine, trace metal uptake; Lycopersicon esculentum; H elianthus annuus
Summary Nicotianamine increased the uptake of FeEDDHA by tomato and sunflower plants growing at pH 5 in nutrient solution with 10- 6 M iron. This effect is connected with an increase of growth and dry matter production , and with a prevention of iron chlorosis.
In a previous paper it was suggested that nicotianamine (NA) could function as a phytosiderophore, owing to the spatial arrangement of its ligand atoms, fulfilling the reguirement of a hexadentate chelate for iron (BuDtsINSKY et al. 1980). Although no indications for this hypothesis have been observed with plants growing in nutrient solution at 10-5 M iron concentration (SCHOLZ et al. 1985), we now present results which clearly show a NA-dependent increase of iron uptake by tomato and sunflower plants if the iron supply was kept at 10-6 M. Experiments were performed with seedlings of Lycopersicon esculentum MILL. cv. Bonner Beste, its NA-free mutant chloronerva and of H elianthus annuus L. , commercial variety. The experimental conditions were the same as described by SCHOLZ et al. (1985). Details are included in the legends to the figures.
Fig. 1 demonstrates the considerable increase of the iron uptake by the tomato variety 'Bonner Beste' upon addition of NA to the leaves or to the nutrient solution. In the absence of NA the plants exhibited an iron chlorosis which was less developed after application of 5 x 10-5 M NA to the leaves and was absent in plants growing in nutrient solution with 5 x 10- 6 M NA. The plants growing in the absence of NA showed short and stunted roots, as usual under iron deficiency condit ions, whereas a much better growth was obtained in the presence of NA. In the mutant chloronerva which is known for its excessive iron absorption at iron concentrations of 10- 5 M or above in the medium Part 21 in the series "The 'normalizing factor' for the tomato Illutant 'chloronerva'''. For p art 20 see RIPPERGER, H., SCHRE IBE R, K., & Faust, J. Liebigs Ann. Chern. 1984 (in press). 2(;
Bioehem. Physiol. Pflanzen , Bd. 180
398
G.
SCHOLZ,
K.
SEIFERT
and K.
n
4 ~
-03
~
8. 2 ~ -g1 <:
untreated
I I I I I I I I I I I I I I I
SCHREIBER
n
5 x 1O-5 MNA
to the leaves
Fig. 1. Effect of nicotianamine on iron uptake. Nicotianamine was supplied to the leaves:) times per day or added to the roots. 69Fe uptake by the tomato mutant chloronerva(--) and its wild-type, variety 'Bonner Beste' (- - -) was determined after 5 days growth in nutrient solution containing 10-6 59FeEDDHA. 8 seedlings per treatment. Plants were pooled, dried and, after wet digestion, counted for radioactivity.
Fig. 2. Effect of 5 x 10-5 nicotianamien in the nutrient solution (left) on root development of Helianthus annuus. Plants cultivated for 6 d in nutrient solution containing 10-6 M FeEDDlIA.
399
Nicotianamine Increases Iron Uptake by Plants
(SCHOLZ et al. 1985) the iron uptake dropped almost to zero in the absence of NA but showed some recovery upon NA supply, at least after its addition to the nutrient medium. The chlorosis was more severe than in untreated wild-type plants and was only weakly influenced by NA. The roots were very poorly developed under all treatments. The opposite response of chloronerva to high (> 10- 5 M) and low (10-6 M) iron supplies indicates that a NA-dependent system for the regulation of iron uptake has been affected by the mutation that can be restored, at least partly, by addition of small amounts of NA. The effect of NA on sunflower plants is shown in Fig. 2 and Tab. 1. Stimulation of growth, prevention of chlorosis and a very significant increase in iron uptake by NA added to the nutrient solution were similar to the results obtained with' Bonner Beste' . Whereas in roots and axis the excess of iron was only little above the increase in dry weight, large amounts were accumulated in the leaves under the influence of NA. This increase exceeds the increase in dry matter production considerably and it is a good explanation for the absence of chlorosis. As far as we know this is the first example of a positive affect of NA on iron uptake by plants. According to MINO et aJ. (1983) NA was ineffective with respect to iron uptake by hclorotic rice seedlings at pH 7 in a nutrient solution with 2 X 10-5 M FeCla, contrary to mugineic acid and 2'-deoxymugineic acid, derivatives of NA, which exerted a high increase of iron uptake and chlorophyll synthesis. These compounds are excreted by the roots of iron deficient rice and barley seedlings and are regarded as phytosiderophores due to their capacity to form very stable complexes with Fe3+. Whereas mugineic ac id and 2'-deoxymugineic acid seem to be involved in the regulation of iron uptake in monocots, NA could perhaps playa similar role in dicots. However, it is still an open question whether NA is directly linke d with iron uptake as a phytosiderophore. Its
Table 1. Effect of nicotionomine on dry tceight ond iron content of Helionthus onnuus. Seedlings were grown in aerated nutrient solution with 10- 6 )1 59FeEDDHA. Part of the vessels were supplied with nicotianamine (N A) to a final concentration of I) x 10-6 lVI. This supply was repeate d after 2 days. After 2 additional days single plants were harvested. Figures are averages ± SD. + = difference between + NA and - NA statistically significant at 5% level, ++ = significant at 1 % level, + + + = significant at 0.1 % level Treatment
-
NA
+ NA
26*
organ
leaves axis roots total leaves axis roots total
number dry weight of plants mg
7
7 8
8
137 39 44 220
± ± ± ±
26.3 8.0 8.3 41.2
192 52 70 314
± 7.7+ ± 17.0++ ± 53.1++
± 34.7++
nmol Fe per plant
per mg dry weight
33 ± 11± 69 ± 113 ±
17.3 2.3 18.2 34.2
0.23 0.28 1.08 0.51
± 28.2+++
0.51 0.33 1.75 0.75
98 17 117 232
± 2.8+++
± 21.5+++ ± 39.1 +++
± 0.09 ± 0.06 ± 0.25 ± 0.07 ± 0.11 +++
± 0.06
± 0.43 ± 0.11+++
400
G. SCHOLZ, K. SEIFERT and K. SCHREIBER, Nicotianamine Increases •.•
positive effect after application to the leaves could also be explained by the affecting of NA-dependent metabolic processes which control the uptake of iron and perhaps of other heavy metals as well. Acknowledgements We wish to express our gratitude to Mr. H. KRAMER, Halle, for the preparation of nicotianamine, to Mrs. G. NIEMSCH and Mr. G. FAUPEL, Gatersleben, for technical assistance and to Dr. K. MUNTZ and Dr. U. W. STEPHAN, Gatersleben, for valuable discussions.
References BUDEZINSKY, M., BUDZIKIEWICZ, H., PROCHAZKA, Z., RIPPERGER, H., ROMER, A., SCHOLZ, G., and SCHREIBER, K.: Nicotianamine, a possible phytosiderophore of general occurrence. Phytochemistry 19, 2295-2297 (1980). MINO, Y., ISHIDA, T., OTA, N., INOUE, M., NOMOTO, K., TAKEMOTO, K., TANAKA, R., and SUGIURA, Y.: Mugineic acid-iron(III) complex and its structurally analogous cobalt(III) complex: Characterization and implication for absorption and transport of iron in gramineous plants. J. Am. Chem. Soc. 105, 4671-4676 (1983). SCHOLZ, G., SCHLESIER, G., and SEIFERT, K.: Effect of nicotianamine on iron uptake by the tomato mutant 'chloronerva'. Physiol. Plant. 63, 99-104 (1985).
Received November 13, 1984; accepted December 14, 1984 Authors' addresses: Dr. GUNTER SCHOLZ (reprints), Zentralinstitut fiir Genetik und Kulturpflanzenforschung, CorrensstraBe 3, DDR - 4325 Gatersleben; Dr. KARLHEINZ SEIFERT, Prof. Dr. KLAUS SCHREIBER, Institut fiir Biochemie der Pflanzen, Weinberg. DDR - 4020 Halle (Saale).
Short Communication
Nicotianamine Increases the Uptake of FeEDDHA by Plants at Micromolar Iron Concentration GUNTER SCHOLZ1) , KARLHEINZ SEIFERT2) and KLAUS SCHREIBER2) Forschungsbereich Biowissenschaften und Medizin der Akademie der Wissenschaften der DDR
1) Zentralinstitut fiir Genetik und Kulturpflanzenforschung, Gatersleben 2) Institut fiir Biochemie der Pfla.nzen, Halle, DDR Key T e r mIn d ex: phytosiderophore, nicotianamine, trace metal uptake; Lycopersicon esculentum; H elianthus annuus
Summary Nicotianamine increased the uptake of FeEDDHA by tomato and sunflower plants growing at pH 5 in nutrient solution with 10- 6 M iron. This effect is connected with an increase of growth and dry matter production , and with a prevention of iron chlorosis.
In a previous paper it was suggested that nicotianamine (NA) could function as a phytosiderophore, owing to the spatial arrangement of its ligand atoms, fulfilling the reguirement of a hexadentate chelate for iron (BuDtsINSKY et al. 1980). Although no indications for this hypothesis have been observed with plants growing in nutrient solution at 10-5 M iron concentration (SCHOLZ et al. 1985), we now present results which clearly show a NA-dependent increase of iron uptake by tomato and sunflower plants if the iron supply was kept at 10-6 M. Experiments were performed with seedlings of Lycopersicon esculentum MILL. cv. Bonner Beste, its NA-free mutant chloronerva and of H elianthus annuus L. , commercial variety. The experimental conditions were the same as described by SCHOLZ et al. (1985). Details are included in the legends to the figures.
Fig. 1 demonstrates the considerable increase of the iron uptake by the tomato variety 'Bonner Beste' upon addition of NA to the leaves or to the nutrient solution. In the absence of NA the plants exhibited an iron chlorosis which was less developed after application of 5 x 10-5 M NA to the leaves and was absent in plants growing in nutrient solution with 5 x 10- 6 M NA. The plants growing in the absence of NA showed short and stunted roots, as usual under iron deficiency condit ions, whereas a much better growth was obtained in the presence of NA. In the mutant chloronerva which is known for its excessive iron absorption at iron concentrations of 10- 5 M or above in the medium Part 21 in the series "The 'normalizing factor' for the tomato Illutant 'chloronerva'''. For p art 20 see RIPPERGER, H., SCHRE IBE R, K., & Faust, J. Liebigs Ann. Chern. 1984 (in press). 2(;
Bioehem. Physiol. Pflanzen , Bd. 180
398
G.
SCHOLZ,
K.
SEIFERT
and K.
n
4 ~
-03
~
8. 2 ~ -g1 <:
untreated
I I I I I I I I I I I I I I I
SCHREIBER
n
5 x 1O-5 MNA
to the leaves
Fig. 1. Effect of nicotianamine on iron uptake. Nicotianamine was supplied to the leaves:) times per day or added to the roots. 69Fe uptake by the tomato mutant chloronerva(--) and its wild-type, variety 'Bonner Beste' (- - -) was determined after 5 days growth in nutrient solution containing 10-6 59FeEDDHA. 8 seedlings per treatment. Plants were pooled, dried and, after wet digestion, counted for radioactivity.
Fig. 2. Effect of 5 x 10-5 nicotianamien in the nutrient solution (left) on root development of Helianthus annuus. Plants cultivated for 6 d in nutrient solution containing 10-6 M FeEDDlIA.
399
Nicotianamine Increases Iron Uptake by Plants
(SCHOLZ et al. 1985) the iron uptake dropped almost to zero in the absence of NA but showed some recovery upon NA supply, at least after its addition to the nutrient medium. The chlorosis was more severe than in untreated wild-type plants and was only weakly influenced by NA. The roots were very poorly developed under all treatments. The opposite response of chloronerva to high (> 10- 5 M) and low (10-6 M) iron supplies indicates that a NA-dependent system for the regulation of iron uptake has been affected by the mutation that can be restored, at least partly, by addition of small amounts of NA. The effect of NA on sunflower plants is shown in Fig. 2 and Tab. 1. Stimulation of growth, prevention of chlorosis and a very significant increase in iron uptake by NA added to the nutrient solution were similar to the results obtained with' Bonner Beste' . Whereas in roots and axis the excess of iron was only little above the increase in dry weight, large amounts were accumulated in the leaves under the influence of NA. This increase exceeds the increase in dry matter production considerably and it is a good explanation for the absence of chlorosis. As far as we know this is the first example of a positive affect of NA on iron uptake by plants. According to MINO et aJ. (1983) NA was ineffective with respect to iron uptake by hclorotic rice seedlings at pH 7 in a nutrient solution with 2 X 10-5 M FeCla, contrary to mugineic acid and 2'-deoxymugineic acid, derivatives of NA, which exerted a high increase of iron uptake and chlorophyll synthesis. These compounds are excreted by the roots of iron deficient rice and barley seedlings and are regarded as phytosiderophores due to their capacity to form very stable complexes with Fe3+. Whereas mugineic ac id and 2'-deoxymugineic acid seem to be involved in the regulation of iron uptake in monocots, NA could perhaps playa similar role in dicots. However, it is still an open question whether NA is directly linke d with iron uptake as a phytosiderophore. Its
Table 1. Effect of nicotionomine on dry tceight ond iron content of Helionthus onnuus. Seedlings were grown in aerated nutrient solution with 10- 6 )1 59FeEDDHA. Part of the vessels were supplied with nicotianamine (N A) to a final concentration of I) x 10-6 lVI. This supply was repeate d after 2 days. After 2 additional days single plants were harvested. Figures are averages ± SD. + = difference between + NA and - NA statistically significant at 5% level, ++ = significant at 1 % level, + + + = significant at 0.1 % level Treatment
-
NA
+ NA
26*
organ
leaves axis roots total leaves axis roots total
number dry weight of plants mg
7
7 8
8
137 39 44 220
± ± ± ±
26.3 8.0 8.3 41.2
192 52 70 314
± 7.7+ ± 17.0++ ± 53.1++
± 34.7++
nmol Fe per plant
per mg dry weight
33 ± 11± 69 ± 113 ±
17.3 2.3 18.2 34.2
0.23 0.28 1.08 0.51
± 28.2+++
0.51 0.33 1.75 0.75
98 17 117 232
± 2.8+++
± 21.5+++ ± 39.1 +++
± 0.09 ± 0.06 ± 0.25 ± 0.07 ± 0.11 +++
± 0.06
± 0.43 ± 0.11+++
400
G. SCHOLZ, K. SEIFERT and K. SCHREIBER, Nicotianamine Increases •.•
positive effect after application to the leaves could also be explained by the affecting of NA-dependent metabolic processes which control the uptake of iron and perhaps of other heavy metals as well. Acknowledgements We wish to express our gratitude to Mr. H. KRAMER, Halle, for the preparation of nicotianamine, to Mrs. G. NIEMSCH and Mr. G. FAUPEL, Gatersleben, for technical assistance and to Dr. K. MUNTZ and Dr. U. W. STEPHAN, Gatersleben, for valuable discussions.
References BUDEZINSKY, M., BUDZIKIEWICZ, H., PROCHAZKA, Z., RIPPERGER, H., ROMER, A., SCHOLZ, G., and SCHREIBER, K.: Nicotianamine, a possible phytosiderophore of general occurrence. Phytochemistry 19, 2295-2297 (1980). MINO, Y., ISHIDA, T., OTA, N., INOUE, M., NOMOTO, K., TAKEMOTO, K., TANAKA, R., and SUGIURA, Y.: Mugineic acid-iron(III) complex and its structurally analogous cobalt(III) complex: Characterization and implication for absorption and transport of iron in gramineous plants. J. Am. Chem. Soc. 105, 4671-4676 (1983). SCHOLZ, G., SCHLESIER, G., and SEIFERT, K.: Effect of nicotianamine on iron uptake by the tomato mutant 'chloronerva'. Physiol. Plant. 63, 99-104 (1985).
Received November 13, 1984; accepted December 14, 1984 Authors' addresses: Dr. GUNTER SCHOLZ (reprints), Zentralinstitut fiir Genetik und Kulturpflanzenforschung, CorrensstraBe 3, DDR - 4325 Gatersleben; Dr. KARLHEINZ SEIFERT, Prof. Dr. KLAUS SCHREIBER, Institut fiir Biochemie der Pflanzen, Weinberg. DDR - 4020 Halle (Saale).