Ferric Ethylenediaminedi-o-hydroxyphenylacetic Acid Research Articles

Foliar applications of iron promote flavonoids accumulation in grape berry of Vitis vinifera cv. Merlot grown in the iron deficiency soil

Flavonoids are important compounds for grape and wine quality. Foliar fertilization with iron compounds has been reported to have a substantial impact on grape composition in the grapevines growing in calcareous soil. However, much less is known about its real impact on flavonoid composition. In the present study, Ferric ethylenediamine di (O-hydroxyphenylacetic) acid (Fe-EDDHA) was foliar applied to Merlot (Vitis vinifera L.) grapevines growing in calcareous soil over two consecutive vintages in order to study its effect on grape flavonoid composition. Fe-EDDHA foliar supply tended to increase grape sugar, anthocyanin and flavonol content, decrease acid content and enhance the juice pH when compared to the control. Principal component analysis showed that the vintage also had influence on grape quality. The results suggested that Fe-EDDHA foliar application had an enhancement effect on grape secondary metabolism, and the effect increased the nutritional value of the consequent grapes and wines.

BIOAVAILABILITY OF IRON TO PSEUDOMONAS FLUORESCENS STRAIN A506 ON FLOWERS OF PEAR

Pseudomonas fluorescens strain A506 (A506) produces an antibiotic toxic to Erwinia amylovora in defined culture media containing at least 0.1 mM FeCl3. To estimate the relative availability of iron on flowers, A506 was transformed with an 'iron biosensor', which consisted of an iron-regulated promoter (pvd) fused to an ice nucleation reporter gene (inaZ). A506 (pvd-inaZ) established high populations on blossoms, ranging from 105 to 107 colony forming units on pear. In two trials on screenhouse grown pear trees, A506 (pvd-inaZ) expressed high ice nucleation activity on blossoms indicating limited iron bioavailability, or a low-iron environment unlikely to induce antibiosis by A506. A506 (pvd-inaZ) also colonized blossoms when mixed with the iron chelate, ferric ethylenediaminedi-(o-hydroxyphenylacetic) acid (FeEDDHA). Co-treatment of flowers with a mixture of A506 (pvd-inaZ) and 3 mM FeEDDHA significantly decreased ice nucleation activity compared to flowers treated with A506 (pvd-inaZ) in water. Lower concentrations (i.e. 0.3 mM FeEDDHA) did not consistently increase iron available to A506 on flowers sufficient to suppress expression of the iron regulated reporter gene construct. These results indicate that pear flowers represent an iron-limited environment to A506 and that co-treatment with at least 3 mM FeEDDHA significantly increases the level of iron biologically available to this bacterium.

Iron Form and Concentration Affect Nutrition of Container-grown Pelargonium and Calibrachoa

Two experiments were completed to determine whether the form and concentration of iron (Fe) affected Fe toxicity in the Fe-efficient species Pelargonium ×hortorum `Ringo Deep Scarlet' L.H. Bail. grown at a horticulturally low substrate pH of 4.1 to 4.9 or Fe deficiency in the Fe-inefficient species Calibrachoa ×hybrida `Trailing White' Cerv. grown at a horticulturally high substrate pH of 6.3 to 6.9. Ferric ethylenediaminedi(o-hydroxyphenylacetic) acid (Fe-EDDHA), ferric ethylenediamine tetraacetic acid (Fe-EDTA), and ferrous sulfate heptahydrate (FeSO4·7H2O) were applied at 0.0, 0.5, 1.0, 2.0, or 4.0 mg ·L–1 Fe in the nutrient solution. Pelargonium showed micronutrient toxicity symptoms with all treatments, including the zero Fe control. Contaminant sources of Fe and Mn were found in the peat/perlite medium, fungicide, and lime, which probably contributed to widespread toxicity in Pelargonium. Calibrachoa receiving 0 mg Fe/L exhibited severe Fe deficiency symptoms. Calibrachoa grown with Fe-EDDHA resulted in vigorous growth and dark green foliage, with no difference from 1 to 4 mg·L–1 Fe. Using Fe-EDTA, 4 mg Fe/L was required for acceptable growth of Calibrachoa, and all plants grown with FeSO4 were stunted and chlorotic. Use of Fe-EDDHA in water-soluble fertilizer may increase the upper acceptable limit for media pH in Fe-inefficient species. However, iron and Mn present as contaminants in peat, irrigation water, or other sources can be highly soluble at low pH. Therefore, it is important to maintain a pH above 6 for Fe-efficient species regardless of applied Fe form or concentration, in order to avoid the potential for micronutrient toxicity.

Bioavailability of Iron to Pseudomonas fluorescens Strain A506 on Flowers of Pear and Apple

ABSTRACT The addition of 0.1 mM FeCl(3) to a defined culture medium induces the bacterial epiphyte Pseudomonas fluorescens strain A506 (A506) to produce an antibiotic toxic to the fire blight pathogen, Erwinia amylovora. Consequently, because A506 is registered and applied as a commercial product to suppress E. amylovora before floral infection of pear and apple, the relative availability of iron to A506 on surfaces of pear and apple flowers is of potential significance. An 'iron biosensor' construct of A506 was developed by transformation with an iron-regulated promoter (pvd) fused to a promoterless ice nucleation reporter gene (inaZ). This construct, A506 (pvd-inaZ), established high populations on pear and apple flowers, ranging from 10(4) to 10(6) CFU/flower. In seven trials on pear and apple trees, A506 (pvd-inaZ) expressed high ice nucleation activity (INA) on flowers, indicating limited iron bioavailability or a low-iron environment unlikely to induce antibiotic production by A506. A506 (pvd-inaZ) also colonized flowers when mixed with chemicals containing iron: FeSO(4) or the iron chelates ferric ethylenediaminedi-(o-hydroxyphenyl-acetic) acid (FeEDDHA) and ferric diethylenetriamine pentaacetate (FeDTPA). These compounds represent an array of commercial iron formulations applied to foliage to avert iron chlorosis. Treatment of flowers with a mixture of A506 (pvd-inaZ) and 3 mM FeEDDHA or FeDTPA significantly decreased INA compared with flowers treated with A506 (pvd-inaZ) in water. Lower concentrations (0.3 mM) of FeEDDHA, however, did not consistently suppress INA. These results indicate that apple and pear flowers represent an iron-limited environment to A506 and that treatment with 3 mM FeEDDHA is needed to increase significantly the level of iron available to this bacterium.

Effectiveness of Various Iron Sources for Correcting Iron Chlorosis in Dwarf Ixora

`Petite Yellow' dwarf ixoras (Ixora spp.) were grown in an alkaline substrate (3 limestone gravel: 2 coir dust) or a poorly aerated composted seaweed substrate to induce iron (Fe) chlorosis. Chlorotic plants were fertilized every 2 months with soil applications of 0.1 g (0.0035 oz) Fe per 2.4-L (0.63-gal) pot using ferrous sulfate, ferric diethylenetriaminepentaacetic acid (FeDTPA), ferric ethylenediaminedi-o-hydroxyphenylacetic acid (FeEDDHA), Hampshire Iron (FeHEDTA plus FeEDTA), ferric citrate, iron glucoheptonate, or DisperSul Iron (sulfur plus ferrous sulfate). Additional chlorotic ixoras growing in a substrate of 3 sedge peat: 2 cypress sawdust: 1 sand were treated every 2 months with foliar sprays of Fe at 0.8 g·L-1 (0.11 oz/gal) from ferrous sulfate, FeDTPA, FeEDDHA, ferric citrate, or iron glucoheptonate. Only chelated Fe sources significantly improved ixora chlorosis when applied to the soil, regardless of whether the chlorosis was induced by an alkaline substrate or a poorly aerated one. As a foliar spray, only FeDTPA was effective in improving chlorosis in dwarf ixora. Leaf Fe content either showed no relationship to plant color or was negatively correlated with plant chlorosis ratings.

Correcting Iron Deficiency in Calibrachoa Grown in a Container Medium at High pH

The objective was to evaluate and compare foliar spray and soil drench application methods of iron (Fe) for correcting Fe deficiency in hybrid calibrachoa (Calibrachoa × hybrida) grown in a container medium at pH 6.9 to 7.4. Untreated plants showed severe chlorosis and necrosis, stunting, and lack of flowering. An organosilicone surfactant applied at 1.25 mL·L-1 (0.160 fl oz/gal) increased uptake of Fe from foliar applications of both ferrous sulfate (FeSO4) and ferric ethylenediamine tetraacetic acid (Fe-EDTA). Foliar sprays at 60 mg·L-1 (ppm) Fe were more effective when Fe was applied as Fe-EDTA than FeSO4. Increasing Fe concentration of foliar sprays up to 240 mg·L-1 Fe from Fe-EDTA or 368 mg·L-1 Fe (the highest concentrations tested) from ferric diethylenetriamine pentaacetic acid (Fe-DTPA) increased chlorophyll content compared with lower spray concentrations, but leaf necrosis at the highest concentrations may have been caused by phytotoxicity. Drenches with ferric ethylenediaminedi(o-hydroxyphenylacetic) acid (Fe-EDDHA) at 20 to 80 mg·L-1 Fe were highly effective at correcting Fe-deficiency symptoms, and had superior effects on plant growth compared with drenches of Fe-DTPA at 80 mg·L-1 Fe or foliar sprays. Efficacy of Fe-DTPA drenches increased as concentration increased from 20 to 80 mg·L-1 Fe. An Fe-EDDHA drench at 20 to 80 mg·L-1 Fe was a cost-effective option for correcting severe Fe deficiency at high medium pH.

Effect of synthetic iron chelates on population densities of Fusarium oxysporum and the biological control agent Pseudomonas putida in soil

Although soil conducive to Fusarium wilt diseases was previously induced to become suppressive by addition of FeEDDHA (ferric ethylenediaminedi-o-hydroxyphenylacetic acid), addition of FeEDTA (ferric ethylenediaminetetraacetic acid) or FeEDDHA to soil infested with F. oxysporum f. sp. conglutinans (the radish wilt pathogen) did not significantly affect inoculum densities in rhizosphere soil in this study. Addition of 100 μg FeEDTA/g soil significantly decreased levels of Pseudomonas putida in rhizosphere soil; however, addition of 100–1000 μg FeEDDHA/g soil significantly increased population densities of P. putida in fallow and rhizosphere soils. The suggested mechanism was that Fe3+ available to the Fusarium was reduced by competition with EDDHA and that such competition in soil may give selective advantage to siderophore-producing antagonists such as P. putida.

Phytotoxicity and some interactions of the essential trace metals iron, manganese, molybdenum, zinc, copper, and boron

Abstract The essential trace elements Fe, Mn, Zn, Cu, and B in high concentrations can produce phytotoxicities. Iron toxicity resulted from 5 × 10‐4 M and 10‐3 M FeSO4, but not from equivalent amounts of FeEDDHA (ferric ethylenediamine di (o‐hydroxyphenylacetic acid) ). Leaf concentrations in bush beans of 465 μg Mn/g, 291 μg B/g, and 321 μg Zn/g all on the dry weight basis resulted in 27%, 45%, and 34% reduction in yields of leaves, respectively. Zinc was concentrated in roots while Mn and B concentrated in leaves. Solution concentrations of MnS04 of 10‐3 and 10‐2 M depressed leaf yields of bush beans by 63% and 83%, respectively, with 5140 and 10780 μg Mn/g dry weight of leaves. Copper concentrations were simultaneously increased and those of Ca were decreased. Bush bean plants grown in Yolo loam soil with 200 μg Cu/g soil had a depression in leaf yield of 26% (with 28. 8 μg Cu/g leaf); plants failed to grow with 500 μg Cu/g soil. A level of 10‐3 M H2MoO4 was toxic to bush beans grown in solution cultur...

Microelement composition of plants grown with low to high levels of sulfur applied to calcareous soil in a glasshouse

PI54619-5-1 soybeans (Glycine max L.), which are very susceptible to Fe deficiency, were grown for 24 days in calcareous (10%) Hacienda loam soil with different levels of S each with and without 2 ppm Fe added as FeEDDHA (ferric ethylenediamine di (o-hydroxyphenylacetic acid). The S application rates ranged from sufficient to neutralize about 15% to more than all of the CaCO3 present if the S were all oxidized. The soil pH values at harvest time ranged from 7.4 to 6.0. The highest S rate was 10% by weight of soil and it overcame Fe deficiency without FeEDDHA. The S treatments resulted in increased concentrations of Fe and other metals in leaves, but the FeEDDHA treatments increased yields more than did S. At the lower levels of S, the effects of S and FeEDDHA on Fe concentrations in leaves were additive, but not at the highest level of S. The FeEDDHA overcame much of the effect that S had on increasing Mn concentrations in leaves. It had a similar effect, particularly at the low S levels, on Zn, Cu, Al, B, and Ni concentrations in leaves. A level of S sufficient to neutralize only 15% of the CaCO3 of the soil increased leaf concentrations of Fe, Mn, Zn, Cu, Al, B, Ni, Si, and P. The effect for Zn, Cu, and Al appreared maximum at this level. A combination of the1/2% S and the FeEDDHA resulted in the most favorable micronutrient balance. Bush beans (Phaseolus vulgaris L. var. Improved Tendergreen) grown in calcareous soil with S insufficient to neutralize all the CaCO3 had increased Mn, Ni, and Mo and decreased Ba levels in leaves. CaSO4 as a source of S did not have the same effects as elemental S.

Zinc induced iron deficiency in soybeans

Abstract When soybeans (Glycine max L. Merr. Bragg) were grown in solution culture, the PI54619–5–1 cultivar was Fe‐deficient when the Zn level was 10‐4 M. Iron contents in leaves were reduced by the high Zn level in the Hawkeye cultivar but less so than with the PI54619–5–1 cultivar. The high Zn resulted in depressed Fe contents in leaves, stems, and roots of both cultivars and in some direct effects of Zn toxicity with the Hawkeye cultivar. A high level of FeEDDHA (ferric ethylenediamine (di(o‐hydroxy‐phenylacetic acid)) partially overcame the Fe deficiency induced by a high Zn level.