Response of Cucumber Plants to Low Doses of Different Synthetic Iron Chelates in Hydroponics

The factors that control the use of iron (Fe) provided by iron chelates in strategy I plants are not well known. In this paper, the effectiveness of low concentrations of a series of pure Fe chelates to supply Fe to cucumber plants in hydroponics was studied. The Fe Chelate Reductase (FCR) of the roots was measured using Fe- ethylene diamine tetraacetic acid (EDTA) as substrate. Despite the differences found in SPAD and biometric indexes among the treatments, FCR and Fe in xylem sap were only significantly larger for the Fe- Ethylene diamine di-(o-hydroxy-p-methylphenyl) acetic acid (EDDHMA) treatment. The trend in nutritional indexes was the opposite to the trend in the stability of the chelates, except for Fe-EDTA that gave the poorest results. A mechanism describing the uptake process, considering the re-oxidation of the Fe (II) reduced by the FCR and the formation of the Fe (II) complex is proposed.     

RELATIVE SUSCEPTIBILITY OF SOME PRUNUS ROOTSTOCKS IN HYDROPONICS TO IRON DEFICIENCY

The susceptibility of eleven Prunus rootstocks to iron (Fe) deficiency was studied in hydroponics by growing them with 20 μM Fe, 0 μM Fe or 3 μM Fe+10 mM sodium bicarbonate. Based on the intensity of leaf chlorosis, the peach-almonds PR 204/84, Stylianidis K and KID2, produced at the Pomology Institute of Naoussa (Greece), showed the same or even greater tolerance than GF 677, the Greek peach-almond Retsou x Nemaguard, the plum-almond Myrandier 617 and the peaches GF 305, IDS 37, Greek wild peach seedling the greatest susceptibility whereas the plums St. Julien GF655/2 and Myrobalan 29C intermediate. Rootstocks without Fe presented significantly lower nitrogen and Fe whereas with bicarbonate significantly lower nitrogen, phosphorus, Fe and zinc. Root ferric chelate reductase activity was significantly increased in ?Fe rootstocks but negatively correlated with their tolerance; physiological and morphological changes were observed along a zone of a few centimeters length, 1–2 mm behind the root tip.     

ELEMENTAL SULFUR IMPREGNATED WITH IRON AS A FERTILIZER SOURCE FOR KENTUCKY BLUEGRASS

Elemental sulfur (S) impregnated with Fe (S-Fe) fertilizer was evaluated on Kentucky bluegrass (KBG; Poa pratensis L.) in three glasshouse studies: (1) with/without Fe as S-Fe, ferrous sulfate (FS), or iron-ethylenediamine-N,N’-bis(2-hydroxyphenylacetic acid) (Fe-EDDHA) to soil (49 kg Fe ha^?1), or foliar Fe-EDDHA (5 kg Fe ha^?1) on two cultivars; (2) 0, 49, 197, or 592 kg Fe ha^?1 of S-Fe deep mixed or surface mixed on two soils; (3) 0 or 49 kg Fe ha^?1 applied as S-Fe on four cultivars. A field study comparing 0 and 49 kg Fe ha^?1 applied as S-Fe to KBG was also conducted. Soil applied S-Fe was assimilated in shoots as efficiently as Fe-EDDHA applied to soil or foliage. Shoot Fe increased significantly with increasing S-Fe in a curvilinear response when deep mixed with soil and in a linear response when surface applied. However, no Fe source tested impacted yield or verdure in these studies.     

Effect of seed and foliar application of nano-zinc oxide,zinc chelate,and zinc sulphate rates on yield and growth of pinto bean (Phaseolus vulgaris) cultivars

Nanofertilizers have received considerable attention due to their increased uptake by plants. Therefore, this study aimed to investigate the effect of zinc oxide (ZnO) nanoparticles and also different zinc (Zn) fertilizers (Zn sulfate, Zn chelate) on vegetative and yield traits of two pinto bean cultivars “KS21191” and “KS21193”. This experiment was a factorial based on completely randomized design with 24 treatments (three fertilizer applications and eight levels of Zn fertilizer). The results showed that twice foliar application compared to seed application and once foliar application improved growth and yield characteristics of both pinto bean cultivars. Also, compared to control treatment, zinc nanofertilizers improved vegetative characteristics (such as plant height, internode length, root and shoot dry, and fresh weight), yield (pods number and seed weight) and quality (zinc content in seed) of both pinto bean cultivars. Among the zinc fertilizer treatments, 0.10% and 0.15% of ZnO nanoparticles were as a superior treatment.     

Prevention of Iron‐Deficiency Induced Chlorosis in Kiwifruit (Actinidia deliciosa) Through Soil Application of Synthetic Vivianite in a Calcareous Soil

Abstract

In this study we have tested the hypothesis that lime‐induced Fe deficiency chlorosis of kiwifruit may be prevented by the application of a synthetic iron(II)‐phosphate analogous to the mineral vivianite [(Fe₃(PO₄)₂·8H₂O)]. Two experiments, under greenhouse and field conditions, were performed. In the greenhouse, 1‐year old micropropagated plants (Actinidia deliciosa, cv. Hayward), grown in 3‐L pots on a calcareous soil, were treated in early autumn with soil‐applied: (1) synthetic vivianite (1.35 g plant^?1) and (2) Fe‐EDDHA (24 mg Fe plant^?1). The synthetic vivianite suspension, prepared by dissolving ferrous sulfate and mono‐ammonium phosphate, was injected into the soil as a sole application whereas the Fe‐EDDHA solution was applied four times at weekly intervals. The field experiment was conducted in a mature drip‐irrigated kiwifruit orchard located on a calcareous soil in the Eastern Po Valley (Italy). Treatments were performed in early autumn by injecting synthetic vivianite (1.8 kg tree^?1) and Fe‐EDDHA (600 mg Fe tree^?1) into four holes in the soil around each tree, at a depth of 25–30 cm. The Fe‐chelate application was repeated at the same rate in the following spring. Untreated (control) plants were used in both experiments. Autumn‐applied Fe fertilisers significantly prevented development of Fe chlorosis under greenhouse conditions whereas in the field only vivianite was effective. In conclusion, these 1‐year results show that vivianite represents an effective alternative to soil‐applied Fe chelates for preventing Fe chlorosis in kiwifruit orchards.     

松仁肽及其Zn2+螯合物的分离纯化、结构表征的对比分析

探究在相同条件下制备得到的松仁肽与其Zn2+螯合物的分离纯化、结构表征,对比分析两者的结构区别及抗氧化能力的变化。采用超滤过滤、葡聚糖凝胶Sephadex G-50和Sephadex G-15分离的方法进行分离纯化;用氨基酸组成、紫外扫描光谱、傅里叶红外光谱、能谱的分析测定结构表征。分离纯化得到抗氧化能力最强的组分P-4-1和P-Zn-3-1,并对该组分进行结构分析。松仁肽与松仁肽-锌螯合物的氨基酸组成分析可得出氨基酸质量分数在螯合前后有所变化。其中天冬氨酸的质量分数由6.306%上升至12.083%,谷氨酸的质量分数由14.953%上升到16.076%。紫外扫描得出松仁肽吸收峰为220 nm,Zn²⁺螯合物的吸收峰为240 nm,发生了红移。红外扫描显示出螯合前与螯合后的透射率、吸收峰和吸收强度均有所变化。在能谱分析中,根据不同元素的能量来辨别不同物质的元素组成,得出的能谱结果显示螯合前无Zn²⁺的能量柱,螯合后出现Zn²⁺。通过对比分析可知抗氧化能力最强的2个组分结构表征有明显的区别,并且与Zn²⁺螯合后的松仁肽抗氧化能力高于未螯合的松仁肽,由此可以推断有Zn²⁺参与的螯合反应会对松仁肽的抗氧化能力有所影响。     

Purification of Algal Calcium-Chelating Peptide and Its Physical Chemical Properties

The Schizochytrium protein, extracted from byproduct of Schizochytrium sp. after lipid extraction, was isolated and hydrolyzed. A specific calcium-binding peptide was purified from the hydrolysate through Sephadex G-25 gel filtration chromatography and C18 reversed-phase high-performance liquid chromatography (RP-HPLC). The calcium-binding capacity of the specific peptide reached up to 136.68 ± 4.6 μg/mg. The amino acid sequence was confirmed as Ser-Ser-Val (SSV) with a molecular weight of 291.15 Da by liquid chromatography electrospray ionization tandem mass spectrometry (LC–ESI–MS/MS). Fourier transformation infrared spectroscopy showed that the major binding sites included oxygen atom from carbonyl group and nitrogen of amino group or imino group. SSV-Ca chelate was confirmed to be a neutral molecular by Zeta potential analysis, and the calcium ion was surrounded by the functional chelating sites of SSV. In addition, thermogravimetry-differential scanning calorimetry (TG-DSC) and calcium releasing assay revealed that the SSV-Ca chelate exhibited excellent thermal stability and solubility in both acidic and basic conditions, which was in favor for calcium absorption in the gastrointestinal tracts of humans. The findings indicate the by-product of Schizochytrium sp. is a promising source for making peptide-calcium chelate as a dietary functional supplement.     

高钛型高炉渣作无土栽培基质的试验研究

通过对高钛型高炉水淬渣的理化指标分析,不含有毒有害元素,通过配加一定比例的有机基质,配制混合基质,是可以用于育苗,并可以用于家庭种植。本试验通过对高钛型高炉水淬渣与草炭的不同配比进行小白菜育苗,通过分析幼苗的长势最终确定,用于育苗的复合基质中,高钛型高炉水淬渣的配入比例不大于50%,均是很好的无机基质。     

泉古菌Sulfolobus islandicus PCNA1的原核表达及其多克隆抗体的制备

泉古菌Sulfolobus islandicus中PCNA有3个同源类似蛋白,本研究选取PCNA1作为研究对象,为获得可溶性表达的PCNA1蛋白,制备多克隆抗体,深入了解PCNA1基因的功能,将PCNA1基因片段克隆到组氨酸标签融合的表达载体pET30a中,利用IPTG诱导,金属螯合亲和层析进行纯化分析表明,融合蛋白大部分可溶。紫外分光光度法测定纯化蛋白的纯度可达90%以上,浓度约为2 mg/mL。免疫家兔制备多克隆抗体,ELISA检测抗血清效价可达1∶10 000以上,Western印迹检测证明抗体特异性良好。