Juglon (5-hidroksi-1,4-naftokinon) ceviz allelopatisinden sorumlu bir allelokimyasaldır. Giberellik asit ($GA_3$) ve
kinetin (KIN)'in tohum çimlenmesi ve fide büyümesi üzerindeki juglon stresi ...etkisinin yenilmesindeki etkinlikleri arpa,
buğday, hıyar, yonca ve domateste araştırıldı. Bitki büyüme düzenleyicileri ile ön muamele gören tohumlar juglon stresi
sonrasında, etkisini büyüme düzenleyicilerinin ne kadar hafiflettiklerini test etmek için kullanıldı. Buğday ve domateste
tohum çimlenmesinin juglon tarafından engellendiği, ancak bunun bitki büyüme düzenleyicileri kullanılarak önemli
ölçüde azaltıldığı belirlenmiştir. Çalışmada kullanılan bütün türlerin fide uzunluğu ve kuru ağırlıkları da juglon tarafından
önemli ölçüde azaltılmış, fakat bu bitki büyütme düzenleyicilerince iyileştirilmiştir. Bu hususta $GA_3$+KIN kombinasyonu
en etkili muamele olmuş, ve fide büyümesi üzerinde en yüksek etki de domates ve buğdayda kaydedilmiştir.
Juglone (5-hydroxy-1,4-naphthoquinone) is an allelochemical responsible for walnut allelopathy. The effects
of gibberellic acid ($GA_3$) and kinetin (KIN) on overcoming the effects of juglone stress on seed germination and seedling
growth were investigated in barley, wheat, cucumber, alfalfa, and tomato. Seeds pre-treated with plant growth regulators
were used to test their effects on the alleviation of juglone stress. It was observed that seed germination in tomato and
wheat was inhibited by juglone and that the plant growth regulators alleviated it significantly. Elongation and dry weight
of the seedlings of all the species used in the study were reduced significantly by juglone, and the plant growth regulators
alleviated them. The most effective treatment was the $GA_3$+KIN combination, which was best on seedling growth in
tomato and wheat.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
In vitro methods were widely used in the conservation of the threatened plants in recent years and it is clear that this trend is increasingly applied to more plant species facing risk of extinction. ...This study aimed to standardise a simple and proper micropropagation system for relic endemic plant species Arabis drabiformis by using shoot tip and internode explants. Shoot tip and internode explants were excised from 30 to 40 day old in vitro germinated seedlings and cultured on Murashige and Skoog (MS) media containing different combinations of benzylamino purine (BAP) and kinetin (Ki). MS medium supplemented with 2.0 ppm BAP was the most effective for shoot formation. Elongated shoots were successfully rooted in the MS medium that contained 0.5 ppm indole-3-butyric acid (IBA). Propagation and growth of plantlets under greenhouse condition were managed successfully.
This study aimed to synthesize and characterize juglone-entrapped poly(d,l-lactic-co-glycolic acid) (PLGA) nanoparticles and compare the antifungal properties of free juglone with its PLGA ...nanoparticle formulation for the first time. The juglone-loaded nanoparticles prepared using the oil-in-water (o/w) single-emulsion solvent evaporation method were characterized by the reaction yield (RY), encapsulation efficiency (EE), polydispersity index (PDI), particle size, zeta potential (ZP), FT-IR, and in vitro release properties and evaluated for their morphological features using SEM. The nanoparticle formulation had size, RY, ZP, EE, and PDI values of 212 nm, 66.91 ± 2.4%, −16.3 ± 0.7 mV, 70.66 ± 3.1%, and 0.083 ± 0.024, respectively. In vitro release showed a triphasic pattern with initial burst followed by sustained release and dormant phase over the study period, releasing about 72.8% in total after 42 days. The antifungal studies against Aspergillus flavus, Candida albicans, and Fusarium spp. using agar dilution and top agar dilution methods indicated that the juglone-encapsulated nanoparticle was more effective than free juglone. This study showed that the top agar method, which was applied for the first time on antifungal activity, is more suitable for the nanoparticular system based on sustained release. Therefore, PLGA nanoparticle formulations may be an important tool for application in many areas for the effective and beneficial use of hydrophobic compounds such as juglone.
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IJS, KILJ, NUK, PNG, UL, UM, UPUK
Elongation, fresh and dry weights of muskmelon seedlings (Cucumis melo cv. Kis kavunu) were enhanced by juglone in intact seeds. In the case of coatless seeds, root elongation decreased but fresh and ...dry weight of the seedlings were increased by juglone. While protein content was slightly increased by juglone in cotyledons of intact seeds, it did not change significantly in coatless seeds. Catechol oxidizing activity of polyphenol oxidase (PPO) enzyme increased in cotyledons of juglone treated intact seeds whereas it did not change significantly in coatless seeds.
3,4-dihydroxyphenethylamine (dopamine) is a neurotransmitter that has vital functions in the nervous system. Dopamine metabolism and reactive oxygen species (ROS) production are highly related ...processes. The present study aims to evaluate the effects of walnut (Juglans regia L.) extract (WE) and 5-hydroxy-1,4 naphthoquinone (juglone) on dopamine levels and oxidative stress. For this purpose, WE and juglone were administered to rats. Serum and brain dopamine levels, total oxidant status (TOS), and total antioxidant status (TAS) were measured after 21 days. The oxidative stress index (OSI) was calculated. WE (300 mg/kg) significantly increased brain dopamine levels. WE and juglone reduced oxidative stress in liver and brain tissues compared to serum. Our results revealed that WE and juglone might have a neuroprotective effect. Further studies are needed to extensively investigate the molecular mechanism of the effects of herbal extracts and phenolic compounds on brain health.
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•Walnut extract increased the level of brain dopamine in rats.•Walnut extract and juglone reduced oxidative stress in brain and liver tissues.•Herbal extracts and secondary metabolites with phenolic character could be beneficial effects on brain health.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Catechol and pyrogallol are allelochemicals which belong to phenolic compounds synthesized in plants. Their antimicrobial activities were investigated on three bacteria (Pseudomonas putida, ...Pseudomonas pyocyanea, Corynebacterium xerosis) and two fungi (Fusarium oxysporum, Penicillium italicum) phytopathogenic species as test organisms using the disc diffusion method. Both catechol and pyrogallol were found to have antibacterial effects on all the bacteria used in the study at 5 and 10 mм concentrations. Catechol has also been found to have an antifungal effect on the fungi used in the study, whereas no antifungal effects of pyrogallol were observed. The most sensitive species among the bacteria was P. putida which was inhibited by the allelochemicals even at 1 mм concentration.
Salicylic acid (SA) is recognized as an exogenous plant growth regulator involved in the regulation of important plant physiological processes. Zinc (Zn) stress alleviation by SA in Epilobium ...hirsutum under in vitro conditions was tested in this study. Primarily, seeds were pre-treated with 0, 0.1, and 0.5 mM SA and exposed to the different Zn concentrations in Murashige and Skoog medium (MS). The shoot tips of plants germinated in a medium containing 0.5 mM SA+10 mg/L Zn were used in shoot multiplication. Secondly, the shoot explants of E. hirsutum cultures were also successfully established in MS medium with 1 mg/L thidiazuron (TDZ)+0.5 mg/L Indole-3 Butyric Acid (IBA). Finally, sterile plantlets were gradually transferred to the hydroponic culture. Zn accumulation of seedlings was the highest in 75 mg/L Zn solutions (13.558.90 mg/kg dry weight (DW)). The high concentration of Zn (75 mg/L) significantly increased the chlorophyll content of the leaves. There was a significant decline in the activity of carbonic anhydrase (CA) in both leaves and roots of seedlings grown under increasing Zn concentrations. The activity of the polyphenol oxidase (PPO) enzyme increased with increasing Zn concentrations in hairy-willowherb. Compared with other concentrations, 75 mg/L Zn had a positive effect on PPO activities in both root and leaf tissues of the plant.
Despite its evidenced beneficial herbicidal, antibacterial, antiviral, antifungal, and antioxidant effects, the application of juglone (5-hydroxy-1,4,-naphthoquinone) is limited due to its low water ...solubility and allelopathic and toxic effects. In recent years, research has aimed to overcome these limitations by increasing its solubility and controlling its release through nanoparticular systems. This is the first study to have synthesised and characterised juglone-loaded polymeric nanoparticles and compared them with free juglone for cytotoxicity in mouse (L929 fibroblasts) and alfalfa cells and for mutagenic potential in
TA98/100. Mouse and plant cells treated with free and nano-encapsulated juglone showed a decrease in cell viability in a dose and time-dependent manner, but this effect was significantly lower with the nano-encapsulated form at lower doses. In the TA98 strain with S9, nano-encapsulated juglone did not exhibit mutagenic effects, unlike the free form. Since all results show that juglone encapsulation with polymeric nanoparticles reduced the toxic and mutagenic effects, it has a promising potential to be applied in medicine, food safety, and agriculture.
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