Accumulation Of Polyphenols Research Articles

Iodine Enhances the Nutritional Value but Not the Tolerance of Lettuce to NaCl

Positive stress or essential and nonessential elements can improve nutritive values (biofortification) of edible plants. In the present study, we evaluate (i) the effect of moderate salinity on lettuce biofortification, evaluated as nutritional bioactive compound accumulation, and (ii) the role of iodine in enhancing salt tolerance by increasing photorespiration and the content of antioxidants in lettuce. Physiological (gas exchange and chlorophyll fluorescence emission) and biochemical (photosynthetic pigment and bioactive compound) analyses were performed on lettuce plants grown under moderate salinity (50 mM NaCl alone or 50 mM NaCl in combination with iodine, KIO3). Our results show that NaCl + iodine treatment improves the nutritional value of lettuce in terms of bioactive compounds acting as antioxidants. More specifically, iodine enhances the accumulation of photosynthetic pigments and polyphenols, such as anthocyanins, under salt but does not improve the salt tolerance. Our findings indicate that iodine application under moderate salinity could be a valid strategy in plant biofortification by improving nutritional bioactive compound accumulation, thus exercising functional effects on human health.

Abiotic Stresses Elicitation Potentiates the Productiveness of Cardoon Calli as Bio-Factories for Specialized Metabolites Production.

Cultivated cardoon (Cynara cardunculus L. var altilis) is a Mediterranean traditional food crop. It is adapted to xerothermic conditions and also grows in marginal lands, producing a large biomass rich in phenolic bioactive metabolites and has therefore received attention for pharmaceutical, cosmetic and innovative materials applications. Cardoon cell cultures can be used for the biotechnological production of valuable molecules in accordance with the principles of cellular agriculture. In the current study, we developed an elicitation strategy on leaf-derived cardoon calli for boosting the production of bioactive extracts for cosmetics. We tested elicitation conditions that trigger hyper-accumulation of bioactive phenolic metabolites without compromising calli growth through the application of chilling and salt stresses. We monitored changes in growth, polyphenol accumulation, and antioxidant capability, along with transcriptional variations of key chlorogenic acid and flavonoids biosynthetic genes. At moderate stress intensity and duration (14 days at 50–100 mM NaCl) salt exerted the best eliciting effect by stimulating total phenols and antioxidant power without impairing growth. Hydroalcoholic extracts from elicited cardoon calli with optimal growth and bioactive metabolite accumulation were demonstrated to lack cytotoxicity by MTT assay and were able to stimulate pro-collagen and aquaporin production in dermal cells. In conclusion, we propose a “natural” elicitation system that can be easily and safely employed to boost bioactive metabolite accumulation in cardoon cell cultures and also in pilot-scale cell culture production.

Foliar biofortification of chervil with selenium and iodine under silicon containing fertilizer supply

Selenium (Se) and iodine (I) are essential elements for humans, and their deficiency is widespread throughout the world. In order to obtain a functional nutritional product with an increased content of these trace elements in the vegetative experiment, foliar biofortification of two chervil varieties with selenium (sodium selenate 10 mg/l) and iodine (potassium iodide 100 mg/l) was carried out without and against the background of the use of silicon-containing fertilizers Siliplant (3 ml/l). The combined and separate application of selenate, iodide and Siliplant increased plants’ biomass. Siliplant utilization increased the accumulation of iodine by 1.7-1.9 times, and selenium supply – by 2.2-3.1 times. A significant increase in ascorbic acid content was provided by the combined supplementation of iodine and selenium (1.25-1.27 times), iodine and silicon (1.46-1.87 times) and joint application of selenium, iodine, and silicon (1.31-1.73 times), while an increase in total antioxidant activity (1.3-1.4 times) was observed for (Se+I) and (Se+I+Si) treatments. High varietal differences in the responsiveness of plants to the selected treatments were manifested, particularly an increase of polyphenols accumulation under separate and joint treatments of chervil with iodine and selenium by 1.26 times in the cultivar 21-20, and the absence of a significant effect in the cultivar 24-20. Taking into account the adequate consumption levels (ACL) of iodine and selenium, 50 g of the resulting functional product can provide up to 79% of iodine ACL and up to 40% in selenium ACL.

Effects of Biodegradable Liquid Film on Cabernet Sauvignon (V. vinifera L.) Grape Quality

Biodegradable liquid film (BLF) improves soil structure and increases plant freezing tolerance after spraying on the surface of soil and plant. In this study, the effects of BLF on grape composition and volatile compounds in Cabernet sauvignon (Vitis vinifera L.) grapes were determined by spraying BLF during the dormant periods over three years. The aim of the study was to evaluate the potential impact of BLF as an overwintering protection measure on grape fruit quality. In 2020 and 2021, BLF spraying increased reducing sugar content and 100-berry weight, decreased titratable acid content, and improved the maturity factor. Compared with the vines not sprayed with BLF, the content of total phenols and total anthocyanins in grape skins showed an increase over the three-year period, with the largest increases of 31.92% and 48.38%, respectively, and the content of total tannins and total flavan-3-ols increased in 2020 and 2021. BLF treatment also increased the total phenolic content in seeds for all three years, reaching a significant level in 2019, 16.38% higher than control treatment (CK). HPLC analysis showed that BLF treatment affected the content and composition of monomeric anthocyanins in grape skins, especially in 2021, BLF treatment significantly increased the content of nine monomeric anthocyanins, and the proportion of acetylated and coumaroylated anthocyanins. However, GC-MS analysis indicated that BLF had little effect on volatile compounds. These results suggest that BLF can be used as an overwintering protection measure in cold regions to promote the accumulation of sugars and polyphenolics, thereby improving overall grape quality.

Potassium deficiency stress tolerance in peanut (Arachis hypogaea) through ion homeostasis, activation of antioxidant defense, and metabolic dynamics: Alleviatory role of silicon supplementation

Potassium (K) scarcity of arable land is one of the important factors that hamper the growth of the plants and reduce yield worldwide. In the current study, we examine the physiological, biochemical, and metabolome response of Arachis hypogaea (GG7 genotype: fast-growing, tall, early maturing, and high yielding) under low K either solitary or in combination with Si to elucidate the ameliorative role of Si. The reduced fresh and dry biomass of peanut and photosynthetic pigments content was significantly alleviated by Si. Si application did not affect the leaf and stem K+, although it enhanced root K+ in K-limitation, which is probably due to up-regulated expression of genes responsible for K uptake. Si improves the potassium use efficiency in K-limitation as compared to control. K-deficiency increased MDA, O2•−, and H2O2 levels in leaf and root of peanut. Si improved/maintained the activity of antioxidative enzymes, which significantly lowered the ROS accumulation in K-limitation. The AsA/DHA and GSH/GSSG ratio was approximately unaffected in both leaf and root, suggesting the maintained cellular redox potential in K-starved peanut. Si promotes accumulation of sugars and sugar alcohols, phytohormones indicating their probable involvement in signal transduction, osmotic regulation, and improvement of stress tolerance. Down-regulation of aspartic acid and glutamic acid while up-regulation of lysine, histidine, and arginine could maintain charge balance in K-deprived peanut. The significant accumulation of polyphenols under K limitation supplemented with Si suggests the role of polyphenols for ROS scavenging. Our results demonstrated that Si as a beneficial element can mitigate K-nutrient toxicity and improve KUE of peanut under K-limitation conditions. Moreover, our results demonstrate that Si application can improve crop yield, quality, and nutrient use efficiency under nutrient limitation conditions.

The apple FERONIA receptor-like kinase MdMRLK2 negatively regulates Valsa canker resistance by suppressing defence responses and hypersensitive reaction.

Valsa canker, caused by the fungus Valsa mali, is one of the most destructive diseases of apple trees in China and other East Asian countries. The plant receptor‐like kinase FERONIA is involved in plant cell growth, development, and immunity. However, little is known about the function of FERONIA in apple defence against V. mali. In this study, we found that MdMRLK2 was highly induced by V. mali in twigs of V. mali‐susceptible Malus mellana but not in those of the resistant species Malus yunnaensis. 35S:MdMRLK2 apple plants showed compromised resistance relative to wild‐type (WT) plants. Further analyses indicated that 35S:MdMRLK2 apple plants had enhanced abscisic acid (ABA) levels and reduced salicylic acid (SA) levels relative to the WT on V. mali infection. MdMRLK2 overexpression also suppressed polyphenol accumulation and inhibited the activities of phenylalanine ammonia‐lyase (PAL), β‐1,3‐glucanase (GLU), and chitinase (CHT) during V. mali infection. Moreover, MdMRLK2 interacted with MdHIR1, a hypersensitive‐induced response protein, and suppressed the MdHIR1‐mediated hypersensitive reaction (HR), probably by impairing MdHIR1 self‐interaction. Collectively, these findings demonstrate that overexpression of MdMRLK2 compromises Valsa canker resistance, probably by (a) altering ABA and SA levels, (b) suppressing polyphenol accumulation, (c) inhibiting PAL, GLU, and CHT activities, and (d) blocking MdHIR1‐mediated HR by disrupting MdHIR1 self‐interaction.

Melatonin priming as a promising approach to improve biomass accumulation and the nutritional values of Chenopodium quinoa sprouts: A genotype-based study

Increasing the production of horticultural crops is one of the most important challenges worldwide. Seed priming is a promising agricultural procedure for supporting growth and quality of economic crops. Among the most efficient seed priming agents that play a significant role in improving plant growth, chemical composition and bioactivity is melatonin (MT). This study was carried out to investigate the impact of MT priming on sprouting of three genotypes of quinoa (Chenopodium quinoa) and their nutritive value. Different primary and secondary metabolites of the three genotypes (regalona, kvl-sra2, Q37) were quantified. MT priming promoted the growth of quinoa genotypes by increasing their biomass accumulation and total nutrient content. Regarding the effect of MT priming on pigments, there was an obvious upward trend in leaf pigments of regalona. Besides, our results showed that MT priming increased the vitamins content such as thiamin and tocopherol content. Essential amino acids, organic acids and unsaturated fatty acids were significantly higher in MT-primed plants relative to the corresponding controls. Further, MT priming enhanced the accumulation of total soluble sugar, polyphenols, and flavonoids, which contribute to higher antioxidant and antidiabetic activities. Interestingly, species-specific responses toward MT priming were noticeable, where kvl-sra2 sprouts showed the highest antioxidant and antidiabetic activities among the three-quinoa genotypes. Overall, the current results suggest that MT priming could be used as a powerful agricultural approach to improve the growth and functional food value of quinoa sprouts.

Ultraviolet-B Irradiation Increases Antioxidant Capacity of Pakchoi (Brassica rapa L.) by Inducing Flavonoid Biosynthesis.

As an important abiotic stress factor, ultraviolet-B (UV-B) light can stimulate the accumulation of antioxidants in plants. In this study, the possibility of enhancing antioxidant capacity in pakchoi (Brassica rapa L.) by UV-B supplementation was assessed. Irradiation with 4 µmol·m−2·s−1 UV-B for 4 h or 2 µmol·m−2·s−1 UV-B for 24 h significantly increased the 1,1–diphenyl–2–picrylhydrazyl (DPPH) scavenging activity and total reductive capacity, as a result of inducing a greater accumulation of total polyphenols and flavonoids without affecting the plant biomass. A high performance liquid chromatography (HPLC) analysis showed that the concentrations of many flavonoids significantly increased in response to UV-B treatment. The activities of three enzymes involved in the early steps of flavonoid biosynthesis, namely phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H), and 4-coumarate: coenzyme A (CoA) ligase (4CL), were significantly increased after the corresponding UV-B treatment. Compared with the control, the expression levels of several flavonoid biosynthesis genes (namely BrPAL, BrC4H, Br4CL, BrCHS, BrF3H, BrF3′H, BrFLS, BrDFR, BrANS, and BrLDOX) were also significantly up–regulated in the UV-B treatment group. The results suggest that appropriate preharvest UV-B supplementation could improve the nutritional quality of greenhouse-grown pakchoi by promoting the accumulation of antioxidants.

AchMYC2 promotes JA-mediated suberin polyphenolic accumulation via the activation of phenylpropanoid metabolism-related genes in the wound healing of kiwifruit (Actinidia chinensis)

Suberin polyphenolic (SPP), a kind of agronomically significant biopolymer, is composed primarily of phenolic acids generally synthesized by phenylpropanoid metabolism. In this study, the transcriptional activation of suberin polyphenolic biosynthesis by jasmonic acid (JA) inducible-transcription factor AchMYC2 was confirmed in wound tissues of kiwifruit (Actinidia chinensis). Three general phenylpropanoid metabolism-related genes, AchPAL, AchC4H and Ach4CL respectively encoding phenylalanine ammonia-lyase (PAL), cinnamic acid-4-hydroxylase (C4H) and 4-coumaric-CoA ligase were determined in the kiwifruit core tissues overexpressing these genes. Besides, the positive regulation of AchMYC2 on AchPAL, AchC4H and Ach4CL was observed. JA-induced AchMYC2 locating in the nucleus activated the transcriptional expression of AchPAL, AchC4H and Ach4CL through binding to their promoters. The results were further evidenced in the kiwifruit core tissues overexpressing of AchMYC2, in which AchMYC2 enhanced the expression levels of AchPAL, AchC4H and Ach4CL and increased the accumulation of phenolic acids including cinnamic acid, p-coumaric acid, caffeic acid, ferulic acid and sinapic acid. Meanwhile, the contents of five phenolic acids in the kiwifruit wound tissues were increased by methyl jasmonate (MeJA), but reduced by diethyldithiocarbamic acid (DIECA, an inhibitor of JA biosynthesis). Together results indicated that AchMYC2 activated AchPAL, AchC4H and Ach4CL transcription to promote JA-mediated suberin polyphenolic accumulation in the wound healing of kiwifruit.

Transcriptome Profiling During Muscadine Berry Development Reveals the Dynamic of Polyphenols Metabolism.

Muscadine grapes accumulate higher amounts of bioactive phenolics compared with other grape species. To identify the molecular events associated with polyphenolic accumulation that influence antioxidant capacity, two contrasting muscadine genotypes (C5 and C6) with varied phenolic/flavonoid content and antioxidant activity were investigated via RNA-sequencing during berry development. The results showed that berry development is concomitant with transcriptome profile changes, which was more pronounced at the véraison (V) stage. Despite that the downregulation pattern of gene expression dominated the upregulation through berry development, the C5 genotype maintained higher expression levels. Comparative transcript profiling allowed the identification of 94 differentially expressed genes with potential relevance in regulating fruit secondary metabolism, including 18 transcription factors and 76 structural genes. The genes underlying the critical enzymes in the modification reactions of polyphenolics biosynthetic pathway, including hydroxylation, methylation, and glycosylation were more pronounced during the immature stages of prevéraison (PrV), V, and postvéraison (PoV) in the C5 genotype, resulting in more accumulation of biologically active phenolic/flavonoid derivatives. The results suggested that muscadine grapes, as in bunch grapes (Vitis sp.); possess a similar mechanism that organizes polyphenolics accumulation; however, the set of total flavonoids (TFs) and structural genes coordinating the pathway varies between the two species.

Effect of salinity on biochemical components of the egg plant (Solanum melongena)

Present study explored the effect of salinity stress on seedling mineral composition, chlorogenic acid and polyphenol oxidase content of the two genotypes (GT25 and GT26) of egg plant (Solanum melongena L.). Selected egg plant genotypes were exposed to salinity stress (25-150 mM NaCl) along with control. Plants were grown in the field of School of Biotechnology, Gautam Buddha University during 2018-19. Drastic impacts of salinity stress as preliminary symptom were seen on seed germination. Genotype GT25 and GT26 were proficient to germinate only up to 100 mM and 75 mM NaCl respectively under salinity treatment. Results showed very poor growth along with necrotic/ dead tissue in the germinated seedlings leaves after the 30 days salt treatment in GT26 in100 mM NaCl treatment. Accumulation of Na+ ions is comparatively lower (67%) in GT25 under 75 mM NaCl concentration. On the contrary mineral (Cu, Mn, K) content, enzymatic activity like chlorogenic acid and polyphenol were resulted higher in GT25 compared to GT26 when subjected to NaCl stress (75 mM). These results indicate that egg plant genotypes respond to salt induced oxidative stress by enzymatic defense systems. The accumulation of polyphenol and chlorogenic acid suggest a role in protective metabolites. Hence it can be concluded that the GT25 possess strong tolerance against salt stress and could be an important genotype resource for the salt tolerance breeding programme of egg plant.

Biochemical composition of some aromatic and medicinal plants after cultivation on the multi circle hydroponic installations

Multi circle hydroponic construction for vegetable and greens cultivation are wide spread and supported of leader investors all over the world because their economic position and ecologic status. Cultivation of aromatic and medicinal plants at multi circle hydroponic construction is usually supplemented the study biochemical composition above parts of plants after cultivation. The goal of study is: analysis biochemical composition above parts of some aromatic and medicinal plants after cultivation at multi circle hydroponic construction. Objects of study - above parts of aromatic and medicinal plants from Lamiaceae-family: Monarda fistulosa L., Nepeta cataria L. , Mentha piperita L., Melissa officinalis L.; from Hypericaceae-family - Hypericum perforatum L. and from Apiaceae-family: Coriandrum sativum L., Anethum graveolens L., Apium graveolens L. Plants were cultivated at the 5 circle hydroponic construction with artificial lighting and automatic nutrition. Seeds of Apiaceae-family were treated with water solutions of natural immunomodulators: linarozide and moldstim. Analytic methods included determination: the dry matter content, antioxidants content and polyphenols content. Statistical methods: one-factorial and two-factorial dispersion analysis (Microsoft Excel, 2010). The first experiment of the cultivation aromatic and medicinal plants at 5 th circle hydroponic installation was successful. The content of dry matter, vitamin C and chlorophylls does not change depends on plants location, but the content sum of polyphenols was significantly higher on the above part of Monarda fistulosa plants from the 4 th circle. The highest content of polyphenols was observed on the above part of Hypericum perforatum L., the smallest content - on the above part of Mentha piperita L. Treatment seeds with natural immunomodulators increased the content of dry matter, antioxidants and polyphenols on the above part of plants from Apiaceae-family. It influenced at the increasing of seed germination, height of plants and weight of above parts. But accumulation of antioxidants and polyphenols on the above parts of Apiaceae-plants was specific for every species.

Effect of basal medium on growth and polyphenols accumulation by Gardenia jasminoides Ellis cell suspension

The goal of this study was to analyze the effect of different medium bases on accumulation of biomass and secondary metabolites production by Gardenia jasminoides Ellis. cell suspension culture. The result revealed that different media have significant effect on biomass accumulation and production of polyphenol compounds. HPLC analyses showed that the higher polyphenol content was achieved when the cells were cultivated on McCOWN Woody plant Medium (WP) media for 14 days on darkness, at 24°C. At this conditions, the cells produced maximal amounts of catechin (24.44±2.46 µg/g DW), chlorogenic acid (20.26 ±3.68 µg/g DW), epicatechin (70.44±7.46 µg/g DW) and rutin (45.90±0.26 µg/g DW). Both MS and WP media were optimal for biomass accumulation. When cultivated on these media, Gardenia cells accumulated maximal amount of dry biomass ADB = 0.99±0.1g/100ml and ADB = 0.93±0.04 g/100ml for МS and WP, respectively. The corresponding growth indexes were GIDW = 1.68±0.2 on MS and GIDW = 1.58±0.07 on WP medium. The reported results are the first step of future optimization of the nutrient medium composition and cultivation conditions essential for the scale -up of cultivation process of G. jasminoides cell suspension culture for mass production of polyphenolic compounds.

Polyphenols-absorption and occurrence in the body system

Polyphenols are commonly present in natural plants and serve as health benefiting food compounds. The health benefits and the metabolites of polyphenols have not yet been fully investigated because of lack of information about their bioavailability. This review was based on the previously reported literature focusing on the absorption and tissue accumulation of polyphenols. Furthermore, the physiological roles and the influx/efflux route(s) of non-absorbable polyphenols in the intestinal membrane were discussed.

Polyphenol components and antioxidant activity of Thymus spp.

This scientific work was aimed to evaluate the antioxidant potential of aromatic plants of Thymus spp. in the East of Ukraine. These plants are known as medicinal and food around the world. All antioxidant parameters were investigated spectrophotometrically: total content of polyphenols (TPC), the total content of phenolic acids (TPAC), the total content of flavonoids (TFC), molybdenum reducing power of extracts (MRP), and antioxidant activity by DPPH method (DPPH). Investigation of ethanolic extracts demonstrated that TPC varied from 57.89 to 123.67 mg/g gallic acid equivalent (GAE) DW for Th. pulegioides, from 61.43 to 168.18 mg GAE/g for Th. serpyllum, and from 47.36 to 115.67 mg GAE/g for Th. vulgaris. TPAC ranged from 27.36 to 50.22 mg/g caffeic acid equivalent (CAE) DW for Th. pulegioides, from 28.58 to 59.62 mg CAE/g for Th. serpyllum, and from 22.95 to 53.82 mg CAE/g for Th. vulgaris. TFC was determined in a range from 29.88 to 61.23 mg/g quercetin equivalent (QE) DW for Th. pulegioides, from 36.0 to 82.43 mg QE/g for Th. serpyllum, and from 24.59 to 55.41 mg QE/g for Th. vulgaris. MRP was detected in the range of 94.65 – 204.76 mg/g Trolox equivalent (TE) DW for Th. pulegioides, 96.06 – 219.0 mg TE/g for Th. serpyllum, and 87.56 – 215.43 mg TE/g for Th. vulgaris. The antioxidant activity of extracts by the DPPH method was 6.34 – 9.23 mg TE/g for Th. pulegioides, 8.11 – 9.21 mg TE/g for Th. serpyllum, and 4.97 – 9.53 mg TE/g for Th. vulgaris. It was established that polyphenol accumulation depended on the growth stage and species. For all species was found a strong correlation between TPC and TFC (r = 0.938, 0.908, and 0.854). Investigated Thymus spp. are a valuable source of antioxidants that can be used in pharmacological studies and the food industry.

Variation of Polyphenol Content and Antioxidant Activity in Some Bilberry (Vaccinium myrtillus L.) Populations from Romania

Fruits of bilberry (Vaccinium myrtillus L.) are valued mainly for their nutraceutical properties, and are among the fruits with the highest antioxidant activity due to their high content of phenolic compounds. The aim of this research was to assess the total polyphenol content and antioxidant activity of fruits in six wild bilberry populations from two regions of Romania over three years. The total polyphenol content was determined according to the Folin–Ciocalteu modified method, while the antioxidant activity was evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging assay. The Padis and Raul Lung populations registered the highest values of polyphenol content and antioxidant activity, as such the fruits of these bilberry populations could be considered potential sources of antioxidants for direct consumption or for use as ingredients for food products or food supplements. Significant variation of total polyphenol content and antioxidant activity was observed both between populations from the same region and from different regions. The low level of broad sense heritability for total polyphenol content and antioxidant activity associated with the high effects of year, and population–year interaction indicates that the accumulation of polyphenols in bilberry fruits is influenced by changes in environmental conditions.

Spatial distribution and time-course of polyphenol accumulation in grape berry (Vitis labruscana cv. ‘Kyoho’)

The spatial distribution and time-course evolution of polyphenol compounds in response to exogenous light and temperature in grape berry (Vitis labruscana cv. ‘Kyoho’) were examined. Results demonstrated that the polyphenol biosynthesis was induced via the up-regulated gene transcription levels during berry ripening. The polyphenol biosynthesis was differentially observed in skins, stems, leaves and seeds, and the more polyphenols were accumulated in seeds; and the polyphenols were significantly distributed in bottom berries of grape clusters. Additionally, the lower temperature (4 ℃) accelerated the polyphenol biosynthesis by 1.3 times after storage of 28 days, whereas the light exposure slightly inhibited the polyphenol biosynthesis of berry during storage at 25 ℃. In conclusion, the data presented in this study shed more light on deeper understanding of the spatial accumulation and time-course evolution of polyphenols in grape berry.

Variation in Phenolic Compounds and Antioxidant Activity of Various Organs of African Cabbage (Cleome gynandra L.) Accessions at Different Growth Stages.

The presence of nutritional and health-benefiting compounds has increased awareness of orphan leafy vegetables such as Cleome gynandra (CG), whose phytochemicals vary among accessions and organs during growth. This study investigated the polyphenol accumulation and antioxidant activities (AOA) of eight CG accessions from the vegetative stage to the seed set stage. Plants were separated into leaves and stem (LS), flowers, and silique organs, and extracts were analyzed for total phenolic content (TPC), total flavonoid content (TFC), rutin and astragalin content, and AOA using 2,2-diphenyl-1-picrylhydrazyl-hydrate (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). There were significant interaction effects of growth stages and accessions that contributed to changes in compounds content and AOA. TPC accumulated in plant generative parts, whereas flavonoids accumulated in young plant organs. HPLC profiling revealed that rutin was the most abundant compound in all organs, with flowers having the highest levels, while astragalin was only found in flowers. Silique extracts, particularly accession KF-14, recorded the highest TPC, which corresponded to the strongest radical scavenging activity in ABTS and DPPH assays and a strong linear correlation. The germplasm contained accessions with significantly different and varying levels of bioactive compounds and AOA. These findings potentiate the exploitation of CG organs such as siliques for AOA, flowers for rutin and astragalin, and young shoots for flavonoids. Moreover, the significant accumulation of the compounds in particular accessions of the germplasms suggest that such superior accessions may be useful candidates in genetic breeding programs to improve CG vegetable.

Effects of Siliceous Natural Nanomaterials Applied in Combination with Foliar Fertilizers on Physiology, Yield and Fruit Quality of the Apricot and Peach Trees.

Siliceous natural nanomaterials (SNNMs), i.e., diatomaceous earth and natural zeolites, have a nanoporous structure with large active surfaces that adsorb cations or polarized molecules. Such nanoporous feature determines the effects related to SNNM utilization as low-risk plant protectants and soil improvers. This work used SNNMs from Romanian quarries as carriers for foliar fertilizers applied to stone-fruit trees, apricot and peach. We determined the effects of SNNMs on the physiology, yield and fruit quality of the treated stone-fruit trees. SNNM application determined impacts specific to the formation of particle films on leaves: reduced leaf temperature (up to 4.5 °C) and enhanced water use efficiency (up to 30%). Foliar fertilizers’ effects on yield are amplified by their application with SNNMs. Yield is increased up to 8.1% by the utilization of SNNMs with foliar fertilizers, compared to applying foliar fertilizer alone. Diatomaceous earth and natural zeolites promote the accumulation of polyphenols in apricot and peach fruits. The combined application of SNNMs and foliar fertilizer enhance the performance of peach and apricot trees.

Influence of rootstock genotype on individual metabolic responses and antioxidant potential of blood orange cv. Tarocco Scirè

In fruit crops, tree rootstock plays a relevant role in the tolerance of biotic and abiotic factors, various qualitative traits and biochemical profiles of the juice. In this work, the fruit quality characteristics of sweet orange Tarocco Sciré grafted onto ten rootstocks were evaluated. Analyses were performed on the fruit juice, coupling the quantification of phenolic compounds (anthocyanins, flavanones, flavones and hydroxycinnamic acids) through hyphenated chromatographic techniques and the assessment of antioxidant potential (measured in vitro). The study was conducted for two consecutive years in which the different minimum temperatures recorded during fruit ripening determined a higher accumulation of polyphenols, especially anthocyanins (63.6 %), and higher levels of antioxidant activity (48.92) in the colder year. The analyses allowed the identification and quantification of 24 phenolic compounds (6 anthocyanins, 5 flavanones, 1 flavone and 12 hydroxycinnamic acids). The results highlighted a significant effect of both rootstocks and the environment (and their interaction) on the metabolic profile of the juice, with low temperatures being directly involved in juice pigmentation and significant differences among the rootstocks within each year of analysis. In addition to temperature, a significant effect of rootstocks on the metabolic profile of the juice was revealed, with C35 and Bitters being the most effective in enhancing anthocyanin accumulation in the fruit of the grafted variety.Altogether, the data presented shed light on the significant role exerted by the rootstock on fruit quality, providing useful insights to guide the selection of rootstocks in novel implants.