Arguta Fruit Research Articles

Actinidia arguta Pulp: Phytochemical Composition, Radical Scavenging Activity, and in Vitro Cells Effects.

Hardy kiwifruit (Actinidia arguta) is a highly appreciated exotic fruit endowed with outstanding bioactive compounds. The present work proposes to characterize the pulp from A. arguta organic fruits, emphasizing its radicals scavenging capacity and effects on intestinal cells (Caco-2 and HT29-MTX). The physicochemical properties and phenolic profile were also screened. The total phenolic and flavonoid contents (TPC and TFC, respectively) of pulp were 12.21 mg GAE/g on dry weight (DW) and 5.92 mg CE/g DW, respectively. A high antioxidant activity was observed (FRAP: 151.41 μmol FSE/g DW; DPPH: 12.17 mg TE/g DW). Furthermore, the pulp did not induce a toxic effect on Caco-2 and HT29-MTX cells viability up to 1000 μg/mL. Regarding in vitro scavenging capacity, the pulp revealed the highest scavenging power against NO. (IC50 =3.45 μg/mL) and HOCl (IC50 =12.77 μg/mL). These results emphasize the richness of A. arguta fruit pulp to be used in different food products.

Relationship between Soil Properties and Fruit Yield of New <i>Actinidia arguta</i> (Siebold & Zucc.) Planch. ex Miq. Cultivars in South Korea

Soil properties are important environmental conditions affecting fruit quality and yield in new cultivars of Actinidia arguta. The yield of three A. arguta cultivars (cv. Autumn Sense, cv. Chungsan, and cv. Greenball) from Wonju city, South Korea was investigated from 2017 to 2019 and the relationships to soil properties are discussed. The yield of cv. Autumn Sense, cv. Chungsan, and cv. Greenball fruits ranged from 6.8 to 24.5, 14.0 to 29.0, and 10.5 to 38.5 kg/vine. cv. Autumn Sense had the highest soil organic matter content and soil C/N ratio over the three-year period. The yield of A. arguta fruits was positively correlated with soil C/N ratio and could be described by a power model (y = axb), suggesting that soil C/N ratio plays an important role in limiting the bioavailability and bioaccumulation of organic matter in A. arguta fruits. In addition, C/N ratio in the soil was influenced by the soil available phosphate. However, the threshold of the C/N ratio for A. arguta fruit differed according to cultivar, and especially the lowest threshold was observed in cv. Chungsan. Therefore, the application of an appropriate C/N ratio depending on the cultivar is required for improved fruit yield. Our results present the soil properties required to increase the yield of the new A. arguta cultivars in South Korea.

Metabolomics Study of Flavonoids and Anthocyanin-Related Gene Analysis in Kiwifruit (Actinidia chinensis) and Kiwiberry (Actinidia arguta)

This study investigated the flavonoid compounds in Actinidia chinensis and Actinidia arguta fruits. A total of 125 flavonoids, including 9 anthocyanins, 12 catechins, 17 flavanones, 48 flavones (including 14 flavone C-glycosides), 29 flavonols, 6 isoflavones, and 4 proanthocyanidins, were identified in “Hongyang” kiwifruit (red flesh), “Jintao” kiwifruit, “Mini Amethyst” kiwiberry (purple flesh), and “Kuilv” kiwiberry. Thirty-nine metabolites showed significantly different contents between “Hongyang” and “Jintao,” and 38 of them showed higher content in “Hongyang,” whereas 39 metabolites showed significantly different contents between “Mini Amethyst” and “Kuilv,” and 31 of them showed higher content in “Mini Amethyst.” This result indicates the superior nutritional value of the pigmented kiwi cultivars in terms of flavonoids. Multivariate statistical analysis indicates that the variation in flavonoid profiles contributes to the pigmentation phenotypes of “Hongyang” and “Mini Amethyst.” Further comparative transcriptomic analysis revealed that structural genes in the anthocyanin synthesis pathway (AcF3H, AcF3′H, AcDFR, AcUFGT) and transcription factors (AcMYB10, AcbHLH5) may be involved in the pigmentation of the red-fleshed A. chinensis, whereas AaF3H, AaF3GT, and AaMYB110 may play important roles in the pigmentation of the purple-fleshed A. arguta. This study provides broader insight into the variation in flavonoid profiles among kiwifruit/berry, evaluates the flavonoid nutrition of the four cultivars, and provides additional evidence for the correlation between the genes and metabolites involved in flavonoid synthesis.

The use of a new explanatory methodology to assess maturity and ripening indices for kiwiberry (Actinidia arguta): Preliminary results

Abstract Harvesting quality is a latent concept that is often summarised by several attributes, which in turn may be described as complex parameters due to their multicomponent structure. Multivariate techniques such as Multiple Factor Analysis (MFA) and Partial least square (PLS) analysis represent suitable tools to investigate quality indices as they are able to compute systems of composite indicators, providing more accurate knowledge than a single attribute. Therefore, the goals of this work are: to describe the evolution of different quality parameters during the harvesting period of new cv Tahi and cv Rua and to analyse their correlations in order to create a model that will highlight new potential harvesting and maturity quality indicators. This will provide knowledge for development of a harvesting index of A. arguta fruit, for which the harvest period is still determined by traditional quality traits. Data from physicochemical, colorimetric and nutraceutical assays were analysed with ANOVA and MFA and fused in a PLS model. We created a PLS model with an R2 value of 0.83 for cv Rua and of 0.44 for cv Tahi. Our results suggest that composite colorimetric parameters may enhance the sensitivity of Hue changes during the harvesting period and are less cultivar-specific than nutraceutical ones. It is suggested that this methodology is applied to larger sample sizes in order to extend the results to the population. Further studies should pay more attention to the use of colorimetric indices and their combination.

Light- and Temperature-Induced Expression of an R2R3-MYB Gene Regulates Anthocyanin Biosynthesis in Red-Fleshed Kiwifruit.

The R2R3 MYB genes associated with the flavonoid/anthocyanidin pathway feature two repeats, and represent the most abundant classes of MYB genes in plants; however, the physiological role and regulatory function of most R2R3 MYBs remain poorly understood in kiwifruit (Actinidia). Here, genome-wide analysis identified 155 R2R3-MYBs in the ‘Red 5′ version of the Actinidia chinensis genome. Out of 36 anthocyanin-related AccR2R3-MYBs, AcMYB10 was the most highly expressed in inner pericarp of red-fleshed kiwifruit. The expression of AcMYB10 was highly correlated with anthocyanin accumulation in natural pigmentation during fruit ripening and light-/temperature-induced pigmentation in the callus. AcMYB10 is localized in the nuclei and has transcriptional activation activity. Overexpression of AcMYB10 elevates anthocyanin accumulation in transgenic A. chinensis. In comparison, A. chinensis fruit infiltrated with virus-induced gene silencing showed delayed red coloration, lower anthocyanin content, and lower expression of AcMYB10. The transient expression experiment in Nicotiana tabacum leaves and Actinidia arguta fruit indicated the interaction of AcMYB10 with AcbHLH42 might strongly activate anthocyanin biosynthesis by activating the transcription of AcLDOX and AcF3GT. In conclusion, this study provides novel molecular information about R2R3-MYBs in kiwifruit, advances our understanding of light- and temperature-induced anthocyanin accumulation, and demonstrates the important function of AcMYB10 in the biosynthesis of anthocyanin in kiwifruit.

MicroRNA858-mediated regulation of anthocyanin biosynthesis in kiwifruit (Actinidia arguta) based on small RNA sequencing.

As important regulators, miRNAs could play pivotal roles in regulation of fruit coloring. Actinidia arguta is a newly emerged fruit tree with extensively application prospects. However, miRNAs involved in A. arguta fruit coloring are unknown. In this study, A. arguta fruit were investigated at three developmental stages by small RNAs high-throughput sequencing. A total of 482 conserved miRNAs corresponding to 526 pre-miRNAs and 581 novel miRNAs corresponding to 619 pre-miRNAs were grouped into 46 miRNA families. Target gene prediction and analysis revealed that miR858, a strongly candidate miRNA, was involved in anthocyanin biosynthesis in which contributes to fruit coloring. The anthocyanin level was determined in three A. arguta cultivars by UPLC-MS/MS (ultra-performance liquid chromatography coupled with tandem mass spectrometry). In addition, qPCR (quantitative real-time PCR), cluster analysis were conducted as well as correlation analysis. All results were combined to propose a model in which describes an association of miRNA and anthocyanin biosynthesis in A. arguta. The data presented herein is the first report on miRNA profile analysis in A. arguta, which can provide valuable information for further research into the regulation of the miRNAs in anthocyanin biosynthesis and fruit coloring.

Molecular cloning and functional characterization of AcGST1, an anthocyanin-related glutathione S-transferase gene in kiwifruit (Actinidia chinensis).

AcGST1, an anthocyanin-related GST, may functions as a carrier to transport anthocyanins from ER to tonoplast in kiwifruit. It was positively regulated by AcMYBF110 through directly binding to its promoter. Anthocyanins are synthesized in the cytoplasmic surface of the endoplasmic reticulum but accumulate predominantly in the vacuole. Previous studies in model and ornamental plants have suggested that a member of the glutathione S-transferase (GST) gene family is involved in sequestration of anthocyanins into the vacuole. However, little is known about anthocyanin-related GST protein in kiwifruit. Here, four putative AcGSTs were identified from the genome of the red-fleshed Actinidia chinensis cv 'Hongyang'. Expression analyses reveal only the expression of AcGST1 was highly consistent with anthocyanin accumulation. Molecular complementation of Arabidopsis tt19 demonstrates AcGST1 can complement the anthocyanin-less phenotype of tt19. Transient expression in Actinidia arguta fruits further confirms that AcGST1 is functional in anthocyanin accumulation in kiwifruit. In vitro assays show the recombinant AcGST1 increases the water solubility of cyanidin-3-O-galactoside (C3Gal) and cyanidin-3-O-xylo-galactoside (C3XG). We further show that AcGST1 protein is localized not only in the ER but also on the tonoplast, indicating AcGST1 (like AtTT19) may functions as a carrier protein to transport anthocyanins to the tonoplast in kiwifruit. Moreover, the promoter of AcGST1 can be activated by AcMYBF110, based on results from transient dual-luciferase assays and yeast one-hybrid assays. EMSAs show that AcMYBF110 binds directly to CAGTTG and CCGTTG motifs in the AcGST1 promoter. These results indicate that AcMYBF110 plays an important role in transcriptional regulation of AcGST1 and, therefore, in controlling accumulation of anthocyanins in kiwifruit.

A MYB/bHLH complex regulates tissue-specific anthocyanin biosynthesis in the inner pericarp of red-centered kiwifruit Actinidia chinensis cv. Hongyang.

Many Actinidia cultivars are characterized by anthocyanin accumulation, specifically in the inner pericarp, but the underlying regulatory mechanism remains elusive. Here we report two interacting transcription factors, AcMYB123 and AcbHLH42, that regulate tissue-specific anthocyanin biosynthesis in the inner pericarp of Actinidia chinensis cv. Hongyang. Through transcriptome profiling analysis we identified five MYB and three bHLH transcription factors that were upregulated in the inner pericarp. We show that the combinatorial action of two of them, AcMYB123 and AcbHLH42, is required for activating promoters of AcANS and AcF3GT1 that encode the dedicated enzymes for anthocyanin biosynthesis. The presence of anthocyanin in the inner pericarp appears to be tightly associated with elevated expression of AcMYB123 and AcbHLH42. RNA interference repression of AcMYB123, AcbHLH42, AcF3GT1 and AcANS in 'Hongyang' fruits resulted in significantly reduced anthocyanin biosynthesis. Using both transient assays in Nicotiana tabacum leaves orActinidia arguta fruits and stable transformation in Arabidopsis, we demonstrate that co-expression of AcMYB123 and AcbHLH42 is a prerequisite for anthocyanin production by activating transcription ofAcF3GT1 and AcANS or the homologous genes. Phylogenetic analysis suggests that AcMYB123 or AcbHLH42 are closely related to TT2 or TT8, respectively, which determines proanthocyanidin biosynthesis in Arabidopsis, and to anthocyanin regulators in monocots rather than regulators in dicots. All these experimental results suggest that AcMYB123 and AcbHLH42 are the components involved in spatiotemporal regulation of anthocyanin biosynthesis specifically in the inner pericarp of kiwifruit.

Infusions and decoctions of dehydrated fruits of Actinidia arguta and Actinidia deliciosa: Bioactivity, radical scavenging activity and effects on cells viability

Actinidia deliciosa and A. arguta fruits (kiwifruit and kiwiberry, respectively) are an excellent source of bioactive compounds. The aim of this paper is to valorize the fruits that are not commercialized (e.g. due to inadequate size or physical damage) in infusions and decoctions. The antioxidant activity, the scavenging activity against reactive species, the phenolic profile and the intestinal effects of infusions and decoctions of dehydrated fruits were evaluated and compared. Decoctions presented the highest antioxidant activity and a good ability to capture HOCl and NO. The phenolic composition of A. arguta present quinic acid, cis-caftaric acid and its derivatives, caffeoyl hexoside, luteolin glucuronide, quercetin derivatives and myristin, while A. deliciosa extracts were characterized by the presence of quinic acid, caffeic acid and its derivatives and caffeoyl hexoside. No adverse effects were observed on Caco-2 and HT29-MTX cells. Kiwiberry decoctions showed to be the best option to keep the fruits benefits.

First Report of Anthracnose Caused by Colletotrichum aenigma on Actinidia arguta in China

HomePlant DiseaseVol. 103, No. 2First Report of Anthracnose Caused by Colletotrichum aenigma on Actinidia arguta in China PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Anthracnose Caused by Colletotrichum aenigma on Actinidia arguta in ChinaY. Wang, H. Y. Qin, Y. X. Liu, S. T. Fan, D. Sun, Y. M. Yang, C. Y. Li, and J. AiY. WangSearch for more papers by this author, H. Y. QinSearch for more papers by this author, Y. X. LiuSearch for more papers by this author, S. T. FanSearch for more papers by this author, D. SunSearch for more papers by this author, Y. M. YangSearch for more papers by this author, C. Y. LiSearch for more papers by this author, and J. Ai†Corresponding author: J. Ai; E-mail: E-mail Address: [email protected]http://orcid.org/0000-0002-7977-1574Search for more papers by this authorAffiliationsAuthors and Affiliations Y. Wang H. Y. Qin Y. X. Liu S. T. Fan D. Sun Y. M. Yang C. Y. Li J. Ai † , Institute of Special Animal and Plant Science, Chinese Academy of Agricultural Sciences, Changchun, 130112, Jilin, China. Published Online:17 Dec 2018https://doi.org/10.1094/PDIS-07-18-1137-PDNAboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Actinidia arguta (Sieb. & Zucc.) Planch. ex Miq. is a fruit tree being newly cultivated worldwide and is a widely distributed wild fruit tree in China (Zhao 2002). Owing to their fruits rich in vitamin C, A. arguta enjoys the labels “world treasure” and “fruit king.” In September 2017, anthracnose symptoms were observed on the fruit of a 6-year-old A. arguta plantation in Dandong, Liaoning Province, China. Symptoms began with light brown round spots that developed into slightly sunken brown or black-brown lesions on infected pericarp; 15 to 20% of the trees exhibited typical anthracnose symptoms. For characterization, 5-mm2 pieces of symptomatic tissue were surface sterilized with 1% NaOCl for 2 min, triple rinsed with sterile water, dried on sterilized filter paper, and cultivated on acidified potato dextrose agar (PDA) medium at 25°C to obtain the pathogenic fungus. Three isolates were cultured on PDA at 25°C under a 12-h/12-h light/dark cycle for 7 days. The average resulting colony diameter was 6.80 ± 0.80 cm. Colonies were round with smooth edges and white aerial mycelia. The surfaces were fluffy and white, and the colonies’ undersides were pale yellow to white. Perithecia and ascospores were produced on PDA. The ascospores were cylindrical, both ends blunt, with slight depressions in the middle, and no setae or conidial discs. Conidial spores were smooth and transparent, cylindrical or stick type, both ends blunt, with small particles inside, evenly distributed, 16.1 to 19.7 × 5.0 to 8.1 µm (average = 17.8 ± 1.03 × 6.01 ± 0.72, n = 50). Appressoria were brown to dark brown, usually scattered or irregular, 7.2 to 11.4 × 4.3 to 8.2 µm (average = 9.29 ± 1.08 × 6.33 ± 0.86, n = 20). Based on morphological and cultural characteristics, the isolates were identified as part of the Colletotrichum gloeosporioides species complex (Deng et al. 2017; Phoulivong et al. 2010; Weir et al. 2012). To confirm the species identification, six DNA regions of the randomly selected strain AACAWY203DRT5 were amplified by polymerase chain reaction and sequenced: rDNA internal transcribed spacers regions (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), calmodulin (CAL), chitin synthase (CHS) (Gan et al. 2017), actin (ACT) (Liang et al. 2017), and β-tubulin (TUB2). A BLASTn algorithm-based search revealed that all sequences (GenBank accession nos. MH476561 for ITS, MH476562 for GAPDH, MH476563 for ACT, MH476564 for CAL, MH476565 for CHS, and MH476566 for TUB2) had 99 to 100% sequence identities with Colletotrichum aenigma (NR_120140 for ITS, JX009913 for GAPDH, KX885151 for ACT, KU251793 for CAL, KX513884 for CHS, and KY820891 for TUB2). Based on these results, the isolate was identified as C. aenigma. To confirm pathogenicity, 18 A. arguta fruits were surface disinfested by immersion in 1% NaOCl for 1 min, triple rinsed with sterile water, and then dried on sterilized filter paper. Inoculations were performed by inoculating 10 μl of a conidial suspension (106 spore/ml) on the fruit surface. As controls, nine fruits were mock inoculated with sterile distilled water. All fruits were maintained at 25°C, about 90% relative humidity and with natural light. After 1 week, symptoms started to develop only on inoculated fruit, whereas control fruit did not develop symptoms. The fungus was only consistently reisolated from the diseased fruits, thus fulfilling Koch’s postulates. To our knowledge, this is the first report C. aenigma causing anthracnose of A. arguta in China. The disease leads to lower fruit quality and decreased yield, and research is needed on management options to minimize losses.

Post-Harvest Warehouse Management for Actinidia arguta Fruits

Post-Harvest Warehouse Management for Actinidia arguta Fruits

Anticholinergic effects of Actinidia arguta fruits and their polyphenol content determined by liquid chromatography-photodiode array detector-quadrupole/time of flight-mass spectrometry (LC-MS-PDA-Q/TOF)

This study discusses polyphenolic compounds identified and quantified in Actinidia arguta fruits by LC-MS-PDA-Q/TOF method and in vitro anticholinergic activity. Notably, of 31 compounds, including 16 flavonols, 7 flavanols, 7 phenolic acids, and 1 anthocyanin were identified or tentatively identified on the basis of their retention times, accurate mass measurements and subsequent mass fragmentation data, or by comparison with reference substances and literature. Among the detected compounds, 27 were reported for the first time in A. arguta fruits. The content of total polyphenols equal 845.54 mg/100 g dry weight (dw), and flavanols predominat (92% of total phenolic compounds). Flavonol derivatives, mainly glycosylated and acetylated forms of quercetin (22.64 mg/100 g dw) and kaempferol (18.40 mg/100 g dw) were quantified. The total content of phenolic acids was 29.63 mg/100 g dw, and neochlorogenic acid predominant. This anticholinergic activity effect of A. arguta fruits can be explained by the Pearson’s correlation found between flavonols (r = 0.709 and 0.678), phenolic acids (r = 0.513 and 0.487), flavan-3-ols (r = 0.466 and 0.443) and anthocyanins (r = 0.312 and 0.301) for acetylcholinesterase (AChE) or butylcholinoesterase (BuChE), respectively. The data compiled from the quantitative polyphenol indicate that A. arguta fruits could be regarded as a promising source of bioactive functional food.

Evaluation of biochemical components and antioxidant capacity of different kiwifruit (Actinidia spp.) genotypes grown in China

ABSTRACTKiwifruit from eight Actinidia genotypes were evaluated for soluble sugar content (SSC), titratable acidity content (TAC), sugar–acid ratio (SAR), vitamin C (Vc) content, superoxide dismutase (SOD) activity, total phenolic content (TPC), total flavonoid content (TFC) and antioxidant capacity using four assays: 2,2ʹ-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging assay; 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay; oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assay. These analyses demonstrated that ‘AnminR1’ and ‘AnminR2’ of Actinidia arguta have significantly higher SSC, TAC and SAR than other Actinidia genotypes, indicating better flavour. The analyses also demonstrated that the antioxidant capacity of Actinidia kolomikta and A. arguta fruits was significantly higher than that of other genotypes (Actinidia chinenesis and Actinidia deliciosa), which was approximately 2.37–5.51 fold higher than A. deliciosa cv. There was extensive variety in the Vc content, SOD activity, TPC and TFC amongst Actinidia genotypes, which significantly correlated with TAC. We determined that significant genotypic differences exist in the biochemical components and TAC of Actinidia fruits. The hardy A. kolomikta and A. arguta genotypes have significantly higher antioxidant capacity than the commercial cultivars of A. chinenesis and A. deliciosa indicating that the hardy Actinida genotypes have more health benefits than the commercial cultivars of Actinidia.

Comparative Transcriptome Analysis of Actinidia arguta Fruits Reveals the Involvement of Various Transcription Factors in Ripening

The fruit of Actinidia arguta is typically climacteric. During ripening, the fruits produce a large amount of ethylene. Although the molecular basis of climacteric fruit ripening has been extensively studied, some aspects such as its transcriptional regulation remain unclear. Here, we compared the transcriptomes of A. arguta fruits collected at commercial harvest (sample d0) and at 6 days after harvest (sample d6) using RNA-seq. A total of 3 659 differentially expressed genes (DEGs) between samples d0 and d6 were detected, of which 2 983 and 1 104 could be functionally annotated with Gene Ontology (GO) and Clusters of Orthologous Groups (COG) pathways. DEGs involved in ethylene biosynthesis and signal transduction were identified, including ACO (c79627), ERF061 (c105131), and ERF6 (c99193). Transcription factors such as ERF, bHLH, NAC, MADS, and MYB were also differentially expressed between samples d0 and d6. Selected DEGs were subjected to further analysis using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and the results coincided with those of RNA-seq. Our data revealed additional transcription factors that are involved in the regulation of fruit ripening. These results provide useful information for future research on the transcriptional regulation of fruit ripening.

Cell wall changes in Actinidia arguta during softening

Abstract Actinidia arguta fruit, differing from conventional kiwifruit A. chinensis ‘Hort16A’ and ‘Hayward’ by size, skin appearance, softening rate and texture, were characterised regarding structural and cell wall changes during softening. Cell wall changes of A. arguta var. arguta ‘Hortgem Tahi’ were examined during softening using histological stains, immunolocalisation and cell wall composition analyses. ‘Hortgem Tahi’ fruit are bite-sized and have a skin that is considered edible by consumers, consisting of a cuticle, a living epidermis and a hypodermis of tightly packed thin-walled cells, containing condensed phenolic material. Beneath is the outer pericarp with large and small parenchyma cells, followed by the inner pericarp with seed-containing locules, and core tissue consisting of small, tightly packed parenchyma cells. Throughout the fruit are large numbers of mucilage-containing cells. At harvest, cell walls stain densely with toluidine blue; as fruit softens, staining is lost in the outer pericarp but retained in the epidermis and hypodermis. At harvest, antibodies directed to cell wall epitopes bind to cell walls with a characteristic labelling pattern, but later as fruit soften these antibodies also label polysaccharides inside the cells. ‘Hortgem Tahi’ softens within five days after harvest. Cell wall composition analyses showed that during the softening process, galactose loss as well as pectin solubilisation started at an earlier firmness stage compared to ‘Hayward’ fruit that take about thirty days to soften. ‘Hortgem Tahi’ shows similar internal structural characteristics and cell wall changes compared with conventional kiwifruit. However, they differ in skin structure, the presence of mucilage filled cells, and the occurrence of pectin labelling within the lumen of cells at the ripe fruit stage which may be responsible for the gelatinous texture of the ripe fruit. The comparatively fast softening rate may be caused by an early reduction of galactose content increasing cell wall porosity that supports pectin solubilisation.

Antioxidant Activity, Total Phenolics and Vitamin C Contents of the Unripe and Ripe Fruit of Hardy Kiwi (Actinidia arguta) ‘Saehan’ as Honey Plant

The aim of this investigation was to find the knowledge of the changes of physiochemicals associated with fruit quality, vitamin C, total phenolics and antioxidant properties during fruit ripening. Changes in antioxidant activity of Actinidia arguta fruit of Saehan cultivar was studied at different ripening stages. Antioxidant activities (free-radical scavenging activity and reducing power) were determined and the total phenolic contents, and vitamin C contents were also analyzed. The highest free-radical scavenging activity (at 100ug/ml) and reducing power (at 100ug/ml) in A. arguta fruit were 45.43% and 0.14, respectively. Total phenolic content and vitamin C content in fruit of 40 days after fruit set were 540.2ug/g and 1238.0ug/g, respectively. In general, the antioxidant activity and the related parameters, including total phenolic content and vitamin C content decreased during fruit ripening. These results improve knowledge of the effect of ripening on the antioxidant activity and related compounds contents that could help to establish the optimum A. arguta fruit harvest data for various usages.

Isolation and characterization of a protease from the Actinidia arguta fruit for improving meat tenderness.

An protease from Actinidia arguta for improving meat tenderness was purified, characterized from wild A. arguta fruit by ammonium sulfate precipitation, Sephdex G-25 gel filtration chromatography, and DEAE Sepharose Fast Flow ion exchange chromatography, and its activity was investigated. The purified protease was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis to obtain a single band of protease. The protease was purified successfully, and found to have a molecular weight of 23.8 kDa (mass spectrometry). The specific activity of the purified protease reached 53,428 U/mg with a 25.5-fold purification factor and 9% activity recovery. Based on N-terminal sequencing results, the A. arguta protease was derived from the class of actinidia proteases that have an N-terminal sequence of VLPDY VDWRS AGAVV. The protease was effective for tenderizing beef and decomposing actomyosin, suggesting the potential application for improving meat tenderness.

Freshwater Sardines of the Pantanal Delay Seed Germination in a Floodplain Tree Species

Most studies involving the consumption of fruit and subsequent secondary dispersal of seeds by vertebrates point to birds and mammals as the main agents of dispersal. However, evidence suggests that fish also perform this important ecological role. After observing the consumption of Banara arguta fruits by fish of the Pantanal floodplain, we decided to investigate the disperser role of the freshwater sardine Triportheus nematurus. Our main goal was to compare the germination of seeds recovered from the intestinal tract of individuals (consumed) with that of seeds collected directly from uneaten ripe fruit (control). While no difference in germination percentage was found between consumed and control seeds, germination speed was higher in control seeds. Delay in germination speed during the flood season is a well-known mechanism adopted by floodplain plants to ensure germination in appropriate conditions. Thus far, few studies have reported on the effect of fish in this process. Furthermore, germination percentage was not affected by the presence of intact seeds in the intestinal tract of T. nematurus, placing this species among potential dispersers of B. arguta fruit.

Bioactivity and nutritional properties of hardy kiwi fruit Actinidia arguta in comparison with Actinidia deliciosa ‘Hayward’ and Actinidia eriantha ‘Bidan’

The aim of this research is to identify and compare the bioactive compounds, antioxidant capacities and binding potentials to human protein in different varieties of hardy kiwi (Actinidia (A.) arguta), ‘Hayward’ (Actinidia deliciosa) and less – known ‘Bidan’ (Actinidia eriantha). Polyphenols, flavonoids, flavanols, tannins, vitamin C, lutein, zeaxanthin and dietary fibers were significantly higher in cultivar ‘M1’ among the A. arguta than in ‘Hayward’. The binding properties of studied kiwi fruits were determined by interaction of polyphenols with human serum albumin (HSA). An internal standard FTIR technique allowed the quantitative comparison of specific IR absorption bands (Amides I, II, III) of different kiwi fruit samples after interaction with HSA. It was shown that the antioxidant and binding capacities and FTIR quantitative estimations of A. arguta fruits were significantly higher than in ‘Hayward’, but lower than the ‘Bidan’. In MS spectra were found some slight differences in A. arguta kiwis in comparison with ‘Hayward’ and ‘Bidan’. Two A. arguta cultivars were similar to ‘Bidan’. The interaction of polyphenols with HSA, evaluated by fluorometry/FTIR, made it possible to compare the bioactivity of different cultivars and families. In conclusion, for the first time fruits A. arguta, cultivated in Poland, were compared with widely consumed kiwi fruits, using advanced analytical methods. The high bioactivity and nutritional value of A. arguta fruits from Polish ecological plantation enables us to recommend them for marketing and consumption.

Natural variation in monoterpene synthesis in kiwifruit: transcriptional regulation of terpene synthases by NAC and ETHYLENE-INSENSITIVE3-like transcription factors.

Two kiwifruit (Actinidia) species with contrasting terpene profiles were compared to understand the regulation of fruit monoterpene production. High rates of terpinolene production in ripe Actinidia arguta fruit were correlated with increasing gene and protein expression of A. arguta terpene synthase1 (AaTPS1) and correlated with an increase in transcript levels of the 2-C-methyl-D-erythritol 4-phosphate pathway enzyme 1-deoxy-D-xylulose-5-phosphate synthase (DXS). Actinidia chinensis terpene synthase1 (AcTPS1) was identified as part of an array of eight tandemly duplicated genes, and AcTPS1 expression and terpene production were observed only at low levels in developing fruit. Transient overexpression of DXS in Nicotiana benthamiana leaves elevated monoterpene synthesis by AaTPS1 more than 100-fold, indicating that DXS is likely to be the key step in regulating 2-C-methyl-D-erythritol 4-phosphate substrate flux in kiwifruit. Comparative promoter analysis identified potential NAC (for no apical meristem [NAM], Arabidopsis transcription activation factor [ATAF], and cup-shaped cotyledon [CUC])-domain transcription factor) and ETHYLENE-INSENSITIVE3-like transcription factor (TF) binding sites in the AaTPS1 promoter, and cloned members of both TF classes were able to activate the AaTPS1 promoter in transient assays. Electrophoretic mobility shift assays showed that AaNAC2, AaNAC3, and AaNAC4 bind a 28-bp fragment of the proximal NAC binding site in the AaTPS1 promoter but not the A. chinensis AcTPS1 promoter, where the NAC binding site was mutated. Activation could be restored by reintroducing multiple repeats of the 12-bp NAC core-binding motif. The absence of NAC transcriptional activation in ripe A. chinensis fruit can account for the low accumulation of AcTPS1 transcript, protein, and monoterpene volatiles in this species. These results indicate the importance of NAC TFs in controlling monoterpene production and other traits in ripening fruits.