Red-fleshed Apple Research Articles

The regulatory module MdBZR1-MdCOL6 mediates brassinosteroid- and light-regulated anthocyanin synthesis in apple.

The anthocyanin content is an important indicator of the nutritional value of most fruits, including apple (Malus domestica). Anthocyanin synthesis is coordinately regulated by light and various phytohormones. In this study on apple, we revealed the antagonistic relationship between light and brassinosteroid (BR) signaling pathways, which is mediated by BRASSINAZOLE-RESISTANT 1 (MdBZR1) and the B-box protein MdCOL6. The exogenous application of brassinolide inhibited the high-light-induced anthocyanin accumulation in red-fleshed apple seedlings, whereas increases in the light intensity decreased the endogenous BR content. The overexpression of MdBZR1 inhibited the anthocyanin synthesis in apple plants. An exposure to a high-light intensity induced the degradation of dephosphorylated MdBZR1, resulting in functional impairment. MdBZR1 was identified as an upstream repressor of MdCOL6, which promotes anthocyanin synthesis in apple plants. Furthermore, MdBZR1 interacts with MdCOL6 to attenuate its ability to activate MdUFGT and MdANS transcription. Thus, MdBZR1 negatively regulates MdCOL6-mediated anthocyanin accumulation. Our study findings have clarified the molecular basis of the integration of light and BR signals during the regulation of anthocyanin biosynthesis, which is an important process influencing fruit quality.

Evaluating the Classification of Freeze-Dried Slices and Cubes of Red-Fleshed Apple Genotypes Using Image Textures, Color Parameters, and Machine Learning

Dried red-fleshed apples are considered a promising high-quality product from the functional foods category. The objective of this study was to compare the flesh features of freeze-dried red-fleshed apples belonging to the ‘Alex Red’, ‘Trinity’, ‘314’, and ‘602’ genotypes and indicate which parameters and shapes of dried samples are the most useful to distinguish apple genotypes. Apple samples were at the stage of harvest maturity. The average fruit weight, starch index, internal ethylene concentration, flesh firmness, total soluble sugar content, and titratable acidity were determined. One hundred apple slices with a thickness of 4 mm and one hundred cubes with dimensions of 1.5 cm × 1.5 cm × 1.5 cm of each genotype were subjected to freeze-drying. For each apple sample (slice or cube), 2172 image texture parameters were extracted from images in 12 color channels, and color parameters L*, a*, and b* were determined. The classification models were developed based on a set of selected image textures and a set of combined selected image textures and color parameters of freeze-dried apple slices and cubes using various traditional machine-learning algorithms. Models built based on selected textures of slice images in 11 selected color channels correctly classified freeze-dried red-fleshed apple genotypes with an overall accuracy reaching 90.25% and mean absolute error of 0.0545; by adding selected color parameters (L*, b*) to models, an increase in the overall accuracy to 91.25% and a decrease in the mean absolute error to 0.0486 were observed. The classification of apple cube images using models including selected texture parameters from images in 11 selected color channels was characterized by an overall accuracy of up to 74.74%; adding color parameters (L*, a*, b*) to models resulted in an increase in the overall accuracy to 80.50%. The greatest mixing of cases was observed between ‘Alex Red’ and ‘Trinity’ as well as ‘314’ and ‘602’ apple slices and cubes. The developed models can be used in practice to distinguish freeze-dried red-fleshed apples in a non-destructive and objective manner. It can avoid mixing samples belonging to different genotypes with different chemical properties. Further studies can focus on using deep learning in addition to traditional machine learning to build models to distinguish dried red-fleshed apple samples. Moreover, other drying techniques can be applied, and image texture parameters and color features can be used to predict the changes in flesh structure and estimate the chemical properties of dried samples.

Mdm-miR858 targets MdMYB9 and MdMYBPA1 to participate anthocyanin biosynthesis in red-fleshed apple.

Anthocyanins are important secondary metabolites in plants. They are important for human health because of their antioxidant activities and because their dietary intake reduces the incidence of cardiovascular and cerebrovascular diseases and tumors. The biosynthesis of anthocyanins and its regulation in fruits and vegetables is a global research hotspot. Compared with cultivated apples, the red-fleshed apple is a relatively new and popular commodity in the market. Previous studies on red-fleshed apples have focused on the basis for the high anthocyanin content and the transcriptional regulation of anthocyanin synthesis. In the present study, we focused on the mechanism of microRNA-mediated post-transcriptional regulation of anthocyanin synthesis in red-fleshed apples. We identified a microRNA (miRNA), designated mdm-miR858, that is specifically expressed in the flesh of apple fruit. The expression level of miR858 was significantly lower in red-fleshed apples than in white-fleshed apples. The overexpression of mdm-miR858 significantly inhibited anthocyanin accumulation, whereas the silencing of mdm-miR858 promoted anthocyanin synthesis in STTM858 transgenic apple calli. Further analyses showed that mdm-miR858 targets the transcription factor genes MdMYB9 and MdMYBPA1 to participate anthocyanin accumulation in apple. Our results also show that MdHY5, a transcription factor in the light signaling pathway, can bind to the promoter of mdm-miR858 to inhibit its transcription, thereby regulating anthocyanin synthesis. Based on our results, we describe a novel HY5-miR858-MYB loop involved in the modulation of anthocyanin biosynthesis. These findings provide new information about how plant miRNAs regulate anthocyanin anabolism and provide a basis for breeding new anthocyanin-rich, red-fleshed apple varieties.

MdMYB305-MdbHLH33-MdMYB10 regulates sugar and anthocyanin balance in red-fleshed apple fruits.

Sugar and anthocyanin are important indicators of fruit quality, and understanding the mechanism underlying their accumulation is essential for breeding high-quality fruit. We identified an R2R3-MYB transcription factor MdMYB305 in the red-fleshed apple progeny, which was positively correlated with fruit sugar content but negatively correlated with anthocyanin content. Transient injection, stable expression [overexpressing and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)], and heterologous transformation of tomato confirmed that MdMYB305 promotes the accumulation of sugar and inhibits the synthesis of anthocyanin. A series of molecular experiments (such as electrophoretic mobility shift and luciferase assays) confirmed that MdMYB305 combines with sugar-related genes (MdCWI1/MdVGT3/MdTMT2) and anthocyanin-related genes (MdF3H/MdDFR/MdUFGT), promoting and inhibiting their activities, and finally regulating the sugar and anthocyanin content of fruits. In addition, the study also found that MdMYB305 competes with MdMYB10 for the MdbHLH33 binding site to balance sugar and anthocyanin accumulation in the fruits, which provides a reference value for exploring more functions of the MYB-bHLH-MYB complex and the balance relationship between sugar and anthocyanin in the future.

Red-fleshed apple flavonoid extract alleviates CCl4-induced liver injury in mice.

In recent years, the global incidence of liver damage has increased. Despite the many known health benefits of red-fleshed apple flavonoids, their potential liver-protective effects have not yet been investigated. In this study, we analyzed the composition of red-fleshed apple flavonoid extract (RAFE) by high-performance liquid chromatography (HPLC). We then induced liver damage in mice with carbon tetrachloride (CCl4) and performed interventions with RAFE to analyze its effect on liver damage, using bifendate as a positive control. The results showed that catechin was the most abundant flavonoid in 'XJ4' RAFE (49.346 mg/100 g). In liver-injured mice, the liver coefficients converged to normal levels following RAFE intervention. Moreover, RAFE significantly reduced the enzymatic activity levels of glutamic oxaloacetic transaminase (ALT), glutamic alanine transaminase (AST), and alkaline phosphatase (ALP) in mouse serum. Furthermore, RAFE significantly increased the content or enzyme activity level of total glutathione, total antioxidant capacity, and superoxide dismutase, and significantly decreased the content of malondialdehyde in the liver of mice. In parallel, we performed histopathological observations of mouse livers for each group. The results showed that RAFE restored the pathological changes caused by CCl4 around the central hepatic vein in mice and resulted in tightly bound hepatocytes. The recovery effect of RAFE was dose-dependent in the liver tissue. Regarding intestinal microorganisms, we found that RAFE restored the microbial diversity in liver-injured mice, with a similar microbial composition in the RAFE intervention group and normal group. RAFE reduced the ratio of Firmicutes to Bacteroidetes, increased the levels of probiotic bacteria, such as Lactobacillus acidophilus, and Clostridium, and reduced the levels of harmful bacteria, such as Erysipelothrix Rosenbach. Therefore, RAFE ameliorated CCl4-induced liver damage by modulating the abundance and composition of intestinal microorganisms in mice. In conclusion, RAFE alleviated CCl4-induced liver damage in mice, with H-RAFE (5 mg kg-1) significantly improving liver damage in mice but M-RAFE (1 mg kg-1) significantly improving the imbalance of intestinal microorganisms in mice. Our research suggests that RAFE could be employed for the adjuvant treatment and prevention of liver damage, and may have important applications in food and medicine.

DENDROFLORA UZHHOROD CITY RIVERFRONTS: CURRENT STATE AND DEVELOPMENT PROSPECTS

The paper presents the results of inventory surveys of tree and shrub plantations on six riverfronts of the city of Uzhhorod: Pravoslavna, Kyivska, and Slovianska are on the left bank, Botanichna, Nezalezhnosti, and Studentska are on the right bank. The taxonomic composition of the dendroflora was determined and analysed, the ratio of introduced and native species, as well as the distribution by age and height were established. The general condition of green areas was characterised. The main species that dominate the plantings are species of the genus Tilia L., Aesculus L., Populus nigra L. var. italica Duroi, Platanus acerifolia (Ait.) Willd., Sophora japonica L., Ginkgo biloba L., and less often highly decorative, flowering sakura Cerasus serrulata (Lindley) G. Don ex Loudon, Malus niedzwetzkyana Dieck ex Koehne, Catalpa bignonioides Walter, as well as coniferous trees of Pinus sylvestris L., Platycladus orientalis (L.) Franco. Among the exotic species, S. japonica and P. acerifolia have proved to be particularly well established in the landscaping of Uzhhorod. Trees of these species in Uzhhorod are durable, resistant to falling out, and differ little in size and shape in plantings, so they retain their aesthetic appearance for a long time and are suitable for forming linear plantings. In total, 1147 specimens of 51 species of trees and shrubs belonging to 23 families grow on the five riversides of Uzhhorod city (excluding Botanichna). The most widespread is linden, with different species totaling 332 specimens present on four riverfronts (Nezalezhnosit, Studentska, Kyivska, Slovianska). By origin, 33 species (63.5 %) are introduced. Trees are represented by 37 species, shrubs by 15 species. Among the species represented, the total number of introducing is 984 specimens (68 % of the total number). The age gradations of the riverfront tree species coincide with the historical periods of planting: Czechoslovakian (70-90 years), Soviet (30-50 years), and modern (5-25 years). Most of the trees on the riverfronts, even those that have been growing since their planting, have not yet reached the limit of their biological age and have a good or satisfactory condition. The analysis revealed the need for a number of measures to improve the riverfronts in order to improve the existing landscapes and enhance their recreational properties.

Effect of pH, light intensity, and fertilizers on acclimatization of endangered rooted plantlets Malus niedzwetzkyana for restoration in nature

Malus niedzwetzkyana is an endemic, endangered, and valuable plant species. To conservation Malus niedzwetzkyana in nature, it is necessary to obtain planting material with a high survival rate. Selection of optimal pH, light intensity, and fertilizers is necessary to obtain high survival rate during the adaptation period of microshoots after micropropagation and in vitro culture. For optimization of adaptation condition of in vitro rooted microshoots of M. niedzwetzkyana were used. This work investigated the effect of pH level, light intensity, and fertilizers on the growth parameters of micropropogated microshoots of M. niedzwetzkyana. To select the optimal pH and substrate four types of substrates were studied: neutral peat, acid peat, neutral soil, and acidic soil. In addition, as the artificial light source two lighting conditions were studied: LED phyto tapes (4680 lx) and fluorescent phytolamps (7410 lx). In result, highest survival rate was obtained in treatments using peat or soil at neutral pH and 7410 lx light intensity. Additionally, to acclimatize the plantlets in a greenhouse the fertilizers effects were studied: potassium nitrate, monoammonium phosphate, Special crystallon, ammonium nitrate. Thus, irrigation with the Special Crystallon was an effective treatment for seedlings and substantial growth was observed in the aboveground and underground parts of the plants post transfer to greenhouse conditions. After 4 months the average height of seedlings, the number of shoots, and the crown diameter were 114.42 cm, 25.67, and 61.83 cm, respectively with 90% survival rate of planting material after three years under natural conditions.

Phytochemical Composition of Red-Fleshed Apple Cultivar ‘Baya Marisa’ Compared to Traditional, White-Fleshed Apple Cultivar ‘Golden Delicious’

We analyzed the red-fleshed apple cultivar ‘Baya Marisa’ and compared it with the traditional, white-fleshed apple cultivar ‘Golden Delicious’. The objective of this study was to compare sugars, organic acids, and phenolic compounds of ‘Baya Marisa’ with the widely known and consumed white-fleshed apple cultivar ‘Golden Delicious’. In addition, flesh firmness, color, and soluble solid content was studied. A total of 46 phenolic compounds were quantified and identified, some for the first time in apples. The study showed that the total analyzed phenolic content (TAPC) was 1.6× higher in the skin of red-fleshed ‘Baya Marisa’ and 1.4× higher in the flesh of red-fleshed ‘Baya Marisa’. Organic acid (citric acid, malic acid, and ascorbic acid) content was higher in the red-fleshed cultivar ‘Baya Marisa’, whereas sugar content (sucrose, glucose, and sorbitol) was similar, except for fructose, which was 1.1× higher in ‘Golden Delicious’. The content of citric acid was 1.6× higher in ‘Baya Marisa’, whereas the content of malic acid was 1.2× higher in ‘Baya Marisa’ and the content of ascorbic acid was 2.8× higher in ‘Baya Marisa’. Among phenolics, total dihydrochalcones in the skin were 3.3× higher in ‘Baya Marisa’ and similar in the flesh compared to ‘Golden Delicious’. Flavonols were 1.4× higher in the skin of ‘Baya Marisa’ and 2.8× higher in the flesh of ‘Golden Delicious’. Anthocyanins were not identified in the white-fleshed cultivar ‘Golden Delicious’. Total hydroxycinnamic acids were 2.0× higher in the skin of ‘Golden Delicious’ and similar in the flesh compared to ‘Baya Marisa’. Total flavanols were 1.8× higher in the skin and 2.2× higher in the flesh of the white-fleshed cultivar ‘Golden Delicious’.

MdMKK9-Mediated the Regulation of Anthocyanin Synthesis in Red-Fleshed Apple in Response to Different Nitrogen Signals.

The mitogen-activated protein kinase (MAPK) signaling cascade is a widely existing signal transduction system in eukaryotes, and plays an important role in the signal transduction processes of plant cells in response to environmental stress. In this study, we screened MdMKK9, a gene in the MAPK family. This gene is directly related to changes in anthocyanin synthesis in the ‘Daihong’ variety of red-fleshed apple (Malus sieversii f neidzwetzkyana (Dieck) Langenf). MdMKK9 expression was up-regulated in ‘Daihong’ tissue culture seedlings cultured at low levels of nitrogen. This change in gene expression up-regulated the expression of genes related to anthocyanin synthesis and nitrogen transport, thus promoting anthocyanin synthesis and causing the tissue culture seedlings to appear red in color. To elucidate the function of MdMKK9, we used the CRISPR/Cas9 system to construct a gene editing vector for MdMKK9 and successfully introduced it into the calli of the ‘Orin’ apple. The MdMKK9 deletion mutants (MUT) calli could not respond to the low level of nitrogen signal, the expression level of anthocyanin synthesis-related genes was down-regulated, and the anthocyanin content was lower than that of the wild type (WT). In contrast, the MdMKK9-overexpressed calli up-regulated the expression level of anthocyanin synthesis-related genes and increased anthocyanin content, and appeared red in conditions of low level of nitrogen or nitrogen deficiency. These results show that MdMKK9 plays a role in the adaptation of red-fleshed apple to low levels of nitrogen by regulating the nitrogen status and anthocyanin accumulation.

MdJa2 Participates in the Brassinosteroid Signaling Pathway to Regulate the Synthesis of Anthocyanin and Proanthocyanidin in Red-Fleshed Apple.

Anthocyanin and proanthocyanidin play important roles in plant secondary metabolism. Although previous studies identified many transcription factors involved in anthocyanin and proanthocyanidin synthesis, the effects of MADS-box transcription factors are unclear in apple. Brassinosteroids (BRs) are steroid hormones that affect plant flavonoid biosynthesis, but the underlying regulatory mechanism is not yet well established. In this study, we identified a MADS-box transcription factor, MdJa2, which contained a highly conserved MADS-box domain and belonged to the STMADS11 subfamily. Additionally, MdJa2 was responsive to BR signal, and the overexpression of MdJa2 inhibited the synthesis of anthocyanin and proanthocyanidin. The silencing of MdJa2 in “Orin” calli promoted anthocyanin and proanthocyanidin accumulations. Moreover, MdJa2 interacted with MdBZR1. MdJa2 was revealed to independently regulate anthocyanin and proanthocyanidin synthesis pathways. The MdJa2–MdBZR1 complex enhanced the binding of MdJa2 to the promoters of downstream target genes. Our research provides new insights into how MADS-box transcription factors in the BR signaling pathway control the accumulations of anthocyanin and proanthocyanidin in red-fleshed apple.

Comparative Evaluation of Juices from Red-Fleshed Apples after Production with Different Dejuicing Systems and Subsequent Storage.

In this work, two vintages (2019 and 2020) of red-fleshed ‘Weirouge’ apples were processed with the innovative spiral filter press technology to investigate juice production in an oxygen-reduced atmosphere. After pressing, a more brilliant red color and appreciably higher amounts of oxidation-sensitive constituents (ascorbic acid, anthocyanins, and colorless (poly)phenols) were seen in spiral filter pressed juices compared to those produced with conventional systems (horizontal filter press and decanter). In a subsequent stability study (24 weeks storage at 4, 20, and 37 °C), the color and phenolic compounds were monitored and differences in the juices produced with the different pressing-systems were widely maintained during the storage period. The analyses of the anthocyanins and colorless (poly)phenols were conducted by UHPLC-DAD-ESI-QTOF-HR-MS/MS and UHPLC-DAD. The spiral filter press emerged as a promising technology for the production of juices with a more attractive color and a better retention of oxidation-sensitive constituents during processing and storage compared to conventional juices.

First Report of Red-Fleshed Apple Anthracnose Caused by Colletotrichum siamense.

The red-fleshed apple (Malus niedzwetzkyana) produces a colored fruit and rich anthocyanins and it has become popular among consumers in Shandong (Yang et al 2020). In recent years, anthracnose diseases have been reported in red-fleshed apple orchards and nurseries in Shandong province, China. The incidence of anthracnose in the red-fleshed apple plantings ranges from 50-90%. Initially, anthracnose lesions on fruit begin as sub-circular shaped, sunken, pale brown. Over time black lesions enlarged and coalesced into large necrotic areas. The sunken centers of mature lesion became filled with slimy pink sporulation. In September 2015, fifteen fruit with anthracnose symptoms and sporulation were collected, and 11 single-spore isolates were obtained. Three representative isolates (JNTW11, JNTW2, JNTW33) were used for morphological and molecular characterization. On PDA, the colonies were initially white and turned into pale brown in three days. Orange-brown pigmentation was produced near the center on the reverse. Aerial mycelium was cottony, dense, pale white to pale gray. Acervuli developed visible orange-pink conidial masses. Conidiophores were colorless, septate, not branched or branched at the base. Conidia were 1-celled, hyaline, subcylindrical, oblong, attenuated with blunt ends, and the average size was 16.7 ± 1.5 × 6.1 ± 0.9 μm (n = 50). Appressoria were brown, obovoid or irregular, 9.2 ± 1.6 × 8.0 ± 1.8 μm (n = 20). The morphological characters matched the descriptions of Colletotrichum gloeosporioides sensu lato (Cannon et al. 2008). Isolates JNTW11, JNTW2, and JNTW33 were subject to bioinformatic characterization by partial sequencing of 6 genetic loci including the ribosomal internal transcribed spacer (ITS), actin (ACT), beta-tub2 (TUB2), calmodulin (CAL), chitin synthase (CHS-1), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) (Weir et al, 2012). The ITS (MT577037, MT577040, MT577042), ACT (MT767712, MT767715, MT767717), TUB2 (MT767723, MT767726, MT767728), CAL (MT767689, MT767692, MT767694), CHS-1(MT767700, MT767703, MT767705), and GAPDH (MT767734, MT767737, MT767739) sequences were deposited in GenBank. The six sets of sequence data were concatenated "ITS-GAPDH-ACT-CHS-1-TUB2-CAL", and the aligned sequences (2,007 bp) had 99.0% similarity to ex-type C. siamense ICMP18578. In a maximum likelihood phylogenetic tree, the highest log likelihood was -9148.55, and the isolates tested were in the C. siamense cluster with 96 % bootstrap support. Thus, the isolates were identified as C. siamense on the basis of multilocus phylogenetic analyses and morphological characters. To complete Koch's postulates, several healthy red-fleshed apple fruit ('Jiuhong', 1 month prior to harvest) were inoculated using colonized and uncolonized hyphal plugs and a blank agar as a control. All inoculated fruit were placed in sterile tissue culture bottles containing 2 layers of wet paper towels at 28 °C under a 12 h light/dark cycle. All fruit developed anthracnose symptoms in 7 days while the controls did not develop any symptoms. The symptoms were similar to those collected from fruit in the field, and same fungus was re-isolated from the lesions. Presently it was known that C. acutatum, C. asianum, C. chrysophilum, C. cuscutae, C. fioriniae, C. fragariae, C. fructicola, C. gloeosporioides, C. godetiae, C. kahawae, C. karstii, C. limetticola, C. melonis, C. noveboracense, C. nymphaeae, C. paranaense, C. rhombiforme, C. salicis, and C. theobromicola could infect M. coronaria, M. domestica, M. prunifolia, M. pumila, and M. sylvestris worldwide. To our knowledge, this is the first report of C. siamense as a pathogen of M. niedzwetzkyana. This finding provides crucial information for the management of anthracnose disease in China.

Phenol metabolic fingerprint and selection of intake biomarkers after acute and sustained consumption of red-fleshed apple versus common apple in humans. The AppleCOR study

The present study aimed to evaluate the metabolism and bioavailability of anthocyanins (ACN) and other phenolics from red-fleshed apple (RFA) and to define the intake biomarkers compared to common white-fleshed apple (WFA). Acute and sustained (6-week) interventions were combined in a randomized, controlled and parallel study with 121 hypercholesterolemic subjects. Another arm consuming ACN-rich infusion from aronia fruit (ARO) provided matched content and profile of ACN. Plasma, urine and faeces samples were analyzed using UPLC-MS/MS. Results showed higher bioavailability of ACN after ARO compared to RFA, showing a clear apple matrix effect. The dihydrochalcone phloretin-2′-O-glucuronide was the most discriminant intake biomarker of both apples. The urinary peonidin-3-O-galactoside was a good biomarker after both ARO and RFA intakes, whereas peonidin-O-arabinoside was reported to be specific from ARO. The elucidation of the phenolic metabolism and the selection of intake biomarkers is a promising approach to relate phenolic compounds and human health.

Red-Fleshed Apples Rich in Anthocyanins and White-Fleshed Apples Modulate the Aorta and Heart Proteome in Hypercholesterolaemic Rats: The AppleCOR Study.

The impact of a red-fleshed apple (RFA) rich in anthocyanins (ACNs), a white-fleshed apple (WFA) without ACNs, and an extract infusion from Aronia fruit (AI) equivalent in dose of cyanidin-3-O-galactoside (main ACN) as RFA was determined by the proteome profile of aorta and heart as key cardiovascular tissues. Hypercholesterolaemic Wistar rats were separated into six groups (n = 6/group; three males and three females) and the proteomic profiles were analyzed using nanoliquid chromatography coupled to mass spectrometry. No adverse events were reported and all products were well tolerated. RFA downregulated C1QB and CFP in aorta and CRP in heart. WFA downregulated C1QB and CFP in aorta and C9 and C3 in aorta and heart, among other proteins. AI downregulated PRKACA, IQGAP1, and HSP90AB1 related to cellular signaling. Thus, both apples showed an anti-inflammatory effect through the complement system, while RFA reduced CRP. Regardless of the ACN content, an apple matrix effect was observed that involved different bioactive components, and inflammatory proteins were reduced.

Accurate Quantification of Anthocyanin in Red Flesh Apples Using Digital Photography and Image Analysis

Red fleshed apples (Malus × domestica Borkh.) differ in colour intensity between cultivars, seasons and sites. The objective of this study was to develop a procedure for predicting anthocyanin content from digital images of flesh discs. Flesh cylinders of uniform colour were excised, scanned and their colours determined in the R, G and B and the L*a*b* colour spaces. Anthocyanin content was also quantified chemically. A calibration line was constructed to predict anthocyanin content of flesh discs of varying colour from a scan or a photograph in the studio or outdoors. Anthocyanin concentration was linearly related to the logarithms of G, B and L*. From these relationships, the anthocyanin content of a flesh disc was predicted, pixel by pixel. Colour corrections were applied using a reference colour chart included in all images. The Finlayson algorithm was most effective for correcting the G parameter obtained by a flatbed scanner. For variable imaging methods (scanning or photography), the Vandermonde algorithm for correcting the L* parameter and the Finlayson algorithm for correcting the G parameter were most effective in predicting anthocyanin content. The procedure allows accurate prediction of anthocyanin content of red fleshed apples from simple colour scans or photographs.

Combined Analysis of Gut Microbiota and Plasma Metabolites Reveals the Effect of Red-Fleshed Apple Anthocyanin Extract on Dysfunction of Mice Reproductive System Induced by Busulfan.

Busulfan is currently an indispensable anti-cancer drug, but the side effects on male reproductive system are so serious. Meanwhile, red-fleshed apples are natural products with high anthocyanin content. In this research, we analyzed the effect of red-fleshed apple anthocyanin extract (RAAE) on busulfan-treated mice. Compared with the busulfan group, main plasma biochemical indicators were significantly improved after RAAE treatment. Compared with BA0 (busulfan without RAAE) group, total antioxidant capacity(T-AOC) and the activity of superoxide dismutase (SOD) and glutathione catalase (GSH-Px) in RAAE treatment groups were obviously increased, while the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly decreased. Malondialdehyde (MDA) was significantly decreased in the RAAE groups. In addition, we found RAAE alleviated busulfan-disrupted spermatogenesis through improving genes expression which are important for spermatogenesis, such as DDX4, PGK2, and TP1. Furthermore, we found that RAAE increased beneficial bacteria Akkermansia and Lactobacillaceae, and significantly depleted harmful bacteria Erysipelotrichia. The correlation studies indicated that RAAE ameliorated busulfan-induced rise in LysoPC levels through regulating gut microbial community and their associated metabolites. In conclusion, this study extends our understanding of the alleviated effect of RAAE on busulfan-induced male reproductive dysfunction through regulating the relationships between gut microbiota and metabolites.

MdMYB10 affects nitrogen uptake and reallocation by regulating the nitrate transporter MdNRT2.4-1 in the red flesh apple.

ABSTRACTNitrate is the major nitrogen source for higher plants. In addition to serving as a nutrient, it is also a signaling molecule that regulates plant growth and development. Although membrane-bound nitrate transporter/peptide transporters (NRT/PTRs) have been extensively studied and shown to regulate nitrate uptake and movement, little is known about how these factors are regulated by the external nitrogen environment. Red-fleshed apple, whose coloration is determined by the transcription factor MdMYB10, had higher nitrate uptake efficiency than non-red-fleshed apple. Nitrate assimilation and utilization were higher in red-fleshed apple cultivars, and comparative transcriptome analysis showed that the expression of genes encoding the NRT2s was increased in red-fleshed apple. In vitro and in vivo experiments showed that MdMYB10 directly bound to the MdNRT2.4-1 promoter to transcriptionally activate its expression, resulting in enhanced nitrate uptake. MdMYB10 also controlled nitrate reallocation from old leaves to new leaves through MdNRT2.4-1. Overall, our findings provide novel insights into the mechanism by which MdMYB10 controls nitrate uptake and reallocation in apple, which facilitates adaptation to a low-nitrogen environment.

Оптимизация факторов, влияющих на адаптацию и рост растений в почвогрунте редкого вида Malus niedzwetzkyana

Planting of a decorative and rare species of wild apple Malus niedzwetzkyana is provided for landscaping of cities. To obtain high-quality planting material, there is wide use of the method of micropropagation. In this study, there were optimized the conditions of adaptation and active growth of micro shoots of Malus niedzwetzkyana in the growth room and greenhouse were obtained by micropropagation. For adaptation, rooted micro shoots were planted in soil with different pH. The results showed that neutralized peat with perlite is the optimal condition for the adaptation of micro-shoots, and KNO3 is the optimal solution for irrigation, where the survival rate was 95%. For further growth in greenhouse conditions, 3 types of fertilizers for irrigation were studied such as carbamide (nitrogen), superphosphate (phosphorus), potassium sulfate (potassium). High survival rate and the greatest increase in all parameters in Malus niedzwetzkyana were obtained by watering with fertilizer with phosphorus. Also, an analysis of the genetic identity between the mother tree and the clones was carried out. SSR analysis using markers Hi04a08, CN444542, Aj000761 showed complete identity between the original tree and the resulting clones. This confirms that micropropagation of Malus niedzwetzkyana is an effective method for obtaining genetically stable, healthy planting material for landscaping.

Flowering features of rare fruit plants of the Rosaceae Juss. family

One of the ways to solve the problem of food security is to increase the proportion of non-traditional crops' fruits in the diet with valuable consumer characteristics and a wide range of application in fruit growing, selection, and greening. The seasonal development rhythm - especially the flowering phase - is important in the study of rare fruit plants introduced into culture as it determines the plants' resistance to adverse environmental factors and the ability to produce full-fledged fruits and seeds. The purpose of this research was to study the flowering characteristics of non-traditional fruit crops of the Rosaceae Juss. family to determine the prospects of their use in selection and greening. From 2012 to 2021, 16 species were studied in the arboretum of the Russian Research Institute of Fruit Crop Breeding (VNIISPK, Orel, Russian Federation). The flowering calendar compiled on the basis of the conducted phenological observations shows various dates of the objects' flowering onset, which makes it possible to use them as ornamental plants when creating parks and gardens of continuous flowering. Chaenomeles Maulei, Malus niedzwetzkyana, Crataegus submollis and Padus virginiana have the most ornamental blossoming. Of these, Chaenomeles Maule has the longest flowering period (more than 20 days). A consistently high flowering degree (4.5-5.0 points) was observed in twelve objects, which determines the prospects of their application in the selection process as sources of certain economically valuable traits: early flowering (Malus prunifolia and Sorbus aria), long-term flowering (Chaenomeles Maulei, Malus prunifolia and Rosa canina), a high ornamental flowering degree (Chaenomeles Maulei, Malus niedzwetzkyana, Crataegus submollis and Padus virginiana).

Оптимизация протокола среднесрочного хранения исчезающего вида Malus niedzwetzkyana

The conservation of biodiversity requires efficient ex situ methods for the storage of plant genetic material outside the natural habitat. This approach allows for the preservation of valuable, endemic, and endangered plant species for a long time. One widely used method is medium-term storage in in vitro culture. In our work, we describe the results of medium-term storage of microclonally propagated shoots of an endangered and endemic species of the Malus niedzwetzkyana. In vitro preservation was realized with the help of osmotic agents in the nutrient medium. For this, there were studied the cultivation conditions such as temperature (4°C and 24°C) and photoperiod (16/8 and growing in the dark), and the composition of nutrient media to slow growth (sucrose, mannitol, PVP, abscisic acid). The research results showed that the optimal condition for medium-term storage of shoots is the QL nutrient medium with the addition of 3% or 6% sucrose under standard conditions (24°C, photoperiod 16/8). The optimized protocol made it possible to preserve Malus niedzwetzkyana explants for 2 months without recultivation. Moreover, the stage of explant recovery was fast, during only one passage.