FruitPhenoBox - a device for rapid and automated fruit phenotyping of small sample sizes.

BACKGROUND: Fruit appearance of apple (Malus domestica Borkh.) is accession-specific and one of the main criteria for consumer choice. Consequently, fruit appearance is an important selection criterion in the breeding of new cultivars. It is also used for the description of older varieties or landraces. In commercial apple production, sorting devices are used to classify large numbers of fruit from a few cultivars. In contrast, the description of fruit from germplasm collections or breeding programs is based on only a few fruit from many accessions and is mostly performed visually by pomology experts. Such visual ratings are laborious, often difficult to compare and remain subjective. RESULTS: Here we report on a morphometric device, the FruitPhenoBox, for automated fruit weighing and appearance description using computer-based analysis of five images per fruit. Recording of approximately 100 fruit from each of 15 apple cultivars using the FruitPhenoBox was rapid, with an average handling and recording time of less than eleven seconds per fruit. Comparison of fruit images from the 15 apple cultivars identified significant differences in shape index, fruit width, height and weight. Fruit shape was characteristic for each cultivar, while fruit color showed larger variation within sample sets. Assessing a subset of 20 randomly selected fruit per cultivar, fruit height, width and weight were described with a relative margin of error of 2.6%, 2.2%, and 6.2%, respectively, calculated from the mean value of all available fruit. CONCLUSIONS: The FruitPhenoBox allows for the rapid and consistent description of fruit appearance from individual apple accessions. By relating the relative margin of error for fruit width, height and weight description with different sample sizes, it was possible to determine an appropriate fruit sample size to efficiently and accurately describe the recorded traits. Therefore, the FruitPhenoBox is a useful tool for breeding and the description of apple germplasm collections.

Zonal Chemical Signal Pathways Mediating Floral Induction in Apple.

Phytohormones that trigger or repress flower meristem development in apple buds are thought to be locally emitted from adjacent plant tissues, including leaves and fruitlets. The presence of fruitlets is known to inhibit adjacent buds from forming flowers and thus fruits. The resulting absence of fruitlets the following season restores flower-promoting signalling to the new buds. The cycle can lead to a biennial bearing behaviour of alternating crop loads in a branch or tree. The hormonal stimuli that elicit flowering is typically referred to as the floral induction (FI) phase in bud meristem development. To determine the metabolic pathways activated in FI, young trees of the cultivar 'Ruby Matilda' were subjected to zonal crop load treatments imposed to two leaders of bi-axis trees in the 2020/2021 season. Buds were collected over the expected FI phase, which is within 60 DAFB. Metabolomics profiling was undertaken to determine the differentially expressed pathways and key signalling molecules associated with FI in the leader and at tree level. Pronounced metabolic differences were observed in trees and leaders with high return bloom with significant increases in compounds belonging to the cytokinin, abscisic acid (ABA), phenylpropanoid and flavanol chemical classes. The presence of cytokinins, namely adenosine, inosine and related derivatives, as well as ABA phytohormones, provides further insight into the chemical intervention opportunities for future crop load management strategies via plant growth regulators.

Self-(in)compatibility in Tunisian apple accessions [Malus domestica. Borkh]: S-genotypes identification and pollen tube growth analysis.

MAIN CONCLUSION: Self-incompatibility studies have revealed a potential use of Tunisian apple resources for crop improvement and modern breeding programs and a likely correlation between the pollen tube growth and flowering period. Apples [Malus domestica. Borkh] exhibit an S-RNase-based gametophytic self-incompatibility (GSI) system. Four primer combinations were used to S-genotype eighteen Tunisian local apple accessions and twelve introduced accessions that served as references. Within the Tunisian local accessions, S2, S3, S7, and S28 S-alleles were the most frequent and were assigned to 14 S-genotypes; among them, S7S28, S3S7, S2S5, and S2S3 were the most abundant. PCA plot showed that population structuring was affected by the S-alleles frequencies and revealed a modern origin of the Tunisian varieties rather than being ancient ones. Nonetheless, the results obtained with 17 SSR markers showed a separate grouping of local Tunisian accessions that calls into question the hypothesis discussed. Pollination experiments showed that the pollen started to germinate within 24 h of pollination but 48 h after pollination in the "El Fessi" accession. The first pollen tubes arrived in the styles within 36 h of pollination in two early flowering accessions known as "Arbi" and "Bokri", and after 72 h of pollination in late flowering "El Fessi" and 48 h after pollination in remaining accessions. The first pollen tube arrests were observed in accessions "Arbi" and "Bokri" within 84 h of pollination, within 108 h of pollination in "El Fessi" and within 108 h of pollination in remaining accessions. In the apple accession called "Boutabgaya," the pollen tubes reached the base of the style within 120 h of pollination without being aborted. Nevertheless, the self-compatible nature of "Boutabgaya" needs more studies to be confirmed. However, our results revealed the malfunction of the female component of the GSI in this accession. To conclude, this work paved the path for further studies to enhance the insight (i) into the relation between the flowering period and the pollen tube growth, (ii) self-compatible nature of "Boutabgaya", and (iii) the origin of the Tunisian apple.

The BTB-BACK-TAZ domain protein MdBT2 reduces drought resistance by weakening the positive regulatory effect of MdHDZ27 on apple drought tolerance via ubiquitination.

Drought stress is one of the dominating challenges to the growth and productivity in crop plants. Elucidating the molecular mechanisms of plants responses to drought stress is fundamental to improve fruit quality. However, such molecular mechanisms are poorly understood in apple (Malus domestica Borkh.). In this study, we explored that the BTB-BACK-TAZ protein, MdBT2, negatively modulates the drought tolerance of apple plantlets. Moreover, we identified a novel Homeodomain-leucine zipper (HD-Zip) transcription factor, MdHDZ27, using a yeast two-hybrid (Y2H) screen with MdBT2 as the bait. Overexpression of MdHDZ27 in apple plantlets, calli, and tomato plantlets enhanced their drought tolerance by promoting the expression of drought tolerance-related genes [responsive to dehydration 29A (MdRD29A) and MdRD29B]. Biochemical analyses demonstrated that MdHDZ27 directly binds to and activates the promoters of MdRD29A and MdRD29B. Furthermore, in vitro and in vivo assays indicate that MdBT2 interacts with and ubiquitinates MdHDZ27, via the ubiquitin/26S proteasome pathway. This ubiquitination results in the degradation of MdHDZ27 and weakens the transcriptional activation of MdHDZ27 on MdRD29A and MdRD29B. Finally, a series of transgenic analyses in apple plantlets further clarified the role of the relationship between MdBT2 and MdHDZ27, as well as the effect of their interaction on drought resistance in apple plantlets. Collectively, our findings reveal a novel mechanism by which the MdBT2-MdHDZ27 regulatory module controls drought tolerance, which is of great significance for enhancing the drought resistance of apple and other plants.

Impact of different storage conditions with combined use of ethylene blocker on 'Shalimar' apple variety.

This research investigates the impact of storage conditions on the quality and preservation of 'Shalimar' apples, a relatively new cultivar known for its resistance to apple scab and powdery mildew. The study explores the efficacy of different storage techniques such as regular atmosphere (RA), controlled atmosphere (CA), and dynamic controlled atmosphere with CO2 Monitoring (DCA-CD), as well as the integration of 1-methylcyclopropene (1-MCP) at different storage temperatures (1 °C and 3 °C). Various fruit quality parameters were monitored under different storage conditions, including firmness, titratable acidity, total soluble solids, background color, respiration, ethylene production, and volatile compounds. The results indicate that the controlled atmosphere (CA) at 1 °C emerges as an efficient method for long-term storage. However, it is noted that CA storage may impact the apple aroma, emphasizing the need for a balance between preservation and consumer acceptability. On the other hand, DCA-CD at variable temperatures (approximately 2.5 °C) offers a promising approach for maintaining fruit quality and a higher concentration of volatile compounds. Integrating 1-MCP enhances firmness, but its impact varies across storage conditions. Principal component analysis (PCA) provides insights into the relationships between storage conditions, fruit quality, and volatile compounds. This study contributes valuable insights into optimizing storage strategies for 'Shalimar' apples, addressing sustainability and quality preservation in apple production.

The Expression of Key Ethylene and Anthocyanin Biosynthetic Genes of 'Honeycrisp' Apples Subjected to the Combined Use of Reflective Groundcovers and Aminoethoxyvinylglycine in the Mid-Atlantic US.

The decreased profitability of important apple cultivars, such as 'Honeycrisp', results from the poor red skin coloration and high fruit drop in the mid-Atlantic US. Apple red skin coloration is determined by the anthocyanin concentration. Reflective groundcovers promote red skin coloration, whereas aminoethoxyvinylglycine (AVG) decreases the ethylene production and fruit drop, thus reducing the coloration. Although our previous study showed that combinations of these practices impact the fruit quality and color, research is lacking regarding their effects at the gene and metabolite levels. In this work, for two years, we compared the differences in the internal ethylene concentration (IEC), red skin coloration, fruit drop, transcript accumulation of key ethylene and anthocyanin biosynthetic pathway-related genes, and total anthocyanin concentration of 'Honeycrisp' apples. The fruit was treated with combinations of reflective groundcover (Extenday) and AVG (130 mg L-1) and was assessed throughout ripening. Extenday-only-treated fruit displayed the highest upregulation of ethylene and anthocyanin biosynthetic-related genes and of total anthocyanins, exceeding 50% blush, while boosting the IEC. In contrast, AVG significantly decreased the expression of key ethylene and anthocyanin biosynthetic-related genes and total anthocyanins, thus preventing apples from reaching 50% blush, while also decreasing the IEC and fruit drop. The combination of Extenday x AVG fine-tuned the transcript accumulation of ethylene and anthocyanin biosynthetic-related genes as well as the total anthocyanins, allowing the 'Honeycrisp' fruit to exceed 50% blush, while increasing the IEC moderately and reducing the fruit drop (as compared to Extenday-only and control), thus enhancing the fruit economic value.

Performance of 'Gala Select' and 'Fuji Suprema' grafted on Geneva series rootstocks under fallow land and replanting conditions in southern Brazil.

Background: Rootstocks less vigorous are among the most crucial management techniques to modernize fruit cultivation. Replanting with fallow land has become necessary due to a lack of land to establish new orchards. Objective: The aim of this study is to determine the effect of various rootstocks of the American Geneva® series on the yield performance of the apple (Malus domestica Borkh) cultivars 'Gala Select' and 'Fuji Suprema' under replanting conditions in southern Brazil. Methods: After two years of fallow land, the experiments were initiated in 2017 and conducted during the 2018, 2019, 2020, and 2021 growing seasons in Painel and Caxias do Sul municipalities at the Santa Catarina and the Rio Grande do Sul State, respectively. The 'Gala Select' and 'Fuji Suprema' were grafted onto the G.202, G.814, G.210, and G.213 Geneva series rootstocks in a tall spindle training system using a randomized complete block design with four replicates. Principal component analysis (PCA) was used to assess the interrelationship among the variable's vigor, productivity, and fruit quality. Results: The PCA result showed significant differences in vigor, productivity, and fruit quality when the G.210 and G.213 and G.814 and G.213 Geneva series rootstocks were used in combination with Gala Select and Fuji Suprema cultivars, respectively. The PCA analysis clustered all cultivar/rootstock combinations into two groups, based on their vigor and productivity and the yield performance and fruit quality data, that differed significantly among combinations and regions. The 'Gala Select'/G.202 and 'Fuji Suprema'/G.213 combinations were less vigorous than the 'Gala Select'/G.210 and 'Fuji Suprema'/G.814 combinations. However, 'Gala Select'/G.210 (semi-dwarfing) and G.213 (dwarfing) are the combinations with high yield performance, productive efficiency and fruit quality, being more reliable to the producer, and less vigorous, resulting in lower labor costs under replating conditions, with two years of fallow land, from 2018 until 2021 growing seasons.

Impact of Cultivation and Storage Conditions on Total Mal d 1 Content and Isoallergen Profile in Apples.

The allergen Mal d 1 is often responsible for adverse allergic reactions to fresh apples in northern and central Europe. The Mal d 1 content and isoallergen profile are proposed to have an impact on the allergenic potential of the fruit. Therefore, we investigated the impact of the cropping system on the Mal d 1 content and the isoallergen profile of apples by mass spectrometry for the varieties 'Jonagored' and 'Topaz'. To monitor the impact of storage time and conditions, apples of the varieties 'Santana' and 'Jonagold' were stored for up to 12 weeks under regular air (RA), under RA in combination with 1-methylcyclopropene (1-MCP) treatment, and under a controlled atmosphere (CA). The impact of the cropping system (integrated production vs organic production) was negligible. However, a significant increase in the Mal d 1 content during storage was observed, being higher when stored under CA conditions than under RA conditions. An additional treatment with 1-MCP prior to RA storage drastically reduced the level of Mal d 1 expression in the flesh of the apples by ∼50%. Furthermore, the content of isoallergens 1.03 and 1.06 increased disproportionately under CA conditions, while under RA conditions, only isoallergen 1.06 was affected. With the 1-MCP treatment, no changes in the isoallergen profile were obvious.

Use of HPLC-MS to Determine the Loss of Metabolites in Apple Juices under Different Storage Conditions.

The focus of this experiment was to compare the color and metabolic profile of apple juice from the red-fleshed cultivar 'Baya Marisa' with the white-fleshed cultivar 'Golden Delicious'. The changes in the phenolic compounds, organic acids, and sugar content during high-temperature short-time pasteurization and after one year of storage under different storage conditions were analyzed. A total of 26 individual phenolic compounds were identified and quantified. The total analyzed phenolics content (TAPC) decreased after pasteurization of the juices of both cultivars. The TAPC of fresh 'Baya Marisa' juice after pasteurization increased or remained the same compared to one-year stored 'Baya Marisa' juice, depending on the storage method. The sucrose content of the apple juice of both cultivars remained the same after pasteurization; interestingly, it decreased significantly after one year of storage, while the fructose and glucose content remained the same after pasteurization and increased significantly after one year of storage for both cultivars.

LC-Q-TOF-MS/MS data of phyllobilins in apple peels cv. 'Gala' during ripening under shelf-life conditions.

During senescence and ripening, higher plants degrade the green pigment chlorophyll to linear tetrapyrrols, referred to as phyllobilins (PBs). This dataset provides chromatograms and mass spectral data of PBs acquired from methanolic extracts of cv. Gala apple peels at five different shelf life (SL) stages. Data were obtained using a (ultra-high) pressure liquid chromatograph (UHPLC) coupled to high resolution quadrupole-time of flight-mass spectrometer (HRMS-Q-TOF). A data-dependent inclusion list (IL) ex professo containing all known masses of PBs was applied to address PBs, and fragmentation patterns were studied to confirm their identity operating a MS2 method. Mass accuracy was set to 5 ppm for parent ion peaks, this parameter was adopted as inclusion criterium. The detection of PBs' appearance during ripening can be helpful for assessing the quality and maturity of the apples.

Influence of cultivar and fertilization treatment on the yield and leaf nutrients content of apple (Malus domestica Borkh.).

Fertilisation strategy can have a big impact on apple (Malus domestica Borkh) yield, with considerable environmental and economic implications. This research paper presents the yield and leaf nutrients content of three apple cultivars fertilised with three treatment regimes over 2 years (2020-202) in Bosnia and Herzegovina. The specific apple cultivars investigated were: Jonagold Decosta, Red Idared and Gala Schnitzer®Schniga, each fertilised with three treatments: T1 (control‒without fertilization); T2 (300 kg ha-1 NPK (6:18:36) + 150 kg/ha N (calcium ammonium nitrate‒CAN)) and T3 (foliar nutrition‒mixture organic-mineral fertilizer commercially named "FitoFert Kristal" (0.6%) (10:40:10) + "FitoFert Kristal" (0.6%) (20:20:20) + "FoliFetril Ca" (0.5%) (N:Ca)) in Bosnia and Herzegovina in the period of two years (2020-2021). Significant differences of different yield categories (yield per tree, yield per hectare and yield efficiency) were found among cultivar/treatment combinations, cultivars, treatments and years. Yield per tree, yield per hectare and yield efficiency were lowest in cultivar Jonagold DeCosta. Fertilization treatment T1 significantly influenced the lowest yield per tree and yield per hectare with the magnitudes 7.55 kg tree-1 and 27.96 t ha-1, respectively. The highest yield efficiency was found in trees fertilised with treatment T3 with 9.21 55 kg tree-1, 34.11 96 t ha-1 and yield efficiency of 0.25 kg cm-2. Six mineral elements in the apple leaf, such as boron (B), calcium (Ca), manganese (Mn), iron (Fe), potassium (K), and zinc (Zn), were presented in known magnitudes. The cultivar Jonagold DeCosta's leaves had the highest K, B, and Zn contents with 8500.8 mg kg-1 FW (i.e. fresh weight of leaves), 33.8 mg kg-1 FW, and 12.2 mg kg-1 FW, respectively, while cultivar Red Idared's leaves had the highest Ca, Fe, and Mg contents. The fertilisation treatment T3 influenced significantly the highest content of Ca (301.37 mg kg-1 FW), Fe (116.5 mg kg-1 FW), B (41.6 mg kg-1 FW), Mn (22.4 mg kg-1 FW), and Zn (14.9 mg kg-1 FW) in leaves, while the highest content of K was found in leaves from trees fertilised with treatment T2 (8130.5 mg kg-1 FW). The experimental outcomes have proven that the cultivar/treatment combinations, cultivars, treatments, and time duration (in years) are the key factors affecting the potassium, calcium, iron, boron, and manganese contents. It was concluded that the foliar application enables easier mobility of elements, which results in a greater number of fruits and larger fruits, which leads to a higher yield. This study is the first of its kind in Bosnia and Herzegovina, and the findings of this research will pave the way for future research activities involving increasing the number of cultivars and different fertilisation treatments on apple yield and leaf mineral composition.

[Effect of Soil Contamination on the Reflective Properties of Reflective Groundcovers]. / Einfluss der Verschmutzung von Reflexionsfolien auf ihr Reflexionsverhalten.

The objective of the present work was to study the effects of contamination on the reflective properties of groundcovers used for enhancing fruit colouration in the orchard. Contamination also affects longevity and possible sustainable re-use of materials. A white, woven textile (polypropylene Lumilys™) and silver aluminium foil were experimentally contaminated with soil, similar to the situation after an autumn storm in a fruit orchard. Clean material served as control.Using a spectrophotometer (StellarNet; Tampa, FL, USA), vertically directed (0°) and diffuse (45°) light reflection in the range of 500-850 nm was compared from clean and contaminated groundcover in the laboratory. Reflection from vertically directed aluminium foil exceeded that of Lumilys™; however, the highest reflection in all spectral measurements was at 45° (diffuse) from the clean woven textile, i.e., in all directions, and exceeded that of aluminium foil. In contrast, the contaminated vertically directed (0°) aluminium foil reflected less light than the clear foil but, surprisingly, reflected much more light at 45° than the clean foil. Both materials showed reflection peaks at 625-640 nm; light spectra and peaks remained unchanged irrespective of soil contamination.Light reflection in the visible range (PAR, 400-700 nm) was concomitantly measured in the field at CKA Klein-Altendorf near Bonn (50°N), Germany, at 0.5 m and 1 m height using a portable TRP­3 light sensor (PP-Systems, Amesbury, MA, USA) on sunny and cloudy days at a solar angle of 49°. Surprisingly, in these field measurements, Lumilys and aluminium foil reflected most light in both directions (0° and 45°) when slightly to moderately contaminated. Only with heavy contamination did the reflection decrease. Both groundcovers reflected more light than the grass in alleyways of fruit orchards or open soil under the trees.UV­B reflection (280-315 nm) was examined in parallel in the field using an X1 optometer (Gigahertz Optik, Türkenfels, Deutschland), as it enhances anthocyanin biosynthesis and red fruit colouration in combination with PAR and low temperature. Straight (0°) UV­B reflection from aluminium foil exceeded that from white woven textile (Lumilys™) on both clear and overcast autumn days. As expected, straight (0°) UV­B reflection from aluminium foil decreased with soil contamination to a certain extent, but it unexpectedly increased from the woven textile with soil contamination.Surface roughness in dependence of contamination was measured non-destructively by a profilometer type VR5200 (Keyence, Osaka, Japan). The roughness index, Sa, increased from 22 to 28 µm with soil contamination of the woven textile and from to 2 to 11 µm with aluminium foil, possibly explaining differences in the observed reflectivity.Overall, the expected severe decline in light reflection (PAR and UV-B) was not seen. In contrast, light (2-3 g soil/m2) and moderate (4-12 g soil/m2) contamination improved light reflection of PAR (400-700 nm) and UV­B (280-315 nm) by woven textile (Lumilys™) and aluminum foil. Thus, with slight contamination the materials can be reused, whereas severe contamination (24-51 g soil/m2) reduces light reflection.

Using HPLC-MS/MS to Determine the Loss of Primary and Secondary Metabolites in the Dehydration Process of Apple Slices.

The aim of this study was to compare peeled and unpeeled dehydrated apple slices of the red-fleshed 'Baya Marisa' and the white-fleshed 'Golden Delicious', to analyze the difference in the content of sugars, organic acids, and phenolic compounds during the heat process of dehydration, and to compare it with our previous study on fresh apples of the same cultivar. The purpose of these study was to see how many primary and secondary metabolites are lost in the dehydration process to better understand what is ingested by consumers in terms of nutritional value. A total of 30 phenolic compounds were identified and quantified, some of them for the first time. The total analyzed phenolic content (TAPC) of the unpeeled dehydrated apple slices was 1.7 times higher in 'Golden Delicious' than in 'Baya Marisa'. The unpeeled dehydrated apple slices of 'Golden Delicious' had higher total hydroxycinnamic acid (2.7×) and dihydrochalcone (1.2×) content. The peeled dehydrated apple slices of 'Baya Marisa' had higher total dihydrochalcone (2.2×) and total flavanol (2.2×) content compared to 'Golden Delicious'. The content of citric and malic acids was higher in the unpeeled and peeled dehydrated apple slices of 'Baya Marisa', compared to 'Golden Delicious'. The content of ascorbic acid was higher in the unpeeled (1.6×) and peeled (1.8×) dried apple slices of 'Baya Marisa'. The content of fructose and glucose was 1.4 times higher in the unpeeled dried apple slices of 'Golden Delicious'.

Apple (Malus domestica Borkh) leaves attenuate indomethacin-induced gastric ulcer in rats.

Malus domestica Borkh, the apple tree, exhibited numerous pharmacological properties including antioxidant, neuroprotective, anti-inflammatory, anticancer and antimicrobial activities. The present work aimed to annotate the secondary metabolites from a butanol fraction of apple leaves (BLE), evaluate the gastro-protective and healing effects of this fraction against indomethacin-induced gastric ulcers in rats and to identify its mechanism of action. BLE (100, and 200 mg/kg) was orally administered in rats as an acute treatment against indomethacin-induced gastric ulcer in comparison with famotidine as reference anti-ulcer drug. The stomachs of rats were collected to determine the ulcer index, the preventive ratio, measure the activity of glutathione peroxidase (GPx), and estimate the expression of cyclooxygenase-2 (COX-2), and heat shock protein 70 (HSP70). Furthermore, we evaluated both inflammatory and oxidative stress markers in the gastric tissues. We also performed histopathological study of gastric mucosa using H&E stain and periodic Schiff base stain to evaluate both gastric injury scores and gastric mucus content respectively. Pretreatment with BLE markedly lowered the severity of gastric injury induced by indomethacin, decreased oxidative stress, inflammatory cytokines, and COX-2 expression in the examined gastric tissues. The gastric healing effect of BLE was associated with increased mucoglycoproteins, and HSP70 expression. Additionally, gastric healing effect of high dose of BLE was superior to that of famotidine in decreasing gastric injury scores, COX-2, inflammatory cytokines, lipid peroxidation and in increasing gastric mucin content, HSP70, and reduced glutathione. These findings indicate that BLE is effective in accelerating ulcer healing by boosting HSP70 expression, and decreasing COX-2 expression, oxidative stress, and gastric inflammation which might be related to the presence of 21 phytoconstituents.

Field study of the fire-blight-resistant cisgenic apple line C44.4.146.

Cisgenesis, the genetic modification of a plant with genes from a sexually compatible plant, was used to confer fire blight resistance to the cultivar 'Gala Galaxy' by amendment of the resistance gene FB_MR5, resulting in the line C44.4.146. To verify whether cisgenesis changed other tree-, flower- or fruit-related traits, a 5-year field trial was conducted with trees of C44.4.146 and multiple control genotypes, including members of the 'Gala' sports group. None of the 44 investigated tree-, flower- or fruit-related traits significantly differed between C44.4.146 and at least one of the control genotypes in all observation years. However, fruits of C44.4.146 and its wild-type 'Gala Galaxy' from tissue culture were paler in color than fruits of 'Gala Galaxy' that had not undergone tissue culture. There was no significant and consistently detected difference in the fruit flesh and peel metabolome of C44.4.146 compared with the control genotypes. Finally, the disease resistance of C44.4.146 was confirmed also when the fire blight pathogen was inoculated through the flowers. We conclude that the use of cisgenesis to confer fire blight resistance to 'Gala Galaxy' in C44.4.146 did not have unintended effects, and that the in vitro establishment of 'Gala Galaxy' had a greater effect on C44.4.146 properties than its generation applying cisgenesis.

Strigolactone regulates adventitious root formation via the MdSMXL7-MdWRKY6-MdBRC1 signaling cascade in apple.

Propagation through stem cuttings is a popular method worldwide for species such as fruit tree rootstocks and forest trees. Adventitious root (AR) formation from stem cuttings is crucial for effective and successful clonal propagation of apple rootstocks. Strigolactones (SLs) are newly identified hormones involved in AR formation. However, the regulatory mechanisms underpinning this process remain elusive. In the present study, weighted gene co-expression network analysis, as well as rooting assays using stable transgenic apple materials, revealed that MdBRC1 served as a key gene in the inhibition of AR formation by SLs. We have demonstrated that MdSMXL7 and MdWRKY6 synergistically regulated MdBRC1 expression, depending on the interactions of MdSMXL7 and MdWRKY6 at the protein level downstream of SLs as well as the direct promoter binding on MdBRC1 by MdWRKY6. Furthermore, biochemical studies and genetic analysis revealed that MdBRC1 inhibited AR formation by triggering the expression of MdGH3.1 in a transcriptional activation pathway. Finally, the present study not only proposes a component, MdWRKY6, that enables MdSMXL7 to regulate MdBRC1 during the process of SL-controlled AR formation in apple, but also provides prospective target genes to enhance AR formation capacity using CRISPR (i.e. clustered regularly interspaced short palindromic repeats) technology, particularly in woody plants.

Antifatigue Effects of the Aqueous Extracts of Myrtle Berries, Apple and Clove: An Animal Study.

Background: Fatigue is one of the most prevalent symptoms, increasing worldwide with no specific medication for fatigue. Iranian traditional medicine (ITM), or Persian medicine, is a reliable source for discovering natural medicine for diseases and their symptoms. Myrtus communis L. (Myrtle), Malus domestica Borkh. (Apple), and Syzygium aromaticum (L.) Merr. & L. M. Perry (Clove) have been utilized as brain and heart tonics in ITM. Based on ITM, cardiac tonics decrease fatigue by enhancing heart function and increasing blood flow to tissues. These plants, particularly myrtle berries, have been utilized as potent enlivening agents that reduce mental fatigue. Objectives: This study aims to investigate the effects of aqueous extracts of these plants on weight-loaded forced swimming (WLFS) tests and three doses of aqueous myrtle extract in an animal model of chronic sleep deprivation-induced fatigue. Methods: Five groups of rats (n = 6) were evaluated: Sham, control, apple-treated, clove-treated, and myrtle-treated groups. After 28 days of treatment, the WLFS test was performed, and swimming time was recorded. Subsequently, central fatigue was induced in rats by chronic sleep deprivation for 21 days. Five groups of rats (n = 6) were evaluated: Sham, control (sleep-deprived, which received water), and three sleep-deprived + treatment groups, which received aqueous myrtle extract (350, 700, and 1000 mg/kg). An open field test on the 20th day and a WLFS test on the 21st day were performed. Results: The myrtle berries significantly increased glucose, reduced lactate dehydrogenase (LDH) levels, and enhanced swimming time. Fatigue caused by chronic sleep deprivation increased malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and LDH while decreased superoxide dismutase (SOD), glucose, and swimming time. In all treatment groups, SOD levels and swimming time were increased, whereas MDA, IL-1ß, and TNF-α levels were decreased significantly. Only the 1000 mg/kg dose significantly reduced LDH levels (P < 0.001). The treatment significantly improved the velocity and the total distance moved in the open-field test. Conclusions: According to the results, the myrtle berries reduced fatigue in two animal models, probably due to its phenolic compounds, flavonoids, and polysaccharides.

Apple Antioxidant Properties as an Effect of N Dose and Rate-Mycorrhization Involvement: A Long-Term Study.

The genetic and/or the agronomic approaches are two main ways to enhance concentrations of biologically active compounds in fruits and vegetables. In this study, the apple antioxidant status was evaluated from the second to the fourth year after planting in relation to an increasing N-dose applied-with or without plant microbial inoculation in the field conditions. Cultivar 'Sampion Arno' was selected to test these relationships. In the growing season, N treatment and inoculation effects were monitored for the apple peel total phenolics and selected individual phenolic compounds ((+)-catechin, (-)-epicatechin, chlorogenic and caffeic acids, rutin and phloridzin) and total ascorbate concentration. Additionally, as an environmental stress marker measurement of glutathione reductase, ascorbate peroxidase and catalase activity were conducted. The year effect was most pronounced, while the N or applied inoculum effects were much weaker. Great differences in antioxidative enzyme activity and phenolic concentrations between years were revealed. Nitrogen fertilization reduced the fruit's global phenolic accumulation compared to the control, but the N-effect varied depending on individual phenolic compounds, N dose and N application method. None of the tested factors influenced the ascorbate concentration. There was a certain tendency to increase antioxidant properties in the control group (without mineral N fertilization) but with the application of bio-fertilizer, which may seem promising for future research in this scope.

Isolation and characterization culturable microbes on the surface of 'Granny Smith' apples treated with electrolyzed water during cold storage.

Response of culturable microbes on the surface of apples treated with slightly alkaline electrolyzed water (SAIEW) is largely unexplored. Thus, the aim of this study was to characterize culturable microbes on the surface of SAIEW treated 'Granny Smith' apples using conventional and molecular approach. Results showed that SAIEW treatments and storage duration influenced culturable microbes isolated from the surface of 'Granny Smith' apples stored at 5 °C for 21 days. Enterobacterial repetitive intergenic consensus (ERIC-PCR) analysis distinctively identified 27 groups of bacteria from 56 plate isolates. Using random amplified polymorphic DNA (RAPD-PCR) typing and RAPD1283 primers, 10 distinct band patterns were identified from 30 fungal isolates. Sequencing of 16S rRNA and intergenic spacer (ITS1 and ITS4) region, identified eight bacteria and four fungi, respectively, to species level. Study showed that SAIEW treatment inhibited growth of Staphylococcus epidermidis, S. capitis, Ochrobactrum soli, and Aspergillus inuii on the surface apples during storage. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01148-2.

Metabolic Pathways for Observed Impacts of Crop Load on Floral Induction in Apple.

The triggers of biennial bearing are thought to coincide with embryonic development in apple and occurs within the first 70 days after full bloom (DAFB). Strong evidence suggests hormonal signals are perceived by vegetative apple spur buds to induce flowering. The hormonal response is typically referred to as the floral induction (FI) phase in bud meristem development. To determine the metabolic pathways activated in FI, young trees of the biennial bearing cultivar 'Nicoter' and the less susceptible cultivar 'Rosy Glow' were forced into an alternate cropping cycle over five years and an inverse relationship of crop load and return bloom was established. Buds were collected over a four-week duration within 70 DAFB from trees that had maintained a four-year biennial bearing cycle. Metabolomics profiling was undertaken to determine the differentially expressed pathways and key signalling molecules associated with biennial bearing. Marked metabolic differences were observed in trees with high and low crop load treatments. Significant effects were detected in members of the phenylpropanoid pathway comprising hydroxycinnamates, salicylates, salicylic acid biosynthetic pathway intermediates and flavanols. This study identifies plant hormones associated with FI in apples using functional metabolomics analysis.