Advances in Mineral Nutrition Transport and Signal Transduction in Rosaceae Fruit Quality and Postharvest Storage

Study on the Bioactive Constituent and Mineral Elements of the Tibetan Medicine E'seguo from Different Regions of Ganzi Prefecture, China

The Tibetan medicinal fruit E'seguo originates from two species, Malus toringoides (Rehd.) Hughes and Malus transitoria (Batal.) Schneid, both unique to the Hengduan Mountains. These species are predominantly found in high-altitude regions of Ganzi Prefecture, Sichuan Province, particularly in the Xianshui River and Yalong River basins. Malus toringoides (Rehd.) Hughes is far more abundant in both resource quantity and distribution compared to Malus transitoria (Batal.) Schneid. However, the nutritional and medicinal differences between the two remain unclear, which significantly impacts the development and utilization of E'seguo resources. This study aimed to measure the mineral content, nutritional components, and medicinal properties of E'seguo from 12 different regions of Ganzi Prefecture to explore the quality differences between these two species and across different regions. ICP-MS (Inductively Coupled Plasma Mass Spectrometry) was used to determine the mineral content, ultraviolet-visible spectrophotometry and potentiometric titration to analyze nutritional indicators, and HPLC (High-Performance Liquid Chromatography) to measure the medicinal components L-malic acid and 2-O-β-D-glucopyranosyl-L-ascorbic acid (AA-2βG). Results indicate that Malus transitoria (Batal.) Schneid contains higher levels of K, Ca, Zn, Mg, and Cu compared to Malus toringoides (Rehd.) Hughes, which has higher Fe and Mn content. Malus toringoides (Rehd.) Hughes from the Kangding and Litang regions showed the highest mineral content, with mineral elements primarily influencing polysaccharide levels, according to Mantel analysis. Nutritional and medicinal analyses revealed that Malus toringoides (Rehd.) Hughes outperformed Malus transitoria (Batal.) Schneid in all metrics except for the sugar-acid ratio. Given the mineral content and taste, Malus transitoria (Batal.) Schneid is better suited for consumption, while Malus toringoides (Rehd.) Hughes has superior medicinal properties, making it more appropriate for medicinal use. In the Malus transitoria (Batal.) Schneid regions, both Luhuo and Daofu are in the Xianshui River basin, with Daofu County producing the higher quality fruit. Among the nine Malus toringoides (Rehd.) Hughes regions, the M10 (Tuoba Township, Ganzi County) near the Yalong River had the highest overall score, followed by M7 (Yade Township, Luhuo County) and M6 (Keke, Xiala Tuo Town, Luhuo County), both of which are near the Xianshui River. In summary, Malus transitoria (Batal.) Schneid generally has higher mineral content, but Malus toringoides (Rehd.) Hughes has larger fruit and higher medicinal value, making the latter more suitable as a medicinal resource. At the same time, the medicinal quality of Xianshui River fruit was higher in the two watersheds of Malus toringoides (Rehd.) Hughes.

PbbHLH155 enhances iron deficiency tolerance in pear by directly activating PbFRO2 and PbbHLH38

Iron (Fe) deficiency is a general stress for many horticulture crops, causing leaf chlorosis and stunted growth. The basic-helix-loop-helix (bHLH) transcription factor (TF) was reported to function in Fe absorption; however, the regulatory mechanism of bHLH genes on iron absorption remains largely unclear in pear. In this study, we found that PbbHLH155 was significantly induced by Fe deficiency. Overexpression of PbbHLH155 in Arabidopsis thaliana and pear calli significantly increases resistance to Fe deficiency. The PbbHLH155-overexpressed Arabidopsis lines exhibited greener leaf color, higher Fe content, stronger Fe chelate reductase (FCR) and root acidification activity. The PbbHLH155 knockout pear calli showed lower Fe content and weaker FCR activity. Interestingly, PbbHLH155 inhibited the expressions of PbFRO2 and PbbHLH38, which were positive regulators in Fe-deficiency responses (FDR). Furthermore, yeast one-hybrid (Y1H) and Dual-Luciferase Reporter (DLR) assays revealed that PbbHLH155 directly binds to the promoters of PbFRO2 and PbbHLH38, thus activating their expression. Overall, our results showed that PbbHLH155 directly promote the expression of PbFRO2 and PbbHLH38 to activate FCR activity for iron absorption. This study provided valuable information for pear breeding.

Profiling of Metabolites in Organically Grown Plums from Norway: Does Location or Cultivar Matter?

The aim of this work was to investigate the influence of two locations and seven cultivars on the profiling of metabolites in organically grown plums (Prunus domestica L.) fruit in Norway. P, K, and Ca were most abundant in the studied fruits, while Ba and Sr formed a clear line between the locations. The most abundant sugars were glucose, fructose, sucrose, and sorbitol, which together accounted for up to 97.00%. Quinic acid and malic acid were the predominant organic acids, while chlorogenic acid, rutin, and kaempferol-3-O-glucoside were the most abundant polyphenols. Plums from Ullensvang were characterized by a higher content of minerals, sugars, organic acids, total polyphenol content (TPC), and radical scavenging activity (RSA), while plums from Telemark had a higher content of quantified polyphenols. The cultivar 'Mallard' had the highest mineral and radical scavenging activity, 'Opal' had the sweetest fruit, 'Jubileum' had the highest acidity, 'Excalibur' had the highest TPC content, and 'Valor' stored the highest content of quantified polyphenols, especially chlorogenic acid. These results provide comprehensive information on the chemical profiles of selected plum cultivars, suggesting that organic plums are a rich source of beneficial compounds that can have a positive impact on human health.

A comparison of the mineral element content of 70 different varieties of pear fruit (Pyrus ussuriensis) in China

Background

Pyrus ussuriensis (Maxim.) is a unique pear tree that grows in northern China. The tree has strong cold resistance and can withstand low temperatures from -30 °C to -35 °C. Due to its unique growth environment, its fruit is rich in minerals and has much higher levels of minerals such as K, Ca and Mg than the fruit of Pyrus pyrifolia (Nakai.) and Pyrus bretschneideri (Rehd.) on the market, and many say the ripe fruit tastes better than other varieties. A comprehensive analysis of the characteristics of mineral elements in the fruits of different varieties of P. ussuriensis will provide a valuable scientific basis for the selection, breeding and production of consumer varieties of P. ussuriensis, and provide a more complete understanding of nutritional differences between fruit varieties.

Methods

In this study, 70 varieties of wild, domesticated and cultivated species of P. ussuriensis from different geographical locations were compared. Targeting four main mineral elements and eight trace mineral elements contained in the fruit, the differences in mineral content in the peel and pulp of different varieties of P. ussuriensis were analyzed, compared and classified using modern microwave digestion ICP-MS.

Results

The mineral elements in the fruit of P. ussuriensis generally followed the following content pattern: K > P > Ca > Mg > Na > Al > Fe > Zn > Cu > Cr > Pb > Cd. The mineral element compositions in the peel and pulp of different fruits were also significantly different. The four main mineral elements in the peel were K > Ca > P > Mg, and K > P > Mg > Ca in the pulp. The mineral element content of wild fruit varieties was higher than that of cultivated and domesticated varieties. Correlation analysis results showed that there was a significant positive correlation between K, P and Cu in both the peel and pulp of P. ussuriensis fruit (P < 0. 01). Cluster analysis results showed that the 70 varieties of P. ussuriensis could be divided into three slightly different categories according to the content of the peel or pulp. According to the contents of the fruit peel, these varieties were divided into: (1) varieties with high Na, Mg, P, K, Fe and Zn content, (2) varieties with high Ca content and (3) varieties with medium levels of mineral elements. According to the fruit pulp content, these varieties were divided into: (1) varieties with high Mg, P and K content, (2) varieties with low mineral element content, and (3) varieties with high Na and Ca content. The comprehensive analysis of relevant mineral element content factors showed that 'SSHMSL,' 'QYL,' 'SWSL' and 'ZLTSL-3' were the best varieties, and could be used as the focus varieties of future breeding programs for large-scale pear production.

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 'Šampion 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.

Plant Growth and Fruit Nutrient Changes in Carica papaya L. Genotypes Subjected to Regulated Deficit Irrigation

The current genotypes of Carica papaya L. cultivated worldwide are considered relatively tolerant or sensitive to drought conditions, depending specifically on the cultivar features and the severity of water shortage. In this work an experimental field was established by subjecting “Intenzza” and “Siluet” to the following water regimes: Control (“CT”), plants irrigated at field capacity (100%); Moderate Deficit Irrigation (“MDI”, watered at 66%); and Severe Deficit Irrigation (“SDI”, watered at 50%). The results indicated that water deficit decreases leaf number leading to a decline of total leaf area, being “Intenzza” equally affected by “SDI” and “MDI”, whereas in “Siluet” the major decrease was induced by “SDI”. Regarding fruit development, in “Intenzza”, “MDI” and “SDI” did not affect fruit number except two dates (120 and 202 DAT), decreased fruit fresh weight (FW), and increased total soluble solutes (TSS) levels, while in “Siluet” only “SDI” reduced fruit FW and watering systems did not change TSS, suggesting a better performance of this cultivar under “MDI”. In addition, drought did not impair fruit mineral concentrations excepting in few dates, and in such cases stressed fruits accumulated a slight minor or even major concentration of some nutrients than control, maintaining consequently suitable organoleptic quality.

Improving Peach Fruit Quality Traits Using Deficit Irrigation Strategies in Southern Tunisia Arid Area

The peach (Prunus persica L.) is one of Tunisia’s major commercial fruit crops and is considered one of the biggest water consumers of all crops. In warm and arid areas of southern Tunisia, irrigation is necessary to ensure orchard longevity and high yield and fruit quality. Nevertheless, under water-scarcity conditions and low water quality, water management should rely on efficient deficit irrigation strategies. In this study, sustained deficit irrigation (DI) and partial root-zone drying (PRD50) at 50% of crop evapotranspiration (ETc) were evaluated for their impact on the primary and secondary metabolites of the peach fruit of early cultivar Flordastar grown in the Tataouine region. A full irrigation (FI) treatment at 100%, etc., was used as a control treatment. Color, dry-matter content, firmness, organic acids, sugars, phenolic compounds, vitamin C, β-carotene and minerals were assessed on harvested mature fruits. Dry-matter content and firmness increased significantly under DI and PRD50 (13% and 15.5%). DI fruit had the highest soluble-solid content (SSC), reaching Brix values of 14.3°. Fruit sorbitol and sucrose contents were not affected by Di and PRD50. Higher glucose in fruit juice was observed in PRD50 (23%) and DI (21.5%) compared to FI, which had the highest malic acid content (33.5–37%). Quinic and citric acids decreased with DI and PRD50, while almost all individual phenolic compounds increased with deficit irrigation. Hydroxycinnamates and anthocyanins were significantly higher in fruits harvested from DI and PRD50 treatments. Proanthocyanidins (catechin and epicatechin) were only improved by DI, while flavone compounds and vitamin C were not affected by irrigation restrictions. β-carotene was higher in fruits yielded under FI (0.71 mg/100 g DM) than DI and PRD50 (0.21–0.43 mg/100 g DM). Macro- and micronutrients significantly increased in DI and PRD50 fruit. A significant difference between DI and PRD50 fruits was observed for Zn and Fe concentrations. This research highlights the positive impact of reduced irrigation on bioactive-fruit quality attributes and the suitability of PRD50 and DI as tools for irrigation management in arid areas of southern Tunisia, contributing to water-saving in orchards and the improvement of fruit commercial value.

Effect of Harvesting in Different Ripening Stages on the Content of the Mineral Elements of Rosehip (Rosa spp.) Fruit Flesh

Studies on the mineral content of different rosehip species/cultivars during the ripening period are very limited. Therefore, the objective of this research was to evaluate the content and composition of the mineral elements of two species and two rosehip cultivars growing on an organic farm. The rosehip fruits were harvested at different ripening stages, five time per season. Mineral composition (K, Ca, Mg, P, Fe, Na, Ti, Cu, B, Mn, Al, Zn, Cr, Co, Ni, As, Mo, Cd and Pb) was analyzed by means inductively coupled plasma mass spectrometry (ICP–MS). The results showed that the ripening stage and species/cultivars had an effect on the contents of the mineral elements. Significantly, the highest content of mineral elements was determined at ripening stage I (Ca, Mg, Ti, Mn, Al and Cr) and IV (K, P, Fe, Cu and B). Species of the Rosa canina accumulated the highest content of mineral elements. Correlation analysis showed that the hue angle had a positive and very strong relationship with six mineral elements: K (r = 0.909), Ca (r = 0.962), Mg (r = 0.965), P (r = 0.945), Fe (r = 0.929) and Ti (r = 0.944).

Pulp Mineral Content of Passion Fruit Germplasm Grown in Ecuador and Its Relationship with Fruit Quality Traits

There are several species of passion fruit grown in South America. However, there is a lack of information about the mineral content in their pulp. Thus, the objective of the present research was to determine the mineral content in the pulp of different germplasms of passion fruit [Passiflora edulis f. flavicarpa (INIAP 2009 and P10), P. alata (Sweet passion fruit), P. edulis f. edulis (Gulupa) and Passiflora sp. (Criollo POR1 and Criollo PICH1)] grown in Ecuador and to determine their relationship with relevant fruit quality traits. The results showed that high Mg content was associated with less peel thickness, soluble solids was negatively related to K and B content, and vitamin C was negatively related to S content. INIAP 2009 had high titratable acidity and fruit weight but low N and Na; P10 showed the highest contents of N, K, Na, Mn and fruit weight but less P, Mg, and Fe; sweet passion fruit showed high S, Zn, Cu, soluble solids, and peel thickness but low K, Ca, B, and titratable acidity; Gulupa had high Mg, B, and Zn but low S, Fe, and Mn; Criollo POR1 showed high N and Fe but low Zn; and Criollo PICH1 showed high P, Ca, Mg, and Cu but low soluble solids and peel thickness. These results provide additional information on passion fruit germplasm grown in Ecuador and constitutes a reference for further breeding programs.

Bioaccumulation of metals, total phenolic and flavonoid contents and antioxidant activity of Rumex acetosella L. from tailings in Žitkovac (Kosovo & Metohija)

The aim of this study was to determine the bioaccumulation of the metals in Rumex acetosella L. collected from the tailings of abandoned mine in Žitkovac (near Kosovska Mitrovica, Kosovo and Metohija), and to establish the possibility of using those plants for medicinal purposes. Concentrations of heavy metals (Mn, Fe, Pb, Ni, Cr, Cu, Cd, Zn, Ca and Mg) in soil, roots and aboveground parts of R. acetosella were determined by wet mineralization with nitric and perchloric acid. The results of the research indicate that R. acetosella accumulates large amounts of Ni, Cu, Pb, Zn, Cr, and Mn. The total phenol content, the total amount of flavonoids and the antioxidant activity of three different extracts of the root and aboveground parts of R. acetosella were determined by spectrophotometric methods. The acetone extracts contain the highest concentration of phenols and flavonoids. Ethyl acetate has proven to be a solvent that releases the least amount of phenols and flavonoids. The methanol extract of aboveground parts has the highest, while acetone root extract has the lowest antioxidant activity. Rumex acetosella can be used for medicinal purposes, but only collected from uncontaminated soil.

Authentication of Transylvanian Spirits Based on Isotope and Elemental Signatures in Conjunction with Statistical Methods

The potential association between stable isotope ratios of light elements and mineral content, in conjunction with unsupervised and supervised statistical methods, for differentiation of spirits, with respect to some previously defined criteria, is reviewed in this work. Thus, based on linear discriminant analysis (LDA), it was possible to differentiate the geographical origin of distillates in a percentage of 96.2% for the initial validation, and the cross-validation step of the method returned 84.6% of correctly classified samples. An excellent separation was also obtained for the differentiation of spirits producers, 100% in initial classification, and 95.7% in cross-validation, respectively. For the varietal recognition, the best differentiation was achieved for apricot and pear distillates, a 100% discrimination being obtained in both classifications (initial and cross-validation). Good classification percentages were also obtained for plum and apple distillates, where models with 88.2% and 82.4% in initial and cross-validation, respectively, were achieved for plum differentiation. A similar value in the cross-validation procedure was reached for the apple spirits. The lowest classification percent was obtained for quince distillates (76.5% in initial classification followed by 70.4% in cross-validation). Our results have high practical importance, especially for trademark recognition, taking into account that fruit distillates are high-value commodities; therefore, the temptation of “fraud”, i.e., by passing regular distillates as branded ones, could occur.

Essential Role of Potassium in Apple and Its Implications for Management of Orchard Fertilization

K (K) is of paramount importance for apple (Malus × domestica Borkh.), not only for tree growth and development but also for the size and quality of fruit yield. The apple plant's demand for K varies, along with the progression of phenological phases, during the growing season. The K demand peaks during ripening of fruits featuring relatively high concentration of K comparable to that of the leaves. The mainstream method of apple tree K fertilization is through application of the fertilizer to the soils to improve K uptake by the roots. The bioavailability of K depends on assorted various factors, including pH, interaction with other nutrients in soil solution, temperature, and humidity. An important role in making the K from soil available for uptake by plants is played by plant growth-promoting microorganisms (PGPM), and the specific role of the PGPM is discussed. Advantages of fertigation (the combination of irrigation and fertilization) as an approach include allowing to balance application rate of K fertilizer against its variable demand by plants during the growing season. Excess K in the soil leads to competitive inhibition of calcium uptake by plants. The K-dependent deficiency of Ca leads to its predominant channeling to the leaves and hence to its decline in fruits. Consequently, the apple fruits affected by the K/Ca imbalance frequently develop physiological disorders in storage. This emphasizes the importance of the balanced K application, especially during the last months of the growing season, depending on the crop load and the actual K demand. The potential use of modern approaches to automated crop load estimation through machine vision for adjustment of K fertilization is underlined.

Nutritional Diversity and Antioxidant Activity of Two Indigenous Quince Ecotypes from Rawalakot, Azad Jammu and Kashmir

Quince fruit is mostly used to produce functional products. Recently, the value of this crop has increased due to demand as industrial raw material. The state of Azad Jammu and Kashmir and specifically Rawalakot, District Poonch, is blessed with climatic conditions which are very much suitable for quince production, and therefore, a huge plantation could be found in wild. In this regard, this study was designed to collect two different accessions of quince (apple-shaped quince (ASQ) and pear-shaped quince (PSQ)) from three different locations (Dhamni (elevation: 5431 ft), Shamsabad (elevation: 5374 ft), and Drake (elevation: 3378 ft)) of Rawalakot, District Poonch, and analyze their physicochemical and mineral nutrients of fruit and the soil. Correlation coefficients were established pairwise. Results showed that physicochemical nutrients were significantly ( $P\le 0.05$ ) higher in ASQ fruits as compared with PSQ fruits. Further, fruits collected from location at higher elevation (Dhamni) showed better results as compared with fruits collected from lower elevations. Moreover, increased amount of nitrogen contents in the soil resulted in increased fruit weight. Similarly, fruit quality indices and bioactive compounds showed a positive correlation with the increased soil nutrient contents. These prediction models for quality of quince could be useful in guiding plant nutrition status and for enhancing fruit production in this region.