Eriobotrya Japonica Lindl Research Articles

UPLC/HR-ESI-MS/MS and GC/MS profiling of Eriobotrya japonica L. fruit in correlation to its antioxidant, anti-inflammatory, and anti-arthritic effects.

Eriobotrya japonica Lindl. (Loquat) fruit is a subtropical edible fruit originally from China. It grows well in Egypt, but it is not widely known. In the current study, the fruit was extracted with 80% ethanol to get the total ethanol extract (TEE). A part of which was fractionated by dichloromethane to yield polar and nonpolar fractions (PF and NPF). The antioxidant and anti-inflammatory activities of the TEE were in vitro evaluated. The complete Freund's adjuvant (CFA) arthritis model was used to explore the in vivo biological assessment of the anti-arthritic properties in vivo of the TEE, PF, and NPF of the fruit. Additionally, the inspected limbs detached from all animals were subjected to histological inspection. Moreover, GC/MS analysis of the unsaponifiable (USF) and saponifiable (SF) fractions of the NPF was performed. Furthermore, 64 metabolites from various chemical classes were identified using UHPLC/HR-MS/MS analysis of the TEE of the fruit in both positive and negative ionization modes. The positive ionization mode of loquat fruit allowed for the first time the detection of two kinds of lyso-glycerophospholipids (Lyso-GPLs): lyso-glycerophosphoethanolamines (Lyso-PtdEtn) and lyso-glycerophosphocholines (Lyso-PtdCho). The fruit extracts exhibited a notable in vivo anti-arthritic activity by decreasing paw thickness in the treated rats and adjusting the inflammatory mediators. The TEE showed the highest anti-arthritic activity, followed by the PF that showed an observed activity, while the NPF exhibited the lowest activity. Histopathological findings showed a marked improvement in the arthritic condition of the excised limbs. Thus, E. japonica fruit may be considered as a promising natural antioxidant and anti-arthritic agent.

Genomic Survey of LRR-RLK Genes in Eriobotrya japonica and Their Expression Patterns Responding to Environmental Stresses.

The impact of global warming is increasing and thus exacerbating environmental stresses that affect plant yield and distribution, including the Eriobotrya japonica Lindl (Loquat tree). Eriobotrya japonica, a member of the Rosaceae family, is valued not only for its nutritious fruit but also for its medicinal purposes, landscape uses, and other pharmacological benefits. Nonetheless, the productivity of Eriobotrya japonica has raised a lot of concern in the wake of adverse environmental conditions. Understanding the characteristics of the LRR-RLK gene family in loquat is crucial, as these genes play vital roles in plant stress responses. In this study, 283 LRR-RLK genes were identified in the genome of E. japonica that were randomly positioned on 17 chromosomes and 24 contigs. The 283 EjLRR-RLK proteins clustered into 21 classes and subclasses in the phylogenetic analysis based on domain and protein arrangements. Further explorations in the promoter regions of the EjLRR-RLK genes showed an abundance of cis-regulatory elements that functioned in growth and development, phytohormone, and biotic and abiotic responses. Most cis-elements were present in the biotic and abiotic responses suggesting that the EjLRR-RLK genes are invested in regulating both biotic and abiotic stresses. Additional investigations into the responses of EjLRR-RLK genes to abiotic stress using the RT-qPCR revealed that EjLRR-RLK genes respond to abiotic stress, especially heat and salt stresses. Particularly, EjapXI-1.6 and EjapI-2.5 exhibited constant upregulation in all stresses analyzed, indicating that these may take an active role in regulating abiotic stresses. Our findings suggest the pivotal functions of EjLRR-RLK genes although additional research is still required. This research aims to provide useful information relating to the characterization of EjLRR-RLK genes and their responses to environmental stresses, establishing a concrete base for the following research.

EjCBF3 conferred cold-resistance through the enhancement of antioxidase activity in loquat (Eriobotrya japonica Lindl.)

Low-temperature is a serious threat to production of plants, and cold damage of loquat (Eriobotrya japonica Lindl.) reduces fruit yield tremendously. C-Repeat Binding Factors (CBFs) are known to work as core regulators for cold adaption in plants. However, loquat EjCBFs and their mechanism for cold tolerance have not been identified. In this study, 3 EjCBFs were discovered from loquat using genome-wide searching strategy, which were candidates responding to low-temperature stress supported by analysis of conserved domains and cis-elements in promoters. The greatest up-regulation was shown on EjCBF3 both in loquat leaves and young fruits subjected to low-temperature treatment. EjCBF3 was located in the cell nucleus of Nicotiana benthamiana (N. benthamiana), and its transcriptional activation activity was verified in yeast. Transient over-expression of EjCBF3 alleviated chilling injury through the increase of antioxidase peroxidase (POD) and superoxide dismutase (SOD) activity in N. benthamiana, and the removal of H2O2 with the application of scavenger attenuated cold damage in loquat leaves. Higher survival rate and lower electrolyte leakage were found in Arabidopsis thaliana (A. thaliana) treated with low-temperature stress with the over-expression (OE) of EjCBF3. Furthermore, the induction of cold-regulated genes (CORs) including COR15A, COR47, COR78, and KIN1 were greater in OE plants than that of wild type (WT) suffering cold stress. Results provide new insights into the cold tolerance of loquat and a novel cold-resistant gene, EjCBF3, for loquat breeding.

Effect of Application of a Cactus Pear Mucilage-Based Edible Coating Enriched with Glycerol and L-Glutamine on Minimally Processed White-Flesh Loquats

Loquat (Eriobotrya japonica Lindl.), a non-climacteric fruit, is susceptible to physical and mechanical damage, as well as decay, especially after minimal processing, resulting in a short postharvest lifespan The objective of our study was to evaluate the impact of a cactus pear (OFI) mucilage-based edible coating enriched with glycerol and l-glutamine on the quality and nutraceutical value of minimally processed white-flesh Martorana loquat fruits during cold storage. After washing and processing the cladodes, mucilage was extracted, and two different coatings (EC1: 60% OFI mucilage, 40% glycerol; EC2: 67% OFI mucilage, 30% glycerol, 3% glutamine) were formulated and compared with an untreated sample (CTR). Our analyses covered various parameters, including color, total soluble solid content, titratable acidity, antioxidant activity, and total phenols. Additionally, sensory analysis was conducted and visual scores were obtained. The results suggest that the application of a cactus pear mucilage-based edible coating, supplemented with glycerol and L-glutamine, effectively preserves the quality attributes of minimally processed loquat fruits.

Loquat and its phytochemical potential: A promising application in food technology

AbstractThis review study highlights the importance of loquat (Eriobotrya japonica Lindl.) in terms of its nutritional, pharmaceutical, and nutraceutical value. The entire plant, including its seeds, leaves, flowers, fruits, and peel, contains a wide range of bioactive compounds, such as phenolics, carotenoids, triterpenic acids, and organic acids. These compounds exhibit a wide range of beneficial properties such as fighting cancer, reducing inflammation, managing diabetes, combating viruses, preventing mutations, inhibiting nitrosamine formation, killing harmful microorganisms, lowering blood sugar levels, inducing cell death, and protecting the liver. The extraction and separation of such compounds will greatly enhance and expand its potential. Furthermore, the waste generated from the seeds and peel can be effectively used for submerged and solid state biomass production.

Multi-parameter joint analysis of the quality of honey

The antioxidant activity of honey is mainly evaluated based on its phenolic acid and total flavonoid content, while other parameters are not considered important. The purpose of this study is to comprehensively evaluate the impact of honey's physicochemical indicators and the altitude of the collection site on its quality. This study measured physical and chemical indicators in Dalbergia hainanensis Merr. et Chun honey (DH), blueberry honey (BH), Eriobotrya japonica Lindl. honey (EH), and Rhus chinensis Mill. honey (RH) and then combined them to comprehensively analyze the influencing factors of honey's antioxidant capacity using correlation analysis, principal component analysis (PCA), and regression analysis. The results showed that the 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS+) clearance ability of DH (17.60 ± 4.61 mg/ml) was significantly better than the other three varieties of honey (p <0.05). The results of the correlation analysis showed that the IC50 of the ABTS+ clearance rate was significantly negatively correlated with total flavonoid, Vitamin B1 (VB1), and Vitamin C (VC) content, as well as the a* and b * values, while positively correlated with elevation. The PCA results showed that the principal components (PCs) with eigenvalues exceeding 1 explained 86.28% of the variation. The IC50 of the ABTS+ clearance rate and altitude play an essential role in PC1, suggesting that two indicators are important in distinguishing different honeys. The regression analysis showed that total flavonoid and Vitamins B1 and C content, as well as elevation, are indispensable parameters affecting the antioxidant properties of honey. These results provide a reference method for evaluating the quality of honey from different places and altitudes.

Effect of Swietenia macrophylla king and Eriobotrya japonica lindl on clinic biochemistry of hyperglycemic Vistar rats

The anti-hyperglycemic activity in ethanolic extracts of mahogany seeds (Swietenia macrophylla king) and medlar leaves (Eriobotrya japonica lindl) have shown to be promising candidates for use in patients with type 2 Diabetes Mellitus due to their high hypoglycemic capacity. In this study, the nutritional composition of the plant material used and a comparison of the effect of ethanolic extracts of mahogany seeds (Swietenia), medlar leaves (Eriobotrya), and metformin on biochemical parameters of hyperglycemic Wistar rats were evaluated. Regarding the nutritional composition, it was found that loquat leaves have a high content of dietary fiber (35 g/100 g bs); while mahogany seed has a good amount of protein (19 %) and lipids (71 %). Swietenia was effective in controlling biochemical parameters of hyperglycemic rats, but at a lower level than metformin. In contrast, Eriobotrya reduced the glucose content, to values without significant differences from the control group in healthy rats. However, the content of cholesterol, triglycerides, and urea; as well as alanine aminotransferase activity, was lower in rats treated with Eriobotrya. In conclusion, both plants are an alternative to control biochemical parameters at normal levels in hyperglycemic individuals.

Transcriptome and biochemical analyses reveal phenolic compounds-mediated flavor differences in loquat (Eriobotrya japonica Lindl.) cultivars Chunhua No.1 and Dawuxing

The novel loquat cultivar ‘Chunhua No.1′ (CH1) is a promising commercial cultivar. However, CH1 has texture characteristics different from those of common loquat, and its formation mechanism remains unclear. Here, we first identified the phenolic compounds of CH1 and its parent (‘Dawuxing’, DWX) and the effect on texture formation. The special presence of stone cells explained the flavor differences in CH1. Chlorogenic acid, neochlorogenic acid, and coniferyl alcohol were the main phenolic compounds in loquat, and the high content of coniferyl alcohol was a potential factor for the rough texture of CH1. Transcriptome reveals that phenylpropanoid metabolism was activated during CH1 fruit texture formation. Kyoto Encyclopedia of Genes and Genomes (KEGG) identified 51 structural genes involved in phenylpropanoid biosynthesis, and Weighted Gene Co-expression Network Analysis (WGCNA) identified four structural genes and 88 transcription factors. These findings provide new insights into the phenolic metabolism and flavor formation of loquat fruit.

Functional Evaluation of Loquat (Eriobotrya japonica Lindl.) Flower Water Extracts and Its Potential Use in Tea

In traditional Chinese medicine, loquat leaves have been commonly used to relieve cough and expectoration. Recently, it has been proved that loquat fruit, kernels, leaves, and flowers can be used as herbal medicines to prevent cardiovascular diseases, cancer, inflammation, and other chronic diseases. This study extracted the loquat flowers (LF) at different temperatures and times to prepare the LF water extract (LFWE). In addition, the antioxidant activity and anti-inflammatory performance of LF extract were evaluated. Moreover, the potential of developing sugar-free LF tea was evaluated. The results showed that the LFWE with a temperature above 80°C and heating for 60 min had a higher content of bioactive compounds, which was significantly different compared with other extraction conditions (p<0.05); antioxidant ability trial results showed the performance of the same trend (p<0.05). However, LFWE was not toxic to cell viability, and the amount of PGE2 production was significantly lower than that of the induced group (p<0.05), thus considerably inhibiting the production of PGE2, a marker of inflammation and effectively reducing inflammatory responses. The LF tea prepared at 90°C for different times (15, 30, 45, and 60 min) showed a significant decrease in L∗ value as the extraction time increased significantly to darkness. In addition, the sensory evaluation results revealed that the overall acceptability scores of LF tea extracted for 45 min were the highest, and there was a significant difference (p<0.05). Hence, LF is one of the good products for functional beverages and foods.

Dynamic Changes of Phenolic Composition, Antioxidant Capacity, and Gene Expression in 'Snow White' Loquat (Eriobotrya japonica Lindl.) Fruit throughout Development and Ripening.

The newly released 'Snow White' (SW), a white-fleshed loquat (Eriobotrya japonica Lindl.) cultivar, holds promise for commercial production. However, the specifics of the phenolic composition in white-fleshed loquats, along with the antioxidant substances and their regulatory mechanisms, are not yet fully understood. In this study, we examined the dynamic changes in the phenolic compounds, enzyme activities, antioxidant capacity, and gene expression patterns of SW during the key stages of fruit development and ripening. A total of 18 phenolic compounds were identified in SW, with chlorogenic acid, neochlorogenic acid, and coniferyl alcohol being the most predominant. SW demonstrated a stronger antioxidant capacity in the early stages of development, largely due to total phenolics and flavonoids. Neochlorogenic acid may be the most significant antioxidant contributor in loquat. A decline in enzyme activities corresponded with fruit softening. Different genes within a multigene family played distinct roles in the synthesis of phenolics. C4H1, 4CL2, 4CL9, HCT, CCoAOMT5, F5H, COMT1, CAD6, and POD42 were implicated in the regulation of neochlorogenic acid synthesis and accumulation. Consequently, these findings enhance our understanding of phenolic metabolism and offer fresh perspectives on the development of germplasm resources for white-fleshed loquats.

Cardioprotective study of Eriobotrya japonica leaf extracts against carbon tetrachloride induced toxicity in rats

The Rosaceae family includes the evergreen subtropical tree known as Eriobotrya japonica Lindl (loquat). To test the effect of several E. japonica leaf extracts on shielding the heart from carbon tetrachloride (CCl4) cytotoxic effects, we employed carbon tetrachloride (CCl4), a highly toxic chemical, to cause cardiotoxicity in rats. The heart function enzymes that were examined were lactate dehydrogenase (LDH) and Creatine Kinase. When compared to both the hazardous and normal groups, it was discovered that the protective dose of ethyl acetate extract (200 mg/Kg) and aqueous extract (100 and 200 mg/Kg) lowered the cardiac indicators. Total protein, malondialdehyde (MDA), and non-protein sulfhydryls (NP-SH) indicators were used to assess myocardial oxidative stress. Rats pretreated with ethyl acetate (200 mg/Kg) and aqueous extract (100 and 200 mg/Kg) showed higher levels of total protein than the control group. When compared to the silymarin group, all of the loquat leaf extracts examined in this study increased the amount of the MDA enzyme. The data also demonstrated that, when compared to the results from the normal group, aqueous extract (100 and 200 mg/Kg) enhanced the amount of NP-SH. The histopathology showed that administration of all loquat leaf extracts at doses of (100 mg/kg, 200 mg/kg) before CCl4 intoxication greatly reduced the modifications that were exhibited by CCl4 and preserved cardiac muscles that were very equivalent to those of normal control. Based on the aforementioned data, we deduced that loquat leaf aqueous extract provided the highest protection for heart tissue against the effects of CCl4 intoxication. Through chemical examination of the methanolic extract, four flavonoids were extracted and identified. Their structures were found to be kaempferol-3-O-rhamnoside 1, quercetin-3-O-rhamnoside 2, quercetin-3,7 di-O-glycerides 3, and roseoside 4.

Genome-Wide Characterization of MADS-box Genes Identifies Candidates Associated with Flower and Fruit Development in Loquat (Eriobotrya japonica Lindl.)

The MADS-box transcription factors have garnered substantial attention due to their crucial involvement in various biological processes, particularly in flower organogenesis. A comprehensive investigation into the MADS-box genes remains lacking in loquat (Eriobotrya japonica Lindl.). In the current study, to preliminarily explore the potential candidate genes related to flower and fruit development, a genome-wide analysis was carried out to identify and characterize the MADS-box gene family in loquat. Among the 125 identified EjMADS-box members, 49 genes belonged to type Ⅰ, which were subsequently assigned to three subfamilies: Mα (25 genes), Mβ (10 genes), and Mγ (14 genes). Additionally, 76 genes fell under type II, which were categorized into two groups: MIKCC (70 genes) and MIKC* (6 genes). Through the collinearity analysis and comparison of the gene numbers between loquat and other Rosaceae genomes, it was revealed that the type Ⅱ MADS-box members were expanded in Maloideae after a whole genome duplication. The gene expression analysis utilizing various tissues during flower development revealed that the expression patterns of the ABCDE model homologs were conserved in loquat. In addition, several candidate genes potentially involved in flower bud differentiation (EjMADS107/109) and fruit expansion (EjMADS24/46/49/55/61/67/77/86) were identified. This analysis could serve as a fundamental basis for investigating the molecular functions of the MADS-box genes in the development of flowers as well as fruits in loquat.

Insights into the volatile flavor and quality profiles of loquat (Eriobotrya japonica Lindl.) during shelf-life via HS-GC-IMS, E-nose, and E-tongue

Loquat fruits are among the most popular Chinese fruits because of their unique taste and aroma. The quality profiles of these fruits during 18 days of shelf-life at 20 °C were elucidated by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS), E-nose, and E-tongue. During shelf-life period, the properties and variations of 43 (20 aldehydes, 7 esters, 6 ketones, 1 alcohol, and 1 furan) volatile flavored compounds were determined by GC-IMS, which showed that the contents of methyl 3-methyl butanoate, ethyl acetate, and dimethyl ketone gradually decrease with prolonged shelf-life time, while (E)-2-heptenal, heptanal, (E)-2-pentenal, 1-penten-3-one 3-pentanone and 2-pentylfuran increase. The PCA based on the signal intensity of GC-IMS and E-nose, revealed that loquat fruits are well distinguished at different shelf-life times. The taste profile alternates as the storage time increases, along with higher pH, and lower amounts of total soluble solids, vitamin C, and total phenolics. The visual plots of GC-IMS, E-nose, and E-tongue had good consistency, and they characterized the aroma characteristics of loquat fruits well during different shelf-life periods. The findings of this research provide a useful understanding of the flavors of loquat fruits during their prolonged shelf-life, and a potential research basis for advancements in the loquat industry.

Warm temperature during floral bud transition turns off EjTFL1 gene expression and promotes flowering in Loquat (Eriobotrya japonica Lindl.)

The Rosaceae family includes several deciduous woody species whose flower development extends over two consecutive growing seasons with a winter dormant period in between. Loquat (Eriobotrya japonica Lindl.) belongs to this family, but it is an evergreen species whose flower bud initiation and flowering occur within the same growing year. Vegetative growth dominates from spring to late summer when terminal buds bloom as panicles. Thus, its floral buds do not undergo winter dormancy until flowering, but a summer heat period of dormancy is required for floral bud differentiation, and that is why we used loquat to study the mechanism by which this summer rest period contributes to floral differentiation of Rosaceae species. As for the deciduous species, the bud transition to the generative stage is initiated by the floral integrator genes. There is evidence that combinations of environmental signals and internal cues (plant hormones) control the expression of TFL1, but the mechanism by which this gene regulates its expression in loquat needs to be clarified for a better understanding of its floral initiation and seasonal growth cycles. Under high temperatures (>25ºC) after floral bud inductive period, EjTFL1 expression decreases during meristem transition to the reproductive stage, and the promoters of flowering (EjAP1 and EjLFY) increase, indicating that the floral bud differentiation is affected by high temperatures. Monitoring the apical meristem of loquat in June-August of two consecutive years under ambient and thermal controlled conditions showed that under lower temperatures (<25ºC) during the same period, shoot apex did not stop growing and a higher EjTFL1 expression was recorded, preventing the bud to flower. Likewise, temperature directly affects ABA content in the meristem paralleling EjTFL1 expression, suggesting signaling cascades could converge to refine the expression of EjTFL1 under specific conditions (Tª<25ºC) during the floral transition stage.

Exogenously applied zinc improves sugar-acid profile of loquat (Eriobotrya japonica Lindl.) by regulating enzymatic activities and expression of their metabolism-related genes

Soluble sugars and organic acids are the most abundant components in ripe fruits, and they play critical roles in the development of fruit flavor and taste. In this study, loquat trees were sprayed with 0.1, 0.2 and 0.3% zinc sulphate. The contents of soluble sugars and organic acids were determined using HPLC-RID and UPLC-MS, respectively. The activities of key enzymes involved in sugar-acid metabolism were measured and expression profiling of related genes was done using RT-qPCR. The results revealed that 0.1% zinc sulphate was a promising treatment among other Zn applications with respect to the increased levels of soluble sugars and decreased acid contents in loquats. Correlation analysis showed that the enzymes i.e., SPS, SS, FK, and HK were may be involved in the regulation of fructose and glucose metabolism in the fruit pulp of loquat. While, the activity of NADP-ME showed negative and NAD-MDH showed a positive correlation with malic acid content. Meanwhile, EjSPS1-4, EjSS2-4, EjHK1-3, and EjFK1-6 may play an important role in soluble sugar metabolism in the pulp of loquat fruits. Similarly, EjPEPC2, EjPEPC3, EjNAD-MDH1, EjNAD-MDH3-5, EjNAD-MDH6 and EjNAD-MDH13 may have a vital contribution to malic acid biosynthesis in loquat fruits. This study provides new insights for future elucidation of key mechanisms regulating soluble sugars and malic acid biosynthesis in loquats.

EjFAD8 Enhances the Low-Temperature Tolerance of Loquat by Desaturation of Sulfoquinovosyl Diacylglycerol (SQDG).

Loquat (Eriobotrya japonica Lindl.) is an evergreen fruit tree of Chinese origin, and its autumn-winter flowering and fruiting growth habit means that its fruit development is susceptible to low-temperature stress. In a previous study, the triploid loquat (B431 × GZ23) has been identified with high photosynthetic efficiency and strong resistance under low-temperature stress. Analysis of transcriptomic and lipidomic data revealed that the fatty acid desaturase gene EjFAD8 was closely associated with low temperatures. Phenotypic observations and measurements of physiological indicators in Arabidopsis showed that overexpressing-EjFAD8 transgenic plants were significantly more tolerant to low temperatures compared to the wild-type. Heterologous overexpression of EjFAD8 enhanced some lipid metabolism genes in Arabidopsis, and the unsaturation of lipids was increased, especially for SQDG (16:0/18:1; 16:0/18:3), thereby improving the cold tolerance of transgenic lines. The expression of ICE-CBF-COR genes were further analyzed so that the relationship between fatty acid desaturase and the ICE-CBF-COR pathway can be clarified. These results revealed the important role of EjFAD8 under low-temperature stress in triploid loquat, the increase expression of FAD8 in loquat under low temperatures lead to desaturation of fatty acids. On the one hand, overexpression of EjFAD8 in Arabidopsis increased the expression of ICE-CBF-COR genes in response to low temperatures. On the other hand, upregulation of EjFAD8 at low temperatures increased fatty acid desaturation of SQDG to maintain the stability of photosynthesis under low temperatures. This study not only indicates that the EjFAD8 gene plays an important role in loquat under low temperatures, but also provides a theoretical basis for future molecular breeding of loquat for cold resistance.

Forest Plant Water Utilization and the Eco-Hydrological Regulation in the Karst Desertification Control Drainage Area

Subtropical forests in southwestern karst areas are the top priority for ecosystem restoration, as studying the water absorption strategies of the major plants in these regions is crucial to determining the species distribution and coexistences within these seasonal subtropical forests, which will help us to cope with the forest ecosystem crisis under future climate change. We used the stable isotope ratios (δD and δ18O) of tree xylem and soil water to assess the seasonal changes in the water use patterns and hydrological niche separations of four dominant tree species in seasonal subtropical forests in southwestern karst areas. The results showed that the soil water’s isotopic composition varied gradiently in the vertical direction and that the variation of the soil water’s isotopic composition was greater in the shallow layer than in its depths. Juglans regia (HT) mainly depended on soil water at a depth of 30–60 cm (41.8 ± 6.86%) and fissure water (32.5 ± 4.21%), while Zanthoxylum bungeanum Maxim (HJ) and Eriobotrya japonica Lindl (PP) had the same water use pattern. In the dry season, HT competed with HJ and PP for water resources, and in the rainy season, HJ and PP competed with Lonicera japonica (JYH), while HJ competed with PP all the time. JYH and HT were in a separate state of hydrologic niche and they did not pose a threat to each other. Coexisting trees are largely separated along a single hydrological niche axis that is defined by their differences in root depth, which are closely related to tree size. Our results support the theory of hydrological niche isolation and its potential responses in relation to drought resistance. This study provides a method for determining more efficient plant combinations within karst forest vegetation habitats and its results will have important implications for ecosystem vegetation restoration.

Postharvest Biology and Technology of Loquat (Eriobotrya japonica Lindl.)

Loquat (Eriobotrya japonica Lindl.) fruit is a rich source of carotenoids, flavonoids, phenolics, sugars, and organic acids. Although it is classified as a non-climacteric fruit, susceptibility to mechanical and physical bruising causes its rapid deterioration by moisture loss and postharvest decay caused by pathogens. Anthracnose, canker, and purple spot are the most prevalent postharvest diseases of loquat fruit. Cold storage has been used for quality management of loquat fruit, but the susceptibility of some cultivars to chilling injury (CI) consequently leads to browning and other disorders. Various techniques, including cold storage, controlled atmosphere storage, hypobaric storage, modified atmosphere packaging, low-temperature conditioning, heat treatment, edible coatings, and postharvest chemical application, have been tested to extend shelf life, mitigate chilling injury, and quality preservation. This review comprehensively focuses on the recent advances in the postharvest physiology and technology of loquat fruit, such as harvest maturity, fruit ripening physiology, postharvest storage techniques, and physiological disorders and diseases.

Physiological, Morphological, and Biochemical Responses of Soybean [Glycine max (L.) Merr.] to Loquat (Eriobotrya japonica Lindl.) Leaf Extract Application on Pb-Contaminated Soil

Lead (Pb) is a non-essential element; however, plants uptake it from soils rich in Pb. Soybean [Glycine max (L.) Merr.] is an important legume crop, and Pb toxicity exerts negative impacts on its growth and yield. This study investigated the role of foliar-applied loquat (Eriobotrya japonica Lindl.) leaf extract in improving the morphological, physiological, and biochemical traits of soybean plants under Pb toxicity. Soybean plants were exposed to four Pb concentrations (0, 200, 400, and 800 µg/L) and supplemented with 0% or 5% loquat leaf aqueous extract (EJLE). Data relating to pigments, proline, total soluble sugars, malondialdehyde (MDA), hydrogen peroxide (H2O2), non-enzymatic antioxidant, i.e., [ascorbic acid (AsA), glutathione (GSH), total phenolic contents (TPC), and total flavonoids content (TFC)] and enzymatic antioxidant, i.e., [superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), and glutathione reductase (GR)] were recorded. Total chlorophyll contents and carotenoids were significantly decreased by Pb stress, while lycopene and anthocyanin contents were increased. Similarly, proline, total soluble sugars, MDA, H2O2, AsA, GSH, TPC, TFC, SOD, CAT, POD, APX, and GR were increased under Pb stress. Foliar spray of EJLE lowered MDA and H2O2 accumulation and increased the contents of chlorophylls, carotenoids, lycopene, anthocyanins, proline, total soluble sugars, and the antioxidant system. The increase in the activities of antioxidant enzymes lowered the adverse effects of Pb stress in soybean. Similarly, the application of EJLE lowered Pb accumulation in different plant parts compared to those receiving no EJLE. It is concluded that EJLE can improve the Pb tolerance of soybean plants by enhancing morphological, physiological, and biochemical traits. However, the actual mechanisms behind these improvements warrant further investigation.

Sorbitol induces flower bud formation via the MADS-box transcription factor EjCAL in loquat.

Sorbitol is an important signaling molecule in fruit trees. Here, we observed that sorbitol increased during flower bud differentiation (FBD) in loquat (Eriobotrya japonica Lindl.). Transcriptomic analysis suggested that bud formation was associated with the expression of the MADS-box transcription factor (TF) family gene, EjCAL. RNA fluorescence in situ hybridization showed that EjCAL was enriched in flower primordia but hardly detected in the shoot apical meristem. Heterologous expression of EjCAL in Nicotiana benthamiana plants resulted in early FBD. Yeast-one-hybrid analysis identified the ERF12 TF as a binding partner of the EjCAL promoter. Chromatin immunoprecipitation-PCR confirmed that EjERF12 binds to the EjCAL promoter, and β-glucuronidase activity assays indicated that EjERF12 regulates EjCAL expression. Spraying loquat trees with sorbitol promoted flower bud formation and was associated with increased expression of EjERF12 and EjCAL. Furthermore, we identified EjUF3GaT1 as a target gene of EjCAL and its expression was activated by EjCAL. Function characterization via overexpression and RNAi reveals that EjUF3GaT1 is a biosynthetic gene of flavonoid hyperoside. The concentration of the flavonoid hyperoside mirrored that of sorbitol during FBD and exogenous hyperoside treatment also promoted loquat bud formation. We identified a mechanism whereby EjCAL might regulate hyperoside biosynthesis and confirmed the involvement of EjCAL in flower bud formation in planta. Together, these results provide insight into bud formation in loquat and may be used in efforts to increase yield.