Morphological and genetic characterization of jackfruit (Artocarpus heterophyllus) in the Kayunga and Luwero districts of Uganda.

BACKGROUND: Jackfruit (Artocarpus heterophyllus) is an economically valuable fruit tree in Uganda. However, the production of jackfruit in Uganda is low. Additionally, because of deforestation, genetic erosion of the resource is predicted before its exploitation for crop improvement and conservation. As a prerequisite for crop improvement and conservation, 100 A. heterophyllus tree isolates from the Kayunga and Luwero districts in Uganda were characterized using 16 morphological and 10 microsatellite markers. RESULTS: The results from the morphological analysis revealed variations in tree height, diameter at breast height (DBH), and crown diameter, with coefficient of variation (CV) values of 20%, 41%, and 33%, respectively. Apart from the pulp taste, variation was also observed in qualitative traits, including tree vigor, trunk surface, branching density, tree growth habit, crown shape, leaf blade shape, fruit shape, fruit surface, flake shape, flake color, flake flavor and pulp consistency/texture. Genotyping revealed that the number of alleles amplified per microsatellite locus ranged from 2 to 5, with an average of 2.90 and a total of 29. The mean observed (Ho) and expected (He) heterozygosity were 0.71 and 0.57, respectively. Analysis of molecular variance (AMOVA) indicated that 81% of the variation occurred within individual trees, 19% among trees within populations and 0% between the two populations. The gene flow (Nm) in the two populations was 88.72. The results from the 'partitioning around medoids' (PAM), principal coordinate analysis (PCoA) and genetic cluster analysis further revealed no differentiation of the jackfruit populations. The Mantel test revealed a negligible correlation between the morphological and genetic distances. CONCLUSIONS: Both morphological and genetic analyses revealed variation in jackfruit within a single interbreeding population. This diversity can be exploited to establish breeding and conservation strategies to increase the production of jackfruit and hence boost farmers' incomes. However, selecting germplasm based on morphology alone may be misleading.

ERECTA Modulates Seed Germination and Fruit Development via Auxin Signaling in Tomato.

Tomato (Solanum lycopersicum) breeding for improved fruit quality emphasizes selecting for desirable taste and characteristics, as well as enhancing disease resistance and yield. Seed germination is the initial step in the plant life cycle and directly affects crop productivity and yield. ERECTA (ER) is a receptor-like kinase (RLK) family protein known for its involvement in diverse developmental processes. We characterized a Micro-Tom EMS mutant designated as a knock-out mutant of sler. Our research reveals that SlER plays a central role in controlling critical traits such as inflorescence development, seed number, and seed germination. The elevation in auxin levels and alterations in the expression of ABSCISIC ACID INSENSITIVE 3 (ABI3) and ABI5 in sler seeds compared to the WT indicate that SlER modulates seed germination via auxin and abscisic acid (ABA) signaling. Additionally, we detected an increase in auxin content in the sler ovary and changes in the expression of auxin synthesis genes YUCCA flavin monooxygenases 1 (YUC1), YUC4, YUC5, and YUC6 as well as auxin response genes AUXIN RESPONSE FACTOR 5 (ARF5) and ARF7, suggesting that SlER regulates fruit development via auxin signaling.

Cytological, Phytohormone, and Transcriptome Analyses Provide Insights into Persimmon Fruit Shape Formation (Diospyros kaki Thunb.).

Fruit shape is an important external feature when consumers choose their preferred fruit varieties. Studying persimmon (Diospyros kaki Thunb.) fruit shape is beneficial to increasing its commodity value. However, research on persimmon fruit shape is still in the initial stage. In this study, the mechanism of fruit shape formation was studied by cytological observations, phytohormone assays, and transcriptome analysis using the long fruit and flat fruit produced by 'Yaoxianwuhua' hermaphroditic flowers. The results showed that stage 2-3 (June 11-June 25) was the critical period for persimmon fruit shape formation. Persimmon fruit shape is determined by cell number in the transverse direction and cell length in the longitudinal direction. High IAA, GA4, ZT, and BR levels may promote long fruit formation by promoting cell elongation in the longitudinal direction, and high GA3 and ABA levels may be more conducive to flat fruit formation by increasing the cell number in the transverse direction and inhibiting cell elongation in the longitudinal direction, respectively. Thirty-two DEGs related to phytohormone biosynthesis and signaling pathways and nine DEGs related to cell division and cell expansion may be involved in the persimmon fruit shape formation process. These results provide valuable information for regulatory mechanism research on persimmon fruit formation.

Comparative analysis of POD genes and their expression under multiple hormones in Pyrus bretschenedri.

BACKGROUND: Class III peroxidase (POD) enzymes play vital roles in plant development, hormone signaling, and stress responses. Despite extensive research on POD families in various plant species, the knowledge regarding the POD family in Chinese pear (Pyrus bretschenedri) is notably limited. RESULTS: We systematically characterized 113 POD family genes, designated as PbPOD1 to PbPOD113 based on their chromosomal locations. Phylogenetic analysis categorized these genes into seven distinct subfamilies (I to VII). The segmental duplication events were identified as a prevalent mechanism driving the expansion of the POD gene family. Microsynteny analysis, involving comparisons with Pyrus bretschenedri, Fragaria vesca, Prunus avium, Prunus mume and Prunus persica, highlighted the conservation of duplicated POD regions and their persistence through purifying selection during the evolutionary process. The expression patterns of PbPOD genes were performed across various plant organs and diverse fruit development stages using transcriptomic data. Furthermore, we identified stress-related cis-acting elements within the promoters of PbPOD genes, underscoring their involvement in hormonal and environmental stress responses. Notably, qRT-PCR analyses revealed distinctive expression patterns of PbPOD genes in response to melatonin (MEL), salicylic acid (SA), abscisic acid (ABA), and methyl jasmonate (MeJA), reflecting their responsiveness to abiotic stress and their role in fruit growth and development. CONCLUSIONS: In this study, we investigated the potential functions and evolutionary dynamics of PbPOD genes in Pyrus bretschenedri, positioning them as promising candidates for further research and valuable indicators for enhancing fruit quality through molecular breeding strategies.

Impact of exogenous melatonin foliar application on physiology and fruit quality of wine grapes (Vitis vinifera) under salt stress.

Soil salinisation is an important abiotic stress faced in grape cultivating, leading to weakened plant vigour and reduced fruit quality. Melatonin as a novel hormone has shown positive exogenous application value. Therefore, this study used wine grape (Vitis vinifera ) 'Pinot Noir' as a test material to investigate the changes of foliar spraying with different concentrations of melatonin on the physiology and fruit quality of wine grapes in a field under simulated salt stress (200mmolL-1 NaCl). The results showed that foliar spraying of melatonin significantly increased the intercellular CO2 concentration, maximum photochemical quantum yield of PSII, relative chlorophyll and ascorbic acid content of the leaves, as well as the single spike weight, 100-grain weight, transverse and longitudinal diameters, malic acid, α-amino nitrogen and ammonia content of fruits, and decreased the initial fluorescence value of leaves, ascorbate peroxidase activity, glutathione content, fruit transverse to longitudinal ratio and tartaric acid content of plants under salt stress. Results of the comprehensive evaluation of the affiliation function indicated that 100µmolL-1 melatonin treatment had the best effect on reducing salt stress in grapes. In summary, melatonin application could enhance the salt tolerance of grapes by improving the photosynthetic capacity of grape plants under salt stress and promoting fruit development and quality formation, and these results provide new insights into the involvement of melatonin in the improvement of salt tolerance in crop, as well as some theoretical basis for the development and industrialisation of stress-resistant cultivation techniques for wine grapes.

Genetic tapestry of Capsicum fruit colors: a comparative analysis of four cultivated species.

KEY MESSAGE: Genome-wide association study of color spaces across the four cultivated Capsicum spp. revealed a shared set of genes influencing fruit color, suggesting mechanisms and pathways across Capsicum species are conserved during the speciation. Notably, Cytochrome P450 of the carotenoid pathway, MYB transcription factor, and pentatricopeptide repeat-containing protein are the major genes responsible for fruit color variation across the Capsicum species. Peppers (Capsicum spp.) rank among the most widely consumed spices globally. Fruit color, serving as a determinant for use in food colorants and cosmeceuticals and an indicator of nutritional contents, significantly influences market quality and price. Cultivated Capsicum species display extensive phenotypic diversity, especially in fruit coloration. Our study leveraged the genetic variance within four Capsicum species (Capsicum baccatum, Capsicum chinense, Capsicum frutescens, and Capsicum annuum) to elucidate the genetic mechanisms driving color variation in peppers and related Solanaceae species. We analyzed color metrics and chromatic attributes (Red, Green, Blue, L*, a*, b*, Luminosity, Hue, and Chroma) on samples cultivated over six years (2015-2021). We resolved genomic regions associated with fruit color diversity through the sets of SNPs obtained from Genotyping by Sequencing (GBS) and genome-wide association study (GWAS) with a Multi-Locus Mixed Linear Model (MLMM). Significant SNPs with FDR correction were identified, within the Cytochrome P450, MYB-related genes, Pentatricopeptide repeat proteins, and ABC transporter family were the most common among the four species, indicating comparative evolution of fruit colors. We further validated the role of a pentatricopeptide repeat-containing protein (Chr01:31,205,460) and a cytochrome P450 enzyme (Chr08:45,351,919) via competitive allele-specific PCR (KASP) genotyping. Our findings advance the understanding of the genetic underpinnings of Capsicum fruit coloration, with developed KASP assays holding potential for applications in crop breeding and aligning with consumer preferences. This study provides a cornerstone for future research into exploiting Capsicum's diverse fruit color variation.

Fine-grained recognition of bitter gourd maturity based on Improved YOLOv5-seg model.

Bitter gourd, being perishable, requires timely harvesting. Delayed harvesting can result in a substantial reduction in fruit quality. while premature harvesting leads to underdeveloped fruit and decreased yields, the continuous flowering pattern in bitter gourd underscores the significance of accurately assessing fruit growth and ensuring timely harvesting for subsequent fruit setting and development. The current reliance on the experience of production personnel represents a substantial inefficiency. We present an improved real-time instance segmentation model based on YOLOv5-seg. The utilization of dynamic snake convolution enables the extraction of morphological features from the curved and elongated structure of bitter gourd. Diverse branch blocks enhance feature space diversity without inflating model size and inference time, contributing to improved recognition of expansion stages during bitter gourd growth. Additionally, the introduction of Focal-EIOU loss accurately locates the boundary box and mask, addressing sample imbalances in the L2 stage. Experimental results showcase remarkable accuracy rates of 99.3%, 93.8%, and 98.3% for L1, L2, and L3 stages using mAP@0.5. In comparison, our model outperforms other case segmentation models, excelling in both detection accuracy and inference speed. The improved YOLOv5-seg model demonstrates strong performance in fine-grained recognition of bitter gourd during the expansion stage. It efficiently segments bitter gourd in real-time under varying lighting and occlusion conditions, providing crucial maturity information. This model offers reliable insights for agricultural workers, facilitating precise harvesting decisions.

Genome-wide characterization of cytochrome P450 genes reveals the potential roles in fruit ripening and response to cold stress in tomato.

Plant cytochrome P450 (CYP) superfamily, the largest enzyme metabolism family, has been identified in many species and plays a vital role in plant development and stress response via secondary metabolite biosynthesis. A comprehensive identification and functional investigation of CYPs in tomato plants would contribute to deeper understanding of their biological significance. In this study, 268 tomato CYP genes were identified and found to be unevenly located on 12 chromosomes. Based on the phylogenetic analysis, these 268 SlCYPs were classed into two distinct clades (A-type and non-A-type) and nine clans, including 48 families. Moreover, 67 tandem and 22 WGD (whole genome duplication)/segmental duplication events were detected, of which 12 SlCYP genes experienced both WGD/segmental and tandem duplication events, indicating that tandem duplication plays a major role in the expansion of the SlCYP family. Besides, 48 pairs containing 41 SlCYP and 44 AtCYP genes were orthologous, while 216 orthologous pairs were obtained between tomato and potato. The expression level of all SlCYP genes in tomato tissues at different development stages was analyzed, and most expressed SlCYPs showed a tissue-specific pattern. Meanwhile, 143 differentially expressed SlCYPs were identified under cold stress. Furthermore, the RT-qPCR results indicated that SlCYPs may be involved in fruit ripening and cold tolerance in tomato seedlings. These findings provide valuable insights into the evolutionary relationships and functional characteristics of SlCYPs, which can be utilized for further investigation of fruit metabolic pathways and cold tolerance in tomato.

Intercropping fruit trees in tea plantation improves soil properties and the formation of tea quality components.

Intercropping has been recommended as a beneficial cropping practice for improving soil characteristic and tea quality. However, there is limited research on the effects of intercropping fruit trees on soil chemical properties, soil aggregate structure, and tea quality components. In this study, intercropping fruit trees, specifically loquats and citrus, had a significant impact on the total available nutrients, AMN, and AP in soil. During spring and autumn seasons, the soil large-macroaggregates (>2 mm) proportion increased by 5.93% and 19.03%, as well as 29.23% and 19.14%, respectively, when intercropping loquats and citrus. Similarly, intercropping waxberry resulted in a highest small-macroaggregates (0.25 mm-2 mm) proportion at 54.89% and 77.32%. Soil aggregate stability parameters of the R0.25, MWD, and GMD were generally considered better soil aggregate stability indicators, and significantly improved in intercropping systems. Intercropping waxberry with higher values for those aggregate stability parameters and lower D values, showed a better soil aggregate distribution, while intercropping loquats and citrus at higher levels of AMN and AP in different soil aggregate sizes. As the soil aggregate sizes increased, the AMN and AP contents gradually decreased. Furthermore, the enhanced levels of amino acids were observed under loquat, waxberry, and citrus intercropping in spring, which increased by 27.98%, 27.35%, and 26.21%, respectively. The contents of tea polyphenol and caffeine were lower under loquat and citrus intercropping in spring. These findings indicated that intercropping fruit trees, specifically loquat and citrus, have immense potential in promoting the green and sustainable development of tea plantations.

Development of Multimodal Fusion Technology for Tomato Maturity Assessment.

The maturity of fruits and vegetables such as tomatoes significantly impacts indicators of their quality, such as taste, nutritional value, and shelf life, making maturity determination vital in agricultural production and the food processing industry. Tomatoes mature from the inside out, leading to an uneven ripening process inside and outside, and these situations make it very challenging to judge their maturity with the help of a single modality. In this paper, we propose a deep learning-assisted multimodal data fusion technique combining color imaging, spectroscopy, and haptic sensing for the maturity assessment of tomatoes. The method uses feature fusion to integrate feature information from images, near-infrared spectra, and haptic modalities into a unified feature set and then classifies the maturity of tomatoes through deep learning. Each modality independently extracts features, capturing the tomatoes' exterior color from color images, internal and surface spectral features linked to chemical compositions in the visible and near-infrared spectra (350 nm to 1100 nm), and physical firmness using haptic sensing. By combining preprocessed and extracted features from multiple modalities, data fusion creates a comprehensive representation of information from all three modalities using an eigenvector in an eigenspace suitable for tomato maturity assessment. Then, a fully connected neural network is constructed to process these fused data. This neural network model achieves 99.4% accuracy in tomato maturity classification, surpassing single-modal methods (color imaging: 94.2%; spectroscopy: 87.8%; haptics: 87.2%). For internal and external maturity unevenness, the classification accuracy reaches 94.4%, demonstrating effective results. A comparative analysis of performance between multimodal fusion and single-modal methods validates the stability and applicability of the multimodal fusion technique. These findings demonstrate the key benefits of multimodal fusion in terms of improving the accuracy of tomato ripening classification and provide a strong theoretical and practical basis for applying multimodal fusion technology to classify the quality and maturity of other fruits and vegetables. Utilizing deep learning (a fully connected neural network) for processing multimodal data provides a new and efficient non-destructive approach for the massive classification of agricultural and food products.

Phenomics and transcriptomic profiling of fruit development in distinct apple varieties.

Apple is one of the most economically important and popular temperate fruit trees. The domestication of apple has resulted in substantial phenotypic differences, particularly between wild and cultivated varieties. However, the relationship between gene expression and phenotypic variations in apple remains poorly understood. Here, we present a comprehensive dataset featuring five distinct apple varieties, including two wild varieties and three representative cultivated varieties. The dataset comprises of both phenomics data, encompassing twelve fruit quality-related traits continuously measured over two years, and transcriptomic data obtained at different developmental stages with three biological replicates. We performed basic quality control process, gene expression normalization and differential gene expression analysis to demonstrate the utility and reliability of the dataset. Our findings indicate that gene expression strongly related with phenotypic variations in apple. This dataset serves as a valuable resource, encompassing phenomics and transcriptomic data in multiple formats, thereby facilitating further exploration of the relationships between gene expression and phenotypic traits in apple.

Epigenomic mechanism regulating the quality and ripeness of apple fruit with differing harvest maturity.

Harvest maturity significantly affects the quality of apple fruit in post-harvest storage process. Although the regulatory mechanisms underlying fruit ripening have been studied, the associated epigenetic modifications remain unclear. Thus, we compared the DNA methylation changes and the transcriptional responses of mature fruit (MF) and immature fruit (NF). There were significant correlations between DNA methylation and gene expression. Moreover, the sugar contents (sucrose, glucose, and fructose) were higher in MF than in NF, whereas the opposite pattern was detected for the starch content. The expression-level differences were due to DNA methylations and ultimately resulted in diverse fruit textures and ripeness. Furthermore, the higher ethylene, auxin, and abscisic acid levels in MF than in NF, which influenced the fruit texture and ripening, were associated with multiple differentially expressed genes in hormone synthesis, signaling, and response pathways (ACS, ACO, ZEP, NCED, and ABA2) that were regulated by DNA methylations. Multiple transcription factor genes involved in regulating fruit ripening and quality via changes in DNA methylation were identified, including MIKCC-type MADS-box genes and fruit ripening-related genes (NAP, SPL, WRKY, and NAC genes). These findings reflect the diversity in the epigenetic regulation of gene expression and may be relevant for elucidating the epigenetic regulatory mechanism underlying the ripening and quality of apple fruit with differing harvest maturity.

Transcriptomic Analysis of Alternative Splicing Events during Different Fruit Ripening Stages of Coffea arabica L.

To date, genomic and transcriptomic data on Coffea arabica L. in public databases are very limited, and there has been no comprehensive integrated investigation conducted on alternative splicing (AS). Previously, we have constructed and sequenced eighteen RNA-seq libraries of C. arabica at different ripening stages of fruit development. From this dataset, a total of 3824, 2445, 2564, 2990, and 3162 DSGs were identified in a comparison of different fruit ripening stages. The largest proportion of DSGs, approximately 65%, were of the skipped exon (SE) type. Biologically, 9 and 29 differentially expressed DSGs in the spliceosome pathway and carbon metabolism pathway, respectively, were identified. These DSGs exhibited significant variations, primarily in S1 vs. S2 and S5 vs. S6, and they involve many aspects of organ development, hormone transduction, and the synthesis of flavor components. Through the examination of research findings regarding the biological functions and biochemical pathways associated with DSGs and DEGs, it was observed that six DSGs significantly enriched in ABC transporters, namely, LOC113712394, LOC113726618, LOC113739972, LOC113725240, LOC113730214, and LOC113707447, were continually down-regulated at the fruit ripening stage. In contrast, a total of four genes, which were LOC113732777, LOC113727880, LOC113690566, and LOC113711936, including those enriched in the cysteine and methionine metabolism, were continually up-regulated. Collectively, our findings may contribute to the exploration of alternative splicing mechanisms for focused investigations of potential genes associated with the ripening of fruits in C. arabica.

Anatomical, histochemical, and developmental approaches reveal the long-term functioning of the floral nectary in Tocoyena formosa (Rubiaceae).

Tocoyena formosa has a persistent floral nectary that continues producing nectar throughout flower and fruit development. This plant also presents an intriguing non-anthetic nectary derived from early-developing floral buds with premature abscised corolla. In this study, we characterize the structure, morphological changes, and functioning of T. formosa floral nectary at different developmental stages. We subdivided the nectary into four categories based on the floral and fruit development stage at which nectar production started: (i) non-anthetic nectary; (ii) anthetic nectary, which follows the regular floral development; (iii) pericarpial nectary, derived from pollinated flowers following fruit development; and (iv) post-anthetic nectary that results from non-pollinated flowers after anthesis. The nectary has a uniseriate epidermis with stomata, nectariferous parenchyma, and vascular bundles, with a predominating phloem at the periphery. The non-anthetic nectary presents immature tissues that release the exudate. The nectary progressively becomes more rigid as the flower and fruit develop. The main nectary changes during flower and fruit development comprised the thickening of the cuticle and epidermal cell walls, formation of cuticular epithelium, and an increase in the abundance of calcium oxalate crystals and phenolic cells near the vascular bundles. Projections of the outer periclinal walls toward the cuticle in the post-anthetic nectary suggest nectar reabsorption. The anatomical changes of the nectary allow it to function for an extended period throughout floral and fruit development. Hence, T. formosa nectary is a bivalent secretory structure that plays a crucial role in the reproductive and defensive interactions of this plant species.

A tomato NAC transcription factor, SlNAP1, directly regulates gibberellin-dependent fruit ripening.

In tomato (Solanum lycopersicum), the ripening of fruit is regulated by the selective expression of ripening-related genes, and this procedure is controlled by transcription factors (TFs). In the various plant-specific TF families, the no apical meristem (NAM), Arabidopsis thaliana activating factor 1/2 (ATAF1/2), and cup-shaped cotyledon 2 (CUC2; NAC) TF family stands out and plays a significant function in plant physiological activities, such as fruit ripening (FR). Despite the numerous genes of NAC found in the tomato genome, limited information is available on the effects of NAC members on FR, and there is also a lack of studies on their target genes. In this research, we focus on SlNAP1, which is a NAC TF that positively influences the FR of tomato. By employing CRISPR/Cas9 technology, compared with the wild type (WT), we generated slnap1 mutants and observed a delay in the ethylene production and color change of fruits. We employed the yeast one-hybrid (Y1H) and dual-luciferase reporter (DLR) assays to confirm that SlNAP1 directly binds to the promoters of two crucial genes involved in gibberellin (GA) degradation, namely SlGA2ox1 and SlGA2ox5, thus activating their expression. Furthermore, through a yeast two-hybrid (Y2H), bimolecular fluorescence complementation (BIFC) and luciferase (LUC) assays, we established an interaction between SlNAP1 and SlGID1. Hence, our findings suggest that SlNAP1 regulates FR positively by activating the GA degradation genes directly. Additionally, the interaction between SlNAP1 and SlGID1 may play a role in SlNAP1-induced FR. Overall, our study provides important insights into the molecular mechanisms through which NAC TFs regulate tomato FR via the GA pathway.

In-field and non-destructive determination of comprehensive maturity index and maturity stages of Camellia oleifera fruits using a portable hyperspectral imager.

To efficiently detect the maturity stages of Camellia oleifera fruits, this study proposed a non-invasive method based on hyperspectral imaging technology. First, a portable hyperspectral imager was used for the in-field image acquisition of Camellia oleifera fruits at three maturity stages, and ten quality indexes were measured as reference standards. Then, factor analysis was performed to obtain the comprehensive maturity index (CMI) by analyzing the change trends and correlations of different indexes. To reduce the high dimensionality of spectral data, the successive projection algorithm (SPA) was employed to select effective feature wavelengths. The prediction models for CMI, including partial least squares regression (PLSR), support vector regression (SVR), extreme learning machine (ELM), and convolutional neural network regression (CNNR), were constructed based on full spectra and feature wavelengths; for CNNR, only the raw spectra were used as input. The SPA-CNNR model exhibited more promising performance (RP = 0.839, RMSEP = 0.261, and RPD = 1.849). Furthermore, PLS-DA models for maturity discrimination of Camellia oleifera fruits were developed using full wavelength, characteristic wavelengths and their fusion CMI, respectively. The PLS-DA model using the fused dataset achieved the highest maturity classification accuracy, with the best simplified model achieving 88.6 % accuracy in prediction set. This study indicated that a portable hyperspectral imager can be used for in-field determination of the internal quality and maturity stages of Camellia oleifera fruits. It provides strong support for non-destructive quality inspection and timely harvesting of Camellia oleifera fruits in the field.

Screening and classification of rosehip (Rosa canina L.) genotypes based on horticultural characteristics.

BACKGROUND: During the pandemic, the interest in colorful wild small fruits increased due to their positive effects on health. Also it has become very important to offer species with high nutritional value as fresh or processed products for human consumption due to increasing world population and decreasing arable land. In this context, we characterized the horticultural characteristics of 11 rosehip genotypes grown from seeds. RESULTS: Citric acid was determined as the main organic acid in all the genotypes investigated. The mean values of the organic acids obtained from all the genotypes were found to be as follows: citric acid (7177 mg L-1), malic acid (3669 mg L-1), tartaric acid (1834 mg L-1), oxalic acid (1258 mg L-1), carboxylic acid (631.9 mg L-1), shikimic acid (157.8 mg L-1), ascorbic acid (155 mg L-1), and acetic acid (20.9 mg L-1). Ellagic acid was the dominant phenolic compound (90.1 mg L-1 - 96.2 mg L-1) in all genotypes. The average values obtained from all genotypes for total phenolics, total flavonoids, and antioxidant activity were 37 261 mg GAE L-1, 526.2 mg quercetin L-1, and 93.6%, respectively. These characteristics had the lowest coefficients of variation, which indicated that all genotypes were similar regarding high biochemical with antioxidant effect. In addition, fruit width, fruit length, and fruit weight varied between 13.0 and 17.3 mm, 20.7 and 25.5 mm, and 1.4 and 2.7 g, respectively. CONCLUSIONS: The genotypes were categorized according to different purposes, such as suitability for wine production, making vinegar, etc. While the pomological characteristics were strongly positively correlated among themselves, they were generally found to be negatively correlated with the phytochemical characteristics. Categorizing genotypes according to different usage purposes can improve the agricultural and industrial application of rosehip and enhance their breeding efficacy.

Functional analysis of fasciclin-like arabinogalactan in carotenoid synthesis during tomato fruit ripening.

Carotenoids are important pigmented nutrients synthesized by tomato fruits during ripening. To reveal the molecular mechanism underlying carotenoid synthesis during tomato fruit ripening, we analyzed carotenoid metabolites and transcriptomes in six development stages of tomato fruits. A total of thirty different carotenoids were detected and quantified in tomato fruits from 10 to 60 DPA. Based on differential gene expression profiles and WGCNA, we explored several genes that were highly significant and negatively correlated with lycopene, all of which encode fasciclin-like arabinogalactan proteins (FLAs). The FLAs are involved in plant signal transduction, however the functional role of these proteins has not been studied in tomato. Genome-wide analysis revealed that cultivated and wild tomato species contained 18 to 22 FLA family members, clustered into four groups, and mainly evolved by means of segmental duplication. The functional characterization of FLAs showed that silencing of SlFLA1, 5, and 13 were found to contribute to the early coloration of tomato fruits, and the expression of carotenoid synthesis-related genes was up-regulated in fruits that changed phenotypically, especially in SlFLA13-silenced plants. Furthermore, the content of multiple carotenoids (including (E/Z)-phytoene, lycopene, γ-carotene, and α-carotene) was significantly increased in SlFLA13-silenced fruits, suggesting that SlFLA13 has a potential inhibitory function in regulating carotenoid synthesis in tomato fruits. The results of the present study broaden the idea of analyzing the biological functions of tomato FLAs and preliminary evidence for the inhibitory role of SlFLA13 in carotenoid synthesis in fruit, providing the theoretical basis and a candidate for improving tomato fruit quality.

Regulatory mechanism of GA3 application on grape (Vitis vinifera L.) berry size.

Gibberellin A3 (GA3) is often used as a principal growth regulator to increase plant size. Here, we applied Tween-20 (2%)-formulated GA3 (T1:40 mg/L; T2:70 mg/L) by dipping the clusters at the initial expansion phase of 'Red Globe' grape (Vitis vinifera L.) in 2018 and 2019. Tween-20 (2%) was used as a control. The results showed that GA3 significantly increased fruit cell length, cell size, diameter, and volume. The hormone levels of auxin (IAA) and zeatin (ZT) were significantly increased at 2 h (0 d) -1 d after application (DAA0-1) and remained significantly higher at DAA1 until maturity. Conversely, ABA exhibited an opposite trend. The mRNA and non-coding sequencing results yielded 436 differentially expressed mRNA (DE_mRNAs), 79 DE_lncRNAs and 17 DE_miRNAs. These genes are linked to hormone pathways like cysteine and methionine metabolism (ko00270), glutathione metabolism (ko00480) and plant hormone signal transduction (ko04075). GA3 application reduced expression of insensitive dwarf 2 (GID2, VIT_07s0129g01000), small auxin-upregulated RNA (SAUR, VIT_08s0007g03120) and 1-aminocyclopropane-1-carboxylate synthase (ACS, VIT_18s0001g08520), but increased SAUR (VIT_04s0023g00560) expression. These four genes were predicted to be negatively regulated by vvi-miR156, vvi-miR172, vvi-miR396, and vvi-miR159, corresponding to specific lncRNAs. Therefore, miRNAs could affect grape size by regulating key genes GID2, ACS and SAUR. The R2R3 MYB family member VvRAX2 (VIT_08s0007g05030) was upregulated in response to GA3 application. Overexpression of VvRAX2 in tomato transgenic lines increased fruit size in contrast to the wild type. This study provides a basis and genetic resources for elucidating the novel role of ncRNAs in fruit development.

A histone deacetylase, FaSRT1-2, plays multiple roles in regulating fruit ripening, plant growth and stresses resistance of cultivated strawberry.

Sirtuins (SRTs) are a group of nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase that target both histone and nonhistone proteins. The biological function of SRT in horticultural plants has been rarely studied. In this study, FaSRT1-2 was identified as a key member of the 8 FaSRTs encoded in cultivated strawberry genome. Transient overexpression of FaSRT1-2 in strawberry fruit accelerated ripening, increased the content of anthocyanins and sugars, enhanced ripening-related gene expression. Moreover, stable transformation of FaSRT1-2 in strawberry plants resulted in enhanced vegetative growth, increased sensitivity to heat stress and increased susceptibility to Botrytis cinerea infection. Interestingly, knocking out the homologous gene in woodland strawberry had the opposite effects. Additionally, we found the content of stress-related hormone abscisic acid (ABA) was decreased, while the growth-related gibberellin (GA) concentration was increased in FaSRT1-2 overexpression lines. Gene expression analysis revealed induction of heat shock proteins, transcription factors, stress-related and antioxidant genes in the FaSRT1-2-overexpressed plants while knocked-out of the gene had the opposite impact. In conclusion, our findings demonstrated that FaSRT1-2 could positively promote strawberry plant vegetative growth and fruit ripening by affecting ABA and GA pathways. However, it negatively regulates the resistance to heat stress and B. cinerea infection by influencing the related gene expression.