First Report of Melon Severe Mosaic Orthotospovirus infecting cucurbits in the United States.

Cucurbits (family Cucurbitaceae) includes globally important fruit and vegetable crops. Virus diseases pose a serious threat to cucurbits, limiting crop quality and yield (Regina et al. 2021). In fall 2023, leaf and fruit samples from two squash plants with chlorotic mosaic symptoms and fruit distortion from Monroe and Pope counties in Arkansas were received for diagnosis at the University of Arkansas Division of Agriculture Plant Clinic. Based on symptoms, samples were assessed for melon severe mosaic orthotospovirus (MeSMV) using the ImmunoStrip® developed for detection of the virus (Agdia® Inc., Elkhart, Indiana). The presence of MeSMV was also confirmed by RT-PCR using the Agdia Tospovirus group PCR primers. An amplicon was sequenced and showed 91% sequence identity to the MESMV type isolate (NC_033834, VE440-A). To further verify the results, nucleic acids from a squash sample from Pope County were extracted as described by Poudel et al. (2013), DNase treated, and sequenced on an Oxford Nanopore MinION as described by Liefting et al. (2021). A total of 25,914 raw reads were analyzed using VirFind (Ho and Tzanetakis 2014), which identified 112 reads mapping to the three segments of MeSMV. Primers for all three RNAs were developed and amplified 638, 650, and 1153 nt of the S, M, and L segments of the virus respectively. The amplicons were sequenced bidirectionally and show 89-93% identity to the type isolate from Mexico (GenBank accessions PP301332-4). MeSMV has only been identified in Mexico and can cause significant losses to honeydew melon, zucchini, and cucumber (Ciuffo et al. 2009). Thus, this is the first report of MeSMV outside Mexico. Given the severity of the symptoms observed in cucurbit crops, the virus poses a potential threat to the cucurbit industry in the United States. Growers should be aware of this virus and take the necessary precautions to prevent its spread in the field.

Effect of Cucurbit Host, Production Region, and Season on the Population Structure of Pseudoperonospora cubensis in Florida.

Pseudoperonospora cubensis, the causal agent of Cucurbit downy mildew (CDM), is one of the most important diseases affecting cucurbit production in the United States. This disease is especially damaging to Florida production areas, as the state is a top producer of many cucurbit species. In addition, winter production in central and south Florida likely serves as a likely source of P. cubensis inoculum for spring and summer cucurbit production throughout the eastern United States, where CDM is unable to overwinter in the absence of a living host. Over 2 years (2017 and 2018) and four seasons (spring 2017, spring 2018, fall 2017, and fall 2018), 274 P. cubensis isolates were collected from cucurbit hosts at production sites in south, central, and north Florida. The isolates were analyzed with 10 simple sequence repeat (SSR) markers to establish population structure and genetic diversity and further assigned to a clade based on a qPCR assay. Results of population structure and genetic diversity analyses differentiated isolates based on cucurbit host and clade (1 or 2). Of the isolates assigned to clade by qPCR, butternut squash, watermelon, and zucchini were dominated by clade 1 isolates, whereas cucumber isolates were split 34 and 59% between clades 1 and 2, respectively. Clade assignments agreed with isolate clustering observed within discriminant analysis of principal components (DAPC) based on SSR markers, although watermelon isolates formed a group distinct from the other clade 1 isolates. For seasonal collections from cucumber at each location, isolates were typically skewed to one clade or the other and varied across locations and seasons within each year of the study. This variable population structure of cucumber isolates could have consequences for regional disease management. This is the first study to characterize P. cubensis populations in Florida and evaluate the effect of cucurbit host and clade-type on isolate diversity and population structure, with implications for CDM management in Florida and other United States cucurbit production areas.

Two new cucurbitane-type triterpenoid saponins from the fruit of Citrullus colocynthis.

Two new cucurbitane-type triterpenoid saponins, 2,20ß,22ß-trihydroxy-16α,23(R)-epoxycucurbita-1,5,24-triene-3,11-dione 2-O-ß-D-glucopyranoside (1), 2,20ß,22α-trihydroxy-16α,23(S)-epoxycucurbita-1,5,11,24-tetraene-3-one 2-O-ß-D-glucopyranoside (2) were isolated from the fruit of Citrullus colocynthis (L.) Schrad. Their structures were elucidated by mass spectrometry, IR, 1D, and 2D NMR spectroscopy, etc. Besides, both of the compounds showed significant hepatoprotective activities at 10 µM against paracetamol-induced HepG2 cell damage.

Sexual dimorphism in a dioecious species with complex, specialist-pollinated flowers.

PREMISE: Pollinators with flower constancy and long nectar-feeding organs should favor less or no sexual dimorphism in the individual flowers of dioecious plants. This hypothesis is deduced because such pollinators can discriminate between intersexual flower size differences, and morphological differences between male and female flowers often diminish pollen transfer. METHODS: We compared floral traits and pollinator behavior between male and female flowers in the hawkmoth-pollinated species, Trichosanthes cucumeroides. In field studies, we removed petal fringes on both sexes and observed pollinators to assess the role of elaborate petal fringes in pollinator attraction and pollination success for each flower sex. RESULTS: Female flowers had a similar front flower size and fringe extension as male flowers, supporting our hypothesis. In contrast, females allocated fewer resources to floral biomass. Additionally, they had smaller and narrower petal lobes, lower fringe density, shorter tubes with inferior nectar rewards, and lower display size than males, which is inconsistent with the hypothesis. Nocturnal hawkmoths prefer flowers with long fringe extensions. Fringe removal significantly decreased hawkmoth visitations to both female and male flowers but reduced success only in females. A literature survey indicated that female flowers of specialist-pollinated species are similar in size or larger than the males and thus tend to attract more pollinators compared with female flowers of generalist-pollinated species. CONCLUSIONS: Female flowers have evolved fringe extensions that are similar to those of male flowers, likely increasing pollinator attraction even slightly, and had less biomass in other floral parts and produced less nectar compared with male flowers. Our findings imply that female-biased resource limitation and flower-size sensitivity of pollinators together exert sex-specific selection of floral traits in T. cucumeroides.

Influence of plant domestication on plant-pollinator interactions: Floral attributes and floral visitor communities in wild and cultivated squash plants.

PREMISE: Domestication of plant species results in phenotypic modifications and changes in biotic interactions. Most studies have compared antagonistic plant-herbivore interactions of domesticated plants and their wild relatives, but little attention has been given to how domestication influences plant-pollinator interactions. Floral attributes and interactions of floral visitors were compared between sister taxa of the genus Cucurbita (Cucurbitaceae), the domesticated C. moschata, C. argyrosperma ssp. argyrosperma and its wild progenitor C. argyrosperma ssp. sororia in the place of origin. METHODS: We conducted univariate and multivariate analyses to compare floral morphological traits and analyzed floral reward (nectar and pollen) quantity and quality between flowers of wild and domesticated Cucurbita taxa. Staminate and pistillate flowers of all three taxa were video recorded, and visitation and behavior of floral visitors were registered and analyzed. RESULTS: Most floral morphological characteristics of flowers of domesticated taxa were larger in both staminate and pistillate flowers. Staminate and pistillate flowers presented distinct correlations between floral traits and integration indices between domesticated and wild species. Additionally, pollen quantity and protein to lipid ratio were greater in domesticated species. Cucurbit pollen specialists, Eucera spp., had the highest probability of visit for all Cucurbita taxa. CONCLUSIONS: We provide evidence that floral traits of domesticated and wild Cucurbita species experienced different selection pressures. Domesticated Cucurbita species may have more resources invested towards floral traits, thereby increasing attractiveness to pollinators and potentially plant reproductive success. Wild ancestor plant populations should be conserved in their centers of origin to preserve plant-pollinator interactions.

Elucidation of genetic variation and population structure of melon genetic resources in the NARO Genebank, and construction of the World Melon Core Collection.

Numerous genetic resources of major crops have been introduced from around the world and deposited in Japanese National Agriculture and Food Research Organization (NARO) Genebank. Understanding their genetic variation and selecting a representative subset ("core collection") are essential for optimal management and efficient use of genetic resources. In this study, we conducted genotyping-by-sequencing (GBS) to characterize the genetic relationships and population structure in 755 accessions of melon genetic resources. The GBS identified 39,324 single-nucleotide polymorphisms (SNPs) that are distributed throughout the melon genome with high density (one SNP/10.6 kb). The phylogenetic relationships and population structure inferred using this SNP dataset are highly associated with the cytoplasm type and geographical origin. Our results strongly support the recent hypothesis that cultivated melon was established in Africa and India through multiple independent domestication events. Finally, we constructed a World Melon Core Collection that covers at least 82% of the genetic diversity and has a wide range of geographical origins and fruit morphology. The genome-wide SNP dataset, phylogenetic relationships, population structure, and the core collection provided in this study should largely contribute to genetic research, breeding, and genetic resource preservation in melon.

Genome-Wide Identification of BES1 Gene Family in Six Cucurbitaceae Species and Its Expression Analysis in Cucurbita moschata.

The BES1 (BRI1-EMSSUPPRESSOR1) gene family play a vital role in the BR (brassinosteroid) signaling pathway, which is involved in the growth and development, biotic, abiotic, and hormone stress response in many plants. However, there are few reports of BES1 in Cucurbita moschata. In this study, 50 BES1 genes were identified in six Cucurbitaceae species by genome-wide analysis, which could be classified into 3 groups according to their gene structural features and motif compositions, and 13 CmoBES1 genes in Cucurbita moschata were mapped on 10 chromosomes. Quantitative real-time PCR analysis showed that the CmoBES1 genes displayed differential expression under different abiotic stress and hormone treatments. Subcellular localization showed that the most of CmoBES1 proteins localized in nucleus and cytoplasm, and transactivation assay indicated 9 CmoBES1 proteins played roles as transcription factors. Our analysis of BES1s diversity, localization, and expression in Curcubitaceae contributes to the better understanding of the essential roles of these transcription factors in plants.

Armeria maritima (Mill.) Willd. Flower Hydromethanolic Extract for Cucurbitaceae Fungal Diseases Control.

The cliff rose (Armeria maritima), like other halophytes, has a phenolics-based antioxidant system that allows it to grow in saline habitats. Provided that antioxidant properties are usually accompanied by antimicrobial activity, in this study we investigated the phytochemicals present in a hydromethanolic extract of A. maritima flowers and explored its antifungal potential. The main phytocompounds, identified by gas chromatography-mass spectrometry, were: hexadecanoic acid, octadecanoic acid, 9-octadecenoic acid, 3-(3,4-dihydroxy-phenyl)-acrylic acid ethyl ester, and benzeneacetaldehyde. The antifungal activity of the extract and its main constituents-alone and in combination with chitosan oligomers-was tested against six pathogenic taxa associated with soil-borne diseases of plant hosts in the family Cucurbitaceae: Fusarium equiseti, F. oxysporum f. sp. niveum, Macrophomina phaseolina, Neocosmospora falciformis, N. keratoplastica, and Sclerotinia sclerotiorum. In in vitro tests, EC90 effective concentrations in the 166-865 µg·mL-1 range were obtained for the chitosan oligomers-A. maritima extract conjugate complexes, lower than those obtained for fosetyl-Al and azoxystrobin synthetic fungicides tested for comparison purposes, and even outperforming mancozeb against F. equiseti. In ex situ tests against S. sclerotiorum conducted on artificially inoculated cucumber slices, full protection was achieved at a dose of 250 µg·mL-1. Thus, the reported results support the valorization of A. maritima as a source of biorationals for Cucurbitaceae pathogens protection, suitable for both organic and conventional agriculture.

Citrullus colocynthis (L.) Schrad.: A Promising Pharmaceutical Resource for Multiple Diseases.

Citrullus colocynthis (L.) Schrad. (Cucurbitaceae) is widely distributed in the desert areas of the world. The fruit bodies of C. colocynthis are recognized for their wide range of nutraceutical potential, as well as medicinal and pharmaceutical uses. The plant has been reported for various uses, such as asthma, bronchitis, cancer, colic, common cold, cough, diabetes, dysentery, and jaundice. The fruit has been extensively studied for its biological activities, which include insecticide, antitumor, and antidiabetic effects. Numerous bioactive compounds have been reported in its fruit bodies, such as essential oils, fatty acids, glycosides, alkaloids, and flavonoids. Of these, flavonoids or caffeic acid derivatives are the constituents associated with the inhibition of fungal or bacterial growth, whereas eudesmane sesquiterpenes or sesquiterpene lactones are most active against insects, mites, and nematodes. In this review, the scientific evidence for the biological activity of C. colocynthis against insecticide, cytotoxic, and antidiabetic effects is summarized.

Na+ Sensitivity of the KAT2-Like Channel Is a Common Feature of Cucurbits and Depends on the S5-P-S6 Segment.

Inhibition of Shaker K+ channel activity by external Na+ was previously reported in the melon (Cucumis melo L.) inwardly rectifying K+ channel MIRK and was hypothesized to contribute to salt tolerance. In this study, two inward Shaker K+ channels, CsKAT2 from cucumber (Cucumis sativus) and ClKAT2 from watermelon (Citrullus lanatus), were identified and characterized in Xenopus oocytes. Both channels were inwardly rectifying K+ channels with higher permeability to potassium than other monovalent cations and more active when external pH was acidic. Similarly to MIRK, their activity displayed an inhibition by external Na+, thus suggesting a common feature in Cucurbitaceae (Cucumis spp., Citrullus spp.). CsKAT2 and ClKAT2 are highly expressed in guard cells. After 24 h of plant treatment with 100 mM NaCl, the three KAT2-like genes were significantly downregulated in leaves and guard cells. Reciprocal chimeras were obtained between MIRK and Na+-insensitive AtKAT2 cDNAs. The chimera where the MIRK S5-P-S6 segment was replaced by that from AtKAT2 no longer showed Na+ sensitivity, while the inverse chimera gained Na+ sensitivity. These results provide evidence that the molecular basis of the channel blockage by Na+ is located in the S5-P-S6 region. Comparison of the electrostatic property in the S5-P-S6 region in AtKAT2 and MIRK revealed four key amino acid residues potentially governing Na+ sensitivity.

Comparative genomics and genomic diversity of Pseudomonas syringae clade 2b-a in Australia.

BACKGROUND: A zucchini disease outbreak with unusual symptoms associated with Pseudomonas syringae clade 2b was identified in Bundaberg, Australia during autumn 2016. To investigate the genetic diversity of the 11 Australian isolates obtained from the outbreak, the genomes were compared to the publicly available P. syringae strains in phylogroup 2. RESULTS: Average nucleotide identity refined the P. syringae clade 2b-a into four clusters (Cluster A, B, C1 and C2), an expansion from the previously identified A, B and C. Australian isolates were in Cluster A, C1 and C2. Genomic analyses highlighted several key factors that may contribute to the virulence of these isolates. Six orthologous groups, including three virulence factors, were associated with P. syringae phylogroup 2 cucurbit-infecting strains. A region of genome plasticity analysis identified a type VI secretion system pathway in clade 2b-a strains which could also contribute to virulence. Pathogenicity assays on isolates KL004-k1, KFR003-1 and 77-4C, as representative isolates of Cluster A, C1 and C2, respectively, determined that all three isolates can infect pumpkin, squash, watermelon and zucchini var. Eva with different levels of disease severity. Subsequently, type III effectors were investigated and four type III effectors (avrRpt2, hopZ5, hopC1 and hopH1) were associated with host range. The hopZ effector family was also predicted to be associated with disease severity. CONCLUSIONS: This study refined the taxonomy of the P. syringae clade 2b-a, supported the association between effector profile and pathogenicity in cucurbits established in a previous study and provides new insight into important genomic features of these strains. This study also provided a detailed and comprehensive resource for future genomic and functional studies of these strains.

Momordica balsamina: phytochemistry and pharmacological potential of a gifted species.

Momordica balsamina L. (Cucurbitaceae), frequently named balsam apple, southern balsam pear or African pumpkin, is a vegetable with high nutritional value, being mostly used as food in sub-Saharan Africa. It has also been largely used in traditional medicine to treat several diseases, such as malaria fevers and diabetes. As a member of the Cucurbitaceae family, the main constituents are cucurbitane-type triterpenoids, with different oxidation patterns, named cucurbitacins. This review aims at summarizing our contribution to the phytochemical study of M. balsamina and the evaluation of the isolated cucurbitacins and derivatives as multidrug resistance reversers in cancer cells and bacteria. In this way, the selective antiproliferative activity against multidrug resistant cancer cells of cucurbitacins obtained from M. balsamina, their ability as P-glycoprotein inhibitors in cancer cells overexpressing this ABC transporter, as well as efflux pump inhibitors in resistant bacteria strains are reviewed. Moreover, the in vitro antimalarial activity of cucurbitacins and acyl derivatives against the blood and liver-stages of Plasmodium strains, and the in vivo activity of selected compounds is also reviewed. Besides our work, edible and medicinal uses, and other studies mainly reporting the biological activities of M. balsamina extracts, such as antidiabetic, antibacterial, anti-inflammatory, and antioxidant properties are also addressed.

In vitro evidence of the antitumor capacity of Solanaceae and Cucurbitaceae in colon cancer: A systematic review.

Colon cancer is the fourth leading cause of cancer deaths around the world. Despite advances in understanding its etiology and in diagnosis and treatment, new therapeutic strategies are still required. In this sense, the Solanaceae and Cucurbitaceae families have been widely used to treat various pathologies, including cancer, for their bioactive components. The objective of this systematic review was to analyze the antitumor activity of the bioactive components present in extracts from Solanaceae and Cucurbitaceae families using different in in vitro models of colon cancer. 241 publications have been identified (published from January 2008 to January 2020) from different electronic data base. 44 articles were included, 26 of which examined the Solanaceae family. The antitumor activity exhibited by this family was due to the withanolide-type steroid compounds they harbor. 18 articles were related to the Cucurbitaceae family. This family is characterized by their production of cucurbitacin-type triterpenoid compounds and their derivatives, which confer antitumor activity. In conclusion, the different genera belonging to both families are an important source of bioactive compounds with relevant activity against colon cancer. More experimental and in vivo studies will be required to corroborate their antitumor activity and to leverage them in future clinical practice.

Momordica charantia L. improves airway hyperresponsiveness and suppresses inflammation in a murine model of allergic asthma.

OBJECTIVE: To evaluate the effect of a hydroethanolic extract of Momordica charantia L. ("bitter melon", Cucurbitaceae) leaves (MCHA) on ovalbumin (OVA)-induced asthma model. Balb/c mice were sensitized twice and challenged for 4 alternate days with OVA and then treated with MCHA (500 mg/kg) for 7 consecutive days. METHODS: Control groups received treatment with normal saline or dexamethasone (2 mg/kg) on the same day. We assessed in vivo bronchial hyperresponsiveness and ex-vivo inflammation and mucus production in bronchoalveolar lavage (BAL), lung homogenates, and lung tissue. RESULTS: MCHA significantly improved airway hyperresponsiveness near baseline levels. MCHA administration significantly improved airway and lung inflammation, demonstrated by decreased total and inflammatory cells in BAL, lower levels of IL-5 and IL-13 in lung homogenate, and fewer inflammatory cells in lung tissue. Additionally, MCHA significantly diminished goblet cells in lung tissue. CONCLUSIONS: Administration of a hydroethanolic extract of M. charantia leaves was effective in treating OVA-induced asthma in an animal model.

Colletotrichum orbiculare strains distributed in Japan: race identification and evaluation of virulence to cucurbits.

The pathogen Colletotrichum orbiculare is causal fungus of cucurbit anthracnose. Multiple races have been identified in the United States, suggesting that it is necessary to cultivate suitable resistant cultivars and breed new cultivars with the most suitable resistance gene. This study examined the pathogenicity and virulence of 20 strains in Japan to clarify the existence of races and virulence differences. Based on the symptoms on inoculated cotyledons and true leaves of watermelon, we could evaluate the compatibility of each strain to each host cultivar. Our analysis based on the reaction to the host cultivar harboring the resistance gene Ar-1 (Cla001017) revealed the existence of three races in Japan. An alarming result was that a race that overcame Ar-1, which is a target gene in current watermelon breeding in Japan, is present in Japan. The cucumber and melon host cultivars showed diverse symptoms, whereas a squash cultivar was resistant to all strains. Three strains caused severe damage even to the most resistant cucumber cultivar 'Ban Kyuri' and resistant cultivars harboring Cssgr, a well-known gene conferring loss-of-susceptibility resistance. Screening genetic resources for novel resistance genes using strains with high virulence is of vital importance for watermelon, cucumber, and melon production.

Phytochemical evaluation of Cucumis prophetarum: protective effects against carrageenan-induced prostatitis in rats.

Phytochemical study of the MeOH extract of Cucumis prophetarum fruits (family Cucurbitaceae) by using different chromatographic techniques led to the isolation of three metabolites; spinasterol (1), cucurbitacin B (2), and 2-O-ß-D-glucopyranosylcucurbitacin E (3). Their chemical structures were created on the basis of physical, chemical, spectroscopic data 1D (1H and 13C NMR), and 2D NMR (HSQC and HMBC), as well as similarity with literature data. Cucurbitacin B (Cu-B) (2) was found to be the major constituent. Potential protective activities of MeOH extract, CHCl3, and EtOAc fractions and Cu-B were evaluated against carrageenan-induced prostatic inflammation in rats. Acute toxicity was assessed by evaluating LD50. Pretreatment with CHCl3 fraction and Cu-B ameliorated the rise in the prostate index and obviously protected against histopathological changes. Further, MeOH, extract, CHCl3, and EtOAc fractions as well as Cu-B significantly protected against oxidative stress in prostatic tissues. The anti-inflammatory activities of the extract, fractions and Cu-B were confirmed by ameliorating the rise in prostatic content of the inflammatory mediators TNF-α, IL-1ß, COX-2, and iNOS induced by carrageenan. In addition, the rise in the chemotactic factors were myeloperoxidase (MPO), F4-80, and monocyte chemoattractant protein-1 (MCP-1) was significantly hampered. In conclusion, three known compounds (1-3) were isolated from Cucumis prophetarum fruits. Cu-B (2) was the major identified compound. Particularly, CHCl3 fraction and isolated Cu-B exhibited potent anti-inflammatory activity against carrageenan-induced prostatitis. The anti-inflammatory activity can be attributed, at least partly, to inhibition of neutrophil and macrophage infiltration into prostatic tissues.

Characterization of Pseudomonas syringae Isolated from Systemic Infection of Zucchini in Australia.

Zucchini plants with symptoms including twisted petioles, necrotic leaves, crown rot, and internal fruit rot were found in Bundaberg, Australia, at a commercial field for the first time during late autumn 2016, resulting in direct yield losses of 70 to 80%. Three Pseudomonas syringae strains isolated from symptomatic leaf (KL004-k1), crown (77-4C), and fruit (KFR003-1) were characterized and their pathogenicity evaluated on pumpkin, rockmelon, squash, and zucchini. Biochemical assays showed typical results for P. syringae. The three isolates differed, however, in that two produced fluorescent pigment (KFR003-1 and 77-4C) whereas the third, KL004-k1, was nonfluorescent. Multilocus sequence analysis classified the isolates to phylogroup 2b. The single-nucleotide polymorphism analysis of core genome from the Australian and closely related international isolates of P. syringae showed two separate clusters. The Australian isolates were clustered based on fluorescent phenotype. Pathogenicity tests demonstrated that all three isolates moved systemically within the inoculated plants and induced necrotic leaf symptoms in zucchini plants. Their identities were confirmed with specific PCR assays for P. syringae and phylogroup 2. Pathogenicity experiments also showed that the Eva variety of zucchini was more susceptible than the Rosa variety for all three isolates. Isolate KL004-k1 was more virulent than 77-4C on pumpkin, rockmelon, squash, and zucchini. This study expands the knowledge of P. syringae isolates that infect cucurbits and provides useful information for growers about the relative susceptibility of a range of cucurbit species.

Impact of LTR-Retrotransposons on Genome Structure, Evolution, and Function in Curcurbitaceae Species.

Long terminal repeat (LTR)-retrotransposons (LTR-RTs) comprise a major portion of many plant genomes and may exert a profound impact on genome structure, function, and evolution. Although many studies have focused on these elements in an individual species, their dynamics on a family level remains elusive. Here, we investigated the abundance, evolutionary dynamics, and impact on associated genes of LTR-RTs in 16 species in an economically important plant family, Cucurbitaceae. Results showed that full-length LTR-RT numbers and LTR-RT content varied greatly among different species, and they were highly correlated with genome size. Most of the full-length LTR-RTs were amplified after the speciation event, reflecting the ongoing rapid evolution of these genomes. LTR-RTs highly contributed to genome size variation via species-specific distinct proliferations. The Angela and Tekay lineages with a greater evolutionary age were amplified in Trichosanthes anguina, whereas a recent activity burst of Reina and another ancient round of Tekay activity burst were examined in Sechium edule. In addition, Tekay and Retand lineages belonging to the Gypsy superfamily underwent a recent burst in Gynostemma pentaphyllum. Detailed investigation of genes with intronic and promoter LTR-RT insertion showed diverse functions, but the term of metabolism was enriched in most species. Further gene expression analysis in G.pentaphyllum revealed that the LTR-RTs within introns suppress the corresponding gene expression, whereas the LTR-RTs within promoters exert a complex influence on the downstream gene expression, with the main function of promoting gene expression. This study provides novel insights into the organization, evolution, and function of LTR-RTs in Cucurbitaceae genomes.

A Review of the Phytochemistry and Pharmacology of the Fruit of Siraitia grosvenorii (Swingle): A Traditional Chinese Medicinal Food.

Siraitia grosvenorii (Swingle) C. Jeffrey ex Lu et Z. Y. Zhang is a unique economic and medicinal plant of Cucurbitaceae in Southern China. For hundreds of years, Chinese people have used the fruit of S. grosvenorii as an excellent natural sweetener and traditional medicine for lung congestion, sore throat, and constipation. It is one of the first species in China to be classified as a medicinal food homology, which has received considerable attention as a natural product with high development potential. Various natural products, such as triterpenoids, flavonoids, amino acids, and lignans, have been released from this plant by previous phytochemical studies. Phar- macological research of the fruits of S. grosvenorii has attracted extensive attention, and an increasing number of extracts and compounds have been demonstrated to have antitussive, expectorant, antiasthmatic, antioxidant, hypoglycemic, immunologic, hepatoprotective, antibacte- rial, and other activities. In this review, based on a large number of previous studies, we summarized the related research progress of the chemical components and pharmacological effects of S. grosvenorii, which provides theoretical support for further investigation of its biological functions and potential clinical applications.

Selected Species of the Cucurbitaceae Family Used in Mexico for the Treatment of Diabetes Mellitus.

In Mexico, Diabetes mellitus (DM) is a serious health problem, and although the current pharmacological treatments for DM such as insulin and oral hypoglycemics are available, the Mexican population continues to use medicinal plants in the treatment of DM. The antidiabetic properties of the plant species that belong to the Cucurbitaceae family has already been recognized worldwide. Since Mexico is one of the most important centers of diversity of Cucurbitaceae, the present work contributes to the review of the most used species of Cucurbitaceae in the treatment of DM in Mexico. The reviewed species (Cucurbita ficifolia, C. maxima, C. moschata, C. pepo, Ibervillea sonorae, Sechium edule, Citrullus lanatus, Cucumis melo, and C. sativus) revealed that the antidiabetic effects exerted are effective in a number of mechanisms involved in the complex pathogenesis of DM: hypoglycemic, antioxidant, anti-inflammatory, anti-obesity, protective effects on diverse organs and cells, as well as in the control of dyslipidemias; furthermore, the select species of the Cucurbitaceae family could also be essential components of diets for the control of DM in patients with the disease. Thus, the Cucurbitaceae species selected in the present work represent a source of antidiabetic agents that perhaps establish the bases for novel clinical treatments.