Apical Necrosis Research Articles

Characterization of Caulimovirid-like Sequences from Upland Cotton (Gossypium hirsutum L.) Exhibiting Terminal Abortion in Georgia, USA.

In this study, we investigated the potential involvement of endogenous viral elements (EVEs) in the development of apical tissue necrosis, resulting in the terminal abortion of upland cotton (Gossypium hirsutum L.) in Georgia. The high-throughput sequence analysis of symptomatic and asymptomatic plant tissue samples revealed near-complete EVE-Georgia (EVE-GA) sequences closely related to caulimoviruses. The analysis of EVE-GA's putative open reading frames (ORFs) compared to cotton virus A and endogenous cotton pararetroviral elements (eCPRVE) revealed their similarity in putative ORFs 1-4. However, in the ORF 5 and ORF 6 encoding putative coat protein and reverse transcriptase, respectively, the sequences from EVE-GA have stop codons similar to eCPRVE sequences from Mississippi. In silico mining of the cotton genome database using EVE-GA as a query uncovered near-complete viral sequence insertions in the genomes of G. hirsutum species (~7 kb) but partial in G. tomentosum (~5.3 kb) and G. mustelinum (~5.1 kb) species. Furthermore, cotton EVEs' episomal forms and messenger RNA (mRNA) transcripts were detected in both symptomatic and asymptomatic plants collected from cotton fields. No significant yield difference was observed between symptomatic and asymptomatic plants of the two varieties evaluated in the experimental plot. Additionally, EVEs were also detected in cotton seeds and seedlings. This study emphasizes the need for future research on EVE sequences, their coding capacity, and any potential role in host immunity or pathogenicity.

SOIL PROPERTIES AND AGRONOMIC EVALUATION OF TOMATO LINES (SOLANUM LYCOPERSICUM L.) IN THE NORTHWEST REGION OF GABON

The availability of tomato seeds adapted to local production conditions remains one of the major constraints for a sustainable tomato industry in Gabon. An agro-morphological characterization of ten tomato lines enabled us to assess their potential on the soil of the north-western region of Gabon. At this end, the properties of the soil were analyzed on the one hand, then, agronomic parameters of the tomato lineswere assessed on the other. Univariate and multivariate analyses of agronomic data were carried out using R software. Granulometric analysis revealed that the soil had a silty-sandy structure (29% coarse silt, 28.71% coarse sand). The mineralogical composition shows an assimilable phosphorus content of 15.51ppm and concentrations (in meq/100g) of potassium, calcium, sodium and magnesium of 0.41, 0.99, 0.32 and 0.60 respectively. For agronomic results, flowering time ranged from 26 to 36 DAS and first harvests from 70 to 84 DAS. Line L1 was the earliest and L9 the latest. For the yield, lines L4 (26.7 t/ha) and L8 (20.5 t/ha) were the most productive. The fruits with the best sizes were those of lines L2 (87.7 g) and L4 (86.6 g). Lines L1, L4, L5 and L8 were the firmest. The various diseases observed were downy mildew, spoon yellows and apical necrosis, with a moderate severity index (23,08 %) for all lines. These results show the agronomic performance of certain tomato lines on the sandy-loam soils of Gabon and for varietal improvement programs to increase tomatoes productivity in Gabon.

DISCONTINUING DAPT: NOT JUST A MATTER OF SCORES BUT OF INTEGRATED EVALUATION? A KEY ROLE OF IMAGING IN A COMPLEX SCENARIO

Abstract The duration of the dual antiplatelet therapy (DAPT) is a widely debated topic within the scientific community. The latest guidelines on acute coronary syndromes have supported the possibility of different therapeutic approaches tailored to patient characteristics. However, the clinical cardiologist‘s decisions are not always based on certain principles. The following case report is a practical example. Discussion: A 31–years–old man came to our attention after a resuscitated cardiac arrest due to ventricular fibrillation during a motorcycle race. His history was characterized by a previous acute myocardial infarction at the age of thirteen due to a traumatic dissection of the proximal left anterior descending (LAD) coronary artery and ascending aorta treated conservatively, with residual transmural necrosis of the mid and subendocardial anterior wall on cardiac MRI. At the admission, ECG showed ST–segment elevation in the anterior leads. Coronary angiography revealed occlusion of the proximal LAD coronary artery, treated with drug–eluting stent (ONYX 5.0 mm), with evidence of dissection and aneurysmal wall of that segment. The patient started a DAPT with aspirin and prasugrel. At discharge, echocardiogram evidenced a moderate left ventricular dysfunction (ejection fraction 34%) with signs of anterior and apical necrosis. Later, the patient was admitted for a subcutaneous defibrillator implantation, due to persistent moderate ventricular dysfunction. One year after revascularization, a lifelong DAPT strategy with downgrading to clopidogrel was considered the best choice for the following considerations: the young age of the patient, the low bleeding risk (PRECISE DAPT score 8), a not elevated DAPT score (value 2), the revascularization in the aneurysmal segment without an appropriate stent apposition (due to absence of a right sizing) and the previous dissection with sign of partial thrombosis at coronary CT. Conclusions: The anatomical complexity of angioplasty procedures and the delicate balance between ischemic and thrombotic risks have led to continuously evolving therapeutic strategies. The clinical scores currently available cannot often account for complex coronary anatomy. Thus, it‘s essential to consider a personalized approach, individualized on clinical and imaging characteristics, that encompasses ischemic and bleeding risk and procedural data for the appropriate treatment for each patient.

Histologic characterization of spontaneous catecholamine-induced cardiomyopathy in laboratory New Zealand White rabbits.

Catecholamine-induced cardiomyopathy (CCM) is an entity associated with increased levels of catecholamines causing subendocardial and papillary muscle cardiomyocyte degeneration and necrosis. In 2020, 49 autopsies from early rabbit deaths in a colony used for medical device biocompatibility studies were submitted for microscopic examination. Of the 49 rabbits, 26 had histologic changes consistent with CCM. No common stressor for CCM was determined in affected rabbits. Animals were generally male, were 12-16-wk-old, and were found dead or had bloating, lethargy, and/or diarrhea. Those observed with clinical signs were euthanized and autopsied per the organization's standard operating procedures. Heart lesions consisted of various degrees of apical subendocardial myocardial degeneration and necrosis. Common non-cardiac lesions included pulmonary congestion and edema, hepatic congestion and centrilobular hepatocellular degeneration, and/or variable intestinal submucosal edema.

First Report of Broad Bean Wilt Virus 2 Infecting Balsam (Impatiens balsamina) in China.

Balsam (Impatiens balsamina L.) is an ornamental plant cultivated extensively in China and elsewhere, but it has also been used as a medicinal plant for thousands of years (Qian et al., 2023). In 2022, an examination of 10 garden-grown I. balsamina plants in Chaoyang, Beijing, China revealed eight plants with blotches, mosaic symptoms, and deformed leaves (Fig. S1A). Total RNA was extracted from the symptomatic leaf tissue of these eight plants using the TRIzol reagent (Invitrogen, USA). Four RNA preparations (high quality and quantity) were combined for the small RNA sequencing analysis (TIANGEN Biotech Co., China). A total of 16,509,586 clean reads (18-30 nt) were obtained and assembled into larger contigs using Velvet 1.0.5. A search of the National Center for Biotechnology Information non-redundant database using BLASTX indicated 72, 24, and 19 contigs were homologous to broad bean wilt virus 2 (BBWV2), cucumber mosaic virus (CMV), and impatiens cryptic virus 1 (ICV1) sequences (Zheng et al., 2022), respectively. To verify the next-generation sequencing data, the following three sets of primer pairs were designed according to the contig sequences of these three viruses: CMV-F:5'-ATGGACAAATCTGAATCAACCAGTGC-3'/CMV-R: 5'-CCGTAAGCTGGATGGACAACC-3'; BBWV2-F:5'-CAATTTGGACAACTACAATTTGCC-3'/ BBWV2-R: 5'-GCTGAGTCTAAATCCCATCTATC-3'; and ICV1-F: 5'-CGCACAACT CTACAAT GACATGGTC-3'/ICV1-R: 5'-AGTTCCATCGTCCAGTAGGCG-3'. The primers were used to amplify CMV, BBWV2, and ICV1 sequences by reverse transcription-polymerase chain reaction (RT-PCR), with individual RNA preparations serving as the template. The CMV, BBWV2, and ICV1 target sequences were amplified from eight, four, and four samples, respectively (Fig. S1B). To evaluate virus infectivity, Nicotiana benthamiana seedlings were inoculated using a leaf tissue extract prepared from an infected I. balsamina plant. At 7 days post-inoculation, disease symptoms were detected on N. benthamiana systemic leaves (e.g., deformation and apical necrosis) (Fig. S1C). Confirmation tests involving RT-PCR indicated the N. benthamiana plants were infected with BBWV2 and CMV, but not with ICV1 (Fig. S1D). To obtain the complete BBWV2 genome sequence (RNA1 and RNA2), virus-specific PCR primers (Table S1) were designed to produce the terminal sequences via 5' and 3' rapid amplification of cDNA ends (RACE), which was completed using the SMARTer RACE 5'/3' Kit (Clontech, China). The RNA1 and RNA2 sequences comprised 5,957 nt (GenBank: OQ857921) and 3,614 nt (GenBank: OQ857922), respectively. The BLAST analyses revealed RNA1 and RNA2 were similar to sequences in other BBWV2 isolates (sequence identities of 78.88% to 95.15% and 80.83% to 91.51%, respectively). Using the neighbor-joining method and MEGA 7.0, the phylogenetic relationships between the BBWV2 isolated in this study and other isolates were determined on the basis of the full-length RNA1 and RNA2 sequences (Kumar et al., 2016). According to the RNA1 and RNA2 sequences, the BBWV2 isolated in this study was most closely related to the BBWV2 isolate from Gynura procumbens (GenBank: KX686589) and the BBWV2 isolate from Nicotiana tabacum (GenBank: KX650868), respectively (Fig. S1E). To the best of our knowledge, this is the first report of I. balsamina naturally infected with BBWV2 in China. The study findings may be useful for detecting BBWV2 in I. balsamina and for diagnosing and managing the associated disease. The authors declare no conflict of interest. Yanhong Qiu and Haijun Zhang contributed equally to this paper. Funding: This research was supported by the Beijing Academy of Agriculture and Forestry Foundation, China (KYCX202305, QNJJ202131, and KJCX20230214).

Pediatric endodontic considerations in the application of regenerative therapy for immature permanent teeth: a review article

For adult teeth with necrosis or apical periodontitis, regenerative endodontics provides a useful alternative to standard endodontic treatment. This review focuses on the pediatric endodontic considerations in the application of regenerative therapy for immature permanent teeth. A thorough literature search was conducted in the MEDLINE database using the keywords "pediatric, regenerative, therapy, endodontics, immature, permanent, and teeth" to find relevant publications published between 2017 and 2024. Additionally, Google Scholar was used to find and access pertinent scientific publications using the appropriate search terms. Various inclusion criteria were applied to select the articles for review. The selected articles were published between 2020 and 2024 and included discussions on several specific elements. Topics covered include the criteria for case selection for regenerative endodontics. Overall, the existing evidence indicates that using regenerative endodontic techniques to treat adult permanent teeth with apical periodontitis or necrosis may successfully lead to the resolution of apical translucencies and the absence of clinical signs and symptoms. With slight modifications to the clinical procedure, regenerative dentistry methods can be effectively applied to specific cases, such as those involving a small apical foramen, decreased blood supply, and a lack of growth factors. However, additional research is required to determine the optimal conditions for achieving successful treatment outcomes.

Pseudomonas syringae induced pathogenicity in Mangifera indica leads to severe apical necrosis

Pseudomonas syringae induced pathogenicity in Mangifera indica leads to severe apical necrosis

Distribution of Xanthomonas arboricola pv. juglandis and Alternaria species-groups populations associated with brown apical necrosis at different phenological stages of walnut trees

Distribution of Xanthomonas arboricola pv. juglandis and Alternaria species-groups populations associated with brown apical necrosis at different phenological stages of walnut trees

Understanding the association of apical necrosis in flowers and fruits of walnut (Juglans regia L.) with causal microorganisms under field conditions

Understanding the association of apical necrosis in flowers and fruits of walnut (Juglans regia L.) with causal microorganisms under field conditions

Quercetin attenuates deoxynivalenol-induced intestinal barrier dysfunction by activation of Nrf2 signaling pathway in IPEC-J2 cells and weaned piglets

The presence of deoxynivalenol (DON), one of the most frequently occurring mycotoxin, in food and feed has been considered a risk factor to both human and animal health. Molecular mechanisms that regulate DON effects in tissues are still poorly understood. However, recent evidence suggests that nuclear factor erythroid 2-like 2 (Nrf2) may be a major target during mycotoxin-induced intestinal barrier dysfunction. Although quercetin, a plant-derived flavonoid, is known to induce the activation of Nrf2 signaling pathway, its potential to mitigate effects of DON and the implication of Nrf2 in its physiological effects is poorly understood. Therefore, this study was conducted to investigate the protective effects of quercetin in alleviating the DON-induced barrier loss and intestinal injuries in IPEC-J2 cells and weaned piglets and determine the potential role of Nrf2. Quercetin treatment dose-dependently increased mRNA expression of Nrf2 target gene, NQO-1, and concomitantly increased the expression of claudin-4 at both mRNA and protein levels. Quercetin supplementation also reversed the reduction of claudin-4 caused by DON exposure in vivo and in vitro. The decreased membrane presence of claudin-4 and ZO-1 induced by DON was also blocked by quercetin. Furthermore, quercetin attenuated the endocytosis and degradation of claudin-4 caused by DON exposure. The effects of quercetin also included the restoration of transepithelial electrical resistance (TEER) and reduction of FITC-dextran permeability that have been perturbed by DON. However, the protective effects of quercetin against DON exposure were abolished by a specific Nrf2 inhibitor (brusatol), confirming the importance of Nrf2 in the regulation of TJP expression and barrier function by quercetin. In vivo study in weaned pigs showed that DON exposure impaired villus-crypt morphology as indicated by diffuse apical villus necrosis, villus atrophy and fusion. Notably, intestinal injuries caused by DON administration were partly mitigated by quercetin supplementation. Collectively, this study shows that quercetin could be used to prevent the DON-induced gut barrier dysfunction in humans and animals and the protective effects of quercetin against DON-induced intestinal barrier disruption is partly through Nrf2-dependent signaling pathway.

A

The availability of tomato seeds adapted to local production conditions remains one of the major constraints for the tomato sector in Gabon. The development of varieties adapted to pedoclimatic conditions is necessary. An agro-morphological characterization study of ten (10) tomato lines introduced in Gabon was carried out in order to select the best lines for their use in a program of creation and varietal improvement. The objectives were to measure the agro-morphological characteristics of the lines, evaluate the yields, determine the qualities of the fruits and identify the types and levels of infestation of the plants. These lines were evaluated according to a Fisher block device with three repetitions. Univariate (ANOVA) and multivariate (ACP, CAH) analyzes of the data were carried out with the R software. The results revealed variability between the lines for all the traits studied. The flowering time varied between 26 and 36 days after sowing (DAS) and the first harvests varied between 70 and 84 DAS. Line L1 was the earliest and L9 late. For the yield, it varied between 0.6 and 26.7 t/ha. Lines L4 and L8 were the most productive with 26.7 t/ha and 20.5 t/ha respectively. The fruits with the best sizes are those of the L2 and L4 lines with respectively 87.7 g for a rounded shape and 86.6 g for an ovoid shape. Lines L1, L4, L5 and L8 are the firmest. The type of disease observed is downy mildew, spoon yellows and apical necrosis for a moderate severity index for all the lines. These results make it possible to assess the agronomic performance of the lines and to identify promising lines for varietal improvement programs in order to improve productivity for food security.

Flower Induction and Control of Inflorescence Diseases in Mangoes using selected Fungicides and Chemical Fertilizers

Mango (Mangifera indica L.) is widely considered an important fruit and a major crop in tropical and subtropical regions around the world. Mango is susceptible to a variety of diseases throughout its life cycle, but diseases that strike during the flowering stage cause significant losses and have a direct impact on productivity. Flowering in mango is unreliable from season to season because environmental signals for flower initiation are frequently inconsistent. During the current research, we identify the most promising laboratory-grade synthetic chemical, chemical fungicide, or their feasible combination that promotes floral development, induces flowering, and combats inflorescence diseases, which reduce production. For this investigation, a field trial was conducted with multiple treatments. Compared to the control, the potassium nitrate treatment resulted in the highest flowering/flower emergence (8.67%), followed by calcium carbonate (7.33%) and potassium nitrate with the combination of Champion (6.66%) and Cabrio Top (5.32). Minimum flowering occurred on plants treated with fungicides alone, i.e., Contaf Plus (3.33%), compared to the control (1.33%). Contaf Plus was the most effective chemical against all inflorescence diseases in the field. The disease with the highest incidence was blossom blight at 42.90%, followed by apical necrosis at 39%, mango deformity at 17.70%, and powdery mildew at a low of 0.40%. The combined application of potassium nitrate and Copper hydroxide exhibited the best response in the field for inducing flowering and flower set on mango inflorescences, while potassium nitrate and calcium nitrate were the most effective for inducing flowers on mango trees when treated independently. Current research is extensive on the inducement of flowering and inhibition of flower disease through the application of chemicals alone or in combination.

FIRST REPORT OF BASAL ROT CAUSED BY Fusarium equiseti IN ONION CROPS FROM PUEBLA, MEXICO

<p><strong>Background</strong>: Species of the <em>Fusarium</em> genus are considered as devastating phytopathogens of onion crops around the world. <strong>Objective</strong>: This work aimed to know the causal agent of basal rot in onion crops from Puebla-México recorded in 2019. <strong>Methodology</strong>: The causal agent was isolated from diseased samples by tissue incubation in Potato Dextrose Agar medium (PDA) and the pathogenicity tests were done with the causal agent to demonstrate its involvement in basal rot. Monosporic cultures of the causal agent were generated for further microscopic characterization and molecular identification by Internal Transcribed Spacers ITS1 and ITS2. <strong>Results</strong>: According to the pathogenicity tests, the causal agent produced apical constriction and necrosis in the radicle and leaves accompanied by brown spots surrounded by yellowing as those observed in natural conditions. A 533 bp amplicon of the causative agent was obtained by partial amplification of the 5.8S rDNA gene. The sequence of the amplicon was compared with the sequences deposited in the database of the National Center for Biotechnology Information (NCBI) showing 100% homology with <em>Fusarium equiseti</em>. <strong>Implications</strong>: Our investigation reveals <em>F. equiseti</em> as an emergent causal agent of onion basal rot in crops from the community of “La Soledad” Puebla, México. <strong>Conclusion</strong>: Herein we report for the first time <em>F. equiseti</em> as a new phytopathogen of onion and further strategies should be considered for its control.</p>

First Report of Leaf Spot Disease Caused by Stemphylium eturmiunum on Garlic in Korea.

Garlic (Allium sativum L. cv.namdo) is one of the most popular vegetables grown in Korea due to its high demand from the food industry. However, garlic is susceptible to a wide range of pest infestations and diseases that cause a significant decrease in garlic production, locally and globally (Schwartz and Mohan 2008). In early 2019, the occurrence of leaf blight disease was found spreading in garlic cultivation areas around Jeonnam (34.9671107, 126.4531825) province, Korea. Disease occurrence was estimated to affect 20% of the garlic plants and resulted in up to a 3-5% decrease in its total production. At the early stage of infection, disease symptoms were manifested as small, white-greyish spots with the occurrence of apical necrosis on garlic leaves. This necrosis was observed to enlarge, producing a water-soaked lesion before turning into a black-violet due to the formation of conidia. As the disease progressed, the infected leaves wilted, and the whole garlic plants eventually died. To identify the causal agent, symptomatic tissues (brown dried water-soak lesion) were excised, surface sterilized with 1% NaOCl and placed on the Potato Dextrose Agar (PDA) followed by incubation at 25°C in the dark for 5 days. Among ten fungal isolates obtained, four were selected for further analyses. On PDA, fungal colonies were initially greyish white in colour but gradually turned to yellowish-brown after 15 days due to the formation of yellow pigments. Conidia were muriform, brown in colour, oblong (almost round) with an average size of 18 - 22 × 16 - 20 μm (n = 50) and possessed 6 - 8 transverse septa. Fungal mycelia were branched, septate, and with smooth-walled hyphae. Morphological characteristics described above were consistent with the morphology of Stemphylium eturmiunum as reported by Simmons (Simmons, 2001). For molecular identification, molecular markers i.e. internal transcribed spacer (ITS) and calmodulin (cmdA) genes from the selected isolates were amplified and sequenced (White et al., 1990; Carbone and Kohn 1999). Alignment analysis shows that ITS and cmdA genes sequence is 100% identical among the four selected isolates. Therefore, representative isolate i.e. NIHHS 19-142 (KCTC56750) was selected for further analysis. BLASTN analysis showed that ITS (MW800165) and cmdA (LC601938) sequences of the representative isolates were 100% identical (523/523 bp and 410/410 bp) to the reference genes in Stemphylium eturmiunum isolated from Allium sativum in India (KU850545, KU850835) respectively (Woudenberg et al. 2017). Phylogenetic analysis of the concatenated sequence of ITS and cmdA genes confirmed NIHHS 19-142 isolates is Stemphylium eturmiunum. Pathogenicity test was performed using fungal isolate representative, NIHHS 19-142. Conidia suspension (1 × 106 conidia/µL) of the fungal isolate was inoculated on intact garlic leaves (two leaves from ten different individual plants were inoculated) and bulbs (ten bulbs were used) respectively. Inoculation on intact leaves was performed at NIHHS trial farm whereas inoculated bulbs were kept in the closed container to maintain humidity above 90% and incubated in the incubator chamber at 25°C. Result show that the formation of water-soaked symptoms at the inoculated site was observed at 14 dpi on intact leaves whereas 11 dpi on bulbs. As a control, conidia suspension was replaced with sterile water and the result shows no symptoms were observed on the control leaves and bulbs respectively. Re-identification of fungal colonies from symptomatic leaf and bulb was attempted. Result showed that the morphological characteristics and molecular marker sequences of the three colonies selected were identical to the original isolates thus fulfilled Koch's postulates. Early identification of Stemphylium eturmiunum as a causal agent to leaf spot disease is crucial information to employ effective disease management strategies or agrochemical applications to control disease outbreaks in the field. Although Stemphylium eturmiunum has been reported to cause leaf spot of garlic disease in China, France and India (Woudenberg et al. 2017), to our knowledge, this is the first report of causing leaf spot disease on garlic in Korea.

First report of eggplant mottled crinkle virus infecting eggplant in Greece.

During winter 2020-2021, a severe virus-like disease outbreak was observed in eggplant (Solanum melongena L.) hybrids 'Monarca' (F1) and 'Angela' (F1) growing under protected conditions in Heraklion, Crete, Greece. In three greenhouses, the percentage of infected plants reached 100% leading to crop abandonment. Symptoms included leaf mottling and yellowing accompanied with plant stunting and apical necrosis. Extensive fruit damage was due to severe malformation and necrotic lesions on the calyx, peduncle and the endocarp (Sup. Fig. 1). To identify the causal agent, total RNA was extracted from a symptomatic eggplant fruit with PureLink™ RNA Mini Kit (ThermoFisher Scientific, USA), which was subjected to high throughput sequencing (HTS) analysis (Illumina Inc., USA). The de novo assembly of the obtained 25 million, 75 bp, single-end reads with Geneious Prime (Biomatters, New Zealand) and the annotation of the resulting contigs with BLASTn revealed the presence of only eggplant mottled crinkle virus (EMCV, genus Tombusvirus) in the sample. The assembled sequence of EMCV isolate from Greece (EMCV-Gr, GenBank Acc. No. MW716271) was 4764 bp in length, covering the full genome of the virus and showing 96.3 % nucleotide (nt) identity with an isolate identified from calla lilies (Zantedeschia sp.) in Taiwan (AM711119). Five symptomatic and seven asymptomatic 'Monarca' (F1) eggplants, as well as two symptomatic 'Angela' (F1) eggplants were tested by RT-PCR that targeted the capsid protein gene of the virus (Dombrovsky et al., 2009). PCR products of 1184 bp were obtained from the seven symptomatic samples and their Sanger sequencing revealed 100 % nt identity with the respective HTS-derived EMCV sequence. No product was obtained from the analysis of the asymptomatic samples. Mechanical sap transmission of the HTS analysed eggplant sample resulted in necrotic local lesions on Nicotiana rustica and Chenopodium quinoa, necrotic local lesions plus systemic necrosis on N. tabacum cv. Xanthi-nc, cv. Samsun and N. glutinosa, systemic collapse of N. benthamiana, and leaf mottling plus stunting of pepper cv. Yolo Wonder plants (Sup. Fig. 1I). Although no symptoms were observed on tomato plants cv. Ace 55, systemic EMCV infection was detected by RT-PCR. To establish the relationship between the disease and EMCV, infected tissue from N. benthamiana plants was used for the mechanical inoculation of virus-tested negative eggplant seedlings cv. Black beauty. Necrotic spots, shoot necrosis, leaf mottling and mosaic, symptoms were observed (Sup. Fig. J) on the test plants ten days post inoculation and the presence of the virus was confirmed by RT-PCR as described. To the best of our knowledge this is the first report of EMCV infecting eggplant in Greece. The virus was originally described in eggplant in Lebanon (Makkouk et al., 1981) and it is mainly present outside the European Union (EU) territory, including India, Japan, Taiwan, Iran and Israel (Dombrovsky et al., 2009 and references therein). A latent EMCV infection was detected in pear in Italy (Russo et al., 2002) and the virus is considered by the European Food Safety Authority as an exotic virus of the genera Cydonia, Malus, and Pyrus that meets all the criteria to qualify as an EU quarantine pest (Bragard et al., 2019). Τhe severity of the disease observed in Crete leading to the destruction of eggplant greenhouse cultivations, constitutes EMCV as an emerging threat to eggplant and other solanaceous crops for Greece and Europe.

Lactobacillus plantarum metabolites reduce deoxynivalenol toxicity on jejunal explants of piglets

The deterioration of food and feed stuffs and toxic intestinal effects due to fungal colonization and concomitant production of mycotoxins is an increasing concern. The development of fungi resistance to many commonly used chemical preservatives adds further alarm. Therefore, effective detoxification methods would be useful in counteracting this problem. Biotransformation/adsorption of mycotoxins by lactic acid bacteria and their metabolites is a promising approach to minimize the deleterious effects of mycotoxins. The objective of the present study was to evaluate the beneficial effects of Lactobacillus plantarum metabolites in reducing deoxynivalenol intestinal toxicity. To achieve this aim, histological, morphometrical and oxidative stress analyses were performed in the intestinal mucosa of piglets exposed to deoxynivalenol alone or associated with two strains (SN1 and SN2) of L. plantarum subsp. plantarum metabolites. Metabolites were obtained after dichloromethane (D) or ethyl acetate (A) extraction. Jejunal explants were exposed to the following treatments for 2 and 4 h a) culture medium (control group); b) deoxynivalenol (DON, 10 μM); c) L. plantarum metabolites DSN1; d) L. plantarum metabolites DSN1+DON; e) L. plantarum metabolites DSN2; f) L. plantarum metabolites DSN2+DON; g) L. plantarum metabolites ASN1; h) L. plantarum metabolites ASN1+DON; i) L. plantarum metabolites ASN2; j) L. plantarum metabolites ASN2+DON. The metabolites were incubated 1 h previously to DON challenge (one and 3 h of exposure). Histological assessment showed DON-treated explants with villi fusion and atrophy, multifocal apical necrosis and cuboid or flattened enterocytes with 2 and 4 h of exposure, while LP metabolites groups individually or associated with DON remained like control. The density of goblet cells in villi and crypts was reduced in DON explants compared to control group with 2 and 4 h of exposure; on the other hand, a significant increase in this parameter was achieved in LP metabolites groups compared to DON. Morphometric evaluation showed no difference in villi height or crypts depth in any treated explants. Overall, oxidative stress response assessments showed that explants exposed to SN1 extracted with dichloromethane and ethyl acetate, and SN2 extracted with dichloromethane reduced superoxide anion production. In conclusion, L. plantarum metabolites induced beneficial effects in intestinal mucosa, reducing the toxic effects of DON on intestinal morphology and oxidative response.

Xanthomonas arboricola pv. juglandis and pv. corylina: Brothers or distant relatives? Genetic clues, epidemiology, and insights for disease management.

BackgroundThe species Xanthomonas arboricola comprises up to nine pathovars, two of which affect nut crops: pv. juglandis, the causal agent of walnut bacterial blight, brown apical necrosis, and the vertical oozing canker of Persian (English) walnut; and pv. corylina, the causal agent of the bacterial blight of hazelnut. Both pathovars share a complex population structure, represented by different clusters and several clades. Here we describe our current understanding of symptomatology, population dynamics, epidemiology, and disease control.Taxonomic statusBacteria; Phylum Proteobacteria; Class Gammaproteobacteria; Order Lysobacterales (earlier synonym of Xanthomonadales); Family Lysobacteraceae (earlier synonym of Xanthomonadaceae); Genus Xanthomonas; Species X. arboricola; Pathovars: pv. juglandis and pv. corylina.Host range and symptomsThe host range of each pathovar is not limited to a single species, but each infects mainly one plant species: Juglans regia (X. arboricola pv. juglandis) and Corylus avellana (X. arboricola. pv. corylina). Walnut bacterial blight is characterized by lesions on leaves and fruits, and cankers on twigs, branches, and trunks; brown apical necrosis symptoms consist of apical necrosis originating at the stigmatic end of the fruit. A peculiar symptom, the vertical oozing canker developing along the trunk, is elicited by a particular genetic lineage of the bacterium. Symptoms of hazelnut bacterial blight are visible on leaves and fruits as necrotic lesions, and on woody parts as cankers. A remarkable difference is that affected walnuts drop abundantly, whereas hazelnuts with symptoms do not.DistributionBacterial blight of walnut has a worldwide distribution, wherever Persian (English) walnut is cultivated; the bacterial blight of hazelnut has a more limited distribution, although disease outbreaks are currently more frequently reported. X. arboricola pv. juglandis is regulated almost nowhere, whereas X. arboricola pv. corylina is regulated in most European and Mediterranean Plant Protection Organization (EPPO) countries.Epidemiology and controlFor both pathogens infected nursery material is the main pathway for their introduction and spread into newly cultivated areas; additionally, infected nursery material is the source of primary inoculum. X. arboricola pv. juglandis is also disseminated through pollen. Disease control is achieved through the phytosanitary certification of nursery material (hazelnut), although approved certification schemes are not currently available. Once the disease is present in walnut/hazelnut groves, copper compounds are widely used, mostly in association with dithiocarbamates; where allowed, antibiotics (preferably kasugamycin) are sprayed. The emergence of strains highly resistant to copper currently represents the major threat for effective management of the bacterial blight of walnut.Useful websites https://gd.eppo.int/taxon/XANTJU, https://gd.eppo.int/taxon/XANTCY, https://www.euroxanth.eu, http://www.xanthomonas.org

Una complicación endodóntica inusual después de una cirugía de alargamiento coronal: Reporte de un Caso

A gummy smile is a form of excessive gingival display when smiling. The excessive gingival display due to altered eruption is likely to benefit from crown lengthening surgery in order to restore the esthetic smile. Case Report: The potential complications of the crown lengthening surgery include possible esthetic deformities, dentine hypersensitivity, transient mobility, and root resorption. The present case report reveals a rare complication happened after an esthetic crown lengthening surgery which was performed to correct the gummy smile of a 37-year-old female. The patient experienced dull throbbing pain and mild tender to percussion on tooth 11, 3 weeks after the surgery, and the symptoms did not improve after the composite restorations were placed at the cervical regions. Instead, the tooth was tender to percussion and palpation with a sign of coronal discoloration. Pulp necrosis was confirmed with the clinical tests. A cone-beam computed tomography was taken after the root canal treatment, and apical fenestration on tooth 11 was noted. Therefore, this case report shows the possible correlation between crown lengthening surgery on a tooth with apical fenestration and pulp necrosis, if the apical vasculature is severed accidentally during the procedure. Conclusion: A cone-beam computed tomography should be considered prior to the surgery and extra precaution during the surgery may reduce the risk of severing the apical vasculature if apical fenestration is evidenced.

First Report of Alternaria alternata and Fusarium spp. Causing Brown Apical Necrosis in Walnut Fruit in Southern Chile

This is the first report of Alternaria alternata and Fusarium spp. causing brown apical necrosis (BAN) in walnut fruit in southern Chile. English walnut (Juglans regia L.) is the second most widely grown fruit in Chile. The bacterial pathogen Xanthomonas arboricola pv. juglandis affects walnut production in Chile and has been associated with apical necrosis symptom and premature fruit drop; this research focused on determining if fungal pathogens were associated with this damage. The presence of BAN in commercial walnut orchards in southern Chile reveals the need for improved phytosanitary programs to control this disease.

Cucurbit leaf crumple virus (CuLCrV) associated to watermelon disease in Campeche state, Mexico.

An annual recurrent disease causing yield reduction in cultivated watermelon (Citrullus lanatus) was documented by the growers in different farms of Campeche state, Mexico. In April 2019 and March 2020 open field grown watermelon plants showed symptoms such as leaf curling, crumpling, and leaf basal or apical necrosis (Figure S1), with an incidence ranging from 30 up to 80%. These plants also presented high populations of whitefly, especially in the most affected fields. In order to identify the causal agent of the disease, a total of 22 symptomatic watermelon plants were collected in four locations from Campeche state. Total nucleic acids (DNA and RNA) were extracted from these leaf samples. Initially, RT-PCR analysis was performed with specific primers (Table S1) for cucurbit-infecting Crinivirus transmitted by whitefly but the expected size PCR product for those viruses was not amplified in any of these samples. To investigate the presence of cucurbit-infecting begomoviruses, PCR was performed by using specific primers for those begomoviruses reported in Mexico and north/central America including Squash leaf curl virus (SLCV), Watermelon chlorotic stunt virus (WmCSV), Melon chlorotic leaf curl virus (MCLCuV), and Cucurbit leaf crumple virus (CuLCrV) (Table S1). Only the expected amplicon size of ~1089 bp for CuLCrV was amplified from DNA extracts from all 22 watermelon samples, suggesting a single cucurbit-associated virus. The putative complete genome of the CuLCrV Campeche isolate was amplified by circular DNA enrichment using a Rolling Circle Amplification (RCA) procedure from two representative samples, followed by enzymatic digestion using BamHI, EcoRI, KpnI, and SacI enzymes (Inoue-Nagata et al., 2004). Expected linearized full-length viral components (~2.7 kb) were obtained with EcoRI and SacI, and both products, from one selected sample, were cloned in to pGreen0029 vector and were fully sequenced. Sequence analysis of the EcoRI clone, designated as LV2019Camp_A (deposited in GenBank accession no. MW273384) revealed the highest identity of 97.52% to CuLCrV DNA-A isolate Baja California Sur isolate (GeneBank accession no. MN625831.1), whereas the KpnI clone, designated as LV2019Camp_B (deposited in GenBank accession no. MW273385), shared 94.87% identity with DNA B of CuLCrV isolate Arizona (GeneBank accession no. AF327559.1). Subsequently, CuLCrV isolate Campeche-derived agroinfectious clone, was obtained by constructing a partial dimeric tandem repeat of both DNA-A and DNA-B components (Bang et al., 2014). Twelve watermelon plants were agroinfiltrated with the infectious clone at the fourth true leaf stage, resulting in symptomatic plants (11/12) exhibiting leaf yellowing, curling, and crumpling 15 days after agroinfiltrated (Figure S1), and CuLCrV infection was confirmed by PCR specific detection using DNA extract from non-inoculated leaves. Previously CuLCrV has been detected in the USA (Arizona, Texas, California, Florida, South Carolina, and Georgia), and north Mexico (Coahuila) infecting cucurbits including squash, cucumber, cantaloupe, pumpkin, and watermelon (Brown et al., 2000., Keinath et al., 2018), in both single and mixed infection with other whitefly transmitted RNA viruses (CYSDV, genera Crinivirus), and DNA viruses (SLCV, genera Begomovirus) (Kuo et al., 2007). To our knowledge, this is the first report of CuLCrV infecting a cucurbit crop in the Campeche state from the Yucatán peninsula, in Mexico.