Search Results (7)

Shiraz disease (SD) is one of the most destructive viral diseases of grapevines in Australia and is known to cause significant economic loss to local growers. Grapevine virus A (GVA) was reported to be the key pathogen associated with this disease. This study aimed to better understand the diversity of GVA variants both within and between individual SD and grapevine leafroll disease (LRD) affected grapevines located at vineyards in South Australia. Amplicon high throughput sequencing (Amplicon-HTS) combined with median-joining networks (MJNs) was used to analyze the variability in specific gene regions of GVA variants. Several GVA^II variant groups contain samples from both vineyards studied, suggesting that these GVA^II variants were from a common origin. Variant groups analyzed by MJNs using the overall data set denote that there may be a possible relationship between variant groups of GVA and the geographical location of the grapevines. Full article

Foeniculum vulgare (fennel) is a medicinal and aromatic plant species from Apiaceae (Umbelliferae) and has been extensively used to treat digestive and pulmonary diseases. This plant is relatively sensitive to salinity. To investigate the effect of salinity stress at levels of 0, 40, and 80 mM NaCl in combination with 0 and 5% v/v vermicompost mixed with soil on the growth as well as the physiological and biochemical traits of two fennel landraces planted in Urmia and Shiraz areas, a factorial experiment was conducted as a randomized complete block design in three replications under greenhouse conditions. The plants were sampled in the flowering stage eleven weeks after cultivation. As the results showed, vermicompost treatment together with salinity stress could enhance the growth traits of the plants, such as the length and dry weight of shoots; leaf area and dry weight of roots; photosynthetic pigments, i.e., chlorophylls and carotenoids; membrane stability index; relative water content, soluble sugar, soluble protein, proline, total phenol, and anthocyanin in the shoots; mineral elements, i.e., phosphate, nitrate, zinc, molybdenum, magnesium, and iron in the shoots; and potassium and calcium in the shoots and roots. The interaction of vermicompost and salinity also decreased the aldehydes, total flavonoids, activity of catalase enzyme and shoot starch, soluble sugar and root proline, and sodium content of both shoots and roots. In a comparison of the two studied fennel landraces, the Shiraz landrace emerged to be less affected by salinity stress. In saline conditions, vermicompost caused a change in the physiological and biochemical parameters of both fennel landraces and improved their growth. The improvement in the growth conditions in the Urmia landrace was more obvious due to the use of vermicompost. Using vermicompost plus 40 mM NaCl salinity, the dry weight of the shoot and leaf surface of the Urmia landrace increased by about 3 and 2.5 times, respectively, and under 80 mM NaCl, the dry weight of the shoot and leaf surface increased by 2.7 and 1.2 times compared to the control. According to the experiments, it seems that vermicompost can limit the harmful effects of salinity on fennel plants by affecting photosynthetic pigments, osmolytes, phenolic compounds, antioxidants, the stability of membranes, and the availability of water and essential minerals. Full article

Grapevine trunk diseases (GTDs) impact the sustainability of vineyards worldwide and management options are currently limited. Biological control agents (BCAs) may offer a viable alternative for disease control. With an aim to develop an effective biocontrol strategy against the GTD pathogen Neofusicoccum luteum, this study investigated the following: (1) the efficacy of the strains in suppressing the BD pathogen N. luteum in detached canes and potted vines; (2) the ability of a strain of Pseudomonas poae (BCA17) to colonize and persist within grapevine tissues; and (3) the mode of action of BCA17 to antagonize N. luteum. Co-inoculations of the antagonistic bacterial strains with N. luteum revealed that one strain of P. poae (BCA17) suppressed infection by 100% and 80% in detached canes and potted vines, respectively. Stem inoculations of a laboratory-generated rifampicin-resistant strain of BCA17 in potted vines (cv. Shiraz) indicated the bacterial strain could colonize and persist in the grapevine tissues, potentially providing some protection against GTDs for up to 6 months. The bioactive diffusible compounds secreted by BCA17 significantly reduced the spore germination and fungal biomass of N. luteum and the other representative GTD pathogens. Complementary analysis via MALDI-TOF revealed the presence of an unknown cyclic lipopeptide in the bioactive diffusible compounds, which was absent in a non-antagonistic strain of P. poae (JMN13), suggesting this novel lipopeptide may be responsible for the biocontrol activity of the BCA17. Our study provided evidence that P. poae BCA17 is a potential BCA to combat N. luteum, with a potential novel mode of action. Full article

Shiraz disease (SD) is an economically important virus-associated disease that can significantly reduce yield in sensitive grapevine varieties and has so far only been reported in South Africa and Australia. In this study, RT-PCR and metagenomic high-throughput sequencing was used to study the virome of symptomatic and asymptomatic grapevines within vineyards affected by SD and located in South Australia. Results showed that grapevine virus A (GVA) phylogroup II variants were strongly associated with SD symptoms in Shiraz grapevines that also had mixed infections of viruses including combinations of grapevine leafroll-associated virus 3 (GLRaV-3) and grapevine leafroll-associated virus 4 strains 5, 6 and 9 (GLRaV-4/5, GLRaV-4/6, GLRaV-4/9). GVA phylogroup III variants, on the other hand, were present in both symptomatic and asymptomatic grapevines, suggesting no or decreased virulence of these strains. Similarly, only GVA phylogroup I variants were found in heritage Shiraz grapevines affected by mild leafroll disease, along with GLRaV-1, suggesting this phylogroup may not be associated with SD. Full article

Syrah decline, first identified in Southern France in the 1990s, has become a major concern in the global grape and wine industry. This disease mainly affects Syrah (Shiraz) grapevines. Characteristic symptoms include the bright and uniform reddening of leaves throughout the canopy in late summer or early fall; the appearance of abnormalities on the trunk, mainly at the graft union (swelling, pits, grooves, and necrosis); and a reduction in vine vigor, yield and berry quality. Diseased vines may die a few years after disease onset. Damages to the vine are even more pronounced in cool climate regions such as Ontario (Canada), where the affected vines are subjected to very cold and prolonged winters, leading to large numbers of vine deaths. Despite the extensive efforts of the global grape research community over the past few decades, the etiology of this disease remains unclear. In this study, we conducted extensive analyses of viruses in declining Syrah vines identified in commercial vineyards in the Niagara region (Ontario, Canada) through high-throughput sequencing, PCR, RT-PCR and the profiling of genetic variants of select viruses. Multiple viruses and viral strains, as well as three viroids, were identified. However, an unequivocal causal relationship cannot be established between Syrah decline and any of these viruses, although the possibility that certain virus or genetic variants, or both in combination, may contribute to the disease cannot be excluded. Gleaning all information that is available to date, we feel that the traditional approach and an insistence on finding a single cause for such a complex disorder in a woody perennial fruit crop involving grafting will prove to be futile. We hope that this study offers new conceptual perspectives on the etiology of this economically important but enigmatic disease complex that affects the global grape and wine industry. Full article

Background: Additional inflammatory responses and subsequent damage—arising from enhance transcriptional activity or forming the more active protein due to existence of polymorphic sites in the pro-inflammatory cytokines gene loci—give rise to myocardial infarction susceptibility. Objectives: The aim of our study was to explore whether two interleukin-13 gene polymorphisms (−1512A/C and +2044G/A) could serve as underpins genetic susceptibility of myocardial infarction. Methods: The Iranian population that belong to the Parsis ethnic group was involved in the present study. A total 250 patients with definite myocardial infarction—meeting hypertension, hypercholesterolemia, hyperglycemia, and coronary artery disease requirements—were recruited from the Shiraz urban hospitals. 250 age- and sex-matched healthy individuals without a history of cardiovascular disease and heart disease related risk factors constituted the control group. PCR-restriction fragment length polymorphism technique applied to genotyping at −1512A/C and +2044G/A loci. Hardy–Weinberg equilibrium test was performed (combined cases and controls). The differences of the genotype frequencies in cases and controls were analyzed using a chi-square test. Logistic regression analysis was performed to assess the association between the genotypes and most important risk factors for myocardial infarction. All statistical analyses were performed in SPSS Version 22.0. p-values below 0.05 were hailed as statistically significant. Results: Deviation from Hardy–Weinberg equilibrium was not significant in the −1512A/C locus. Statistically significant difference between our study groups was found in genotype frequency of the −1512A/C. This variant was found in associated with myocardial infarction risk factors. The +2044G/A polymorphism was not in Hardy–Weinberg equilibrium and no significant difference observed in the distribution of +2044G/A genotype frequency among cases and controls. However, further analysis revealed that this genotype associated with an increased susceptibility to myocardial infarction risk factors. Conclusions: The presence of interleukin-13 −1512A/C and +2044G/A gene polymorphisms underpin myocardial infarction predisposition in the ethnic Parsis of the Iranian population. Full article

Grapevine viruses are found throughout the viticultural world and have detrimental effects on vine productivity and grape and wine quality. This report provides a comprehensive and up-to-date review on grapevine viruses in Australia with a focus on “Shiraz Disease” (SD) and its two major associated viruses, grapevine virus A (GVA) and grapevine leafroll-associated virus 3 (GLRaV-3). Sensitive grapevine cultivars like Shiraz infected with GVA alone or with a co-infection of a leafroll virus, primarily GLRaV-3, show symptoms of SD leading to significant yield and quality reductions in Australia and in South Africa. Symptom descriptors for SD will be outlined and a phylogenetic tree will be presented indicating the SD-associated isolates of GVA in both countries belong to the same clade. Virus transmission, which occurs through infected propagation material, grafting, and naturally vectored by mealybugs and scale insects, will be discussed. Laboratory and field-based indexing will also be discussed along with management strategies including rogueing and replanting certified stock that decrease the incidence and spread of SD. Finally, we present several cases of SD incidence in South Australian vineyards and their effects on vine productivity. We conclude by offering strategies for virus detection and management that can be adopted by viticulturists. Novel technologies such as high throughput sequencing and remote sensing for virus detection will be outlined. Full article