The potential use of carvacrol for the control of <Emphasis Type="Italic">Meloidogyne javanica</Emphasis>

The protein kinase HOG1 in high osmolarity glycerol pathway is one of mitogen-activated protein kinases and plays an important role in fungi cellular responses to external stress and stimuli. In this study, AlHOG1, a yeast HOG1 homolog, was isolated from tobacco pathogenic fungus Alternaria longipes and its disrupted mutants were generated using homologous recombination. Compared with the wild-type strain, the mutants grew slower under Minimal-Media, produced less conidia on Potato-Dextrose-Agar and showed a retardation phenotype in conidial germination rate. Colony color observation indicated that AlHOG1 most likely negatively regulated melanin production under nutrients-deficient or osmotic stress. The same action mode of AlHOG1 on hyphal growth in response to certain carbon or nitrogen sources was speculated. Additionally, the disrupted strains were sensitive to osmotic and oxidative stress, and showed increased resistance to dicarboximide, phenylpyrrole and carbendazim fungicides. Meanwhile, results from the comparative analysis between the AlHOG1- and the AlHK1 (encoding a group III histidine kinase)-disrupted mutants showed that AlHOG1 mediated-pathway was partly regulated by the upstream AlHK1 kinase for cellular resistance to salts osmotic stress and that AlHK1 was a primary regulator for cellular sugar and fungicides stress adaptation and likely modulated both AlHOG1-mediated pathway and other unknown mechanisms. Noteworthily, AlHOG1 but not AlHK1 was confirmed to be associated with high concentration glycerol adaptation, which is the first report to our knowledge. Overall, our results indicated that AlHOG1 was involved in multiple physiological processes in A. longipes, including mycelial and conidial development, melanin production, nutrients sensing and multi-stress responses.     

Postharvest Biological Control of Botrytis cinerea on Kiwifruit by Volatiles of [Isabella] Grapes

ABSTRACT The potential of volatile substances emitted by 'Isabella' grapes (Vitis labrusca) to control gray mold (Botrytis cinerea) on 'Hayward' kiwifruit (Actinidia deliciosa) was studied. The closed Mariotte system was used as a bioassay method to analyze quantitatively the biological action of these volatiles on B. cinerea growth. In vivo experiments compared the effects of volatiles from 'Isabella' grapes versus volatiles from 'Roditis' grapes (V. vinifera) and a B. cinerea control on the growth and disease development of B. cinerea on kiwifruit. The effect of the volatiles on the growth of B. cinerea was tested at various temperatures and times of inoculation after the wounding of kiwifruit, as well as using various weights and developmental stages of the grapes. The 'Isabella' volatiles limited the incidence of infection by reducing both the inoculum density and the activity of the pathogen. The weight and developmental stage of the grapes were important in the degree of inhibitory action of the 'Isabella' volatiles. The inhibitory action was more pronounced at 21 degrees C irrespective of the inoculation time after wounding. The study shows the potential for successful biological control of B. cinerea on kiwifruit by volatiles from 'Isabella' grapes.     

Reliability of indicators of sheep welfare assessed by a group observation method

Assessments of animal-based outcomes form the core of routine veterinary clinical examinations and are being increasingly used as indicators of animal welfare. A method of group observation that did not require gathering and handling of individual sheep, was used to assess eight animal-based indicators of sheep welfare: demeanour, skin irritation, wool loss, excessive panting, coughing, lameness, and cleanliness of the ventral abdominal and 'breech' (perineum/gluteal/caudal hindlimb) areas. The inter-observer reliability of two or three observers who independently assessed these indicators was tested on 2406 adult sheep and growing lambs across 36 farms and the intra-observer reliability of an experienced, veterinary assessor--the 'test standard observer'--was assessed on 88 adult sheep during four on-farm assessments. Observer reliability was evaluated using Cronbach's alpha (α) comparison of the recorded proportion (%) of sheep affected by each welfare condition and by binomial logistic regression modelling. High levels of inter-observer reliability were identified for the assessment of group lameness (α 0.76-1.00) and cleanliness of the breech area (α 0.97-1.00). Excellent intra-observer reliability was determined for lameness (α 0.99), cleanliness of the breech area (α 0.97), demeanour (α 1.00) and wool loss (α 1.00). In addition, proportion data and logistic regression models identified few between-observer differences. The results suggest that welfare outcomes based on observations of the behaviour and physical appearance of individual animals within a group may offer a reliable and feasible measurement tool for the on-farm assessment of sheep welfare.     

Exploration of the antiplatelet activity profile of betulinic acid on human platelets

Betulinic acid, a natural pentacyclic triterpene acid, presents a diverse mode of biological actions including antiretroviral, antibacterial, antimalarial, and anti-inflammatory activities. The potency of betulinic acid as an inhibitor of human platelet activation was evaluated, and its antiplatelet profile against in vitro platelet aggregation, induced by several platelet agonists (adenosine diphosphate, thrombin receptor activator peptide-14, and arachidonic acid), was explored. Flow cytometric analysis was performed to examine the effect of betulinic acid on P-selectin membrane expression and PAC-1 binding to activated platelets. Betulinic acid potently inhibits platelet aggregation and also reduced PAC-1 binding and the membrane expression of P-selectin. Principal component analysis was used to screen, on the chemical property space, for potential common pharmacophores of betulinic acid with approved antithrombotic drugs. A common pharmacophore was defined between the NMR-derived structure of betulinic acid and prostacyclin agonists (PGI2), and the importance of its carboxylate group in its antiplatelet activity was determined. The present results indicate that betulinic acid has potential use as an antithrombotic compound and suggest that the mechanism underlying the antiplatelet effects of betulinic acid is similar to that of the PGI2 receptor agonists, a hypothesis that deserves further investigation.