Nanogram amounts of salicylic acid produced by the rhizobacterium Pseudomonas aeruginosa 7NSK2 activate the systemic acquired resistance pathway in bean

Root colonization by specific nonpathogenic bacteria can induce a systemic resistance in plants to pathogen infections. In bean, this kind of systemic resistance can be induced by the rhizobacterium Pseudomonas aeruginosa 7NSK2 and depends on the production of salicylic acid by this strain. In a model with plants grown in perlite we demonstrated that Pseudomonas aeruginosa 7NSK2-induced resistance is equivalent to the inclusion of 1 nM salicylic acid in the nutrient solution and used the latter treatment to analyze the molecular basis of this phenomenon. Hydroponic feeding of 1 nM salicylic acid solutions induced phenylalanine ammonia-lyase activity in roots and increased free salicylic acid levels in leaves. Because pathogen-induced systemic acquired resistance involves similar changes it was concluded that 7NSK2-induced resistance is mediated by the systemic acquired resistance pathway. This conclusion was validated by analysis of phenylalanine ammonia-lyase activity in roots and of salicylic acid levels in leaves of soil-grown plants treated with Pseudomonas aeruginosa. The induction of systemic acquired resistance by nanogram amounts of salicylic acid is discussed with respect to long-distance signaling in systemic acquired resistance

"Pharmacology of salicin derivatives in sheep" : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand

Content removed from thesis due to copyright reasons: Figure 1.20(e). S. viminalis. Retrieved from Valerie J.:http://gardeners-word.blogspot.co.uk/Sheep suffer from pain during various husbandry practices as well as during injury or diseases such as footrot. This pain could be potentially minimised with the use of analgesics such as non-steroidal anti-inflammatory drugs (NSAID). Unfortunately, there are very few registered NSAIDs for sheep. Thus, registered analgesics for cattle, for instance ketoprofen and meloxicam are used in sheep. Again, the high cost of analgesics and associated potential side effects such as reduced fertility, gastric irritation, gastric ulcers etc. evident in other species usually limits their use in sheep. Fear of residues in meat may stop some farmers from using analgesics. Considering these problems, this study was designed as a groundwork to explore a possible and potential use of natural, inexpensive analgesic for sheep. Salicylic acid, a derivative of salicin, is a NSAID used effectively in humans as an analgesic since ancient times in the form of willow bark and leaves. During this research study, the pharmacokinetics of salicylic acid in sheep was analysed after administration of the sodium salt of salicylic acid (sodium salicylate/NaS) intravenously and orally at different dose rates. The analgesic efficacy of salicylic acid in sheep was also studied after administration of sodium salicylate at different dose rates by measuring mechanical and thermal nociceptive thresholds. The minimum therapeutic plasma concentration of salicylic acid for analgesia in sheep ranged from 25 to 30 μg/mL, which was achieved for about 30 minutes by a 200 mg/kg intravenous dose of NaS. During this study it was discovered that thermal nociceptive threshold testing is unable to detect any analgesia from salicylic acid and ketoprofen in sheep. However, mechanical nociceptive threshold testing efficiently detected the analgesic effects of salicylic acid and the positive control, ketoprofen. The seasonal variation of willow salicin content (principal precursor of salicylic acid in willow) was studied over a year. The salicin in willows in New Zealand is higher during the summer months as compared to the winter months of the year, and appears greater in areas subject to drought. The analgesic efficacy of willow leaves can be assessed by feeding the willow leaves to lame sheep as they readily eat willow leaves. However, to assess the analgesia produced by willow in sheep, further research is warranted. Keywords: Salicin, sheep, salicylic acid, analgesia, HPLC, nociceptive testing, willow

Antifungal effect and reduction of Ulmus minor symptoms to Ophiostoma novo-ulmi by carvacrol and salicylic acid

There are still no effective means to control Dutch elm disease (DED), caused by the vascular fungi Ophiostoma ulmi and O. novo-ulmi. Plant phenolics may provide a new strategy for DED control, given their known antifungal activity against pathogens and their involvement in plant defence mechanisms. The in vitro antifungal activity of salicylic acid, carvacrol, thymol, phenol, o-cresol, m-cresol, p-cresol, and 2,5-xylenol against the DED pathogens was tested. Also, the protective effect of watering Ulmus minor seedlings with these compounds was tested against O. novo-ulmi. Salicylic acid, carvacrol, and thymol showed the strongest antifungal in vitro activity, while carvacrol and salicylic acid provided the strongest in vivo protection against O. novo-ulmi (63 and 46% reduction of leaf wilting symptoms with respect to controls, respectively). The effect of the treatments on tree phenology was low, and a significant negative relation was observed between the number of days to bud burst and the leaf wilting symptoms after inoculation, probably determined by genetic differences among the elm tree progenies used. The treatments with salicylic acid, carvacrol and thymol induced the highest shift in phenolic metabolite profile with respect to control trees. The protective effect of carvacrol and salicylic acid is discussed in terms of their combined activity as antifungal compounds and as inductors of tree defence responses

Salicylic acid produced by the rhizobacterium Pseudomonas aeruginosa 7NSK2 induces resistance to leaf infection by Botrytis cinerea on bean

Selected strains of nonpathogenic rhizobacteria can induce a systemic resistance in plants that is effective against various pathogens. In an assay with bean plants, we investigated which determinants of the rhizobacterium Pseudomonas aeruginosa 7NSK2 are important for induction of resistance to Botrytis cinerea. By varying the iron nutritional state of the bacterium at inoculation, it was demonstrated that induced resistance by P. aeruginosa 7NSK2 was iron-regulated. As P. aeruginosa 7NSK2 produces three siderophores under iron limitation, pyoverdin, pyochelin, and salicylic acid, we investigated the involvement of these iron-regulated metabolites in induced resistance by using mutants deficient in one or more siderophores. Results demonstrated that salicylic acid production was essential for induction of resistance to B. cinerea by Fl aeruginosa 7NSK2 in bean and did not exclude a role for pyochelin. A role for pyoverdin, however, could not be demonstrated. Transcriptional activity of salicylic acid and pyochelin biosynthetic genes was detected during P. aeruginosa 7NSK2 colonization of bean. Moreover, the iron nutritional state at inoculation influenced the transcriptional activity of salicylic acid and pyochelin biosynthetic genes in the same way as it influenced induction of systemic resistance to B. cinerea

EPR studies of intermolecular interactions and competitive binding of drugs in a drug-BSA binding model

Understanding intermolecular interactions between drugs and proteins is very important in drug delivery studies. Here, we studied different binding interactions between salicylic acid and bovine serum albumin (BSA) using electron paramagnetic resonance (EPR) spectroscopy. Salicylic acid was labeled with a stable radical (spin label) in order to monitor its mobilized (free) or immobilized (bound to BSA) states. In addition to spin labeled salicylic acid (SL-salicylic acid), its derivatives including SL-benzoic acid, SL-phenol, SL-benzene, SL-cyclohexane and SL-hexane were synthesized to reveal the effects of various drug binding interactions. EPR results of these SL-molecules showed that hydrophobic interaction is the main driving force. Whereas each of the two functional groups (-COOH and -OH) on the benzene ring has a minute but detectable effect on the drug-protein complex formation. In order to investigate the effect of electrostatic interaction on drug binding, cationic BSA (cBSA) was synthesized, altering the negative net charge of BSA to positive. The salicylic acid loading capacity of cBSA is significantly higher compared to that of BSA, indicating the importance of electrostatic interaction in drug binding. Moreover, the competitive binding properties of salicylic acid, ibuprofen and aspirin to BSA were studied. The combined EPR results of SL-salicylic acid/ibuprofen and SL-ibuprofen/salicylic acid showed that ibuprofen is able to replace up to ∼83% of bound SL-salicylic acid, and salicylic acid can replace only ∼14% of the bound SL-ibuprofen. This indicates that ∼97% of all salicylic acid and ibuprofen binding sites are shared. On the other hand, aspirin replaces only ∼23% of bound SL-salicylic acid, and salicylic acid replaces ∼50% of bound SL-aspirin, indicating that ∼73% of all salicylic acid and aspirin binding sites are shared. These results show that EPR spectroscopy in combination with the spin labeling technique is a very powerful method to investigate drug binding dynamics in detail.Turkish Scientific and Technological Research Council (2232-114C082

Growth, Yield and Resistance Responses of Three Cultivars on True Seed Shallots to Twisted Disease with Salicylic Acid Application

Twisted disease is one of the main diseases on shallot caused by Fusarium sp. One method to increase the resistance of shallot cultivars to the twisted disease can be performed by using True Seed Shallot (TSS) combining with a salicylic acid application. TSS is known as free pathogen. The objective of the research was to examine the effects of a salicylic acid application to the growth, yield and resistance responses of TSS on Tuktuk, Sanren and Lokananta cultivars to the twisted disease. The research was arranged in factorial Completely Randomized Design (CRD), consisting of two factors with three replications. The first factor included Tuktuk, Sanren and Lokananta cultivars and the second factor comprised salicylic acid applications (without salicylic acid and inoculation, without salicylic acid with inoculation, immersion treatment of salicylic acid with inoculation, spray treatment with inoculation as well as immersion and spray treatment with inoculation). The results showed that the application of salicylic acid in different treatments had the same effects on the growth, yield and resistance of TSS. An interesting result is found, in which the application of salicylic acid by immersing and spraying could reduce the incidence of twisted disease by 12.5% in TSS. Therefore, the application of salicylic acid by immersing and spraying can be one of the recommended twisted disease management

The Endophytic Bacteria, Salicylic Acid, and Their Combination as Inducers of Rice Resistance Against Xanthomonas Oryzae Pv. Oryzae

Bacterial leaf damage or blight brought by bacteria Xanthomonas oryzae pv. oryzae (X. oryzae pv. oryzae) is considered as an extremely serious disease of rice worldwide, including Indonesia. Induced resistance using chemical and biological agents was considered as a method to control the disease. The objectives of this research were to analyze of endophytic bacteria (Lysinibacillus sphaericus/L.sphaericus) and salicylic acid as the inducers of rice resistance against X. oryzae pv. oryzae. This study used three-factorial incompletely randomized designs to study the effect of endophytic bacteria and salicylic acid on three varieties of rice. The results of the study showed that endophytic bacteria and salicylic acid induced rice resistance to X. oryzae pv. oryzae. This endophytic bacterium was also able to increase the plant height (AUPHGC), the number of tillers (AUNTGC), and the number of productive tillers. The application of salicylic acid at the concentrations of 10 mM was able to suppress the BLB disease and increased the number of tillers and 1000-grain weight. The result of study showed that the endophytic bacteria and salicylic acid could induce resistance of rice varities against BLB disease and increased the number of productive tillers

Treatment of Nongenital Warts

Topical salicylic acid, cryotherapy, and topical fluorouracil are effective for treating nongenital warts. (Strength of Recommendation [SOR]: A, based on a systematic review of randomized controlled trials [RCTs].) Fluorouracil is more expensive than salicylic acid and produces more adverse effects, such as pain and blisters. The combination of salicylic acid and cryotherapy may be better than either treatment alone, although salicylic acid may be more cost-effective than cryotherapy. Bleomycin and interferons should not be used to treat nongenital warts. (SOR: A, based on a meta-analysis.