Yazar "Soylu, EM" seçeneğine göre listele

Listeleniyor 1 - 17 / 17
  • Küçük Resim
    Öğe
    Antimicrobial activities of the essential oils of various plants against tomato late blight disease agent Phytophthora infestans
    (Springer, 2006) Soylu, EM; Soylu, S; Kurt, S
    The aim of this study was to find an alternative to synthetic fungicides currently used in the control of devastating oomycete pathogen Phytophthora infestans, causal agent of late blight disease of tomato. Antifungal activities of essential oils obtained from aerial parts of aromatic plants such as oregano (Origanum syriacum var. bevanii), thyme (Thymbra spicata subsp. spicata), lavender (Lavandula stoechas subsp. stoechas), rosemary (Rosmarinus officinalis), fennel (Foeniculum vulgare), and laurel (Laurus nobilis), were investigated against P. infestans. Both contact and volatile phase effects of different concentrations of the essential oils used were determined by using two in vitro methods. Chemical compositions of the essential oils were also determined by GC-MS analysis. Major compounds found in essential oils of thyme, oregano, rosemary, lavender, fennel and laurel were carvacrol (37.9%), carvacrol (79.8), borneol (20.4%), camphor (20.2%), anethole (82.8%) and 1,8-cineole (35.5%), respectively. All essential oils were found to inhibit the growth of P. infestans in a dose-dependent manner. Volatile phase effect of oregano and thyme oils at 0.3 mu g/ml air was found to completely inhibit the growth of P. infestans. Complete growth inhibition of pathogen by essential oil of fennel, rosemary, lavender and laurel was, however, observed at 0.4-2.0 mu g/ml air concentrations. For the determination of the contact phase effects of the tested essential oils, oregano, thyme and fennel oils at 6.4 mu g/ml were found to inhibit the growth of P. infestans completely. Essential oils of rosemary, lavender and laurel were inhibitory at relatively higher concentrations (12.8, 25.6, 51.2 mu g/ml respectively). Volatile phase effects of essential oils were consistently found to be more effective on fungal growth than contact phase effect. Sporangial production was also inhibited by the essential oil tested. Light and scanning electron microscopic (SEM) observation on pathogen hyphae, exposed to both volatile and contact phase of oil, revealed considerable morphological alterations in hyphae such as cytoplasmic coagulation, vacuolations, hyphal shrivelling and protoplast leakage.
  • [ N/A ]
    Öğe
    Chemical composition and antifungal activity of the essential oil of Artemisia annua L. against foliar and soil-borne fungal pathogens
    (Eugen Ulmer Gmbh Co, 2005) Soylu, EM; Yigitbas, H; Tok, FM; Soylu, S; Kurt, S; Baysal, Ö; Kaya, AD
    The chemical composition of the essential oil of Artemisia annua L. was determined by GC/MS analysis. Among the thirty-seven constituents found, camphor (31.7 %), artemisia ketone (22.3 %), 1,8-cincole (10.1 %), caryophyllene oxide (7.1 %), alpha-copaene (3.4 %) and camphene (3-3 %) were the major components. The in vitro antifungal activity of the essential oil was evaluated against economically important foliar and soil-borne fungal pathogens of tomato, including Sclerotinia sclerotiorum, Botrytis cinerea, Phytophthora infestans and Verticillium dahliae. Both contact and volatile phase effects of different concentrations of the essential oil were determined by using two different methods. Amongst the fungal isolate, S. sclerotiorum was found to be highly sensitive to volatile and contact phase of the essential oil. Minimum fungicidal concentrations of the volatile phase of the essential oil for S. sclerotiorum, B. cinerea, P. infestans and V. dahliae were 1.6, 2.4, 2.4 and 4.4 mu g/ml air, respectively. The essential oil in the contact phase showed minimum fungicidal concentration ranging from 6.4 mu g/ ml to 51.2 mu g/ml. Volatile and contact phase of the essential oils, at 2.4 and 51.2 mu g/ml concentrations, were found to completely inhibit the conidial germination and germ tube elongation of both fungal pathogen tested.
  • Küçük Resim
    Öğe
    First report of alternaria leaf blight caused by Alternaria dauci on carrot in Turkey
    (Blackwell Publishing Ltd, 2005) Soylu, S; Kurt, S; Soylu, EM; Tok, FM
    [Abstract Not Available]
  • Küçük Resim
    Öğe
    First report of cercospora leaf spot on Swiss chard caused by Cercospora beticola in Turkey
    (Blackwell Publishing Ltd, 2003) Soylu, S; Soylu, EM; Kurt, S
    [Abstract Not Available]
  • Küçük Resim
    Öğe
    First report of crater rot caused by Rhizoctonia carotae on carrots (Daucus carota) in Turkey
    (Wiley, 2005) Kurt, S; Soylu, EM; Soylu, S; Tok, FM
    [Abstract Not Available]
  • Küçük Resim
    Öğe
    First report of downy leaf spot of walnuts caused by Microstroma juglandis in Turkey
    (Blackwell Publishing Ltd, 2003) Kurt, S; Soylu, EM; Soylu, S
    [Abstract Not Available]
  • Küçük Resim
    Öğe
  • Küçük Resim
    Öğe
    First report of phloeospora leaf spot on mulberry caused by Phloeospora maculans (= Cylindrosporium maculans) in the East Mediterranean region of Turkey
    (Blackwell Publishing Ltd, 2003) Soylu, S; Kurt, S; Soylu, EM
    [Abstract Not Available]
  • Küçük Resim
    Öğe
    First report of powdery mildew caused by Erysiphe heraclei on dill (Anethum graveolens) in Turkey
    (Blackwell Publishing Ltd, 2003) Soylu, EM; Soylu, S
    [Abstract Not Available]
  • Küçük Resim
    Öğe
    First report of powdery mildew caused by Leveillula taurica on leek (Allium porrum) in Turkey
    (Wiley, 2004) Kurt, S; Soylu, S; Soylu, EM; Tok, FM
    [Abstract Not Available]
  • Küçük Resim
    Öğe
    First report of powdery mildew caused by Podosphaera phaseoli (syn. Sphaerotheca phaseoli) on cowpea (Vigna sinensis) in Turkey
    (Blackwell Publishing Ltd, 2004) Soylu, EM; Soylu, S; Kurt, S
    [Abstract Not Available]
  • Küçük Resim
    Öğe
    Induction of defence-related enzymes and resistance by the plant activator acibenzolar-S-methyl in tomato seedlings against bacterial canker caused by Clavibacter michiganensis ssp michiganensis
    (Blackwell Publishing Ltd, 2003) Baysal, Ö; Soylu, EM; Soylu, S
    Using tomato seedlings, the plant defence activator acibenzolar-S-methyl (benzo-[1,2,3]-thiadiazole-7-carbothioic acid-S-methyl ester, ASM; Bion 50 WG) was assayed for its ability to induce resistance against Clavibacter michiganensis ssp. michiganensis, the causal agent of bacterial canker of tomato. In ASM-pretreated plants, reduction in disease severity (up to 76.3%) was correlated with lower bacterial growth (up to 68.2% lower) during the time course of infection. To understand the possible mechanism of action of ASM, alterations in the activities of peroxidase (POX) and chitinase were assessed as markers of resistance. The enhanced resistance of ASM-treated plants was associated with significant increases in the activities of POX and chitinase.
  • Küçük Resim
    Öğe
    Induction of disease resistance and antioxidant enzymes by acibenzolar-S-methyl against bacterial canker (Clavibacter michiganensis subsp michiganensis) in tomato
    (Springer, 2003) Soylu, EM; Soylu, S; Baysal, Ö
    The plant defence activator acibenzolar-S-methyl (Bion) was assayed on tomato seedlings for its ability to induce multicomponent defence response against Clavibacter michiganensis subsp. michiganensis (Cmm). Pretreatment of plants with ASM reduced the severity of the disease as well as the growth of the bacteria in planta. In ASM-treated plants, reduction in disease severity (up to 75 %) was correlated with the suppression of bacterial growth (up to 68.2%) during the time course of infection. In plants treated with ASM, activities of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione S-transferase (GST) were estimated as markers of resistance. The results indicated that ASM treatment led to enhanced activities of SOD and GST in tomato leaves. A slightly increase in SOD and GST activities was also found in Cmm-infected leaves. However, the increase in enzyme activities occurred much more rapidly and was more strongly enhanced in Cmm-infected leaves that were previously treated with ASM. The involvement of both enzymes in ASM mediated resistance in tomato is discussed.
  • Küçük Resim
    Öğe
    Induction of disease resistance by the plant activator, acibenzolar-S-methyl (ASM), against bacterial canker (Clavibacter michiganensis subsp michiganensis) in tomato seedlings
    (Elsevier Sci Ireland Ltd, 2003) Soylu, S; Baysal, Ö; Soylu, EM
    The plant defence activator acibenzolar-S-methyl (benzo [1,2,3]thiadiazole-7-carbothioic acid-S-methyl ester, ASM; Bion 50 WG) was assayed on tomato seedlings for its ability to induce resistance against Clavibacter michiganensis subsp. michiganensis (Cmm), the causal agent of bacterial canker of tomato. Pre-treatment of plants with ASM reduced the severity of the disease as well as the growth of the bacteria in planta. In ASM-treated plants, reduction in disease severity (up to 75%) was correlated with suppression of bacterial growth (up to 68.2%) during the time course of infection. In plants treated with ASM, activities of peroxidase (POX) and glutathione peroxidase (GPX) were determined as markers of resistance. Applications of ASM induced a progressive and significant increase of both enzymes in locally treated tissues. Such responses were expressed earlier and with a much higher magnitude when ASM-treated seedlings were challenged with the pathogen, thus providing support to the concept that a signal produced by the pathogen is essential for triggering enhanced synthesis and accumulation of these enzymes. No such activities were observed in water-treated control plants. Therefore, the slower symptom development and reduction in bacterial growth in ASM-treated plants might be due to the increase in activity of both oxidative and antioxidative protection systems in planta. (C) 2003 Elsevier Ireland Ltd. All rights reserved.
  • Küçük Resim
    Öğe
    Light and electron microscopy of the compatible interaction between Arabidopsis and the downy mildew pathogen Peronospora parasitica
    (Wiley, 2003) Soylu, EM; Soylu, S
    In this study, we focused on compatible interactions between Peronospora parasitica isolate Emoy-2 and wild-type (Oy-0) and mutant (Ws-eds1 ) Arabidopsis thaliana accessions by using light and transmission electron microscopy (TEM). Light microscopy of compatible interactions revealed that conidia germinated and penetrated through the anticlinal cell walls of two epidermal cells. Rapid spreading of the hyphal growth with formation of numerous haustoria within the mesophyll cells was subsequently followed by profuse sporulation in the absence of host cell necrosis on both wild-type and mutant accessions. TEM observations revealed that coenocytic intercellular hyphae ramified and spread intercellularly throughout the host tissue forming several haustoria in host mesophyll cells. Intracellular haustoria were lobed with the diameter of 6-7 mum. Each haustorium was connected to intercellular hyphae in the absence of apparent haustorial neck. The cytoplasm of the haustorium included the organelles characteristic of the pathogen. Callose-like deposits were frequently observed at sites of penetration around the proximal region of the haustorial neck. Apart from a few callose ensheatments, no obvious response was observed in host cells following formation of haustoria. Most of mesophyll cells contained normal haustoria and the host cytoplasm displayed a high degree of structural integrity. Absence of host cell wall alteration and cell death in penetrated host cell of both accessions suggest that the pathogen exerts considerable control over basic cellular processes and in this respect, response to this biotroph oomycete differs considerably from responses to other pathogens such as necrotrophs.
  • Küçük Resim
    Öğe
    Preliminary characterization of race-specific elicitors from Peronospora parasitica and their ability to elicit phenolic accumulation in Arabidopsis
    (Priel Publ, 2003) Soylu, S; Soylu, EM
    Intercellular washing fluid (IWF) obtained from the susceptible Arabidopsis accession Ws-eds1 inoculated with Peronospora parasitica isolate Emoy-2, contained an elicitor of necrosis with ecotype specificity towards Arabidopsis accessions with particular resistance genes. This elicitor caused necrosis on the highly resistant accessions La-er, Nd-1 and partly on Col-5, but not on the susceptible accessions Ws-eds1 and Oy-0. In resistant plants, injection of IWF caused hypersensitive reaction (HR)-like cell collapse which was associated with the accumulation of phenolics and lignin-like material in walls of cells undergoing cell death. The elicitor is sensitive to proteinase K and pronase enzymes, heating and autoclaving but insensitive to periodate oxidation, freezing and thawing, and is not dialyzable. Results suggest that the elicitor is a protein. Fractionation experiments using size-exclusion membranes revealed that elicitor activity has a molecular weight in excess of 100 kDa.
  • Küçük Resim
    Öğe
    Ultrastructural characterisation of pathogen development and host responses during compatible and incompatible interactions between Arabidopsis thaliana and Peronospora parasitica
    (Academic Press Ltd Elsevier Science Ltd, 2004) Soylu, EM; Soylu, S; Mansfield, JW
    Compatible and incompatible interactions between the Peronospora parasitica isolate Emoy2 and Arabidopsis thaliana accessions were investigated using transmission electron microscopy. The compatible interaction in the susceptible accession Oystese (Oy-0) was characterized by the rapid spread of intercellular hyphae, a high frequency of haustorium formation within host mesophyll cells and the production of conidia in the absence of host cell necrosis. Resistant Arabidopsis accessions Columbia (Col-0), Landsberg erecta (Ler-0) and Wassilewskija (Ws-0) recognize Emoy2 in a gene-for-gene dependent manner. The RPP4 resistance gene in Col-0, RPP1A,B in Ws-0, and RPP5 and RPP8 in Ler-0 confer resistance to Emoy2. The responses observed in Col-0 indicated only partial incompatibility as the plant reaction was characterized by the occurrence of delayed, light sporulation and formation of necrotic flecks. The deposition of ensheathing material around haustoria followed in some cases by host cell death was identified as the main mechanisms of resistance in this accession. Cotyledons of Ler-0 and Ws-0 developed necrotic fleck or pitting symptoms, respectively, but no sporulation. The main characteristics of the resistant responses were the rapid occurrence of the hypersensitive reaction (HR) and deposition of callose-enriched wall appositions (papillae) in penetrated and adjacent cells. Necrosis extended beyond the zone of restricted colonisation in Ws-O. Location of callose in ensheathing material around haustoria and in papillae was confirmed by immunocytochemistry. The macroscopic phenotypes observed depended on the extent of hyphal development and the number of plant cells affected. (c) 2005 Elsevier Ltd. All rights reserved.