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Title:DINAMIKA VSEBNOSTI ANTIOKSIDANTOV V LUBJU NAVADNE SMREKE [Picea abies (L.) H. KARST.] PO OKUŽBI Z GLIVO MODRIVKO [Ceratocystis polonica (SIEM.) C. MOREAU]
Authors:ID Felicijan, Mateja (Author)
ID Urbanek Krajnc, Andreja (Mentor) More about this mentor... New window
ID Kraševec, Nada (Comentor)
Files:.pdf MAG_Felicijan_Mateja_2014.pdf (3,53 MB)
MD5: 8B50C57A0E9DBEF3396702294D454083
 
Language:Slovenian
Work type:Master's thesis
Organization:FKBV - Faculty of Agriculture and Life Sciences
Abstract:Osmerozobi smrekov lubadar (Ips typographus L.) in z njim povezana patogena gliva modrivka Ceratocystis polonica (SIEM.) C. MOREAU sta eden izmed najbolj nevarnih škodljivcev navadne smreke [Picea abies (L.) H. KARST.]. Obrambni sistem lubja smreke zajema tri obrambne mehanizme (konstitutivno, inducirano in sistemsko pridobljeno obrambo) z različnimi obrambnimi strategijami. V sklopu magistrskega dela nas je zanimala dinamika vsebnosti posameznih fenolov, tiolov in askorbata v lubju navadne smreke pri okužbi s patogeno glivo v petmesečnem obdobju med 18. aprilom in 9. septembrom 2011. Začetni odziv na okužbo z glivo C. polonica je spremljal hiter porast večine antioksidantov. Tri dni po okužbi sta se močno povečali koncentraciji izorapontina in taksifolina, vsebnost katehina pa je padla. Kasneje so se koncentracije skupnih fenolov in katehina v floemu okuženih dreves do septembra postopoma povečevale. Nad nivojem kontrole so skozi petmesečno obdobje raziskave ostale tudi koncentracije taksifolina, ki so signifikantno odstopale v aprilu in juniju. Nekoliko višje koncentracije astringina v aprilu in maju so se kot odgovor na okužbo v kasnejših vzorčnih terminih znižale. Podobno se je tudi raven izorapontina v aprilu močno dvignila, nato pa se od junija dalje spustila pod raven kontrole. Za inicialni odziv askorbatno-glutationskega sistema na okužbo s patogeno glivo smo zabeležili značilno visoko raven glutation disulfida, ki ga spremlja nekoliko povišana raven skupnega askorbata in povečana aktivnost glutation reduktaze. Tri tedne kasneje smo v okuženih vzorcih zabeležili močno kopičenje tiolov, medtem ko so koncentracije skupnega askorbata signifikantno padle, redoks stanje askorbata pa se je preusmerilo k bolj oksidiranim vrednostim. Do sredine julija smo v okuženih drevesih izmerili tudi postopno povečevanje koncentracij skupnega glutationa, ki ga spremlja povečana aktivnost glutation reduktaze in obnovljeno redoks stanje glutationa. V septembru je askorbatno-glutationski sistem znotraj lubja okuženih dreves ponovno dosegel ravnovesje. Časovne spremembe koncentracij fenolnih snovi odražajo povečano obremenitev askorbatno-glutationskega sistema, ki je potreben za odstranjevanje v obrambi nastalih fenoksi radikalov. Na podlagi rezultatov lahko zaključimo, da je antioksidativni odziv lubja zaznamovan z nihanji v koncentracijah posameznih obrambnih molekul in določenimi časovnimi spremembami, na podlagi česar predpostavljamo, da je askorbatno-glutationski cikel ključni del obrambe lubja in je posredno vpleten tudi v metabolizem fenolov.
Keywords:navadna smreka Picea abies (L.)H.KARST., gliva modrivka Ceratocystis polonica (SIEM.) C. MOREAU, antioksidanti, fenoli, askorbatno-glutationski sistem
Place of publishing:Maribor
Year of publishing:2014
PID:20.500.12556/DKUM-45153 New window
NUK URN:URN:SI:UM:DK:2XIBGPY3
Publication date in DKUM:01.09.2014
Views:2411
Downloads:273
Metadata:XML DC-XML DC-RDF
Categories:FKBV
:
FELICIJAN, Mateja, 2014, DINAMIKA VSEBNOSTI ANTIOKSIDANTOV V LUBJU NAVADNE SMREKE [Picea abies (L.) H. KARST.] PO OKUŽBI Z GLIVO MODRIVKO [Ceratocystis polonica (SIEM.) C. MOREAU] [online]. Master’s thesis. Maribor. [Accessed 26 March 2025]. Retrieved from: https://dk.um.si/IzpisGradiva.php?lang=eng&id=45153
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Secondary language

Language:English
Title:THE DYNAMICS OF ANTIOXIDANT CONTENTS IN NORWAY SPRUCE [Picea abies (L.) H. KARST.] BARK AFTER BLUE-STAIN FUNGUS [Ceratocystis polonica (SIEM.) C. MOREAU] INFECTION
Abstract:The European spruce bark beetle (Ips typographus L.) and the associated pathogenic blue stain fungus Ceratocystis polonica (SIEM.) C. MOREAU are the most devastating pests regarding Norway spruce [Picea abies (L.) H. KARST.]. The bark defence system involves three defence mechanisms (constitutive, induced defence and systemic acquired resistance) with different defence strategies. In this master thesis we were interested in the temporal dynamics of individual phenolics, thiols and ascorbate in Norway spruce phloem over 5 month period, from April 18th to September 9th, 2011 after inoculation with blue-stain fungus C. polonica. The initial reaction on pathogen infection was characterised by a rapid increase of most antioxidant compounds. Three days after inoculation isorhapontin and taxifolin concentrations significantly increased, whereas catechin contents were significantly lowered. On later sampling dates, total phenolics and catechin concentrations in the phloem of infected trees gradually increased until September. Taxifolin concentrations were higher in the infected samples, showing a double peak with maxima in April and June and later remained above the control level. The slightly accumulated astringin contents in April and May diminished at later sampling dates in response to infection. Similarly, the isorhapontin levels strongly rose in April and were weakly lowered from June onwards. The initial response of the ascorbate-glutathione system to fungal infection was characterised by a significantly more oxidised glutathione pool accompanied by a slightly more reduced ascorbate system and by higher glutathione reductase activity. Three weeks later an obvious accumulation of thiols was monitored, whereas total ascorbate was significantly lowered and the ascorbate redox state shifted towards more oxidised values. Until the middle of July a gradual increase of total glutathione was measured within the infected bark, which was accompanied by significantly increased glutathione reductase activity and restored glutathione redox balance. In September, the ascorbate-glutathione system within the infected bark had reached a new steady-state. Temporal changes in the phenolic contents reflect an increased pressure on the ascorbate-glutathione system as the system is needed for reducing the phenoxyl radicals formed during the defence against pathogens. Based on the presented results, we can conclude that the antioxidant responses were characterised by fluctuations in the concentrations of defence molecules and with certain time-shifts in response, under which we can assume interactions amongst the phenolics and the ascorbate-glutathione system.
Keywords:Norway spruce Picea abies (L.) H. KARST., Blue-stain fungus Ceratocystis polonica (SIEM.) C. MOREAU, Antioxidants, Phenolics, Ascorbate-glutathione system


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