master's thesis
Aspergillus flavus af/R and af/S gene expression after treatment with glutathione S-transferase inhibitors

Maja Grgić (2013)
Josip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Department of Applied Chemistry and Ecology
Sub-department of Biochemistry and Toxicology
Metadata
TitleEkspresija af/R i af/S gena plijesni Aspergillus flavus nakon tretmana inhibitorima glutation S-transferaze
AuthorMaja Grgić
Mentor(s)Tomislav Klapec (thesis advisor)
Abstract
Cilj rada je bio odrediti utjecaj inhibitora glutation S-transferaze na ekspresiju aflR i aflS gena kod plijesni Aspergillus flavus. Uzgajanoj plijesni su bili dodani inhibitori: L-butionin-(S,R)-sulfoksimin, etakrinska kiselina, kvercetin i 1-kloro-2,4-dinitrobenzen. Ekspresija aflR i aflS gena je praćena RT-PCR-om, a koncentracija aflatoksina određena je LC-MS/MS metodom. Najveće smanjenje ekspresije aflR i aflS gena postignuto je uz QC i iznosi 433,5 i 10 369,1 puta, a povećanje ekspresije aflR gena uz EA iznosi 1,1 puta odnosno aflS gena uz BSO 2,1 puta. Kod plijesni tretiranih inhibitorima, najmanja izmjerena količina aflatoksina je uz kombinaciju EA i QC, a najveća uz BSO. Smanjenje ekspresije ovih gena je očekivano reduciralo produkciju aflatoksina, dok je povećanje ekspresije samo aflR ili aflS gena bez povećanja ekspresije drugog također imalo antiaflatoksikogeni učinak. Pretpostavka je da tijekom lag faze rasta plijesni tretiranih navedenim spojevima dolazi do prilagodbe na uvijete rasta, pri čemu može doći do razvoja pojačane otpornosti na oksidativni stres što smanjuje ekspresiju gena na putu biosinteze aflatoksina. Povećanje ekspresije samo jednog od dva praćena gena je teško objasniti bez detaljnijeg ispitivanja molekularno-bioloških procesa u stanicama.
Keywordsmolds Aspergillus flavus aflR aflS RT-PCR glutathione S-transferase aflatoxins
Parallel title (English)Aspergillus flavus af/R and af/S gene expression after treatment with glutathione S-transferase inhibitors
Committee MembersIvica Strelec
Tomislav Klapec
Natalija Velić
Ines Banjari
GranterJosip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Lower level organizational unitsDepartment of Applied Chemistry and Ecology
Sub-department of Biochemistry and Toxicology
PlaceOsijek
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Food Technology
Food Safety and Quality
Study programme typeuniversity
Study levelgraduate
Study programmeFood Science and Nutrition
Academic title abbreviationmag. nutr.
Genremaster's thesis
Language Croatian
Defense date2013-12-12
Parallel abstract (English)
The aim of this study was to determine the effect of glutathione S-transferase inhibitors on the expression of aflR and aflS genes in Aspergillus flavus. The following inhibitors were added to A. flavus: L-buthionine-(S,R)-sulfoximine, ethacrynic acid, quercetin and 1-chloro-2,4-dinitrobenzene. The aflR and aflS gene expressions were tracked using RT-PCR, and aflatoxin concentration was determined by LC-MS/MS. QC showed the strongest reduction of aflR and aflS expression which was increased 433.5 and 10369.1 times, respectively, while EA and BSO showed aflR expression upregulated 1.1 times and aflS expression upregulated 2.1, respectively. The EA and QC combination resulted in the lowest , while BSO addition resulted in the highest amount of aflatoxin. Reduced expression of these genes expectedly lowered aflatoxin production while increased expression either aflR or aflS gene, not accompanied by upregulated expression of the other gene, also had an antiaflatoxigenic effect. It is hypothesized that treated fungi adapted to the growing conditions during the lag phase, which might have included increased resistance to oxidative stress which in turn reduced expression of genes involved in aflatoxin biosynthesis. An increased expression of only one of the regulatory genes is difficult to explain without detailed examination of molecular biological processes within cells.
Parallel keywords (Croatian)plijesni Aspergillus flavus aflR aflS RT-PCR glutation S-transferaza aflatoksini
Resource typetext
Access conditionAccess restricted to students and staff of home institution
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:109:398353
CommitterSanda Hasenay