Authors
Info
E. Y?r?k1 and G.
Albayrak2*??
1Institute of
Science, Programme of Molecular Biology and Genetics, Istanbul University,?
Istanbul, 34134, Turkey
2Department of
Molecular Biology and Genetics, Faculty of Science, Istanbul University,
Istanbul, 34134, Turkey
*Corresponding
Author Email :
gulruh@istanbul.edu.tr
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Abstract
Aim: This study was
conducted to investigate the quelling of tri4 and tri5 genes
associated with deoxynivalenol, most common class B trichothecene, via siRNA
application.
Methodology: In this study,
one Fusarium graminearum (4F) and two F. culmorum (9F and 20F)
isolates, expressing high levels of tri4 and tri5 genes, were
targeted for siRNA-based silencing. Full length tri4 and tri5 genes were
amplified from all isolates, sequenced and then subjected to CLUSTALW
analysis for designing siRNA molecules. Totally designed six siRNAs were
separately co-transfected together with helper plasmids (pEGFP75 and pAN7-1)
as 36 combinations into protoplast cultures and quelling was analysed via
real time polymerase chain reaction, thin layer chromatography and
spectrofluorimetric analysis.
Results: Alignment of both
tri4 and tri5 genes? sequencing revealed high levels of
similarity between isolates (94-99% and 95-100%, respectively). Transfection
efficiency ranged from 50?0.00/5x104 to 99.33?10.06/5x104
and relative fluorescence unit values were calculated between 1.37?0.07 and
2.89?0.06. The 0.7 kb length fragments of hph and GFP were amplified
from transfectants. The real time PCR revealed that tri4 was completely
suppressed in 30 experimental sets whereas down-regulations of tri5, ranging
from 74.5 to 99%, was detected in remaining 6 experiment groups. Thin layer
chromatography assay also showed that siRNA-transfected Fusarium samples
showed no deoxynivalenol spots.
Interpretation: This study
revealed that tri4 and tri5 genes can be targeted in the
development of less deoxynivalenol (DON)-producing strains through RNAi.
Moreover, current study has great importance as it demonstrates that quelling
can be used as a potential strategy in controlling diseases caused by
phytopathogenic species.
Key words: Fusarium sp., Gene
expression, Gene silencing, Transfection, Trichothecene
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