Investigating the roles of micrornas in biotic stress responses and functional characterization of a novel ztl-type f-box protein via virus induced gene silencing

Download
2009
Dağdaş, Yasin Fatih
Barley and wheat are the two most important crop species in Turkey. Molecular studies for increasing crop yield of these species are very important for the economic benefits of Turkey. Powdery mildew and yellow rust are the two main pathogens, infecting barley and wheat, respectively in our country and causing a great amount of yield loss each year. Till now, classical genetics studies were performed in order to develop resistant barley and wheat cultivars, but these studies have not been succesful. Therefore, molecular plant-pathogen interactions studies are starting to become the new tool to fight against pathogens. In this thesis, two important aspects of plant microbe interactions were investigated. In the first part, the role of microRNAs (miRNAs) in powdery mildew-barley pathosysytem, and yellow rust-wheat pathosystem were studied. The expression levels of miRNAs and their putative targets were investigated via miRNA microarray analysis and qRT-PCR, respectively, in response to virulent and avirulent pathogen infections. These data were used to establish a new model for powdery mildew-barley and yellow rust-wheat pathosystems. In the second part, functional analysis of a novel F-box gene, which was a ZTL-type F-box, was performed by using Barley Stripe Mosaic Virus mediated Virus Induced Gene Silencing. This F-box gene (HvDRF) (Hordeum vulgare Disease Related F-box) was induced upon yellow rust infection and we studied its role in powdery mildew infection. The results confirmed HvDRF as a positive regulator of race specific immunity and enlarged the roles of ZTL-type F-box proteins to biotic stress responses.

Suggestions

Expression analysis of NAC type transcription factors on wheat seedlings under abiotic stress conditions
Baloğlu, Mehmet Cengiz; Yücel, Ayşe Meral; Öktem, Hüseyin Avni; Department of Biology (2011)
Wheat is the most important grain crop grown in our country providing greatest part of the daily nutritional requirement. Abiotic factors including salinity, drought, cold and heat stresses affect quality and yield of wheat varieties used for the production of both bread and pasta flour. NAC proteins form one of the widest families of plant specific transcription factors. Members of this family are related with development, defense and abiotic stress responses. TaNAC69-1 and TtNAM-B2 genes were isolated fro...
Functional analysis of a mirna putatively involved in powdery mildew disease susceptibility in barley
Dağdaş, Gülay; Akkaya, Mahinur S.; Department of Biotechnology (2009)
Barley is one of the most important crop species in Turkey and powdery mildew is one of the most common pathogen decreasing yield in barley. For this problem, agricultural biologists apply breeding technologies in order to select and propagate resistant barley cultivars. However, this is not a permanent solution since pathogens evolve rapidly to overcome plant resistance mechanisms. On the other hand, molecular plant pathologists are trying to understand basic mechanisms underlying plant-pathogen interactio...
Xylooligosaccharide production from cotton and sunflower stalks
Ak, Özlem; Bakır, Ufuk; Department of Biotechnology (2008)
In this study, the aim was enzymatic xylooligosaccharide production from cotton and sunflower stalks, two of main agricultural residues in Turkey. In first two parts of the study, alkali extracted xylan from both of the stalks was hydrolyzed by commercial xylanases Veron and Shearzyme. The effect of temperature, pH, enzyme and substrate concentrations were investigated to determine optimum enzymatic hydrolysis conditions of xylan. Sunflower and cotton stalk xylans were hydrolyzed by Shearzyme more efficient...
Genetic screening of Turkish wheat varieties for the durable resistance gene, Lr34
Boylu, Barış; Akkaya, Mahinur S.; Hakkı, Erdoğan Eşref; Department of Biotechnology (2011)
Wheat diseases such as rusts and powdery mildews are among the most important and ancient diseases that affect wheat cultivation worldwide. The pathogen race specific resistance genes cannot maintain long lasting resistance. On the other hand, the presence of genes confers the non-race specific resistance last much longer. The durable resistance phenotypes in wheat against various rust and powdery mildew diseases were reported as Lr34, Yr18, and Pm38 separately; nevertheless, they were known to locate very ...
Particle bombardment transformation of some Turkish wheat cultivars with TaNAC69-1 and TtNAMB2 genes
Battal, A.; BALOĞLU, MEHMET CENGİZ; Kavas, M.; Yücel, Mustafa; Öktem, Hüseyin Avni (2012-09-23)
Wheat is one of the most important crop plants in the world.The production of wheat is seriously affected by biotic (pests,bacterial and fungal diseases) and abiotic (drought, salinity andfreezing) stresses. NAC family proteins (NAM/ATAF1-2/CUC2) areplant specific transcription factors and related with development,defense and abiotic stress responses.TaNAC69-1andTtNAMB2genes are the transcription factors from this protein family. Theaim of this study was to transform of some Turkish ...
Citation Formats
Y. F. Dağdaş, “Investigating the roles of micrornas in biotic stress responses and functional characterization of a novel ztl-type f-box protein via virus induced gene silencing,” M.S. - Master of Science, Middle East Technical University, 2009.