Bacterial expression of an effector protein of yellow rust pathogen and a resistance protein of wheat and characterization of the effector protein


Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Kimya Bölümü, Türkiye

Tezin Onay Tarihi: 2019

Öğrenci: SAYIT MAHMUT ERDOĞAN

Eş Danışman: MAHİNUR AKKAYA, SALİH ÖZÇUBUKÇU

Özet:

Yellow rust is one of the most important wheat disease encountered in large parts of the world and in our country caused by a pathogen which is called as Puccinia striiformis f. sp. tritici (Pst). Rapid alterations in the pathogen virulency can make previously resistant varieties susceptible to the disease. Finding out common or species-specific genes, participated in the plant-pathogen interactions will provide an understanding of the biological mechanisms of the disease. Within the scope of this thesis followings were carried out: Coding region of TaYr10 protein, which resists Avr containing pathogen races, were separated into its domains and these domains were expressed in E.coli expression strains and purified by Immobilized Metal Affinity Chromatography (IMAC), Ultrafiltration and Size Exclusion Chromatography (SEC). Similarly, coding gene of the candidate effector protein of Puccinia striiformis f. sp. tritici (Pst), pstSCR1 which causes disease was expressed in E.coli expression strains and purified by IMAC, ultrafiltration and SEC. Among the studied proteins, only PstSCR1 protein achieved the requisite amount and purity to further study the structural analysis. Using the pure PstSCR1 protein, structural analyses were carried vi out by SAXS and NMR and as a result, 3D structure of the protein was identified in nanometer levels by SAXS. Additionally, secondary structure of the PstSCR1 protein was identified by CDS and the melting point of the protein was determined DSF. The data obtained in these studies provide important clues at the molecular level for the future studies about the disease mechanism of the pathogen and possible effector-resistance protein interactions.