Fire blight disease caused by Erwinia amylovora is a destructive bacterial pathogen mainly on pears, apples and quinces from Rosaceae family. In this study, it was aimed determination of total protein amounts in different apple cultivars (Braeburn, Fuji, Gala and Golden), pear cultivars (Santa Maria and Williams) and quince cultivars (Eşme and Ekmek) in the infections of two virulent E. amylovora strains (Ea234-1 and Ea240-3) according as the time. It was taken leaf samples after leaf inoculation with E. amylovora (108 CFU ml-1) at 24th, 36th and 72nd hours. For verification of the infections, re-isolations were made from bacteria inoculated plants and the agent was identified as E. amylovora by biochemical, physiological and molecular tests. In determining the amounts of total protein and in the SDS-PAGE analyses were used Bradford and Laemmli methods, respectively, and absorbance values of protein extracts derived from the leaf samples taken, were obtained at 595 nm wavelength. According to the findings obtained; after infection of E. amylovora in the apple varieties comparing to controls, total protein concentrations at 24th hours increased and a decrease in the amount of 36th to 72nd hours and Braeburn has the highest protein content was determined. In the pear varieties, while total protein concentrations at 24th and 36th hours increased, a decrease in the amount of 72nd hour, and Santa Maria variety has the highest protein content was detected. In the quince varieties, total protein concentrations at 72th hour increased and Eşme variety has the highest protein content was identified. As a result of SDS-PAGE analysis, protein fractions which have different molecular weights were obtained. The protein bands were defined approximately 55-70 kDa and 35-55 kDa molecule weight on apple and quince varieties, respectively and also approx. 55-70 kDa in pear varieties.

Iron (Fe) is an important trace mineral for plant development, and plants grown in Fe deficiency experience yield losses due to the leaf chlorosis. In addition to agronomic measures that can be taken to minimize these losses, new plant genotypes can be developed effectively through genetic engineering. While dicots such as Arabidopsis thaliana use a reduction-based strategy to uptake high amounts of iron from the rhizosphere, the chelation strategy has evolved in Gramineous plants including barley (Hordeum vulgare). In this study, barley NICOTIANAMINE SYNTHASE1 (HvNAS1) gene, which is responsible for the production of nicotianamine that can complex with iron, was cloned and expressed at a constitutive high level in Arabidopsis plants. The expression levels of Arabidopsis genes encoding for the proteins involved in iron uptake increased together with HvNAS1 in the T3 Arabidopsis plants. Moreover, the root lengths, root and stem fresh weights, ferric chelate reductase enzyme activities of the plants also increased in the transgenic Arabidopsis plants under Fe deficiency. In addition, significant increases in iron and zinc levels were determined in the roots and shoots of transgenic Arabidopsis plants. As a result, transgenic Arabidopsis plants overexpressing the barley HvNAS1 gene can take up more iron from the rhizosphere and carry this iron to the shoots. This study demonstrates the power of genetic engineering to develop Arabidopsis plants overexpressing the HvNAS1 gene and therefore tolerate iron deficiency.