The chemical characteristics and anatomy of Caucasian fir (Abies nordmanniana subsp. nordmanniana) crown gall tumors infected by Agrobacterium tumefaciens

Abstract

In this study, chemical and anatomical properties of tumorous and normal root of Abies nordmanniana subsp. nordmanniana were compared. The amount of hemicellulose in tumorous root was identifed to be 5.34% higher on average than in normal root. However, the amount of lignin was measured to be around 5.78% less. It was determined that the amount of extractive substance, 1% NaOH, cold and hot water dissolution also increased with the formation of tumors. In the study, carbohydrate analysis of samples was also made and it was found out that the amount of glucose, xylose, mannose and galactose of the roots containing tumor were 2.27%, 1.18%, 1.1%, 0.37% more than normal root, respectively. On the other hand, the crystallinity of tumorous roots was decreased in spite of the increase in the amount of cellulose with the formation of tumors. According to the elemental analysis results, it was observed that carbon formation increased with tumor formation. These results were also supported by FTIR-ATR characterization and thermal analysis results. In the anatomical comparison, it was observed that tracheid lengths, tracheid thicknesses and lumen thicknesses decreased with tumor formation. Traumatic resin canals were observed in the cross sections of the tumorous root samples. In addition, it was determined that the annual ring separation was less prominent in the cross section, and the cell diameters were smaller and their location was more dispersed.