SYSTEMIC ACQUIRED RESISTANCE (SAR) -EFFECT OF BTH AGAINST FIRE BLIGHT
The plant activator benzothiadiazole (BTH) was assayed for its systemic acquired resistance (SAR) effect against fire blight on the highly susceptible apple rootstock M26. The experiment was carried out under controlled climatic conditions in the greenhouse. Moreover, as a marker of resistance, in physiological studies, enzymatic activities of peroxidase (PO) and, as a component of an antioxidative protection system, glutathione-S-transferase (GST), were estimated. Pre-inoculation application of BTH at 2-day intervals to the foliage of M26 rootstocks reduced the severity of the disease as well as the growth of bacteria in the tissue. Reduction of disease severity was correlated with a decreasing effect on the growth of bacteria of up to 51 % during the course of infection. In physiological studies, a marked increase of PO and GST activities were found after BTH application in inoculated and uninoculated plants between 28 and 168 h after application. This was considered to be an indication of the induction of resistance (IR) in fire blight host plants protected with BTH.
Baysal, O., Laux, P. and Zeller, W. (2002). SYSTEMIC ACQUIRED RESISTANCE (SAR) -EFFECT OF BTH AGAINST FIRE BLIGHT. Acta Hortic. 590, 269-272
Systemic acquired resistance (SAR), BTH, Erwinia amylovora, apple rootstock M26