Growth-inhibiting effect of azoxystrobin and its ability to inhibit sugar consumption in winter wheat sprouts and roots

Abstract

This study aimed to assess the prospects for the use of azoxystrobin, a fungicide of the strobilurin class, for increasing the resistance of winter wheat to low temperatures. The effect of azoxystrobin on growth processes, cell viability and the content of water-soluble carbohydrates in winter wheat (Triticum aestivum L.), the Ikutskaya variety, was studied. In comparison with other synthetic strobilurins, azoxystrobin is more frequently used in multicomponent fungicidal preparations. Azoxystrobin is a broad-spectrum fungicide that inhibits complex III of the mitochondrial electron transport chain. Experiments were carried out in laboratory conditions using 3-day-old etiolated winter wheat sprouts. The sprouts were grown in a dark place at a temperature of +24 °C on azoxystrobin solutions dissolved in a 0.36% aqueous solution of dimethyl sulfoxide, distilled water and a 0.36% dimethyl sulfoxide solution. The effect of various azoxystrobin concentrations (2.5, 5, 10 and 20 μM) on the growth of sprouts and roots was assessed, along with the viability of sprout and root cells. Azoxystrobin had a concentration-dependent growth-inhibiting effect on sprouts and roots. At concentrations of 2.5 μM and 20 μM, the inhibition degree for sprouts varied from 2.8% to 41.7%, respectively. For roots, these values comprised 34.6 and 63.1%, respectively. The growth-inhibiting effect was not accompanied by a decrease in the cell viability of sprouts and roots, which was assessed using in vivo staining with fluorescein diacetate (FDA). The effect of azoxystrobin at a concentration of 10 μM on the sugar content in germinated sprouts was also evaluated. At this concentration of azoxystrobin, the sugar content was higher by 3.6% in sprouts germinated on a dimethyl sulfoxide solution. Since growth inhibition and sugar accumulation are important factors in plant adaptation to low temperatures, further research into effects of azoxystrobin on the physiological and biochemical parameters of plants associated with the development of low-temperature resistance seems justified.