The effect of manganese(II) excess on growth and antioxidant status of barley seedlings

Abstract

Manganese belongs to the group of heavy metals, which at high concentrations can have a negative effect on plant development. Typical soils of the Kirov region are acid podzolic and sod-podzolic soils, which are characterized by high content of manganese compounds available for plants. Studied was the effect of manganese(II) ions at the concentrations of 30.0, 60.0 and 90.0 mg/l on the growth and antioxidant activity (AOA) of the superoxide dismutase enzyme (SOD) in the organs of 7 and 14-day-old barley plants grown in aquatic culture. Varieties and forms of barley 346-09, 29-11, Farmer 198-12, Forward and Bionik, resistant to acidic soils (Al3 +, H+) served as objects for the research; Belgorodskij 100 variety was used as standard. When manganese was added to the solution for growing, a decrease in root length and an increase in AOA of SOD in plant roots were noted. It was concluded that increased concentrations of manganese had an effect on the morphometric parameters and on AOA SOD of barley seedlings. It has been established that increasing the dose of manganese in the solution for growing leads to a decrease in the length of the roots. AOA SOD varied in different organs of plants of some varieties, and its more significant change in the experiment compared with the control was revealed in the roots. Judging by morphometric indicators, the Belgorodskij 100 variety was the least resistant to Mn2+ ionic toxicity, the root length of which in the control was 15.7±0.4 cm, and in the experiment 13.2±0.3; 12.2±0.1; 11.5±0.3 cm in accordance with the dose of manganese 30, 60 and 90 mg / l. According to the level of AOA SOD, the most sensitive variety was Farmer 198-12, its change of AOA SOD in the roots (% of control) was 158.8; 167.2 and 169.4% in accordance with the dose of manganese 30.0; 60.0 and 90.0 mg / l (AOA SOD in the control was 52.4±0.4%; in the experiment 83.2±2.2; 87.6±2.0 and 88.7±0.6, respectively), and in the shoots ˗ 121.0; 128.3 and 125.6 %, respectively (66.7±7.9 % in the control and 80.7±0.5; 85.6±1.4; 83.8±0.6 % in the experiment in accordance with the dose of Mn 2+).