THE EFFECTS OF METHYLPHOSPHONIC ACID AND CYANOBACTERIA NOSTOC LINCKIA PRESENT IN THE GROWING MEDIUM ON THE VITAL FUNCTIONS OF BARLEY PLANTS
The effect of the presence of cyanobacteria (CB) Nostoc linckia and methylphosphonic acid (MPhA) (0.5 and 1 mM) in the growing medium on the vital indices of barley plants in water culture is investigated. The state of the pigment complex of barley plants was studied and the activity of lipid peroxidation (LPO) by spectrophotometric method. It has been found that the MPhA causes activation of oxidative stress in plants that manifested in the reduction of green pigments and pigments-antioxidants (carotenoids, anthocyanins). The activity of LPO in the leaves of test plants increased. The addition of Nostoc linckia activated process of oxidative stress in plants of barley which was manifested by a significant accumulation of LPO products in the roots and leaves of plants as well as by reduced carotenoids. Probably the CB themselves have toxic effects on the test plants. The presence of the CB in the growing medium has no marked protective effect on the plant in case of the contamination by MPhA. The addition of the CB somewhat decreased the toxic effect of the MPhA (0.5 mM) which was reflected in the activation of the accumulation of pigments, but in this context an increase in the activity of LPO was revealed. The revealed feature indicates that the presence of Nostoc linckia does not reduce the toxic effect of the MPhA on the plants. This type of treatment (the introduction into the growing medium) is not effective and cannot be used to reduce the negative impact of methylphosphonate on barley plants.