Aromatic Plants in Weed Control: Influence on the Bromus Antioxidant System and Soil Microorganism Growth

Abstract

Natural compounds produced in plant metabolism can offer an alternative method to the chemical control of weeds. The aim of this study was to evaluate the effects of Salvia sclarea L. and Clinopodium menthifolium Host on the bromus (Bromush mollish L.) antioxidant properties to explore the potential of these aromatic plants in weed control. The impact of bioherbicides on the growth of beneficial microorganism present in the soil is less known. Consequently, the second aim was to evaluate the effects of S. sclarea and C. menthifolium on the growth of beneficial microorganism so as to assess theirs possible side effects when applied as bioherbicides. Two different concentrations (0.1% and 0.2%) of the aqueous extract of S. sclarea and C. menthifolium were assayed. Both tested extracts caused a change in peroxidase (POD) activity in leaves and roots of the bromus plants. Furthermore, both extracts induced lipid peroxidation in bromus leaves. In addition, tested extracts showed positive effects on the growth of some beneficial bacteria. The results indicate that S. sclarea and C. menthifolium aqueous extracts have negative effects on the antioxidant system in bromus plants with no inhibitory effects on the growth of the beneficial mycorrhizal bacteria and fungi.

Phytotoxic and Insecticidal Activity of Industrial Hemp (Cannabis sativa L.) Extracts against Plodia interpunctella Hübner—A Potential Sunflower Grain Protectant

“…POD can exhibit simultaneous oxidant and anti-oxidant capabilities and is an important factor in the integrated defense response of plants to a variety of stresses [70]. An increase in antioxidative enzyme activity has been reported in other studies on the allelochemical mode of action on different target plant species: Bromus [65,69,[71][72][73][74]. However, from our results, it can be inferred that hemp extracts possess some allelochemicals that might have significantly increased and/or decreased the antioxidant enzyme and phenolic metabolism activity in sunflower seedlings.…”

“…Some of them can act as antioxidants. The fact that an allelochemical can act as an antioxidant or prooxidant depends on different factors: chemical structure, concentration of allelochemicals, and sensitivity of the acceptor plant [64,65]. Supposing that allelochemicals act as prooxidants to target plant species, their action leads to modification of reactive oxygen species (ROS) production and metabolism, which is associated with the degradation of cell compounds (proteins, lipids, and nucleic acids) and structures (mainly biomembranes).…”

“…Many plants are reported to increase the level of antioxidants, both enzymatic and non-enzymatic, in response to biotic or abiotic environmental stresses [64,66]. Allelochemicals can cause oxidative damage in target plants and induce so-called allelopathic stress by producing a high amount of ROS during response to environmental stresses, as evidenced by the enhanced activity of ROS-scavenging enzymes and higher intensity of lipid peroxidation [65,67].…”