Leaf Extracts of Invasive Woody Species Demonstrate Allelopathic Effects on the Growth of a Lawn Grass Mixture

Biochemical composition was studied in the leaf litter of alien woody species included in the 100 most aggressive invasive species of Europe: Ailanthus altissima, Quercus rubra, Acer negundo, Robinia pseudoacacia, and Elaeagnus angustifolia. Using GC-MS, we detected 187 metabolites in the leaf litter, which are phenolic acids and their derivatives, carbohydrates and their derivatives, polyphenolic compounds, cyclic esters, glycosides, and amino acids and their derivatives. Species-specific metabolites were identified for each species. The main allelochemicals in the leaf litter extract of Q. rubra are determined mainly by the relative abundance of phenolic and fatty acids and their esters, whereas those in the leaf litter extract of R. pseudoacacia are determined by carbohydrates and their derivatives and ester of fatty acid, and those in the leaf litter extract of A. altissima are determined by glycosides. Profiles of macro- and microelements were characterized. It was found that aqueous extracts of leaf litter from all the invasive woody plants under study have a negative effect on the seed germination and initial growth of Vicia cracca and Avena strigosa used for the reclamation of disturbed urban and industrial lands. At the same time, V. cracca is potentially more sensitive

Aromatic Plants Metabolic Engineering: A Review

Secondary metabolites of aromatic plants are used in many health applications as drugs, pheromones, insecticides, fragrances, and antioxidants. Due to the huge commercial demand for these secondary metabolites, the need to overcome the insufficient productivity of aromatic plants has become a significant challenge. Plant breeding is a traditional, labor-intensive, and limited method to improve the ability of aromatic plants to produce secondary metabolites. Modern methods of biotechnology, including genetic engineering and genome editing, can be useful and cost-effective in improving aromatic plants, as they can increase the efficiency of obtaining plants with high productivity and the creation of resistant forms and breeding lines. This review illustrates the importance of developing methods for the modification of aromatic plants belonging to different families, with a predictable quality, resistance to adverse factors and pests, and intensive growth and high yields and productivity of valuable essential oils. Particular attention is paid to successful examples of the modification of aromatic plants, applied methods, and principal approache