Formation Of Mycorrhizal Symbiosis Research Articles

Formation of arbuscular mycorrhizal symbiosis and its effect on the possibility of infection by parasitic plants

Aim. The purpose of the work is to analyze the data available in the literature on the mechanisms of formation of mycorrhizal symbiosis, in particular, the participation of strigolactones in this process and the influence of mycorrhizal symbiosis on the possibility of plant infection by parasitic plants. Results. The article provides a brief overview of the formation of arbuscular mycorrhizal symbiosis and the role of strigolactones in this process. Evidence is provided that strigolactones secreted by roots into the rhizosphere are signal molecules for AM fungi, as they stimulate their metabolism and induce spore germination, growth and branching of hyphae of AM fungi. In turn, AM fungi release signaling molecules that initiate processes related to the formation of symbiosis in plants. Conclusions. Data available in the literature indicate that strigolactones play an important role in the formation of mycorrhizal symbiosis. Mycorrhizal plants are often less susceptible to infection by parasitic plants, which may depend on the species of both the host plant and the AM fungus. The formation of mycorrhizal symbiosis can be a factor that weakens the infection by parasitic plants, the study of this issue can be important for increasing the effectiveness of the fight against parasitic plants.

Effects of Different Arbuscular Mycorrhizal Fungi on Physiology of Viola prionantha under Salt Stress

Arbuscular mycorrhizal (AM) fungi distribute widely in natural habits and play a variety of ecological functions. In order to test the physiological response to salt stress mediated by different AM fungi, Viola prionantha was selected as the host, the dominant AM fungus in the rhizosphere of V. philippica growing in Songnen saline-alkali grassland, Rhizophagus irregularis, and their mixtures were used as inoculants, and NaCl stress was applied after the roots were colonized. The results showed that V. philippica could be colonized by AM fungi in the field and the colonization rate ranged from 73.33% to 96.67%, and Claroideoglomus etunicatum was identified as the dominant AM fungi species in the rhizosphere of V. philippica by morphology combined with sequencing for AM fungal AML1/AML2 target. Inoculation with both the species resulted in the formation of mycorrhizal symbiosis (the colonization rate was more than 70%) and AM fungi significantly enhanced plants’ tolerance to salt stress of varying magnitude. Higher activity of antioxidant enzymes and augmented levels of proline and other osmoregulators were observed in AM plants. The content of MDA in CK was higher than that in the inoculations with the stress of 100, 200, and 250 mM. All indices except soluble protein content and MDA content were significantly correlated with AM fungal colonization indices. The analysis for different AM fungal effects showed that the mixtures and R. irregularis worked even better than C. etunicatum. These results will provide theoretical support for the exploration and screening of salt-tolerant AM fungi species and also for the application of AM-ornamental plants in saline-alkali urban greening.

Influence of herbicide on plants in connection with formation of arbuscular mycorrhizal symbiosis

Aim. The aim of the work is to analyze the available literature data on the effect of herbicides on the formation of mycorrhizal symbiosis. Results. The article gives a brief overview of the influence of herbicides with different mechanism of action on the formation and functioning of arbuscular mycorrhizal symbiosis. The direct and indirect effects of herbicides on the AM fungi, the different selectivity of AM fungi to herbicides and other factors influencing the effect of herbicides on biodiversity of AM fungi and the formation of mycorrhizal symbiosis are considered. Conclusions. Herbicides with different mechanism of action can have a significant effect on the diversity of AM fungi present in the soil, the formation and functioning of mycorrhizal symbiosis. Their effect on the AM fungi can be either direct or indirect due to the influence on the host plant. AM fungi, in turn, can also influence the selectivity of the plant to herbicides. Studies on the effect of herbicides on mycorrhizal symbiosis may be important for increasing the herbicide efficiency.
 Keywords: herbicides, arbuscular mycorrhizal fungi, mycorrhizal symbiosis.