Transcriptomic analyses reveal the effects of herbicides on the mycelium of Morchella sextelata

Morchella sextelata, recognized for its medicinal properties and distinctive taste, is a highly valued edible mushroom. Despite its commercial importance, the mushroom's susceptibility to environmental factors and its reactions to herbicides commonly used in cultivation have not been extensively studied. This research aimed to explore how four prevalent herbicides—Trifluralin, Pendimethalin, S-metolachlor, and Acetochlor—affect the mycelial growth of Morchella sextelata. The study involved cultivating the mycelium in a Potato Dextrose Agar (PDA) medium with concentrations of herbicides at ten times the standard application rate, followed by measuring the degree of mycelial growth inhibition. Employing transcriptomic analysis, RNA sequencing was conducted on the mycelium exposed to the herbicides. The subsequent transcriptome profiling indicated that the application of these herbicides impacted various biological pathways within Morchella sextelata, with a notable influence on glycolysis/gluconeogenesis and the glyoxylate cycle, which are crucial for energy production and metabolic processes. While Trifluralin and Pendimethalin demonstrated a less pronounced negative impact on mycelial growth, the study concluded that all tested herbicides were detrimental to Morchella sextelata. It is thus recommended that, in agricultural practice, the use of herbicides be approached with caution, and that application rates be strictly adhered to in order to ensure the healthy cultivation of Morchella sextelata and minimize potential pesticide residue issues. PDA medium was applied with 10 times the normal application concentration of T, P, S, A herbicides, respectively, inoculated with Morchella sextelata, placed in culture at 20°C for 5 days, the growth length of the mycelium was measured and recorded, and three replications were set up for each group, and CK was inoculated with PDA medium without added herbicides. The percentage of mycelial growth inhibition (MGI) was determined as follows: MGI (%) =[(dc-dt)/dc]*100%, where Dc and Dt are the mean diameters (cm) in the control and treatment groups, respectively.