Allelopathy of Wild Mushrooms—An Important Factor for Assessing Forest Ecosystems in Japan

Influence of Pholiota spp. (Strophariaceae, Basidiomycote) mycelial biomass on seed germination and seedlings growth of Lepidum sativum L. and Cucumis sativus L

Basidiomycetes represent a very diverse group of eukaryotic organisms in terms physiological parameters. Some organisms such as plants or fungi release certain secondary metabolites, which can affect the organisms around them. Some of the substances released by mushrooms could have effects on the growth and further development of nearby plants. Studies of fungi and their biologically active components have grown significantly, with the aim of potential introduction to various biotechnological processes.The allelopathic effect of Pholiota species has been investigated in this study. Mycelial biomass of seven screened Pholiota species were tested to study cucumber (Cucumis sativus L.) and lettuce (Lepidium sativum L.) seed germination and the sprouting growth. The results of our experiment showed that the biomass of the species of the genus Pholiota did not affect the germination of seeds of both plant species. 100% seed germination was recorded in both control and experimental samples. The addition of mycelial biomass of the Pholiota species led to a suppressive allelopathic effect, which affects seed germination, the length of the studied plant (both shoots and roots), as well as changes the morphology of the roots (pubescence, changes in lateral roots). The inhibitory effect on sprouting length was 8,6%-87,1% in the case of C. sativus and 42,2%-91,8% if specify for L. sativum in depence on Pholiota species. Allelopathic properties of Pholiota subochracea, where sprouting growth ratio did not exceed 12.9%, compared to the control group, should be noted. This result suggests that Pholiota mushrooms have a significant regulatory effect on lettuce and cucumber sprouting growth. The given results suggest that the studied species may play a significant role in relationships within ecosystems.

First Broad Screening of Allelopathic Potential of Wild and Cultivated Plants in Turkey

Turkey has one of the richest plant diversities in the Mediterranean region. In the current literature, no broad screening has been conducted on the potential allelopathy of plants from Turkey. This study aimed to evaluate the allelopathic activity of a large number of plants from Turkey for the first time and to determine the species with significant plant growth inhibitory potentials by bioassay. Dried samples of different plant parts were collected from local herbalists. The sandwich method was used to evaluate the potential allelopathy of 126 medicinal plants belonging to 55 families. The results of lettuce radicle and hypocotyl growth for 10 and 50 mg sample treatment conformed to normal distribution. Significant inhibition on lettuce radicle elongation with 10 mg sample was observed in 40 species, out of which 27 species showed over 50% inhibitory activity. The results suggested that these species could contain potential inhibitory compounds against lettuce radicle or hypocotyl growth. The calyxes of Hibiscus sabdariffa (3.2% of control) and the seeds of Prunus dulcis (5.7% of control) showed the most potent growth inhibitory activity on lettuce radicle elongation. The potential plant growth inhibitory effects of these plants, together with the fruits of Rhus coriaria and seeds of Prunus mahaleb, have been reported in this study for the first time. All these plants are medicinal, and the results hereby presented provide essential information about the allelopathic effects of medicinal plants from Turkey.

Cordycepin Isolated from Cordyceps militaris: Its Newly Discovered Herbicidal Property and Potential Plant-Based Novel Alternative to Glyphosate

There is currently much interest in finding new phytochemicals among plants and fungi as nature-based alternatives to replace problematic herbicides such as glyphosate, which are preferentially used in agricultural production n. We discovered striking herbicidal potency in Cordyceps militaris (L.) and identified cordycepin as its principal plant growth inhibitor. Cordycepin obtained as an ethyl acetate extract was subjected to column chromatography and evaluated for its bioassay-guided phytotoxic capacity against Raphanus sativus (radish), showing a maximum inhibition on germination and growth of radish (IC50 = 0.052-0.078 mg/mL). Gas chromatography-mass spectrometry (GC-MS) (m/z: 251.2) and liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) ([M + Na]+ m/z: 274.1; [M + H]+ m/z: 252.1) analyses confirmed cordycepin as the major component of the tested column fraction (55.38%). At 0.04 mg/mL, cordycepin showed 3.8-5.9- and 3.3-3.7-fold greater inhibition of the germination and growth of radish than benzoic acid (BA) and glyphosate, respectively. Compared with BA, isolated cordycepin reduced plant chlorophyll and carotenoid contents (2.0-9.5 -fold), while proline, total phenolic and total flavonoid contents were increased 1.2-1.8-fold. Finally, cordycepin promoted electrolyte leakage and malondialdehyde accumulation in radish aerial parts. Thus, cordycepin successfully isolated from Cordyceps militaris is a highly potent plant growth inhibitor with pending worldwide patent and may become a potential plant-based novel alternative to the disputed glyphosate.