Allelopathy is mediated by plant-derived secondary metabolites (allelochemicals) which are released by donor plants and affect the growth and development of receptor plants. The plant root is the first organ which senses soil allelochemicals this results in the production of a shorter primary root. However, the mechanisms underlying this process remain elusive. Here, we report that a model allelochemical benzoic acid (BA) inhibited primary root elongation of Arabidopsis seedlings by reducing the sizes of both the meristem and elongation zones, and that auxin signaling affected this process. An increase in auxin level in the root tips was associated with increased expression of auxin biosynthesis genes and auxin polar transporter AUX1 and PIN2 genes under BA stress. Mutant analyses demonstrated that AUX1 and PIN2 rather than PIN1 were required for the inhibition of primary root elongation during BA exposure. Furthermore, BA stimulated ethylene evolution, whereas blocking BA-induced ethylene signaling with an ethylene biosynthesis inhibitor (Co²⁺), an ethylene perception antagonist (1-methylcyclopropene) or ethylene signaling mutant lines etr1-3 and ein3eil1 compromised BA-mediated inhibition of root elongation and up-regulation of auxin biosynthesis-related genes together with AUX1 and PIN2, indicating that ethylene signal was involved in auxin-mediated inhibition of primary root elongation during BA stress. Further analysis revealed that the BA-induced reactive oxygen species (ROS) burst contributed to BA-mediated root growth inhibition without affecting auxin and ethylene signals. Taken together, our results reveal that the allelochemical BA inhibits root elongation by increasing auxin accumulation via stimulation of auxin biosynthesis and AUX1/PIN2-mediated auxin transport via stimulation of ethylene production and an auxin/ethylene-independent ROS burst.

Macro-fungi play important roles in the soil elemental cycle in terrestrial ecosystems. Many researchers have focused on the interactions between mycorrhizal fungi and host plants, whilst comparatively few studies aim to characterise the relationships between macro-fungi and bacteria in situ. In this study, we detected endophytic bacteria within fruit bodies of ectomycorrhizal and saprophytic fungi (SAF) using high-throughput sequencing technology, as well as bacterial diversity in the corresponding hyphosphere soils below the fruit bodies. Bacteria such as Helicobacter, Escherichia-Shigella, and Bacillus were found to dominate within fruit bodies, indicating that they were crucial in the development of macro-fungi. The bacterial richness in the hyphosphere soils of ectomycorrhizal fungi (EcMF) was higher than that of SAF and significant difference in the composition of bacterial communities was observed. There were more Verrucomicrobia and Bacteroides in the hyphosphere soils of EcMF, and comparatively more Actinobacteria and Chloroflexi in the hyphosphere of SAF. The results indicated that the two types of macro-fungi can enrich, and shape the bacteria compatible with their respective ecological functions. This study will be beneficial to the further understanding of interactions between macro-fungi and relevant bacteria.

Three new species of Russulasection Ingratae, found in Guizhou and Jiangsu Provinces, southern China, are proposed: R. straminella, R. subpectinatoides and R. succinea. Photographs, line drawings and detailed morphological descriptions for these species are provided with comparisons against closely-related taxa. Phylogenetic analysis of the internal transcribed spacer (ITS) region supported the recognition of these specimens as new species. Additionally, R. indocatillus is reported for the first time from China and morphological and phylogenetic data are provided for the Chinese specimens.

Wood-rotting fungi as an important group within the Basidiomycota are known for their ecological role in the forest ecosystem in terms of decaying living and dead trees and recycling nutrients in forest ecosystems. Many new species were revealed in the last five years. In the present study, during an ongoing study on Scytinostroma, a new species of Scytinostroma was found from China. It is described and illustrated on the basis of the morphological and phylogenetic evidence. Scytinostroma bambusinum sp. nov. is described as a new species, based on morphological and molecular evidence. It is characterised by annual, resupinate and broadly ellipsoid basidiomata with white to cream hymenophore, a dimitic hyphal structure with generative hyphae bearing simple septa, the presence of cystidioles and amyloid basidiospores measuring 5.5–7 × 4–5.3 µm. Phylogeny, based on molecular data of ITS and nLSU sequences, shows that the new species forms an independent lineage and is different in morphology from the existing species of Scytinostroma.

In this study, we revealed the molecular mechanism and possible strategies of A. pantherina with weak weathering potential in the uptake of insoluble mineral nutrients by using transcriptome sequencing (RNA-seq) technology and found that ApHAK1 , a K transporter gene of this fungus, plays a very important role in the acquisition of K and P. Ectomycorrhizal (ECM) fungi play critical roles in the uptake of woody plant nutrients in forests that are usually characterized by nutrient limitation and in maintaining the stability of forest ecosystems. However, the regulatory mechanisms of ECM fungi in acquiring nutrients from minerals/rocks are poorly understood. This study investigated the transcriptional regulation of A. pantherina weathering K-containing feldspar and apatite and improves the understanding of fungal-plant interactions in promoting plant nutrition enabling increased productivity in sustainable forestry.