In vitro evidence of root colonization suggests ecological versatility in the genus Mycena

Abstract

Summary The root‐associated habit has evolved on numerous occasions in different fungal lineages, suggesting a strong evolutionary pressure for saprotrophic fungi to switch to symbiotic associations with plants. Species within the ubiquitous, saprotrophic genus Mycena are frequently major components in molecular studies of root‐associated fungal communities, suggesting that an evaluation of their trophic status is warranted. Here, we report on interactions between a range of Mycena species and the plant Betula pendula. In all, 17 Mycena species were inoculated onto B. pendula seedlings. Physical interactions between hyphae and fine roots were examined using differential staining and fluorescence microscopy. Physiological interactions were investigated using 14C and 32P to show potential transfer between symbionts. All Mycena species associated closely with fine roots, showing hyphal penetration into the roots, which in some cases were intracellular. Seven species formed mantle‐like structures around root tips, but none formed a Hartig net. Mycena pura and Mycena galopus both enhanced seedling growth, with M. pura showing significant transfer of 32P to the seedlings. Our results support the view that several Mycena species can associate closely with plant roots and some may potentially occupy a transitional state between saprotrophy and biotrophy.

Mycena genomes resolve the evolution of fungal bioluminescence

“…1b ). This is consistent with recent estimates (78–110 7 and mean 125 1 Mya) and overlaps with the initial rise and diversification of angiosperms 22 , suggesting that they are ecologically associated with fungi acting as saprotrophs or mycorrhizal partners 3 . Finally, the age of bioluminescence which was also the age of functional luciferase in fungi was estimated to originate around 160 million years ago during the late Jurassic ( Fig.…”

“…1a ), and a gilled or porioid hymenophore 2 . Mycena also have a diversity of life history strategies; while many species are saprotrophic, they can be pathogens as well as mycorrhizal 3 . Despite its vast diversity of lifestyles and phenotypes, there are many outstanding questions concerning the basic biology, ecology and genomics of this genus.…”

Root-Associated Mycobiome Differentiate between Habitats Supporting Production of Different Truffle Species in Serbian Riparian Forests

“…High temperatures that are measured in the region in summer [27] and closeness to a water body (flooding or exposure to airborne water from river surface evaporation) may have favored the decomposition of SOM in June/August and, therefore, the establishment of root associations with fungi with high decomposing abilities that would increase plant N intake [110]. It has been confirmed that some saprotrophic fungi (also detected here) can indeed establish a facultative biotrophic relationship with roots [81,88,111]. On the other hand, alkaline soil environment (as detected here) has rarely been connected to ECM domination [7,112].…”

“…and Sebacina sp., as well as endophytes like Cladophialophora sp., Humicola sp., Mycena sp., Mortierella sp.) were commonly detected in ectomycorizomes of black truffle-producing habitats [72,81]. However, Cennococum sp., Entholoma sp., Phallus sp., which were common in autumn black truffle-producing soils are assumed to be more frequent in dry or acidic soils [13,72].…”

“…Highly porous, low aggregated soil with very low total N pool probably trapped in scarce OM ( Supplementary Table S1) may have caused a general shortage of N availability in the upper soil layer of this site in warm seasons [7,107]. Endophytes can transform organic nitrogen to inorganic forms in the rhizosphere, making the nutrient available to their hosts [81,108,109]. High temperatures that are measured in the region in summer [27] and closeness to a water body (flooding or exposure to airborne water from river surface evaporation) may have favored the decomposition of SOM in June/August and, therefore, the establishment of root associations with fungi with high decomposing abilities that would increase plant N intake [110].…”