Transcript profiling of aquaporins during basidiocarp development in Laccaria bicolor ectomycorrhizal with Picea glauca

Abstract

Sporocarp formation is part of the reproductive stage in the life cycle of many mycorrhizal macrofungi. Sporocarp formation is accompanied by a transcriptomic switch and profound changes in regulation of the gene families that play crucial roles in the sporocarp initiation and maturation. Since sporocarp growth requires efficient water delivery, in the present study, we investigated changes in transcript abundance of six fungal aquaporin genes that could be cloned from the ectomycorrhizal fungus Laccaria bicolor strain UAMH8232, during the initiation and development of its basidiocarp. Aquaporins are intrinsic membrane proteins facilitating the transmembrane transport of water and other small neutral molecules. In controlled-environment experiments, we induced basidiocarp formation in L. bicolor, which formed ectomycorrhizal associations with white spruce (Picea glauca) seedlings. We profiled transcript abundance corresponding to six fungal aquaporin genes at six different developmental stages of basidiocarp growth and development. We also compared physiological parameters of non-inoculated to mycorrhizal seedlings with and without the presence of basidiocarps. Two L. bicolor aquaporins--JQ585592, a functional channel for CO2, NO and H2O2, and JQ585595, a functional water channel--showed the greatest degree of upregulation during development of the basidiocarp. Our findings point to the importance of aquaporin-mediated transmembrane water and CO2 transport during distinct stages of basidiocarp development.

Transcriptome data reveal conserved patterns of fruiting body development and response to heat stress in the mushroom-forming fungus Flammulina filiformis

“…We detected the aquaporin gene specifically induced in primordia and stipe tissues ( Fig 2B ; S2A Fig ; S4 Table ). Aquaporins are integral membrane proteins responsible for water and solute transport, and also involved in mycorrhizal formation and plant-fungal interactions during symbiosis establishment [ 26 , 61 ]. Recent study revealed that aquaporins were also developmentally regulated in L .…”

“…Aquaporins are integral membrane proteins responsible for water and solute transport, and also involved in mycorrhizal formation and plant-fungal interactions during symbiosis establishment [26,61]. Recent study revealed that aquaporins were also developmentally regulated in L. bicolor fruiting bodies [26]. However, aquaporins have been discussed mostly in the context of mycorrhizal fungi [62][63][64][65].…”

“…have pioneered our knowledge of the multicellular development, mating pheromone, and receptor signaling pathways in the Agaricomycetes [14][15][16][17][18]. More recently, studies also focused on ecologically or economically important non-model species, which included the saprotrophic fungi (Agaricus bisporus, Flammulina filiformis, Lentinula edodes, Lentinus tigrinus, Cyclocybe aegerita), plant pathogen (Armillaria ostoyae), and the ectomycorrhizal fungi (Laccaria bicolor) [2,[19][20][21][22][23][24][25][26]. These studies broadened our knowledge on fruiting body development and also highlighted conserved expression patterns of some key developmental genes (such as the genes encoding light receptors (white collar complex), transcription factors (c2h2, hom1, hom2), CAZyme and F-box protein etc.…”

Fungal Aquaporins in Ectomycorrhizal Root Water Transport

“…Differential expressions of fungal aquaporins were also observed in a cellspecific pattern, in EcM root tips, free-living mycelium, fungal mantle, Hartig net, and fruiting body. The accumulation of transcripts of Tuber melanosporum aquaporins in the mantle of mycorrhizal tips (Hacquard et al, 2013), the upregulation of several aquaporins in the formation of the fruiting body of L. bicolor (Xu et al, 2016), and the striking upregulation of two aquaporin genes of EcM Cenococcum geophilum induced by the symbiosis interaction with Pinus silvestris (Peter et al, 2016), are some examples of the physiological significance of fungal aquaporins in hyphal cells and at hypharoot interface.…”

The crop of desert truffle depends on agroclimatic parameters during two key annual periods

“…Agroclimatic parameters, such as precipitation or temperature, determine the annual crop for other Basidiomycota mycorrhizal fungi before or during the fruiting season (Martínez-Peña et al 2012). However, unlike the fruiting bodies of other Basidiomycota mycorrhizal fungi, which develop in few days (Teramoto et al 2012;Xu et al 2016), in the case of Ascomycota such as Tuber and Terfezia, their development is slower and usually takes several months (Olivier et al 2012;Le Tacon et al 2014). Therefore, it is expected that long-term environmental factors may influence their development, as has been observed in black truffle (Baragatti et al 2019).…”