Heterogeneous Distribution of Phospholipid Molecular Species in the Surface Culture of Flammulina velutipes: New Facts about Lipids Containing α-Linolenic Fatty Acid

Abstract

Mycelial fungi grow as colonies consisting of polar growing hyphae, developing radially from spore or inoculum. Over time, the colony develops, hyphae are subject to various exogenous or endogenous stimuli, and mycelium becomes heterogeneous in growth, gene expression, biosynthesis, and secretion of proteins and metabolites. Although the biochemical and molecular mechanisms of mycelium heterogeneity have been the subject of many studies, the role of lipids in colony development and zonality is still not understood. This work was undertaken to extend our knowledge of mycelium heterogeneity and to answer the question of how different lipid molecular species are distributed in the surface colony of the basidial fungus Flammulina velutipes and how this distribution correlates with its morphology. The heterogeneity in the lipid metabolism and lipid composition of the fungal mycelium was demonstrated. According to the real-time PCR and LC-MS/MS results, the expression of genes of PC metabolism, accumulation of phospholipid classes, and degree of unsaturation of PC and PE increased in the direction from the center to the periphery of the colony. The peripheral zone of the colony was characterized by a higher value of the PC/PE ratio and a higher level of phospholipids esterified by linolenic acid. Considering that the synthesis of phospholipids in fungi occurs in different ways, we also conducted experiments with deuterium-labeled phospholipid precursors and found out that the Kennedy pathway is the predominant route for PC biosynthesis in F. velutipes. The zonal differences in gene expression and lipid composition can be explained by the participation of membrane lipids in polar growth maintenance and regulation.

Uptake and Metabolic Conversion of Exogenous Phosphatidylcholines Depending on Their Acyl Chain Structure in Arabidopsis thaliana

“…We observed the highest relative content of these molecular species in roots of actively growing control plants, as well as in roots of plants grown on 16:0/16:0 medium. This finding is consistent with our past observations, where an accumulation of C18:3-containing phospholipids (18:3/18:3 PC, 18:3/18:3 PE, 18:2/18:3 PC, 18:2/18:3 PE) was observed in the growing edge of the filamentous fungal colony enriched in vegetative, actively growing hyphae [75]. Such an analogy suggests that the synthesis of 18:3-containing molecular species of PCs and PEs is associated with the monopolar growth of different cells and organs and is a kind of universal reaction of taxonomically distant organisms.…”

Edible and Medicinal Macrofungi

“…Although the biochemical and molecular mechanisms of mycelium heterogeneity with polar growing have been studied in many studies, the role of lipids in colony development and zonality is still not understood. In Reference [ 4 ], Senik at al. used Flammulina velutipes as research material and the heterogeneity in the lipid metabolism and lipid composition of the fungal mycelium was demonstrated [ 4 ].…”

“…In Reference [ 4 ], Senik at al. used Flammulina velutipes as research material and the heterogeneity in the lipid metabolism and lipid composition of the fungal mycelium was demonstrated [ 4 ]. This research on the heterogenicity of the colony will provide the knowledge to explain the processes of hyphal differentiation and mushroom morphogenesis, and also can be used to optimize the yield of the desired lipid metabolite when using fungi as cell factories.…”

Coral Lipidome: Molecular Species of Phospholipids, Glycolipids, Betaine Lipids, and Sphingophosphonolipids

“…Recently, hydroxylated C 18 , C 20 , C 22 , and C 24 FAs were found in different species of fungi [ 93 , 94 , 95 , 96 ]. In the lipids of fungi, these FAs were detected only in TGs and ceramides and absent in PLs [ 96 , 97 , 98 ]. However, hydroxylated PL molecular species (PS 18:1alk/23:4(OH) 2 , PS 18:0alk/24:3(OH) and PS 19:1alk/24:3(OH), PS 18:0alk/18:1(OH)3 and PC 16:0alk/14:0(OH)) were detected in the lipids of gorgonian corals, which are associated with an advanced fungal community [ 47 ].…”