scholarly journals The pleiotropic functions of Intracellular hydrophobins in aerial hyphae and fungal spores

PLoS Genetics ◽  
2021 ◽  
Vol 17 (11) ◽  
pp. e1009924
Author(s):  
Feng Cai ◽  
Zheng Zhao ◽  
Renwei Gao ◽  
Peijie Chen ◽  
Mingyue Ding ◽  
...  
Keyword(s):  
Turgor Pressure ◽  
Fungal Spores ◽  
Aerial Dispersal ◽  
Large Numbers ◽  
Aerial Hyphae ◽  
Superior Surface ◽  
Squeeze Out ◽  
Surface Active ◽  
Pleiotropic Functions ◽  
Water Sensing

Higher fungi can rapidly produce large numbers of spores suitable for aerial dispersal. The efficiency of the dispersal and spore resilience to abiotic stresses correlate with their hydrophobicity provided by the unique amphiphilic and superior surface-active proteins–hydrophobins (HFBs)–that self-assemble at hydrophobic/hydrophilic interfaces and thus modulate surface properties. Using the HFB-enriched mold Trichoderma (Hypocreales, Ascomycota) and the HFB-free yeast Pichia pastoris (Saccharomycetales, Ascomycota), we revealed that the rapid release of HFBs by aerial hyphae shortly prior to conidiation is associated with their intracellular accumulation in vacuoles and/or lipid-enriched organelles. The occasional internalization of the latter organelles in vacuoles can provide the hydrophobic/hydrophilic interface for the assembly of HFB layers and thus result in the formation of HFB-enriched vesicles and vacuolar multicisternal structures (VMSs) putatively lined up by HFBs. These HFB-enriched vesicles and VMSs can become fused in large tonoplast-like organelles or move to the periplasm for secretion. The tonoplast-like structures can contribute to the maintenance of turgor pressure in aerial hyphae supporting the erection of sporogenic structures (e.g., conidiophores) and provide intracellular force to squeeze out HFB-enriched vesicles and VMSs from the periplasm through the cell wall. We also show that the secretion of HFBs occurs prior to the conidiation and reveal that the even spore coating of HFBs deposited in the extracellular matrix requires microscopic water droplets that can be either guttated by the hyphae or obtained from the environment. Furthermore, we demonstrate that at least one HFB, HFB4 in T. guizhouense, is produced and secreted by wetted spores. We show that this protein possibly controls spore dormancy and contributes to the water sensing mechanism required for the detection of germination conditions. Thus, intracellular HFBs have a range of pleiotropic functions in aerial hyphae and spores and are essential for fungal development and fitness.

scholarly journals Intracellular accumulation and secretion of hydrophobin-enriched vesicles aid the rapid sporulation of molds

2020 ◽  
Author(s):  
Feng Cai ◽  
Zheng Zhao ◽  
Renwei Gao ◽  
Mingyue Ding ◽  
Siqi Jiang ◽  
...  
Keyword(s):  
Cell Wall ◽  
Secretory Pathway ◽  
Turgor Pressure ◽  
Accessory Proteins ◽  
Lipid Bodies ◽  
Intracellular Accumulation ◽  
Aerial Dispersal ◽  
Aerial Hyphae ◽  
Superior Surface ◽  
Surface Active

AbstractFungi can rapidly produce large amounts of spores suitable for aerial dispersal. The hydrophobicity of spores is provided by the unique amphiphilic and superior surface-active proteins – hydrophobins (HFBs) – that self-assemble at hydrophobic/hydrophilic interfaces and thus change surface properties. Using the HFB-enriched mold Trichoderma and the HFB-free yeast Pichia pastoris, we revealed a distinctive HFB secretory pathway that includes an intracellular accumulation of HFBs in lipid bodies (LBs) that can internalize in vacuoles. The resulting vacuolar multicisternal structures (VMS) are stabilized by HFB layers that line up on their surfaces. These HFB-enriched VMSs can move to the periplasm for secretion or become fused in large tonoplast-like organelles. The latter contributes to the maintenance of turgor pressure required for the erection of sporogenic structures and rapid HFB secretion by squeezing out periplasmic VMSs through the cell wall. Thus, HFBs are essential accessory proteins for the development of aerial hyphae and colony architecture.

An automatic, multichamber soil-washing apparatus for removing fungal spores from soil

1972 ◽  
Vol 18 (9) ◽  
pp. 1399-1404 ◽  
Author(s):  
J. Bissett ◽  
P. Widden
Keyword(s):  
Fungal Spores ◽  
Soil Washing ◽  
Soil Samples ◽  
Cross Contamination ◽  
Vegetative Mycelium ◽  
Soil Particles ◽  
Large Numbers

An automatic soil-washing apparatus is described which enabled the washing of fungus spores out of large numbers of soil samples simultaneously. Tests of the apparatus indicated that superficial spores were removed from most of the soil particles. This allowed organisms growing in soil as vegetative mycelium to be isolated more readily without the serious competition commonly encountered from organisms sporulating heavily in the soil. Virtually no cross-contamination of soil samples occurred in the multichambered apparatus.

scholarly journals Trait-based aerial dispersal of arbuscular mycorrhizal fungi

2020 ◽  
Author(s):  
V. Bala Chaudhary ◽  
Sarah Nolimal ◽  
Moisés A. Sosa-Hernández ◽  
Cameron Egan ◽  
Jude Kastens
Keyword(s):  
Community Structure ◽  
Mycorrhizal Fungi ◽  
High Throughput Sequencing ◽  
Fungal Spores ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Global Scale ◽  
Arbuscular Mycorrhizas ◽  
List Type ◽  
Aerial Dispersal

SUMMARYDispersal is a key process driving local-scale community assembly and global-scale biogeography of plant symbiotic arbuscular mycorrhizal (AM) fungal communities. A trait-based approach could improve predictions regarding how AM fungal aerial dispersal varies by species.We conducted month-long collections of aerial AM fungi for 12 consecutive months in an urban mesic environment at heights of 20 m. We measured functional traits of all collected spores and assessed aerial AM fungal community structure both morphologically and with high-throughput sequencing.Large numbers of AM fungal spores were present in the air over the course of one year and these spores were more likely to exhibit traits that facilitate dispersal. Aerial spores were smaller than average for Glomeromycotinan fungi. Trait-based predictions indicate that nearly 1/3 of described species from diverse genera demonstrate the potential for aerial dispersal. Diversity of aerial AM fungi was relatively high (20 spore species and 17 virtual taxa) and both spore abundance and community structure shifted temporally.The prevalence of aerial dispersal in arbuscular mycorrhizas is perhaps greater than previously indicated and a hypothesized model of AM fungal dispersal mechanisms is presented. Anthropogenic soil impacts may initiate the dispersal of disturbance-tolerating AM fungal species and facilitate community homogenization.

Functional Morphology of the Mucosa of the Middle Ear and Eustachian Tube

1976 ◽  
Vol 85 (2_suppl) ◽  
pp. 36-43 ◽  
Author(s):  
David J. Lim
Keyword(s):  
Eustachian Tube ◽  
Middle Ear ◽  
Surface Active Agent ◽  
Active Agent ◽  
Biological Significance ◽  
Normal Function ◽  
Middle Ear Mucosa ◽  
Defense Systems ◽  
Large Numbers ◽  
Surface Active

A review of available histological, histochemical and ultrastructural data on middle ear mucosa and the Eustachian tube was made to provide a broad cellular basis for understanding middle ear effusions. The presence of mucociliary defense system in a large part of the Eustachian tube and middle ear is seen as the first line of defense. Secretion by the mucosa has a profound biological significance. Immunoglobulins A, G, and even E and M are produced locally by the mucosa and may contribute to the immunodefense of the middle ear. Secretory lysozyme is also produced by the mucosa and may contribute enzymatic defense of the ear. Mucosal immunoglobulins and lysozyme are significantly elevated in the effusions, which would imply that local defense systems are hyperactive in OME. It also appears that these increases are related to the increase of the secretory cell population. It is also suspected that auditory surface-active agent is produced locally and may facilitate normal function of the tube. The middle ear also can transport macromolecules very rapidly across intact mucosal epithelium. The large numbers of tissue and wandering macrophages found in the mucosa and effusions would also imply that the middle ear is capable of efficient phagocytosis, which may be involved in processing antigen.

scholarly journals MUTANTS PRODUCED BY X-IRRADIATION OF SPORES OF CHAETOMIUM GLOBOSUM AND A COMPARISON WITH THOSE PRODUCED BY ULTRAVIOLET IRRADIATION

1949 ◽  
Vol 32 (6) ◽  
pp. 647-653 ◽  
Author(s):  
J. M. Ford ◽  
D. P. Kirwan
Keyword(s):  
Ultraviolet Irradiation ◽  
Wave Length ◽  
Fungal Spores ◽  
Chaetomium Globosum ◽  
Theoretical Curve ◽  
Striking Difference ◽  
X Rays ◽  
X Ray ◽  
Large Numbers ◽  
X Irradiation

1. Mutants produced by x-irradiation of fungal spores of Chaetomium globosum have been compared with those produced by ultraviolet irradiation. 2. The most striking difference between the mutants produced by x-irradiation and ultraviolet irradiation is the absence in x-ray experiments of the K mutant which is produced in large numbers at short ultraviolet wave lengths. 3. A comparison is made of the relation between x-ray dose and numbers of lethal mutants, and the relation between the short ultraviolet wave length 2804 dose and numbers of lethal mutants. Both are compared with theoretical curves for 1, 2, 5, and 8 quantum hits. 4. The production of lethal mutants by x-rays is shown to be consistent with the theoretical curve for five quantum hits on the sensitive spot of the spore, whereas the production of lethal mutants by the ultraviolet wave length 2804 Å.u. is consistent with two quantum hits.

scholarly journals Surface-active proteins enable microbial aerial hyphae to grow into the air

Microbiology ◽  
2000 ◽  
Vol 146 (4) ◽  
pp. 767-773 ◽  
Author(s):  
Han A. B. Wösten ◽  
Joanne M. Willey
Keyword(s):  
Aerial Hyphae ◽  
Surface Active

The dispersal of colidia of Sclerotinia fructicola (Wint.) Rehm.

1965 ◽  
Vol 16 (4) ◽  
pp. 627 ◽  
Author(s):  
PT Jenkins
Keyword(s):  
Brown Rot ◽  
Glass Slide ◽  
Stone Fruits ◽  
Spore Trap ◽  
Aerial Dispersal ◽  
Air Temperatures ◽  
Large Numbers ◽  
Splash Dispersal ◽  
Peach Orchard ◽  
Water Borne

The dispersal of conidia of Sclerotinia fructicola (Wint.) Rehm. was studied in a peach orchard and in the laboratory, with the use of traps for water-borne spores and an automatic volumetric spore trap. In the orchard, little aerial dispersal was detected by using a trap less than 10 ft from the nearest trees, but large numbers of spores were dispersed by rain falling on sporulating blossoms. In the laboratory, splash droplets from a drop of water falling onto a sporulating fruit or glass slide dusted with conidia were recorded at distances of up to 36 cm. More than two-thirds of the droplets contained spores, the numbers ranging from 3 to more than 7000 per droplet. Aerial dispersal was detected in the laboratory when sporulating peach fruits were placed 3 ft from the volumetric trap. Dispersal was greatest at minimum humidities and maximum air temperatures. The results of the experiments suggest that splash dispersal is more important than aerial dispersal of conidia of S. fructicola in the epidemiology of brown rot of stone fruits.

Use of detergents to facilitate penetration of fixatives into thick-walled fungal spores

1978 ◽  
Vol 36 (2) ◽  
pp. 400-401
Author(s):  
Mercedes R. Edwards
Keyword(s):  
Potassium Permanganate ◽  
Cell Walls ◽  
Fungal Spores ◽  
Thin Sections ◽  
Cell Structures ◽  
Thin Sectioning ◽  
Aerial Hyphae ◽  
Plastic Embedding

Fungi are difficult to prepare for good ultra-thin sectioning. Aerial hyphae and certain types of spores have rigid layered walls with outer coats relatively impermeable to common fixatives such as glutaraldehyde and osmium. The slow penetration of these reagents into the cell apparently leads to the formation of artifacts (e. g., mycelin figures and vesicular systems) indicating bad fixation. Poor plastic embedding ensues and many holes are found in the sections, around cell walls or within the cells. Obtaining suitable thin sections from such materials is almost impossible. This problem has been overcome in part by the use of potassium permanganate, which penetrates fungal cells readily and produces good outline of membranes. However, this fixative can destroy most of the cytoplasmic and nuclear matrices and thus is not adequate for the preservation of ribosomes and other cell structures.

scholarly journals Fungal artillery of zombie flies: infectious spore dispersal using a soft water cannon

2019 ◽  
Vol 16 (159) ◽  
pp. 20190448 ◽  
Author(s):  
Jolet de Ruiter ◽  
Sif Fink Arnbjerg-Nielsen ◽  
Pascal Herren ◽  
Freja Høier ◽  
Henrik H. De Fine Licht ◽  
...  
Keyword(s):  
Aerodynamic Drag ◽  
Pathogenic Fungus ◽  
Turgor Pressure ◽  
Fungal Spores ◽  
House Fly ◽  
Maximum Pressure ◽  
New Host ◽  
Entomophthora Muscae ◽  
Spore Size ◽  
Spore Release

Dead sporulating female fly cadavers infected by the house fly-pathogenic fungus Entomophthora muscae are attractive to healthy male flies, which by their physical inspection may mechanically trigger spore release and by their movement create whirlwind airflows that covers them in infectious conidia. The fungal artillery of E. muscae protrudes outward from the fly cadaver, and consists of a plethora of micrometric stalks that each uses a liquid-based turgor pressure build-up to eject a jet of protoplasm and the initially attached spore. The biophysical processes that regulate the release and range of spores, however, are unknown. To study the physics of ejection, we design a biomimetic ‘soft cannon’ that consists of a millimetric elastomeric barrel filled with fluid and plugged with a projectile. We precisely control the maximum pressure leading up to the ejection, and study the cannon efficiency as a function of its geometry and wall elasticity. In particular, we predict that ejection velocity decreases with spore size. The calculated flight trajectories under aerodynamic drag predict that the minimum spore size required to traverse a quiescent layer of a few millimetres around the fly cadaver is approximately 10 µm. This corroborates with the natural size of E. muscae conidia (approx. 27 µm) being large enough to traverse the boundary layer but small enough (less than 40 µm) to be lifted by air currents. Based on this understanding, we show how the fungal spores are able to reach a new host.

scholarly journals GcSTUA, an APSES Transcription Factor, Is Required for Generation of Appressorial Turgor Pressure and Full Pathogenicity of Glomerella cingulata

2007 ◽  
Vol 20 (9) ◽  
pp. 1102-1111 ◽  
Author(s):  
XingZhang Tong ◽  
Xiuwen Zhang ◽  
Kim M. Plummer ◽  
Kathryn M. Stowell ◽  
Patrick A. Sullivan ◽  
...  
Keyword(s):  
Magnaporthe Grisea ◽  
Turgor Pressure ◽  
Apple Fruit ◽  
Wild Type ◽  
Glomerella Cingulata ◽  
Reproductive Structures ◽  
Aerial Hyphae ◽  
Genes Encoding ◽  
Visible Lesion ◽  
Onion Epidermal Cells

Glomerella cingulata, which infects a number of different hosts, gains entry to the plant tissue by means of an appressorium. Turgor pressure generated within the appressorium forces a penetration peg through the plant cuticle. A visible lesion forms as the fungus continues to grow within the host. A G. cingulata homolog (GcSTUA) of the genes encoding Asm1, Phd1, Sok2, Efg1, and StuA transcription factors in Magnaporthe grisea and other fungi was cloned and shown to be required for infection of intact apple fruit and penetration of onion epidermal cells. Mobilization of glycogen and triacylglycerol during formation of appressoria by the GcSTUA deletion mutant appeared normal and melanization of the maturing appressoria was also indistinguishable from that of the wild type. However, GcSTUA was essential for the generation of normal turgor pressure within the appressorium. As is the case for its homologs in other fungi, GcSTUA also was required for the formation of aerial hyphae, efficient conidiation, and the formation of perithecia (sexual reproductive structures).

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