Trichothecium roseum

History and classification

The genus Trichothecium is small and heterogeneous with seventy-three recorded species. ^[1] This genus Was Reported first in 1809. ^[1] The main members of the genus include Trichothecium polybrochum , Trichothecium cystosporium , Trichothecium pravicovi , and Trichothecium roseum . ^[1] Trichothecium roseum has morphologically different conidiophores and conidia than the other three main species, which has been developed over the years. ^[1] Since Trichotheciumfungi lack a sexual phase, the systematic classification was not uniform following their discovery. ^[1] These fungi were initially grouped into Fungi imperfecti under the Deuteromycetes classification form . ^[1] In 1958, Tubaki expanded Hughes’ classification of soil hyphomycetes , part of the form of Fungi imperfecti , by adding a ninth section in order to accommodate T. roseum and its unique conidial apparatus. ^[6] [7] Trichothecium has been classified under the Sordariomycetes class . ^[1] A recent classification has placed Trichotheciumunder the phylum Ascomycota since they produce conidial courses that are similar to the perfect fungi. ^[1]

Morphology

Trichothecium roseum colonies are flat, granular, and powdery in appearance. ^[1] [2] The color of the colonies appears to be white and develops a light pink to peach color. ^[1] The genus Trichothecium is characterized by its pinkish colored colonies. ^[8]

Conidiophores of T. roseum are usually erect and are 200-300μm in length. ^[9] They arise singly or in loose groups. ^[1] Conidiophores are simple hyphae , ^[10] which are septate in their lower half, ^[6] and bear clusters of conidia at the tip. ^[2] These conidiophores are indistinguishable from vegetative hyphae until production of the first conidium. ^[1] Conidium development is distinctive ^[2] and was first described by Ingold in 1956. ^[6]Conidia arise as a blowout from the side of the conidiophore apex which is thus incorporated into the base of each spore. ^[6] After the first conidium is blown out, before it matures, the apex of the conidiophore directly below blows out a second conidium from the opposite side. ^[6] Conidia are pinched out of the conidiophore, one after the other in the direction of the characteristic zigzag patterned chain. ^[1] Conidia of T.roseum (15-20 × 7.5-10 μm) ^[9] are smooth and clavate. ^[1] Each conidium is two celled with apical cell being larger than the curved basal cell. ^[1] Conidia are light pink and appear translucent under the microscope.^[1] They appear a more saturated pink color when grown in masses in culture or on the surface. ^[1]

Growth and physiology

Trichothecium roseum reproduces asexually by the formation of conidia with no known sexual stage. ^[1] Trichothecium roseum is relatively fast-growing as it can form colonies reaching 9 cm (4 in) in diameter at 20 ° C (68 ° F) on malt extract agar. ^[8] This fungus grows optimally at 25 ° C (77 ° F) with a minimum and maximum growing temperature of 15 ° C (59 ° F) and 35 ° C (95 ° F) respectively. ^[8] Trichothecium roseum can tolerate a wide pH range but grows optimally at pH 6.0. Sporulation occurs rapidly at pH 4.0-6.5 and a combination of low temperature (15 ° C (59 ° F)) and high glucose concentration can increase the size of conidia. ^[8] Treatment ofT. roseum with colchicine increases the number of nuclei in conidia, growth rate, and biosynthetic activities. ^[8] There are a variety of sugars that T. roseum can use including D-fructose, sucrose, maltose, lactose, raffinose, D-galactose, D-glucose, arabinose, and D-mannitol. ^[8] Good growth also occurs in the presence of various amino acids including L-methionine, L-isoleucine, L-tryptophan, L-alanine, L-norvaline, and L-norleucine. ^[8]

Secondary metabolites

Trichothecium roseum can produce numerous secondary metabolites that include toxins, antibiotics, and other biologically active compounds. ^[1] Diterpenoids produced include rosolactone, rosolactone acetate, rosenonolactone, desoxyrosenonolactone, hydroxyrosenonolactones, and acetoxy-rosenonolactone. Several sesquiterpenoids are also produced by T. roseum including crotocin, trichothecolone, trichothecin, trichodiol A, trichothecinol A / B / C, trichodiene, and rosinotoxin. ^{[1] [8] [11]}

Biomedical applications

Trichothecium roseum was found to antagonize pathogenic fungi, such as Pyricularia oryzae ( Magnaporthe oryzae ) and Phytophthora infestans , in vitro . ^[12] It was suggested that the antifungal compound trichothecin was the main contributor to this action. ^[12] In other studies trichothecinol B isolated from T. roseum displayed modest antifungal activity against Cryptococcus albidus and Saccharomyces cerevisiae . ^[13]

Various studies-have Indicated That Trichothecinol A isolated from T. roseum Strongly inhibited TPA-induced tumor promoting on mouse skin carcinogenesis test in May and therefore be valuable for further Top investigation as cancer preventive agent. ^{[13] [14] [15]} Anti-cancer studies have also shown that Trichothecinol has significantly inhibited cancer cell migration and therefore can be developed as a potential new anti-metastatic drug. ^[15]

Habitat and ecology

Trichothecium roseum is a saprophyte ^[10] and is found worldwide. ^[8] Poland, Denmark, France, Russia, Turkey, Israel, Egypt, the Sahara, Chad, Zaire, central Africa, Australia, Polynesia, India, China, and Panama. ^[8] Known habitats of T. roseum include uncultivated soils, forest nurseries, forest under trees, teak, cultivated soils with vegetables, citrus plantations, heathland, dunes, salt-marshes, and garden compost. ^[8] Commonly, this fungus can be isolated from the tree leaf of various trees including birch, pine, fir, cotton, and palm. ^[8]Barley, wheat, oats, maize, apples, grapes, meat products, cheese, beans, hazelnuts, pecans, pistachios, peanuts, and coffee. ^[10] Levels of T. roseum in foods other than fruits are generally low. ^[10]

Plant pathology

There are approximately two hundred and twenty different seedling hosts of T. roseum found worldwide. ^[1] Trichothecium roseum causes pink rot on various fruits and vegetables. ^[1] It is considered both a pathogenetic and a pathogenetic pathogenesis of the fruit / vegetable host by the pathogenesis of primary pathogenesis. ^[1] Disease caused by this fungus is characterized by the development of white powdery mold that eventually turns pink. ^[1]Antagonistic behaviors of T. roseum with certain pathogenic plant fungi was reported by Koch in 1934. ^[16] He started that T. roseumparasitized stroma of Dibotryon morbosum which causes black knot disease in cherry, plum, and apricot trees. ^[16]

Apple disease

Trichothecium roseum is known to produce pink rot on apples particularly following an apple scab infection caused by Venturia inaequalis . ^[1] Studies have shown that rosinotoxin B, a secondary metabolite of T. roseum , can penetrate apple peels and cause lesions. ^[17] Trichothecium roseum also causes a serious problem in China. ^[18] Core rot not only causes economic loss but it is also associated with high levels of mycotoxin production. ^[18] There have been reports of the presence of trichothecenes , specifically T-2 toxin , in infected apples in China. ^[18]T-2 toxin has the highest toxicity of the trichothecenes and poses a threat to those who consume these infections due to its carcinogenicity, neurotoxicity, and immunotoxicity. ^[18]

Grape disease

Trichothecium roseum has been identified, along with Acremonium acutatum , as the two strains of pathogenic fungi, which causes white stains on harvested grapes in Korea. ^[19] The presence of mycelia on the surface of the grapes resulted in a white stained, powdery mildew appearance. ^[19] Trichothecium roseum was identified using fungal morphology and nucleotide sequencing by PCR . ^[19] It appears as though the fungus covers the surface of the grape only and does not penetrate the tissue. ^[19] This stain lowers the quality of grapes and causes serious economic losses. ^[19]

Trichothecin, trichothecolone, and rosenonolactone, which are secondary metabolites of T. roseum , were detected in wines. ^[20] Presence of small quantities of trichothecin can inhibit alcohol fermentation. ^[20] Trichothecium roseum has been reported to increase in wineries in Portugal. ^[20] In this case, T. roseum appeared to grow over the years that were infected with gray rot. ^[20] Mycotoxins have only been detected in these tissues and have been shown to be of poor quality. ^[20] Grape contamination by T. roseum appears to be prominent intemperate climates . ^[20]

Other fruit disease

Cases of T. roseum pink have been reported on numerous other fruits, but have been studied. ^[1] Pink T. roseum has been reported in Korea and Pakistan. ^[21] [22] It also causes blues in muskmelons and watermelons in Japan, the United States, South America, India, and the United Kingdom. ^[1] Trichothecium roseum is reported to grow on bananas and peaches. ^[1]

Prevention of plant disease

Preventive measures can be taken to prevent growth of T. roseum in fruit crops. ^[23] These include adequate ventilation in the storage facility, avoiding injuring and bruising the fruit, and ensuring adequate storage temperatures. ^[23] Pre- and postharvest applications have been suggested to measure T. roseum production on fruit crops. ^[1] In particular, studies have been done to test various compounds to prevent T. roseum growth on several melon types. ^{[3] [4] [5]} Harpin was inoculated on harvested Hami melons and caused significantly reduced lesion diameter and reducedT. roseum growth. ^[3] Silicon oxide and sodium silicate, and reduced diameter. Hami melons. ^[4] Pre-harvest inoculation of rabbit on muskmelons decreased by T. roseum on harvested melons. ^[5]

References