Trichothecium roseum is a fungus in the division Ascomycota first reported in 1809.[1] It is characterized by its flat and granular colonies which are initially white and develop to be light pink in color.[1] This fungus reproduces asexually through the formation of conidia with no known sexual state.[1] Trichothecium roseum is distinctive from other species of the genus Trichothecium in its characteristic zigzag patterned chained conidia.[2] It is found in various countries worldwide and can grow in a variety of habitats ranging from leaf litter to fruit crops.[2] Trichothecium roseum produces a wide variety of secondary metabolites including mycotoxins, such as roseotoxins and trichothecenes, which can infect and spoil a variety of fruit crops.[1] It can act as both a secondary and opportunistic pathogen by causing pink rot on various fruits and vegetables and thus has an economical impact on the farming industry.[1] Secondary metabolites of T. roseum, specifically Trichothecinol A, are being investigated as potential anti-metastatic drugs. Several agents including harpin, silicon oxide, and sodium silicate are potential inhibitors of T. roseum growth on fruit crops.[3][4][5] Trichothecium roseum is mainly a plant pathogen and has yet to show a significant impact on human health.[1]
The genus Trichothecium is small and heterogeneous comprising seventy-three recorded species.[1] This genus was first reported 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 made development of these features the center of extensive study throughout the years.[1] Since Trichothecium fungi lack a sexual phase, systematic classification was not uniform following their discovery.[1] These fungi were initially grouped into Fungi imperfecti under the form classification Deuteromycetes.[1] In 1958, Tubaki expanded Hughes’ classification of soil Hyphomycetes, part of the form class of Fungi imperfecti, by adding a ninth section in order to accommodate T. roseum and its unique conidial apparatus.[6][7] Trichothecium has now been classified under the class Sordariomycetes, phylum Ascomycota.[1]
Trichothecium roseum colonies are flat, granular, and powdery in appearance.[1][2] The color of the colonies appears to be white initially and develop into 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 blowouts 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 from the conidiophore one after another in alternating directions in order to form 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 the 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 colour when grown in masses in culture or on the host surface.[1]
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 in ten days 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 a pH of 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 of T. 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 utilize 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]
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 roseotoxin.[1][8][11]
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 tumour promotion on mouse skin in carcinogenesis tests and therefore may be valuable for further investigation as cancer preventive agent.[13][14][15] Anti-cancer studies have also shown that Trichothecinol A significantly inhibits cancer cell migration and therefore can be developed as a potential new anti-metastatic drug.[15]
Trichothecium roseum is a saprophyte[10] and is found worldwide.[8] It has been found in soils in various countries including Poland, Denmark, France, Russia, Turkey, Israel, Egypt, the Sahara, Chad, Zaïre, central Africa, Australia, Polynesia, India, China, and Panama.[8] Known habitats of T. roseum include uncultivated soils, forest nurseries, forest soils under beech trees, teak, cultivated soils with legumes, citrus plantations, heathland, dunes, salt-marshes, and garden compost.[8] Commonly, this fungus can be isolated from the tree leaf litter of various trees including birch, pine, fir, cotton, and palm.[8] It has also been isolated from several food sources such as 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]
There are approximately two hundred twenty-two different plant hosts of T. roseum found worldwide.[1] Trichothecium roseum causes pink rot on various fruits and vegetables.[1] It is considered both a secondary and opportunistic pathogen since it tends to enter the fruit/vegetable host through lesions that were caused by a primary pathogen.[1] Disease caused by this fungus is characterized by the development of white powdery mold that eventually turns pink.[1] Antagonistic behaviours of T. roseum with certain plant pathogenic fungi was reported by Koch in 1934.[16] He started that T. roseum actively parasitized stroma of Dibotryon morbosum which causes black knot disease in cherry, plum, and apricot trees.[16]
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 roseotoxin B, a secondary metabolite of T. roseum, can penetrate apple peels and cause lesions.[17] Trichothecium roseum also causes apple core rot which is 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 individuals who consume these infected apples due to its carcinogenicity, neurotoxicity, and immunotoxicity.[18]
Trichothecium roseum was identified, along with Acremonium acutatum, as the two strains of pathogenic fungi which caused 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 into the tissue.[19] This stain lowers the quality of the 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 rot has been reported to be increasing in wineries in Portugal.[20] In this case, T. roseum appeared to grow over rotten grapes that were infected with gray rot.[20] Mycotoxins were only detected in wines that were made with grapes that had gray rot and thus these toxins may be indicators of poor quality grapes.[20] Grape contamination by T. roseum appears to be prominent in temperate climates.[20]
Cases of T. roseum pink rot have been reported on numerous other fruits, however detailed studies have yet to be pursued.[1] Pink T. roseum rot has been reported on tomatoes in Korea and Pakistan.[21][22] It also causes pink rot in muskmelons and watermelons in Japan, the United States, South America, India, and the United Kingdom.[1] Trichothecium roseum is reported to grow also on bananas and peaches.[1]
Preventative measures can be taken to avoid growth of T. roseum in fruit crops.[23] These include ensuring 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 as measures to control T. roseum production on fruit crops.[1] In particular, studies have been done on testing 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 thus decreased T. roseum growth.[3] Silicon oxide and sodium silicate also reduced the severity of pink rot and lesion diameter in harvested Hami melons.[4] Pre-harvest inoculation of harpin on muskmelons decreased the amount of pink rot caused by T. roseum on harvested melons.[5]
Trichothecium roseum is a fungus in the division Ascomycota first reported in 1809. It is characterized by its flat and granular colonies which are initially white and develop to be light pink in color. This fungus reproduces asexually through the formation of conidia with no known sexual state. Trichothecium roseum is distinctive from other species of the genus Trichothecium in its characteristic zigzag patterned chained conidia. It is found in various countries worldwide and can grow in a variety of habitats ranging from leaf litter to fruit crops. Trichothecium roseum produces a wide variety of secondary metabolites including mycotoxins, such as roseotoxins and trichothecenes, which can infect and spoil a variety of fruit crops. It can act as both a secondary and opportunistic pathogen by causing pink rot on various fruits and vegetables and thus has an economical impact on the farming industry. Secondary metabolites of T. roseum, specifically Trichothecinol A, are being investigated as potential anti-metastatic drugs. Several agents including harpin, silicon oxide, and sodium silicate are potential inhibitors of T. roseum growth on fruit crops. Trichothecium roseum is mainly a plant pathogen and has yet to show a significant impact on human health.
Trichothecium roseum è un fungo ascomicete parassita delle piante. Provoca il marciume rosa delle pere.
Trichothecium roseum è un fungo ascomicete parassita delle piante. Provoca il marciume rosa delle pere.
Trichothecium roseum (Pers.) Link – gatunek grzybów należący do rzędu rozetkowców (Hypocreales)[1].
Pozycja w klasyfikacji według Index Fungorum: Trichothecium, Incertae sedis, Hypocreales, Hypocreomycetidae, Sordariomycetes, Pezizomycotina, Ascomycota, Fungi[1].
Po raz pierwszy zdiagnozował go w 1794 r. Ch.H. Persoon nadając mu nazwę Trichoderma roseum. Obecną, uznaną przez Index Fungorum nazwę nadał mu w 1809 r. J.H. Link[1].
Spotykana jest głównie anamorfa; teleomorfa (Hypomyces roseus) powstaje bardzo rzadko[3].
Na pożywce PCA kolonie rozwijają się umiarkowanie silnie, tworząc zamszowatą, płasko rozpostartą na podłożu grzybnię. Początkowo jest ona biała, potem różowa lub pomarańczowa. Konidiofory są identyczne, jak strzępki grzybni wegetatywnej. Są wyprostowane, nierozgałęzione, często z przegrodami w pobliżu podstawy i mają mniej lub bardziej chropowate ściany. Na ich szczycie znajdują się komórki konidiotwórcze, w których enteroblastycznie powstają zarodniki konidialne. Drugie i następne konidium powstaje poniżej poprzedniego i odgraniczającej go przegrody. Wskutek tego w trakcie wytwarzania konidiów komórka konidiotwórcza ulega skracaniu i powstają bazypetalne łańcuszki, w których konidia ułożone są spiralnie wokół komórki[4][3]. Konidia są gruszkowate, dwukomórkowe i mają rozmiar 12–18 × 8–10 μm[5].
Jest rozpowszechniony na całym świecie. Żyje w glebie jako saprotrof na martwych szczątkach roślin, ale również w gospodarstwach domowych i magazynach na produktach spożywczych, zwłaszcza na produktach mącznych[4]. Na jabłkach po zbiorze, w czasie ich przechowywania wywołuje różową pleśń jabłek powodującą ich gnicie[5]. Opisano występowanie Trichothecium roseum na ponad 20 gatunkach roślin. Wywołuje min. pleśnienie owoców i nasion u wielu gatunków. W przechowalniach owoców i warzyw wyrządza duże szkody[6].
Wytwarza wiele metabolitów wtórnych: antybiotyki i inne związki biologicznie czynne oraz mykotoksyny[6]. Jedną z nich jest silnie trująca dla ludzi i zwierząt trichotecyna[3].
Trichothecium roseum (Pers.) Link – gatunek grzybów należący do rzędu rozetkowców (Hypocreales).
Trichothecium roseum je grzib[9], co go nojprzōd ôpisoł Christiaan Hendrik Persoon, a terŏźnõ nazwã doł mu Heinrich Friedrich Link 1809. Trichothecium roseum nŏleży do zorty Trichothecium, rzyndu Hypocreales, klasy Sordariomycetes, grōmady Ascomycota i krōlestwa grzibōw.[10][11] Żŏdne podgatōnki niy sōm wymianowane we Catalogue of Life.[10]
Wikispecies mo informacyje ô Trichothecium roseum.Trichothecium roseum je grzib, co go nojprzōd ôpisoł Christiaan Hendrik Persoon, a terŏźnõ nazwã doł mu Heinrich Friedrich Link 1809. Trichothecium roseum nŏleży do zorty Trichothecium, rzyndu Hypocreales, klasy Sordariomycetes, grōmady Ascomycota i krōlestwa grzibōw. Żŏdne podgatōnki niy sōm wymianowane we Catalogue of Life.
ばら色かび病（ばらいろかびびょう、Trichothecium roseum、トリコセシウム・ローゼム）は、カビ（ トリコセシウム属菌）による植物の病気の一つ。
主に水分や糖分の多い、果実（メロン、イチゴ、リンゴなど）、果菜類（キュウリ、トマトなど）で発病する。発症部にはピンクや橙色の菌糸体が生じ、果肉が腐敗する[1][注 1]。
気温が20℃前後で多湿の場合、特に施設栽培（ビニールハウスなど）で発生する[2]。
食べると苦味があるが、この成分はククルビタシンとされている[3]。トリコセシウム属菌に汚染された場合、メロン自身が菌への防御作用のため、ククルビタシンの産生を増す（食べると口腔内が舌がしびれるほど）[4][3]。
メロンの場合は、Pink-mold rotとも呼ばれる[5]。
特にアムスメロンなど、皮が薄い品種で被害が多発している[6]。
キュウリの場合は、葉にも発病する[2]。
根、クラウン部、葉柄、ランナーの順に発病し、最後には苗が枯死する[7]。
まず果実のへた下部分から褐色に変色し、果実の中へも菌が進行するが、外観からは分かりにくい[2]。
兵庫県立健康環境科学センター（2003年の年報2号）によると、バラ色カビ病の原因菌であるトリコセシウム・ローゼムが、苦味成分のトリコテシンを産生することが確認された[8]。
ビニールハウスの場合、多湿にならないよう換気を徹底する[2]。
