Pestalotiopsis—Morphology, Phylogeny, Biochemistry and Diversity

Fungal Diversity (2011) 50:167–187 DOI 10.1007/s13225-011-0125-x Pestalotiopsis—morphology, phylogeny, biochemistry and diversity Sajeewa S. N. Maharachchikumbura & Liang-Dong Guo & Ekachai Chukeatirote & Ali H. Bahkali & Kevin D. Hyde Received: 8 June 2011 /Accepted: 22 July 2011 /Published online: 31 August 2011 # Kevin D. Hyde 2011 Abstract The genus Pestalotiopsis has received consider- are morphologically somewhat similar. When selected able attention in recent years, not only because of its role as GenBank ITS accessions of Pestalotiopsis clavispora, P. a plant pathogen but also as a commonly isolated disseminata, P. microspora, P. neglecta, P. photiniae, P. endophyte which has been shown to produce a wide range theae, P. virgatula and P. vismiae are aligned, most species of chemically novel diverse metabolites. Classification in cluster throughout any phylogram generated. Since there the genus has been previously based on morphology, with appears to be no living type strain for any of these species, conidial characters being considered as important in it is unwise to use GenBank sequences to represent any of distinguishing species and closely related genera. In this these names. Type cultures and sequences are available for review, Pestalotia, Pestalotiopsis and some related genera the recently described species P. hainanensis, P. jesteri, P. are evaluated; it is concluded that the large number of kunmingensis and P. pallidotheae. It is clear that the described species has resulted from introductions based on important species in Pestalotia and Pestalotiopsis need to host association. We suspect that many of these are be epitypified so that we can begin to understand the probably not good biological species. Recent molecular genus/genera. There are numerous reports in the literature data have shown that conidial characters can be used to that various species produce taxol, while others produce distinguish taxa; however, host association and geograph- newly discovered compounds with medicinal potential and ical location is less informative. The taxonomy of the still others cause disease. The names assigned to these genera complex remains confused. There are only a few novel compound-producing taxa lack an accurate taxo- type cultures and, therefore, it is impossible to use gene nomic basis, since the taxonomy of the genus is markedly sequences in GenBank to clarify species names reliably. It confused. Until the important species have been epitypi- has not even been established whether Pestalotia and fied with living strains that have been sequenced and Pestalotiopsis are distinct genera, as no isolates of the deposited in public databases, researchers should refrain type species of Pestalotia have been sequenced, and they from providing the exact name of species. : Keywords Epitypify Host occurrence Pestalotia S. S. N. Maharachchikumbura L.-D. Guo (*) Pestalosphaeria . Pigmentation . Secondary metabolites . Key Laboratory of Systematic Mycology & Lichenology, Taxol Institute of Microbiology, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China e-mail: [email protected] Introduction S. S. N. Maharachchikumbura : E. Chukeatirote : K. D. Hyde (*) School of Science, Mae Fah Luang University, Thasud, Chiang Rai 57100, Thailand Pestalotoiopsis Steyaert is an appendage-bearing conidial e-mail: [email protected] anamorphic form (coelomycetes) in the family Amphi- : sphaeriaceae (Barr 1975, 1990;Kangetal.1998, 1999), and A. H. Bahkali K. D. Hyde molecular studies have shown that Pestalotiopsis is mono- College of Science, Botany and Microbiology Department, King Saud University, phyletic (Jeewon et al. 2002, 2003, 2004). Species of P.O. Box: 2455, Riyadh 1145, Saudi Arabia Pestalotiopsis are common in tropical and temperate 168 Fungal Diversity (2011) 50:167–187 ecosystems (Bate-Smith and Metcalfe 1957)andmaycause conidial forms. Steyaert (1949) also introduced two new plant disease (Das et al. 2010), are often isolated as genera, Truncatella Steyaert for 4-celled conidial forms and endophytes (Liu et al. 2006; Wei et al. 2007; Watanabe et Pestalotiopsis Steyaert for the 5-celled forms, while the 6- al. 2010), or occur as saprobes (Wu et al. 1982; Agarwal and celled forms remained in Pestalotia. Pestalotia was consid- Chauhan 1988; Yanna et al. 2002;Huetal.2007; Liu et al. ered to be a monophyletic genus and Steyaert (1949) 2008a). The genus has received much attention from the suggested that the type species could be distinguished from scientific community. However, this not because of its Pestalotiopsis by it cupulate conidiomata and distoseptate pathogenic nature (Hyde and Fröhlich 1995; Rivera and median cells. Steyaert (1949) further divided Pestalotiopsis Wright 2000; Yasuda et al. 2003), but rather because its into additional sections based on the number of apical species have been shown to produce many important appendages. These were the Monosetulatae, Bistulatae, secondary metabolites (Strobel et al. 1996a, 2002;Ding Trisetulatae and Multisetulatae, which were further divided et al. 2008a, b; Aly et al. 2010;Xuetal.2010). The aim of into subdivisions. Conidia with a single setulae (apical the present paper on Pestalotia, Pestalotiopsis and similar appendage) were included in the Monosetulatae, which was genera is to review (1) historical aspects, (2) morpholog- further divided into forms with simple and branched setulae. ical and molecular studies, (3) life mode of taxa, (4) Conidia with two setulae or on average two setulae were species numbers and (5) biochemical production by selected included in the Bistulatae. Conidia with three setulae or on species. The problems of understanding the genus are average three setulae were included in the Trisetulatae, discussed and the work needed to resolve these problems which was further divided by concolorous or versicolorous elaborated. In most cases problems arise due to misidentifica- conidia, fusiform or claviform conidia and spatulate or non- tion of taxa and the review illustrates the importance of the spatulate setulae. Conidia with more than three setulae were correct identification of strains before they are used in included in the Multisetulatae. Steyaert (1949) reduced biochemical or other studies. Monochaetia (Sacc.) Allesch. from its generic state and placed species with single setula in section Monosetulatae of Pestalotiopsis and Truncatella. Steyaert (1949)provided History descriptions of 46 species and Pestalotiopsis guepinii (Desm.) Steyaert was considered to be the type species of De Notaris (1839) introduced the genus Pestalotia De Not. the newly introduced genus. Pestalotiopsis guepinii is based on the generic type Pestalotia pezizoides De Not., characterized by 4-euseptate and fusiform conidia with a which occurred on the leaves of Vitis vinifera in Italy. This hyaline basal cell. Steyaert’s introduction of the genus species is characterized by 6-celled conidia with four Pestalotiopsis was not supported by Moreau (1949), deeply olivaceous central cells, distosepta, hyaline terminal Servazzi (1953) and Guba (1956, 1961). Steyaert (1953a, cells and simple or branched appendages arising from the b, 1961, 1963), however, published further evidence in apex (Fig. 1.). Steyaert (1949) revised Pestalotia and support of his new genus with answers to the criticisms divided the genus into three main groups based on the made by others. Fig. 1 Pestalotia pezizoides De Not. BPI0406483, a Conidia b conidiogenous cells. Scale bars: a–b=20 μm Fungal Diversity (2011) 50:167–187 169 The primary work on Pestalotia was carried out by Guba markers vary between host and environment (Egger 1995). (1961) in his “Monograph of Monochaetia and Pestalotia”. Hu et al. (2007) showed that colony morphology (colour, Guba (1961) divided the genus into the sections quad- growth rate and texture) is highly variable within single riloculate, quinqueloculatae and sexloculatae for 4-celled isolates of Pestalotiopsis; this phenomenon can be easily conidia, 5-celled conidia and 6-celled conidia respectively. observed through repeated subculturing. Also within a single For his sections, Guba (1961) used a simple but very species, conidial morphology (shape and colour of the effective system as proposed by Klebahn (1914), which was median cells), growth rate and fruiting structure, may vary based on the number conidial cells. Guba (1961) further (Jeewon et al. 2003). Satya and Saksena (1984)observed subdivided the sections into different categories, mainly on Pestalotiopsis glandicola (Castagne) Steyaert and P. versi- the basis of conidial form, colour, and the position, and color var. polygoni and found that the intensity of the median character of the setulae. Monochaetia was retained as a cells varied with culture and host and concluded that colour distinct genus based on its single apical appendage, while of median cells cannot be used to judge their taxonomic Pestalotiopsis and Truncatella, the new genera proposed by position. Dube and Bilgrami (1965)observedPestalotiopsis Steyaert (1949), were synonymised with Pestalotia. Guba darjeelingensis Dube, Bilgrami & H.P. Srivast. and showed (1961) described 258 species of Pestalotia in his mono- morphological variation of conidia in culture (dimension, graph. Steyaert (1956) argued that the retention of Mono- length of the setulae, shape, number of cells and the colour chaetia as a distinct genus based on a single character, a of the cells). Similar observations were made by Purohit and single apical appendage was incorrect,

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