title: A phylogenetic evaluation of whether endophytes become saprotrophs at host senescence.
abstract: Fungal endophytes and saprotrophs generally play an important ecological role within plant tissues and dead plant material. Several reports based solely on morphological observations have postulated that there is an intimate link between endophytes and saprotrophs. This study aims to provide valuable insight as to whether some endophytic fungi manifest themselves as saprotrophs upon host decay. Ribosomal DNA-based sequence comparison and phylogenetic relationships from 99 fungal isolates (endophytes, mycelia sterilia, and saprotrophs) recovered from leaves and twigs of Magnolia liliifera were investigated in this study. Molecular data suggest there are fungal taxa that possibly exist as endophytes and saprotrophs. Isolates of Colletotrichum, Fusarium, Guignardia, and Phomopsis, which are common plant endophytes, have high sequence similarity and are phylogenetically related to their saprotrophic counterparts. This provides evidence to suggest that some endophytic species change their ecological strategies and adopt a saprotrophic lifestyle. The implication of these findings on fungal biodiversity and host specificity is also discussed.
authors.affiliation: Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Itthayakorn
authors.initials: I
authors.lastname: Promputtha
authors.forename: Saisamorn
authors.initials: S
authors.lastname: Lumyong
authors.forename: Vijaykrishna
authors.initials: V
authors.lastname: Dhanasekaran
authors.forename: Eric Huge Charles
authors.initials: EH
authors.lastname: McKenzie
authors.forename: Kevin David
authors.initials: KD
authors.lastname: Hyde
authors.forename: Rajesh
authors.initials: R
authors.lastname: Jeewon
mesh_terms: D001203:Ascomycota / Q000145:classification / Q000235:genetics / Q000254:growth & development; D044822:Biodiversity; D020231:Colletotrichum / Q000145:classification / Q000235:genetics / Q000254:growth & development; D004275:DNA, Ribosomal / Q000737:chemistry; D005658:Fungi / Q000145:classification* / Q000235:genetics / Q000254:growth & development; D005670:Fusarium / Q000145:classification / Q000235:genetics / Q000254:growth & development; D031566:Magnolia / Q000254:growth & development / Q000382:microbiology*; D020081:Phyllachorales / Q000145:classification / Q000235:genetics / Q000254:growth & development; D010802:Phylogeny; D018515:Plant Leaves / Q000254:growth & development / Q000382:microbiology; D017422:Sequence Analysis, DNA; D013997:Time Factors
chemical_list: D004275:DNA, Ribosomal