Can leaf degrading enzymes provide evidence that endophytic fungi becoming saprobes?

Abstract

The diversity of endophytic and saprobic fungi from Magnolia liliifera leaves were observed and analyzed to establish relationships. Nine endophytes were morphologically and phylogenetically similar to the saprobes; Colletotrichum gloeosporioides, Colletotrichum sp. 2, Corynespora cassiicola, Fusarium sp. 1, Guignardia mangiferae, Leptosphaeria sp., Phomopsis sp. 2, Phomopsis sp. 6, and Phomopsis sp. 10. The endophytes were found to produce the same degrading enzymes as their saprobic counterparts. The isoform of β-mannanase produced from each of endophyte and saprobe counterparts were similar. Fungal succession and enzyme production patterns during leaf decomposition were correlated. The occurrence of saprobes was found to be related to the enzymes that the fungi produce. The study provides further compelling evidence that endophytes can switch lifestyle to saprobes.

Molecular and Pathogenic Study of <i>Guignardia</i> spp. Isolates Associated to Different Hosts

“…This was demonstrated for G. mangiferae species, which was able to produce the same degradating enzymes as its saprobic counterpart [32]. This is probably the case of the G. mangiferae isolates of this study that were obtained from symptomless tissues of different hosts, as well as the isolates obtained in guava ripe fruit rot symptoms.…”

First characterization of endophytic Corynespora cassiicola isolates with variant cassiicolin genes recovered from rubber trees in Brazil

“…and Dendrocalamus spp. (Hyde et al 2001), Ischyrolepis subverticella (Lee et al 2004) and Magnolia liliifera (Promputtha et al 2007(Promputtha et al , 2010Kodsueb et al 2008). …”

“…Several studies proposed that fungal endophytes become saprotrophs when the host plants senesce (Promputtha et al 2007(Promputtha et al , 2010Okane et al 2008;Porras-Alfaro and Bayman 2008). The close phylogenetic relationships between endophytes and saprotrophs isolated from healthy, mature and decaying leaves and twigs of Magnolia liliifera, including C. cassiicola isolates, suggest that these fungi have the ability to change their lifestyle during host senescence (Promputtha et al 2007).…”

“…This supports the concept of latent saprotrophism. Promputtha et al (2010) demonstrated that a C. cassiicola endophyte and its saprobic counterpart, which was found during the middle to late stages (8-56 days) of leaf decomposition, were both able to produce laccase. The authors hypothesized that laccase activity from the C. cassiicola endophyte allows it to persist as a saprobe during decomposition.…”

Transient leaf endophytes are the most active fungi in 1-year-old beech leaf litter

“…By contrast, the non-Clavicipitacean leaf-endophytes were rarely found to have beneficial effects for the host plant (Hyde and Soytong 2008;Rodriguez et al 2009;Khan et al 2016). While several saprotrophic fungi were recently shown to be capable of biotrophic interactions with host plants (Smith et al 2017), growing evidence suggests that some endophytic fungi become saprobes after leaf fall (Guo et al 2001(Guo et al , 2003Promputtha et al 2002Promputtha et al , 2005Promputtha et al , 2007Promputtha et al , 2010Shirouzu et al 2009;Suryanarayanan 2013;Saikkonen et al 2015;Szink et al 2016;Promputtha et al 2017). Their endophytic occurrence might thus be just one stage in their life cycle.…”