TY - JOUR
T1 - Antifungal activities of metal-tolerant endophytes against Ganoderma boninense under the influence of metal stress
AU - Sim, Carrie Siew Fang
AU - Cheow, Yuen Lin
AU - Ng, Si Ling
AU - Ting, Adeline Su Yien
PY - 2019/3
Y1 - 2019/3
N2 - Five endophytic fungal isolates (Bipolaris sp. LF7, Diaporthe miriciae LF9, Trichoderma asperellum LF11, Phomopsis asparagi LF15, Saccharicola bicolour LF22) were tested for their tolerance to various concentrations of Al3+, Cu2+, Pb2+, Zn2+ and Cd2+. All isolates exhibited Tolerance Index (TI) exceeding 1, suggesting growth stimulation of the endophytes under metal stress. The antifungal activities of the endophytes against Ganoderma boninense (GB) (via the production of metabolites) were observed in metal and non-metal treatments. Production of alkaloids, terpenoids and sterols by the endophytes were enhanced under metal stress. In addition, endophytes demonstrated inhibition towards GB via the production of inhibitory compounds (Bipolaris sp. LF7, P. asparagi LF15), competition (D. miriciae LF9, S. bicolour LF22) as well as mycoparasitism (T. asperellum LF11), in the absence and presence of metals. The endophytes also induced changes in GB hyphae with highly branched hyphal tips observed in non-metal treatment. The inhibitory activities of the endophytes were also observed under metal stress, with prominent swollen hyphae and scarcer GB mycelium. Metals such as Cd2+ and Cu2+ affect enzymes required for hyphal formation thus resulting in swelling of hypha. Of all the isolates, T. asperellum LF11 has the most potential to inhibit GB, in both conditions (presence and absence of metal stress). Results from this study provide early indications on the potential use of metal-tolerant endophytes as biocontrol agents towards G. boninense in soils with metals.
AB - Five endophytic fungal isolates (Bipolaris sp. LF7, Diaporthe miriciae LF9, Trichoderma asperellum LF11, Phomopsis asparagi LF15, Saccharicola bicolour LF22) were tested for their tolerance to various concentrations of Al3+, Cu2+, Pb2+, Zn2+ and Cd2+. All isolates exhibited Tolerance Index (TI) exceeding 1, suggesting growth stimulation of the endophytes under metal stress. The antifungal activities of the endophytes against Ganoderma boninense (GB) (via the production of metabolites) were observed in metal and non-metal treatments. Production of alkaloids, terpenoids and sterols by the endophytes were enhanced under metal stress. In addition, endophytes demonstrated inhibition towards GB via the production of inhibitory compounds (Bipolaris sp. LF7, P. asparagi LF15), competition (D. miriciae LF9, S. bicolour LF22) as well as mycoparasitism (T. asperellum LF11), in the absence and presence of metals. The endophytes also induced changes in GB hyphae with highly branched hyphal tips observed in non-metal treatment. The inhibitory activities of the endophytes were also observed under metal stress, with prominent swollen hyphae and scarcer GB mycelium. Metals such as Cd2+ and Cu2+ affect enzymes required for hyphal formation thus resulting in swelling of hypha. Of all the isolates, T. asperellum LF11 has the most potential to inhibit GB, in both conditions (presence and absence of metal stress). Results from this study provide early indications on the potential use of metal-tolerant endophytes as biocontrol agents towards G. boninense in soils with metals.
KW - Biocontrol
KW - Culture filtrate
KW - Dual culture
KW - Metabolite
KW - Metal tolerance
KW - Phytochemical test
UR - http://www.scopus.com/inward/record.url?scp=85058704110&partnerID=8YFLogxK
U2 - 10.1016/j.biocontrol.2018.12.004
DO - 10.1016/j.biocontrol.2018.12.004
M3 - Article
AN - SCOPUS:85058704110
SN - 1049-9644
VL - 130
SP - 9
EP - 17
JO - Biological Control
JF - Biological Control
ER -