Poster Presentation Science Protecting Plant Health 2017

Evaluating the influence of Pb(II) on the production of volatiles by endophytic Trichoderma asperelllum LF11 against Ganoderma boninense (#357)

Carrie Siew Fang Sim 1 , Chen Son Yue 2 , Adeline Su Yien Ting 1
  1. School of Science, Monash University, Sunway, Selangor, Malaysia
  2. Faculty of Applied Sciences and Computing, Tunku Abdul Rahman University College, Jalan Genting Kelang, Kuala Lumpur, Malaysia

Endophytes are a group of microorganisms inhabiting plants without harming their hosts. They have been studied for their biocontrol activities towards numerous pathogens, expressed primarily through the production of volatile and non-volatile inhibitors. This study aims to evaluate the production of volatile inhibitors by endophytic Trichoderma asperellum LF11 against pathogenic Ganoderma boninense, under the influence of Pb(II) stress. Pb(II) is a non-essential, common metal in the environment, which causes toxicity to living organisms at higher concentrations. The assay was first performed using the double-plate assay with agar supplemented with 10 and 25 ppm Pb(II). The growth inhibition of G. boninense was calculated and compared to cultures in control (0 ppm Pb(II)). The volatiles produced were then extracted via solid phase microextraction and profiled using the gas chromatography mass spectrometry (SPME-GCMS). Results from the double-plate assay revealed that G. boninense was suppressed by T. asperellum LF11 at 0 ppm (50.68%), and in the presence of 10 ppm (48.15%) and 25 ppm (31.17%) of Pb(II). The SPME-GCMS profiling of volatiles produced under the influence of 0 and 10 ppm Pb(II) revealed that the number of volatile compounds increased in 10 ppm (a total of 26, 13, 18 volatiles) than in 0 ppm Pb(II) (10, 7, 11 compounds) detected in plates inoculated with G. boninense, T. asperellum LF11 and T. asperellum LF11+G. boninense, respectively. The compounds 6-pentyl-2H-pyran-2-one (6-PP) and 2-pentylfuran were produced by T. asperellum LF11 in the presence and absence of Pb(II). These two compounds were reported to benefit hosts by restricting pathogen growth and regulating plant growth. Our findings suggest that T. asperellum LF11 remained effective in inhibiting G. boninense through the production of volatiles even under metal stress by Pb(II).