Authors:
Wan Rusmarini, Umi Kalsom Md Shah, Mohd Puad Abdullah, Suhaila Mamat,
Tan Geok Hun
|
Abstract:
Endophytes can produce enzymes which facilitate their initial colonisation of plant tissues and
direct interactions with microbial pathogens. In this study, endophytic fungus from the stem of
healthy dragon fruit (Hylocereus spp.) was successfully identified as Trichoderma harzianum
T3.13. T. harzianum T3.13 was shown to have the ability to produce antagonistic activity against
Neoscytalidium dimidiatum U1, a pathogen fungus from the stem of unhealthy dragon fruit. The
chitinolytic activities of T. harzianum T3.13 were 0.194 U/ml in a medium containing 3% (w/v)
of colloidal chitin as sole carbon source. Semi-quantitative RT-PCR was used to quantify the
expression patterns of the genes during the interaction of T. harzianum T3.13 with pathogen N.
dimidiatum U1 and control pathogen Colletotrichum gloeosporioides, respectively. The
expression of the exc1 and chit42 genes were observed to be present before and after the
interaction occurred in the presence of N. dimidiatum U1. However, the expression of the
bgn13.1 gene increased after 24 hours up to 96 hours of interaction in the presence of N.
dimidiatum U1. In the presence of C. gloeosporioides, the expression of bgn13.1 and chit42 gradually decreased during the interaction although the expression of the exc1 gene did not
change. The results suggested that the endophytic fungus T. harzianum T3.13 has the potential as
a good biological control agent against N. dimidiatum U1 and C. gloeosporioides. Thus, the
study provided an insight into cellular and molecular interactions between T. harzianum T3.13
and pathogenic fungi. |
