CV

Current research

Chitin is a polysaccharide composed of β-1,4 N-acetyl-D-glucosamine units. It is highly distributed in nature, as a component of fungal cell walls, insect and crustacean exoskeletons and in zooplankton. Chitinases are hydrolytic enzymes that play important roles in fungal biology, e.g. growth and morphological development, nutrient acquisition and aggressive interactions.

The availability of fungal genome sequence information has shown that the diversity of the fungal chitinase gene family is larger than previously thought. This project investigates the biological function of previously uncharacterized chitinase subgroups, in model species such as Neurospora crassa and Aspergillus nidulans as well as in biocontrol fungi such as Clonostachys rosea and Trichoderma atroviride. The project focus on the generation and analysis of gene knock-out strains, coupled with expression studies using quantitative PCR and in vivo reporter technology (gfp, chRFP).

Currently we use 12 N. crassa  and 3 A. nidulans mutants for screening for phenotypic effects on colony formation and morphology, sexual reproduction, linear growth rate, aerial hyphae formation and interspecific interaction ability. Certain chitinase null mutants exhibit reduced growth rate, no sexual development and sporulation defects. Other null mutants exhibit reduced intraspecific interaction ability. The function of these genes will be studied further in biocontrol fungi.

Publications

1. Bardas G.A., Tzelepis G.D., Lotos L. and Karaoglanidis G.S. 2009. First report of Botrytis cinerea causing gray mold of pomegranate (Punica granatum) in Greece. Plant Disease 93: pp1346
2. Bardas G.A., Tzelepis G.D., Lotos L. and Karaoglanidis G.S. 2009. First report of Penicillium glabrum causing fruit rot of pomegranate (Punica granatum) in Greece. Plant Disease 93: pp1347

Announcements

1. Tzelepis G. D. Lotos L. Ch., Giokas G. and Lagopodi A. L. (2010). Isolation from the rhizosphere of a new biocontrol agent against the fungus Fusarium oxysporum f.sp. radicis –  lycopersici. Greek national phytopathological conference. Corfu, Greece. 5 - 8 October 2010
2. Tzelepis G. D.. Kamou Ν.N, Panteris Ε. , . Tzamos S.E. and Lagopodi  Α.L. (2010). Observations of the interactions between the phytopathogenic fungus Fusarium oxysporum f. sp. radicis-lycopersici and the biocontrol agents Pseudomonas chlororaphis PCL1391 and Clonostachys rosea IK726 on tomato roots using autofluorescent proteins. Greek national phytopathological conference. Corfu, Greece. 5 - 8 October 2010
3. Tzelepis G .D. and Lagopodi A.L. (2009). Study of interactions between Clonostachys rosea IK726 and Pseudomonas chlororaphis PCL1391 in biocontrol of Fusarium oxysporum f.sp. radicis – lycopersici (2009). 5th IOBC workshop on Uppsala, Sweden 10 -13 June 2009
4. Tzelepis G .D. and Lagopodi A.L. (2008). Influence of fungicides in the mycelial growth of the fungus Clonostachys rosea IK726. Greek national phytopathological conference. Nafplio, Greece. 10-13 October 2008