Abstract

The possible mechanisms of plant colonization by endophytic Phomopsis sp. strain B3 was examined in this study. The ability for the endophytic fungi to produce cavities in the surface of straw and the conditions influencing the laccase production were investigated. The results showed that endophytic fungus B3 could decompose plant materials by producing laccase to form a series of cavities on straw. Fermentation test indicated that using cellulose-Na as the optimal carbon source, NH₄Cl as optional nitrogen sources and keeping the culture temperature at 25°C could significantly increase the production of laccase. Both ways of using host leaf instead of potato extract as culture basis and adding NaCl to culture medium could inhibit the fungal production of laccase, but have little influence on the growth. Adjusting the product of laccase may be the key strategy for the strain B3’s invasion.

Key words: Phomopsis sp., endophytic fungi, laccase, invasion, host.