THE PILOT UNIT OF ICSN - EXCELLENCE IN THE FIELD OF BIOACTIVE MICROBIAL SECONDARY METABOLITES

Role of fungal secondary metabolites in plant infection

The hemibiotrophic ascomycete fungus Colletotrichum higginsianum, the causal agent of crucifer anthracnose disease, is responsible for severe yield losses on brassica crops in tropical and subtropical regions. In addition to cultivated Brassica and Raphanus (cabbages and radishes), it also infects the model plant Arabidopsis thaliana which allow in-depth dissection of plant-pathogen interactions. C. higginsianum has a great potential of more than 77 biosynthetic pathways, meaning potentially 77 different families of compounds are biosynthesized. Among these 77 biosynthetic pathways, 23 are active during infection of the host plant of which 19 remain silent in vitro.

The NPC project aims at: (i) activating plant-specific biosynthetic pathways in vitro; (ii) elucidating chemical structures of the intermediates and end-products of these pathways; (iii) deciphering the roles of the natural products of C. higginsianum during plant infection by using both innovative and longstanding bioassays.

Partner: Dr. Richard O’Connell, BIOGER (Biology and Risks management in Agriculture), French National Institute for Agricultural Research (INRA) – AgroParisTech, Thiverval-Grignon, France

The NPC project was initiated in the frame of the “Chaires d’Excellence” program of the French National Research Agency (ANR), project FUNAPP, grant ANR-12-CHEX-0008.


25Sans titre6

Life cycle of Colletotrichum higginsianum when infecting Arabidopsis thaliana


Waves-down

Activation of secondary metabolism pathways in successive waves during infection (top) Comparative analysis of secondary metabolites produced in vitro by wild-type and mutant strains of Colletotrichum higginsianumusing using HPLC (bottom)

in_vitro_arabidopsis

In vitro grown Arabidopsis thaliana for high-throughput bioassay screenings