10th INTERNATIONAL VERTICILLIUM SYMPOSIUM 16-20 ...

CHARACTERISATION OF POTENTIAL PATHOGENICITY-RELATED GENE VL_6.2 OF VERTICILLIUM LONGISPORUMHAIQUAN XU, ARNE WEIBERG AND PETR KARLOVSKYInstitute of Plant Pathology and Plant Protection, Göttingen University,Grisebachstrasse 6, 37077 Göttingen, Germanywww.gwdg.de/~instphyt/karlovsky/Gene Vl_6.2 of Verticillium longisporium was identified in a cDNA-AFLP screeningas induced by metabolites from xylem sap of Brassica napus. The expression ofVl_6.2 in planta increased significant as compared to growth in vitro in xylemsimulatingmedium.The full-lengt Vl_6.2 gene was isolated from a genome library of V. longisporum.The gene has an ORF of 4540 nucleotides, two introns and translated cDNA ispredicted to code for 1536 amino acids (aa). Sequencing cDNA confirmed theprediction. The protein contains four putative WSC carbohydrate binding domains.The expression of Vl_6.2 was suppressed to 70% of its activity by expressing antisenseRNA in Verticillium longisporium as determined by real-time RT PCR. Theeffect of silencing on the infection of is currently being investigated.SDS-containing medium inhibited the growth of strains with the silenced Vl_6.2 geneto a larger extent than the wild type strain.Because of the low efficiency of antisense strategy, we are generating strains withVl_6.2 silenced by RNAi strategy.59