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ARS Home » Midwest Area » West Lafayette, Indiana » Crop Production and Pest Control Research » Research » Publications at this Location » Publication #147437
Title: CZK3, A MAP KINASE KINASE KINASE HOMOLOG IN CERCOSPORA ZEAE-MAYDIS, REGULATES CERCOSPORIN SYNTHESIS, FUNGAL DEVELOPMENT, AND PATHOGENESIS

Author
item SHIM, WON BO - PURDUE UNIVERSITY
item Dunkle, Larry

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 6/2/2003
Publication Date: 6/2/2003
Citation: SHIM, W., DUNKLE, L.D. CZK3, A MAP KINASE KINASE KINASE HOMOLOG IN CERCOSPORA ZEAE-MAYDIS, REGULATES CERCOSPORIN SYNTHESIS, FUNGAL DEVELOPMENT, AND PATHOGENESIS. PHYTOPATHOLOGY. 2003. v. 93 (Suppl.1): Abstract p. 78-79.

Interpretive Summary:

Technical Abstract: C. zeae-maydis causes gray leaf spot of maize and produces the phytotoxin cercosporin. Little is known about the biosynthetic pathway or factors that regulate cercosporin production. Analysis of a cDNA subtraction library representing genes up-regulated during toxin biosynthesis revealed a sequence highly similar to MAP kinases in other fungi. Sequence analysis indicated that the gene, designated CZK3, contains a 4119-bp ORF and encodes a polypeptide highly similar to Wis4, a MAP KKK in S. pombe. Gene disruption of CZK3 suppressed expression of genes predicted to participate in cercosporin synthesis and abolished cercosporin production. The disrupted mutant grew faster than wild type but was deficient in conidiation and elicited only small chlorotic spots on inoculated maize leaves. Complementation restored wild-type levels of conidiation, growth rate, and virulence as well as cercosporin production. The results suggest that cercosporin is a virulence factor in maize pathogenesis, but the pleiotropic effects of CZK3 disruption precluded definitive conclusions.