THE ROLE OF PKS1 MEDIATED SECONDARY METABOLISM IN HOST PENETRATION AND COLONIZATION DURING RICE BLAST DISEASE
MAGNAPORTHE ORYZAE CAUSES DEVASTATING RICE BLAST DISEASES ALL OVER THE WORLD. THIS FUNGUS DIFFERENTIATES A SPECIALIZED INFECTION STRUCTURE, THE APPRESSORIUM, TO PENETRATE THE RICE LEAVES DURING INITIATION OF THE DISEASE. A LAYER OF CONDENSED MELANIN IS FORMED IN THE APPRESSORIUM TO MAINTAIN A HIGH TURGOR PRESSURE THEREIN TO FACILITATE THE HOST PENETRATION. HOWEVER, OTHER MECHANISMS THAT ARE RELATED TO THE APPRESSORIAL PENETRATION REMAIN ELUSIVE. IN THIS STUDY, WE DESCRIBE A PKS1 (POLYKETIDE SYNTHASE) CONTAINING GENE CLUSTER, WHICH IS ESSENTIAL FOR THE APPRESSORIAL FUNCTION. PKS1 DELETION MUTANT GENERATES NON-FUNCTIONAL APPRESSORIA THAT FAIL TO ELABORATE A PROPER PENETRATION PORE OR CONSEQUENTLY FAIL TO PENETRATE THE HOST SURFACE. THE PKS1-DELETION MUTANT ALSO SHOWED DEFECTS IN MELANIN DEPOSITION AND SEPTIN LOCALIZATION. THE ABC3 TRANSPORTER AND A SERINE HYDROLASE FSH1 SHARE THE AFOREMENTIONED GENE CLUSTER WITH PKS1. THESE GENES ARE CO-REGULATED WITH PKS1 AND ARE REQUIRED FOR THE PENETR
Magnaporthe oryzae, PKS, secondary metabolism, appressorium, gene cluster,melanin
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