The Gene fpkl, Encoding a cAMP-dependent Protein Kinase CatalyticSubunit Homolog, is Required for Hyphal Growth, Spore Germination, andPlant Infection in Fusarium verticillioides

摘要

Fusarium verticillioides is an important pathogen of maize,being responsible for ear rots, stalk rots, and seedling blightworldwide. During the past decade, F. verticillioideshascaused several severe epidemics of maize seedling blight inmany areas of China, which lead to significant losses. Inorder to understand the molecular mechanisms regulatingfungal development and pathogenicity in this pathogen,we isolated and characterized the gene fpkl (GenBankAccession No. EF405959) encoding a homolog of the cAMP-dependent protein kinase catalytic subunit, which includeda 1,854-bp DNA sequence from ATG to TAA, with a 1,680-bpcoding region, and three introns (lengths: 66 bp, 54 bp, and54 bp), and the predicated protein precursor had 559 aa.The mutant pkl, which was disrupted of the fpkl gene,showed reduced vegetative growth, fewer and shorter aerialmycelia, strongly impaired conidiation, and reduced sporegermination rate. After germinating, the fresh hypha wasstubby and lacking of branch. When inoculated in susceptiblemaize varieties, the infection of the mutant fpkl wasdelayed and the infection efficiency was reduced comparedwith that of the wild-type strain. All this indicated that genefpkl participated in hyphal growth, conidiophore production,spore germination, and virulence in F. verticillioides.