title: Genome-wide identification, classification and expression analysis in fungal-plant interactions of cutinase gene family and functional analysis of a putative ClCUT7 in Curvularia lunata.
abstract: Cutinase is described as playing various roles in fungal-plant pathogen interactions, such as eliciting host-derived signals, fungal spore attachment and carbon acquisition during saprophytic growth. However, the characteristics of the cutinase genes, their expression in compatible interactions and their roles in pathogenesis have not been reported in Curvularia lunata, an important leaf spot pathogen of maize in China. Therefore, a cutinase gene family analysis could have profound significance. In this study, we identified 13 cutinase genes (ClCUT1 to ClCUT13) in the C. lunata genome. Multiple sequence alignment showed that most fungal cutinase proteins had one highly conserved GYSQG motif and a similar DxVCxG[ST]-[LIVMF](3)-x(3)H motif. Gene structure analyses of the cutinases revealed a complex intron-exon pattern with differences in the position and number of introns and exons. Based on phylogenetic relationship analysis, C. lunata cutinases and 78 known cutinase proteins from other fungi were classified into four groups with subgroups, but the C. lunata cutinases clustered in only three of the four groups. Motif analyses showed that each group of cutinases from C. lunata had a common motif. Real-time PCR indicated that transcript levels of the cutinase genes in a compatible interaction between pathogen and host had varied expression patterns. Interestingly, the transcript levels of ClCUT7 gradually increased during early pathogenesis with the most significant up-regulation at 3 h post-inoculation. When ClCUT7 was deleted, pathogenicity of the mutant decreased on unwounded maize (Zea mays) leaves. On wounded maize leaves, however, the mutant caused symptoms similar to the wild-type strain. Moreover, the ClCUT7 mutant had an approximately 10 % reduction in growth rate when cutin was the sole carbon source. In conclusion, we identified and characterized the cutinase family genes of C. lunata, analyzed their expression patterns in a compatible host-pathogen interaction, and explored the role of ClCUT7 in pathogenicity. This work will increase our understanding of cutinase genes in other fungal-plant pathogens.
authors.affiliation: Institute of Applied Microbiology and Plant Pathogenic Fungi, Agricultural College, Heilongjiang Bayi Agricultural University, Daqing, 163319, Heilongjiang, People's Republic of China. liutongamy@sina.com.|Department of Plant and Environmental Protection Sciences, University of Hawaii, 3190 Maile Way, Honolulu, HI, 96822, USA. liutongamy@sina.com.
authors.forename: Tong
authors.initials: T
authors.lastname: Liu
authors.affiliation: Institute of Applied Microbiology and Plant Pathogenic Fungi, Agricultural College, Heilongjiang Bayi Agricultural University, Daqing, 163319, Heilongjiang, People's Republic of China.
authors.forename: Jumei
authors.initials: J
authors.lastname: Hou
authors.affiliation: Institute of Applied Microbiology and Plant Pathogenic Fungi, Agricultural College, Heilongjiang Bayi Agricultural University, Daqing, 163319, Heilongjiang, People's Republic of China.
authors.forename: Yuying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute of Applied Microbiology and Plant Pathogenic Fungi, Agricultural College, Heilongjiang Bayi Agricultural University, Daqing, 163319, Heilongjiang, People's Republic of China.
authors.forename: Yazhong
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Department of Plant and Environmental Protection Sciences, University of Hawaii, 3190 Maile Way, Honolulu, HI, 96822, USA.
authors.forename: Wayne
authors.initials: W
authors.lastname: Borth
authors.affiliation: Institute of Applied Microbiology and Plant Pathogenic Fungi, Agricultural College, Heilongjiang Bayi Agricultural University, Daqing, 163319, Heilongjiang, People's Republic of China.
authors.forename: Fengzhou
authors.initials: F
authors.lastname: Zhao
authors.affiliation: Institute of Applied Microbiology and Plant Pathogenic Fungi, Agricultural College, Heilongjiang Bayi Agricultural University, Daqing, 163319, Heilongjiang, People's Republic of China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Plant and Environmental Protection Sciences, University of Hawaii, 3190 Maile Way, Honolulu, HI, 96822, USA.
authors.forename: John
authors.initials: J
authors.lastname: Hu
authors.affiliation: Institute of Applied Microbiology and Plant Pathogenic Fungi, Agricultural College, Heilongjiang Bayi Agricultural University, Daqing, 163319, Heilongjiang, People's Republic of China. zuoyhu@163.com.
authors.forename: Yuhu
authors.initials: Y
authors.lastname: Zuo
mesh_terms: D000595:Amino Acid Sequence; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017124:Conserved Sequence; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D054884:Host-Pathogen Interactions; D005810:Multigene Family; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D004718:Saccharomycetales / Q000201:enzymology / Q000502:physiology*; D037521:Virulence Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003313:Zea mays / Q000382:microbiology*
chemical_list: D005656:Fungal Proteins; D037521:Virulence Factors; D002265:Carboxylic Ester Hydrolases; C019952:cutinase
keywords: Compatible interaction; Cutinase; Expression patterns; Pathogenicity