A genome survey of Moniliophthora perniciosa gives new insights into Witches' Broom Disease of cacao.
BACKGROUND
The basidiomycete fungus Moniliophthora perniciosa is the causal agent of Witches' Broom Disease (WBD) in cacao (Theobroma cacao). It is a hemibiotrophic pathogen that colonizes the apoplast of cacao's meristematic tissues as a biotrophic pathogen, switching to a saprotrophic lifestyle during later stages of infection. M. perniciosa, together with the related species M. roreri, are pathogens of aerial parts of the plant, an uncommon characteristic in the order Agaricales. A genome survey (1.9x coverage) of M. perniciosa was analyzed to evaluate the overall gene content of this phytopathogen.


RESULTS
Genes encoding proteins involved in retrotransposition, reactive oxygen species (ROS) resistance, drug efflux transport and cell wall degradation were identified. The great number of genes encoding cytochrome P450 monooxygenases (1.15% of gene models) indicates that M. perniciosa has a great potential for detoxification, production of toxins and hormones; which may confer a high adaptive ability to the fungus. We have also discovered new genes encoding putative secreted polypeptides rich in cysteine, as well as genes related to methylotrophy and plant hormone biosynthesis (gibberellin and auxin). Analysis of gene families indicated that M. perniciosa have similar amounts of carboxylesterases and repertoires of plant cell wall degrading enzymes as other hemibiotrophic fungi. In addition, an approach for normalization of gene family data using incomplete genome data was developed and applied in M. perniciosa genome survey.


CONCLUSIONS
This genome survey gives an overview of the M. perniciosa genome, and reveals that a significant portion is involved in stress adaptation and plant necrosis, two necessary characteristics for a hemibiotrophic fungus to fulfill its infection cycle. Our analysis provides new evidence revealing potential adaptive traits that may play major roles in the mechanisms of pathogenicity in the M. perniciosa/cacao pathosystem.
Mondego
Jorge M C
JM
Laboratório de Genômica e Expressão, Departamento de Genética e Evolução, Instituto de Biologia, Universidade Estadual de Campinas, CP 6109, 13083-970, Campinas, SP, Brazil. jmcmondego@lge.ibi.unicamp.br
Carazzolle
Marcelo F
MF
Costa
Gustavo G L
GG
Formighieri
Eduardo F
EF
Parizzi
Lucas P
LP
Rincones
Johana
J
Cotomacci
Carolina
C
Carraro
Dirce M
DM
Cunha
Anderson F
AF
Carrer
Helaine
H
Vidal
Ramon O
RO
Estrela
Raíssa C
RC
García
Odalys
O
Thomazella
Daniela P T
DP
de Oliveira
Bruno V
BV
Pires
Acássia Bl
AB
Rio
Maria Carolina S
MC
Araújo
Marcos Renato R
MR
de Moraes
Marcos H
MH
Castro
Luis A B
LA
Gramacho
Karina P
KP
Gonçalves
Marilda S
MS
Neto
José P Moura
JP
Neto
Aristóteles Góes
AG
Barbosa
Luciana V
LV
Guiltinan
Mark J
MJ
Bailey
Bryan A
BA
Meinhardt
Lyndel W
LW
Cascardo
Julio Cm
JC
Pereira
Gonçalo A G
GA
D000363:Agaricales / Q000235:genetics* / Q000472:pathogenicity; D002099:Cacao / Q000382:microbiology*; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000235:genetics; D020224:Expressed Sequence Tags; D005800:Genes, Fungal; D016681:Genome, Fungal; D023281:Genomics; D008957:Models, Genetic; D005810:Multigene Family; D010935:Plant Diseases / Q000382:microbiology*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D004271:DNA, Fungal