title: Transcriptomics and systems biology analysis in identification of specific pathways involved in cacao resistance and susceptibility to witches' broom disease.
abstract: This study reports on expression analysis associated with molecular systems biology of cacao-Moniliophthora perniciosa interaction. Gene expression data were obtained for two cacao genotypes (TSH1188, resistant; Catongo, susceptible) challenged or not with the fungus M. perniciosa and collected at three time points through disease. Using expression analysis, we identified 154 and 227 genes that are differentially expressed in TSH1188 and Catongo, respectively. The expression of some of these genes was confirmed by RT-qPCR. Physical protein-protein interaction (PPPI) networks of Arabidopsis thaliana orthologous proteins corresponding to resistant and susceptible interactions were obtained followed by cluster and gene ontology analyses. The integrated analysis of gene expression and systems biology allowed designing a general scheme of major mechanisms associated with witches' broom disease resistance/susceptibility. In this sense, the TSH1188 cultivar shows strong production of ROS and elicitors at the beginning of the interaction with M. perniciosa followed by resistance signal propagation and ROS detoxification. On the other hand, the Catongo genotype displays defense mechanisms that include the synthesis of some defense molecules but without success in regards to elimination of the fungus. This phase is followed by the activation of protein metabolism which is achieved with the production of proteasome associated with autophagy as a precursor mechanism of PCD. This work also identifies candidate genes for further functional studies and for genetic mapping and marker assisted selection.
authors.affiliation: Centro de Biotecnologia e Genética-CBG, Departamento de Ciências Biológicas-DCB, Universidade Estadual de Santa Cruz-UESC, Rodovia Ilhéus-Itabuna, km 16, 45662-900 Ilhéus-BA, Brasil.
authors.forename: Braz Tavares
authors.initials: BT
authors.lastname: da Hora Junior
authors.forename: Joice de Faria
authors.initials: Jde F
authors.lastname: Poloni
authors.forename: Maíza Alves
authors.initials: MA
authors.lastname: Lopes
authors.forename: Cristiano Villela
authors.initials: CV
authors.lastname: Dias
authors.forename: Karina Peres
authors.initials: KP
authors.lastname: Gramacho
authors.forename: Ivan
authors.initials: I
authors.lastname: Schuster
authors.forename: Xavier
authors.initials: X
authors.lastname: Sabau
authors.forename: Júlio Cézar De Mattos
authors.initials: JC
authors.lastname: Cascardo
authors.forename: Sônia Marli Zingaretti Di
authors.initials: SM
authors.lastname: Mauro
authors.forename: Abelmon da Silva
authors.initials: Ada S
authors.lastname: Gesteira
authors.forename: Diego
authors.initials: D
authors.lastname: Bonatto
authors.forename: Fabienne
authors.initials: F
authors.lastname: Micheli
mesh_terms: D001487:Basidiomycota / Q000502:physiology; D002099:Cacao / Q000235:genetics* / Q000382:microbiology*; D016000:Cluster Analysis; D060467:Disease Resistance / Q000235:genetics* / Q000276:immunology; D004198:Disease Susceptibility / Q000276:immunology; D020869:Gene Expression Profiling / Q000379:methods*; D018506:Gene Expression Regulation, Plant; D053263:Gene Regulatory Networks / Q000235:genetics*; D017343:Genes, Plant / Q000235:genetics; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D060066:Protein Interaction Maps; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D049490:Systems Biology / Q000379:methods*; D059467:Transcriptome / Q000235:genetics
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger