Genome sequence and effectorome of Moniliophthora perniciosa and Moniliophthora roreri subpopulations

Ceslaine Santos Barbosa,Karina Peres Gramacho,Caio Suzart Argolo,Thiago Mafra Batista,Glória Regina Franco,Edson Mário De Andrade Silva,Mariana Araújo Barreto,Carlos Priminho Pirovani,Karina Solis Hidalgo,Rute R Da Fonseca,Daniel Oliveira Jordão Do Amaral,Fabienne Micheli,Mariana Rocha De Carvalho,Enrique Arévalo-Gardini

doi:10.1186/s12864-018-4875-7

Abstract

BackgroundThe hemibiotrophic pathogens Moniliophthora perniciosa (witches’ broom disease) and Moniliophthora roreri (frosty pod rot disease) are among the most important pathogens of cacao. Moniliophthora perniciosa has a broad host range and infects a variety of meristematic tissues in cacao plants, whereas M. roreri infects only pods of Theobroma and Herrania genera. Comparative pathogenomics of these fungi is essential to understand Moniliophthora infection strategies, therefore the detection and in silico functional characterization of effector candidates are important steps to gain insight on their pathogenicity.ResultsCandidate secreted effector proteins repertoire were predicted using the genomes of five representative isolates of M. perniciosa subpopulations (three from cacao and two from solanaceous hosts), and one representative isolate of M. roreri from Peru. Many putative effectors candidates were identified in M. perniciosa: 157 and 134 in cacao isolates from Bahia, Brazil; 109 in cacao isolate from Ecuador, 92 and 80 in wild solanaceous isolates from Minas Gerais (Lobeira) and Bahia (Caiçara), Brazil; respectively. Moniliophthora roreri showed the highest number of effector candidates, a total of 243. A set of eight core effectors were shared among all Moniliophthora isolates, while others were shared either between the wild solanaceous isolates or among cacao isolates. Mostly, candidate effectors of M. perniciosa were shared among the isolates, whereas in M. roreri nearly 50% were exclusive to the specie. In addition, a large number of cell wall-degrading enzymes characteristic of hemibiotrophic fungi were found. From these, we highlighted the proteins involved in cell wall modification, an enzymatic arsenal that allows the plant pathogens to inhabit environments with oxidative stress, which promotes degradation of plant compounds and facilitates infection.ConclusionsThe present work reports six genomes and provides a database of the putative effectorome of Moniliophthora, a first step towards the understanding of the functional basis of fungal pathogenicity.

Highlights

The hemibiotrophic pathogens Moniliophthora perniciosa and Moniliophthora roreri are among the most important pathogens of cacao
With the availability of the reference genomes for M. perniciosa and M. roreri, we report genomes of six Moniliophthora isolates: i) two isolates of M. perniciosa that differ in pathogenicity level to cacao plants; ii) one M. perniciosa isolate from Ecuador; iii) two M. perniciosa isolates representative of the host subpopulations previously defined by Patrocínio et al [9]; and iv) one M. roreri isolate representative from Peru (Bolivar group according to Phillips-Mora et al [19])
Moniliophthora perniciosa and M. roreri isolates and DNA isolation In the present work we used five M. perniciosa genomes; representative of previously described subpopulations within the Solanaceae (2) and of the Malvaceae (3) families [9, 20,21,22], and one M. roreri genome obtained from Theobroma cacao at the Instituto de Cultivos Tropicales (ICT), Peru

Summary

Introduction

The hemibiotrophic pathogens Moniliophthora perniciosa (witches’ broom disease) and Moniliophthora roreri (frosty pod rot disease) are among the most important pathogens of cacao. Moniliophthora perniciosa has a broad host range and infects a variety of meristematic tissues in cacao plants, whereas M. roreri infects only pods of Theobroma and Herrania genera. Comparative pathogenomics of these fungi is essential to understand Moniliophthora infection strategies, the detection and in silico functional characterization of effector candidates are important steps to gain insight on their pathogenicity. Witches’ Broom (WB) and Frosty Pod Rot (FPR) diseases of cacao; respectively caused by Moniliopththora perniciosa (Stahel) Aime Phillips-Mora (2005) and Moniliophthora roreri H. FPR is a quarantine disease in Brazil, and it is still not reported in the country, there is a great risk of its spread into the cacao-producing areas of Brazil due to their proximity with countries in which the disease is present

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