Bioinformatics for metagenome projects of the bacterium Candidatus Liberibacter, agent of huanglongbing (ex-greening) as well as transcriptome and shotgun of citrus leprosis mite (Brevipalpus phoenicis)

• Grant number: 06/00768-2
• Support Opportunities: Scholarships in Brazil - Technical Training Program - Technical Training
• Start date: May 01, 2006
• End date: July 31, 2007
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Marcos Antonio Machado
• Grantee: Marcelo da Silva Reis
• Host Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil
• Associated research grant: 05/00718-2 - Studies on the bacterium Candidatus Liberibacter spp., causal agent of citrus huanglongbing (ex-greening): diagnosis, biology and management, AP.TEM

Abstract

The advances in Molecular Biology techniques registered in the last years, together with the advances in Computer Science, have lead to the development of a field nowadays known as Bioinformatics. The huge amount of data generated by the nucleotide sequencing demands that a great part of the job must be done in silico, beginning with the data organization into a proper information system, the sequence analysis, the following computational identification and annotation. The bioinformatician must have good knowledge of both Computer Science and Biology. The Centro APTA Citros Sylvio Moreira has the world's largest Citrus EST (Expressed Sequence Tags) and shotgun libraries, plus another databases such as viruses (Tristeza, Leprosis, Viroids), bacteria (Xylella fastidiosa, Xanthomonas axonopodis pv citri) and finished fungi (Phytophthora parasitica) or in construction (Guignardia citricarpa and Alternaria alternata). The manutention of these information systems, as well the needed in silico analysis, are performed by the candidate for the Fellowship. Huanglongbing is one of the most destructive and severe diseases of citrus and causes damages in the plant development (chlorosis, leaf drop, and reduction of growth and roots) and fruit (misshapen, seed abortion, drop, and growth reduction). The causal agent is a phloem-limited bacterium, which has not been isolated so far, and is transmitted by the Asian citrus psyllid (Diaphorina citri), an insect easily found in Brazil. Under a multidisciplinary effort that has been made by putting together various research groups in the state of Sao Paulo, a Thematic Project, linked to this Fellowship Proposal, seeks to enhance the knowledge on the Huanglongbing pathosystem, which is still completely not understood under the conditions of the state of Sao Paulo. In spite of this, the objectives of this proposal involve to uncover partially the bacterium´s genome, develop alternative systems for diagnostics, identify the bacterial diversity, find out how the bacterium multiplies in the citrus and other hosts tissues, study the effects of temperature over the severity and intensity of symptoms and bacterial multiplication as well as to evaluate the acquisition and persistence of the bacterium in the vector insect. Identification of these factors will provide the basis for orderly dissection of the processes underlying pathogenicity and, as a result, ways for the management of the disease and its vector.