Search for alternative hosts to Candidatus Liberibacter asiaticus, the causal agent of citrus Huanglongbing (HLB)

• Grant number: 13/05605-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2013
• End date: June 30, 2014
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Juliana de Freitas Astúa
• Grantee: Flávia Crivelari Fassis
• Host Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil

Abstract

Citriculture is a very important activity in Brazilian agribusiness. However, it has been affected by a number of phytosanitary issues that interfere with its productivity. The disease Huanglongbing (HLB, previously known as greening), associated with the systemic bacteria Candidatus Liberibacter spp., has been detected in Brazilian orchards and has caused great loss to the citrus industry. The disease causes a series of characteristic symptoms such as micronutrients deficiency in young leaves, reduced size, and asymmetric fruits, seed abortion, and uneven coloring. Although there are recent studies describing the main characteristics of the HLB pathosystem and research on this disease has been intensified, it is still necessary to go deeper into its epidemiology. For nearly all the plant-pathogen interactions involving perennial and arboreal species, alternative hosts are sought, specially model plants, which can ease the study of the diseases and their pathogens. With respect to the HLB, periwinkles have been used as an alternative host, primarily due to the high multiplication rate of Candidatus Liberibacter spp. inside their tissues, compared to citrus. Yet, periwinkles are an alternative host, but not a model plant, widely used for biological studies. Thus, the objective of this work is to determine if the model-plants Arabidopsis thaliana, Nicotiana benthamiana, and Lycopersicon esculentum cv. Micro-Tom can also host Ca. Liberibacter asiaticus (CaLas), and if they can be used in interaction studies with this pathogen, what would be of great interest for works related to HLB in citrus. (AU)