PREVENTING HLB EPIDEMICS FOR ENSURING CITRUS SURVIVAL IN EUROPE

Funder

Organizational Unit

Publications

HLB e a psila-africana-dos citrinos: um novo problema e novas soluções

Publication . Magalhães, Tomás; Duarte, Beatriz; Poeira, Rita; Neto, Luís; Marques, N T.; Duarte, Amilcar

Os citrinos são uma cultura importante na Península Ibérica, fazendo parte da dieta mediterrânica e contribuindo para a economia dos dois países. Atualmente a citricultura desta região está ameaçada por uma doença devastadora, o huanglongbing, uma vez que a psila-africana-dos-citrinos, vetor da bactéria que causa esta doença, já se encontra em quase toda a região costeira de Portugal e também no norte de Espanha. A bactéria não foi até agora detetada, mas para travar o vetor, tem sido usada a luta biológica com um parasitóide da psila. A gravidade desta ameaça à nossa citricultura obriga a que se adotem novas abordagens de proteção fitossanitária, incluindo estratégias coletivas, abrangendo várias explorações agrícolas.

2022-02Journal article

Open Access

Comparing the response of Citrus ×limon and Citrus ×sinensis to Trioza erytreae infestation using a proteomic approach

Publication . Magalhães, Tomás; Dandlen, Susana; L, Anjos; Power, Deborah; Pereira, José Alberto; Duarte, Amilcar; Marques, Natália

Citrus production is on high alert because of the devastating disease Huanglongbing (HLB), caused by the bacteria Candidatus Liberibacter spp.. With no viable treatment, current management practices rely on the control of its vectors, such as the African citrus psyllid,Trioza erytreae (Del Guercio 1918), which is already in the Mediterranean region (Portugal and north of Spain). This vector develops better in some citrus hosts, with Citrus ×limon described as the preferred host. To better understand the molecular response of citrus hosts to the psyllid, the phloem proteome of lemon (Citrus ×limon) and orange (Citrus ×sinensis) plants infested with T. erytreae was compared with equivalent non infested plants. Infestation was established with isolated plants by exposing them to 10 T. erytreae adults. Nymphs of T. erytreae at the 4-5th instar stage were removed from plants and infested leaf phloem was extracted. In control plants phloem was extracted from leaves of a similar size and developmental stage. The experiment was done under controlled conditions of temperature, light and humidity. Phloem was analyzed by nanoLC-MS/MS. A total of 48 and 1265 differentially abundant proteins (DAP) were identified in lemon and orange plants, respectively, with 18 proteins common to both species. The topmost enriched GO terms retrieved for upregulated proteins in lemon plants were assigned to organic acid and cellular amino acid metabolic processes. The topmost enriched GO terms in orange plants included organonitrogen compound metabolic process, cellular component assembly, establishment of protein localization, while downregulated terms were associated with carbohydrate metabolic process. This study revealed that T. erytreae infestation promoted distinct modifications in the phloem proteome of lemon and orange plants. This work is part of a group of studies that focus on this insect-plant interaction that aims for more informed and improved T. erytreae control.

2022-11-08Conference object

Restricted

Water vapor pressure deficit in Portugal and implications for the development of the invasive African citrus Psyllid Trioza erytreae

Unknown

Changes in olfactory sensitivity during the European eel (Anguilla Anguilla) life cycle

Publication . Huertas, Mar; Canario, Adelino V. M.; Hubbard, Peter

The aim of this study was to test whether physiological changes are paralleled by changes in olfactory function during different stages of the European eel’s life-cycle. Sensitivity to diverse odorants (amino acids, bile acids, bile fluids, Na+ and Ca2+) was assessed by extra-cellular recording from the olfactory nerve of seawater or freshwater and immature or mature males. Sensitivity to amino acids did not differ markedly, whether fresh- or seawater-adapted, immature or mature. Sensitivity to bile acids and bile fluid, however, depended on the physiological status; in general, freshwater eels were more sensitive to bile acids than seawater fish.

2008Conference object

Restricted

Current distribution of the African citrus psyllid Trioza erytreae in Portugal: relation to climatic conditions

Publication . Duarte, Beatriz; Poeira, Rita; Magalhães, Tomás; Paiva, Paulo; Soares, Celestino; Neto, Luís; Marques, Natália; Duarte, Amilcar

The onset of Trioza erytreae, the African citrus psyllid, in the northwest of the Iberian Peninsula (north of Portugal and northwest of Spain) caused great concern among citrus growers in Europe. This insect is a vector of the bacteria Candidatus Liberibacter spp., the causal agent of huanglongbing, one of the most devastating citrus diseases. The first report of T. erytreae presence in mainland Europe refers to an area with isolated citrus trees and no significant citrus orchards. However, it was predictable that T. erytreae could spread quickly reaching the most important citrus growing area, in the south. Therefore, the Portuguese citrus industry is the first to be threatened in Europe, but the entire European citrus industry is at risk. In addition to the containment measures taken by the Portuguese and Spanish Phytosanitary Services, several models were made to predict how the African citrus psyllid could advance through the territory of the two countries. Releases of the parasitoid Tamarixia dryi were used for psyllid control. Despite that, T. erytreae has moved south and is on the verge of reaching the most important Portuguese citrus-producing area, which is connected to the citrus-growing areas of the other Mediterranean countries. This advance took place along the coast, without reaching interior regions of the country, where, according to some models, a high-water vapor pressure deficit hinders the insect's development in warmer areas. Populations of T. erytreae dropped significantly in 2021 and 2022, making it difficult to detect even in previously infested areas. This doesn't give farmers peace of mind because the presence of T. erytreae, even in low populations, could lead to a quick spread of huanglongbing, if or when the disease arrives in Europe. Therefore, it is crucial to continue to monitor T. erytreae populations and implement the necessary containment measures for the vector.

2024Journal article

Restricted