Transcriptomic profile of the predatory mite Amblyseius swirskii (Acari: Phytoseiidae) on different host plants

Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is a predatory mite, effective at controlling whiteflies and thrips in protected crops. However, on tomato its efficacy as a biocontrol agent is hindered, most probably by the plant trichomes and their exudates. Our aim was to characterize the response of A. swirskii to the tomato trichome exudates and identify three major detoxification gene sets in this species: cytochromes P450 (CYPs), glutathione S-transferases (GSTs) and carboxyl/cholinesterases (CCEs). Mites were exposed separately to tomato and pepper, a favourable host plant for A. swirskii, after which their transcriptional responses were analysed and compared. The de novo transcriptome assembly resulted in 71,336 unigenes with 66.1% of them annotated. Thirty-nine A. swirskii genes were differentially expressed after transfer on tomato leaves when compared to pepper leaves; some of the expressed genes were associated with the metabolism of tomato exudates. Our results illustrate that the detoxification gene sets CYPs, GSTs and CCEs are abundant in A. swirskii, but do not play a significant role when in contact with the tomato exudates

Digestive proteases in bodies and faeces of the two-spotted spider mite, Tetranychus urticae

31 p.-3 fig.-3 tab.-2 fig. supl.-1 tab. supl.Digestive proteases of the phytophagous mite Tetranychus urticae have been characterised by comparing their activity in body and faecal extracts. Aspartyl, cathepsin B- and L-like and legumain activities were detected in both mite bodies and faeces, with a specific activity of aspartyl and cathepsin L-like proteases about 5- and 2-fold higher, respectively, in mite faeces than in bodies. In general, all these activities were maintained independently of the host plant where the mites were reared (bean, tomato or maize). Remarkably, this is the first report in a phytophagous mite of legumain-like activity, which was characterised for its ability to hydrolyse the specific substrate Z-VAN-AMC, its activation by DTT and inhibition by IAA but not by E-64. Gel free nanoLC–nanoESI-QTOF MS/MS proteomic analysis of mite faeces resulted in the identification of four cathepsins L and one aspartyl protease (from a total of the 29 cathepsins L, 27 cathepsins B, 19 legumains and two aspartyl protease genes identified the genome of this species). Gene expression analysis reveals that four cathepsins L and the aspartyl protease identified in the mite faeces, but also two cathepsins B and two legumains that were not detected in the faeces, were expressed at high levels in the spider mite feeding stages (larvae, nymphs and adults) relative to embryos. Taken together, these results indicate a digestive role for cysteine and aspartyl proteases in T. urticae. The expression of the cathepsins B and L, legumains and aspartyl protease genes analysed in our study increased in female adults after feeding on Arabidopsis plants over-expressing the HvCPI-6 cystatin, that specifically targets cathepsins B and L, or the CMe trypsin inhibitor that targets serine proteases. This unspecific response suggests that in addition to compensation for inhibitor-targeted enzymes, the increase in the expression of digestive proteases in T. urticae may act as a first barrier against ingested plant defensive proteins.This work was supported by a Grant from CSIC (Grant CSIC-201040E049 to F.O), Ministerio de Ciencia e Innovación (Grant AGL11-23650 to I.D.) and the Government of Canada through Genome Canada and the Ontario Genomics Institute (Grant OGI-046 to V.G.), and the Ontario Research Fund-Global Leadership in Genomics and Life Sciences (Grant GL2-01-035 to V.G.).Peer reviewe

Mutations in the Bacillus thuringiensis Cry1Ca toxin demonstrate the role of domains II and III in specificity towards Spodoptera exigua larvae

Several mutants of the Bacillus thuringiensis Cry1Ca toxin affected with regard to specific activity towards Spodoptera exigua were studied. Alanine was used to replace single residues in loops 2 and 3 of domain II (mutant pPB19) and to replace residues 541– 544 in domain III (mutant pPB20). Additionally, a Cry1Ca mutant combining all mutations was constructed (mutant pPB21). Toxicity assays showed a marked decrease in toxicity against S. exigua for all mutants, while they retained their activity against Manduca sexta, confirming the importance of these residues in determining insect specificity. Parameters for binding to the specific receptors in BBMV (brush border membrane vesicles) of S. exigua were determined for all toxins. Compared with Cry1Ca, the affinity of mutant pPB19 was slightly affected (2-fold lower), whereas the affinity of the mutants with an altered domain III (pPB20 and pPB21) was approx. 8-fold lower. Activation of Cry1Ca protoxin by incubation with S. exigua or M. sexta BBMV revealed the transient formation of an oligomeric form of Cry1Ca. The presence of this oligomeric form was tested in the activation of the different Cry1Ca mutants, and we found that those mutated in domain II (pPB19 and pPB21) could not generate the oligomeric form when activated by S. exigua BBMV. In contrast, when oligomerization was tested using BBMV prepared from M. sexta, all of the Cry1Ca mutants showed the formation of a similar oligomeric form as did the wild-type toxin. Our results show how modification of insect specificity can be achieved by manipulation of different parts of the toxin structure involved in different steps of the mode of action of B. thuringiensis [email protected]; [email protected]

Los neonicotinoides modifican la composición bacteriana de la melaza y la preferencia de los parasitoides por esta fuente de alimento

Los neonicotinoides son los insecticidas sistémicos más ampliamente utilizados a escala global a pesar de que resultan tóxicos para los insectos beneficiosos que se alimentan de néctar o melaza. Varios estudios han demostrado que los insectos beneficiosos no son capaces de discriminar entre néctar contaminado y no contaminado con neonicotinoides. Sin embargo, esto nunca se ha comprobado para la melaza, la principal fuente de carbohidratos en muchos ecosistemas agrícolas. Para abordar esta cuestión, recogimos la melaza excretada por Planococcus citri Risso (Hemiptera: Pseudococcidae) que se habían alimentado de plantas tratadas y no tratadas con el neonicotinoide tiametoxam

Gutación de las plantas: una fuente nutritiva de alimento para insectos

La gutación de las plantas es un fluido que proviene del xilema y del floema y que es secretado en el borde de las hojas de muchas especies de plantas. Hasta ahora, todos los estudios previos han considerado la gutación de las plantas como una fuente de agua para los insectos. En este trabajo, hipotetizamos que la gutación de las plantas puede servir como una fuente de alimento rico en nutrientes para los insectos, y además con efectos sobre la comunidad de insectos. En esta investigación, utilizando el arándano como sistema de estudio, demostramos que las gotas de la gutación contienen una cantidad significativa de carbohidratos y proteínas. Además, insectos con distintos hábitos alimenticios, como un herbívoro, un parasitoide y un depredador vieron incrementada su longevidad y su fecundidad cuando se alimentaron de gotas de gutación comparado con los que se alimentaron de agua

Integración intercultural en el contexto universitario cubano: programa de intervención psicosocial para su promoción.

La subjetividad es un factor mediador de la producción y reproducción de la contradicción integración - exclusión en el contacto intercultural. El presente estudio tuvo como objetivo proponer un programa de intervención psicosocial, para la promoción de la integración intercultural en la Universidad Central "Marta Abreu" de Las Villas, desde un enfoque histórico-cultural de las mediaciones por la subjetividad. La investigación se adscribió al modelo de investigación interventiva y a un enfoque cualitativo constructivo interpretativo. En este marco, se realizó una sistematización de experiencias y se propuso un programa de intervención psicosocial. El programa para la promoción de la integración intercultural desde un enfoque histórico-cultural de las mediaciones por la subjetividad integra: fundamentos teórico-metodológicos psicosociales, la estructura organizativa y la evaluación del programa. La evaluación del programa, antes de su implementación, correspondió al tipo de evaluación cualitativa, ex ante y externa. Produjo valoraciones sobre las fortalezas y debilidades del programa, así como recomendaciones para hacer más efectivo el programa de intervención, en función de las cuales se introdujeron modificaciones Subjectivity is a mediating factor in the production and reproduction of the integration - exclusion contradiction in intercultural contact. The objective of the study was to propose a program of psychosocial intervention for the promotion of intercultural integration at the Central University of Las Villas from a historical-cultural approach of mediations by subjectivity. The research was ascribed to the interventional research model and to a qualitative constructive interpretive approach. Within this framework, a systematization of experiences was carried out and a psychosocial intervention program was proposed. The proposed psychosocial intervention program for the promotion of intercultural integration in the UCLV from a historical-cultural approach to mediations by subjectivity content: psychosocial theoretical-methodological foundations, the organizational structure and the evaluation of the program. The evaluation of the psychosocial intervention program before its implementation corresponded to the type of qualitative evaluation, ex ante and external. It produced assessments of the strengths and weaknesses of the program, as well as recommendations to make the intervention proposal more effective, based on which modifications were introduce

Cuidado informal al adulto mayor encamado en un área de salud

Introduction: the informal care of a dependent person often supposes a significant source of stress affecting the life of informal caregivers.Objective: to diagnose the present-day status of informal care of old people confined to bed in the health area of Manuel Piti Fajardo Polyclinic, Guane municipality in Pinar del Río province from July 2015 to October 2016.Methods: observational, descriptive and cross sectional study was conducted, the target group was constituted by 79 informal caregivers of old patients confined to bed and the sample included 35 of them who met the inclusion criteria, using theoretical, empirical and statistical (descriptive statistics) methods in the analysis.Results: the present-day trends in the development of this subject matter were identified, along with the diagnosis of the initial status, determining the regularities that make possible the transformation of its insufficiencies.Conclusions: the results indicate that there is a need for multidisciplinary actions aimed at improving the informal care process, designing and generating interventions that articulate the activity of caregivers, family, basic working team and the community.Introducción: el cuidado informal a una persona dependiente supone con frecuencia notable fuente de estrés que afecta la vida del cuidador informal.Objetivo: diagnosticar el estado actual del cuidado informal al adulto mayor encamado en el área de salud del Policlínico Manuel Piti Fajardo de Guane en Pinar del Río, durante el período de julio 2015 a octubre 2016.Métodos: se realizó un estudio observacional, descriptivo y transversal, constituido por una población de 79 cuidadores informales de adultos mayores encamados y una muestra de 35 de estos, que cumplieron con los criterios de inclusión, utilizando en el análisis métodos teóricos, empíricos y estadísticos (estadística descriptiva).Resultados: se identificaron tendencias actuales en el desarrollo del objeto, se realizó el diagnóstico del estado inicial, determinando regularidades que posibilitan la transformación de sus insuficienciasConclusiones: los resultados indican que existe la necesidad de actuaciones multidisciplinarias encaminadas a perfeccionar el proceso de cuidado informal, diseñando y generando intervenciones que articulen la actividad del cuidador, la familia, el grupo básico de trabajo y la comunidad