High-throughput SuperSAGE for gene expression analysis of Nicotiana tabacum-Rhizoctonia solani interaction.

OBJECTIVE: The ubiquitous soil pathogen Rhizoctonia solani causes serious diseases in different plant species. Despite the importance of this disease, little is known regarding the molecular basis of susceptibility. SuperSAGE technology and next-generation sequencing were used to generate transcript libraries during the compatible Nicotiana tabacum-R. solani interaction. Also, we used the post-transcriptional silencing to evaluate the function of a group of important genes. RESULTS: A total of 8960 and 8221 unique Tag sequences identified as differentially up- and down-regulated were obtained. Based on gene ontology classification, several annotated UniTags corresponded to defense response, metabolism and signal transduction. Analysis of the N. tabacum transcriptome during infection identified regulatory genes implicated in a number of hormone pathways. Silencing of an mRNA induced by salicylic acid reduced the susceptibility of N. tabacum to R. solani. We provide evidence that the salicylic acid pathway was involved in disease development. This is important for further development of disease management strategies caused by this pathogen.

'Candidatus Liberibacter asiaticus', Causal Agent of Citrus Huanglongbing, Is Reduced by Treatment with Brassinosteroids.

Huanglongbing (HLB) constitutes the most destructive disease of citrus worldwide, yet no established efficient management measures exist for it. Brassinosteroids, a family of plant steroidal compounds, are essential for plant growth, development and stress tolerance. As a possible control strategy for HLB, epibrassinolide was applied to as a foliar spray to citrus plants infected with the causal agent of HLB, 'Candidatus Liberibacter asiaticus'. The bacterial titers were reduced after treatment with epibrassinolide under both greenhouse and field conditions but were stronger in the greenhouse. Known defense genes were induced in leaves by epibrassinolide. With the SuperSAGE technology combined with next generation sequencing, induction of genes known to be associated with defense response to bacteria and hormone transduction pathways were identified. The results demonstrate that epibrassinolide may provide a useful tool for the management of HLB.

Expression of a Nicotiana tabacum pathogen-induced gene is involved in the susceptibility to black shank.

Many host genes induced during compatible plant-pathogen interactions constitute targets of pathogen virulence factors that act to suppress host defenses. In order to identify Nicotiana tabacum L. genes for pathogen-induced proteins involved in susceptibility to the oomycete Phytophthora parasitica var. nicotianae, we used SuperSAGE technology combined with next-generation sequencing to identify transcripts that were differentially upregulated during a compatible interaction. We identified a pathogen-induced gene (NtPIP) that was rapidly induced only during the compatible interaction. Virus-induced gene silencing of NtPIP reduced the susceptibility of N. tabacum to P. parasitica var. nicotianae. Additionally, transient expression of NtPIP in the resistant species Nicotiana megalosiphon Van Heurck & Mull. Arg. compromised the resistance to P. parasitica var. nicotianae. This pathogen-induced protein is therefore a positive regulator of the susceptibility response against an oomycete pathogen in tobacco.

High Functional Stability of a Low-cost HBV DNA qPCR Primer Pair and Plasmid Standard.

AIM: We studied the functional stability of a primer pair and the standard curve based on a plasmid carrying full-length HBV genome, from a novel low-cost real-time quantitative polymerase chain reaction (qPCR) assay. The assay was developed at the Center for Genetic Engineering and Biotechnology (CIGB) in Havana, to quantify the serum hepatitis B virus (HBV) DNA from chronic HBV-infected (CHB) patients. MATERIALS AND METHODS: In-house generated oligonucleotides and plasmids were incubated at 37°C during 1 month and compared with the same materials incubated at -20, 4, and 25°C during the same time in qPCR experiments. RESULTS: This work shows that the oligonucleotide pair and the plasmid for the quantitative standard curve are functionally stable in severe temperature conditions during 1 month. Polymerase chain reaction amplification with both materials after its incubation 30 days at 37°C produced similar cycle threshold (CT) values and similar degree of sample quantifications compared with the same materials preserved using the conventional storage conditions at -20°C. CONCLUSION: These results are indicative of the robustness of this low-cost qPCR system for HBV DNA quantification. These results also support that this qPCR assay can be used as a low-cost technology in clinical studies to monitor the viral load changes of serum HBV DNA of CHB patients, which could be used by poor people of third world countries, where there are frequent blackouts and temperature changes that can hinder the primer and plasmid stability. HOW TO CITE THIS ARTICLE: Aguiar J, García G, León Y, Canales E, Silva JA, Gell O, Estrada R, Morán I, Muzio V, Guillén G, Pentón E, Aguilar JC. High Functional Stability of a Low-cost HBV DNA qPCR Primer Pair and Plasmid Standard. Euroasian J Hepato-Gastroenterol 2016;6(1):19-24.

Identification of genes induced upon water-deficit stress in a drought-tolerant rice cultivar.

Among the abiotic stresses, the availability of water is the most important factor that limits the productive potential of higher plants. The identification of novel genes, determination of their expression patterns, and the understanding of their functions in stress adaptation is essential to improve stress tolerance. Amplified fragment length polymorphism analysis of cDNA was used to identify rice genes differentially expressed in a tolerant rice variety upon water-deficit stress. In total, 103 transcript-derived fragments corresponding to differentially induced genes were identified. The results of the sequence comparison in BLAST database revealed that several differentially expressed TDFs were significantly homologous to stress regulated genes/proteins isolated from rice or other plant species. Most of the transcripts identified here were genes related to metabolism, energy, protein biosynthesis, cell defence, signal transduction, and transport. New genes involved in the response to water-deficit stress in a tolerant rice variety are reported here.

Correlación del diagnóstico clínico ultrasonográfico y anatomopatológico de la miomatisis uterina Hospital Carlos Robertos Huembes: enero 1993-diciembre 1994

Se realizó un estudio descriptivo, de conocimiento del problema en donde se revisaron 116 casos de pacientes ginecológicas con el diagnóstico de miomatosis uterina, en el Hospital Carlos Roberto Huembes de Managua, en el período comprendido entre el primero deenero de 1993 y el 31 de diciembre de 1994. El objetivo del estudio fue analizar la sensibilidad del ultrasonido como método auxiliar diagnóstico para miomatosis uterina correlacionándola con el diagnóstico clínico, transoperatorio y de anatomía patológica. Siendo las variables: Edad, paridad, diagnóstico clínico, diagnóstico ultrasonográfico, hallazgos transoperatorios y diagnóstico de anatomía patológica. Del estudio se obtuvo que : 63 pacientes se ubicaron entre los 30 y 40 años, 47 porciento de todas las pacientes tenían una paridad entre 4 a 8 partos, 78 porciento del total de las pacientes fueron diagnósticadas clínicamente como miomatosis uterina en el área de consulta externa; 84 porciento de las pacientes fueron confirmadas en el acto operatorio y 65 porciento fué confirmado el diagnóstico de miomatosis uterina por el departamento de anatomía patológica. Otros diagnósticos fueron; Adenomiosis, CACA, NIC III, Mockenberg. Además se obtuvo una relación clínico-ecográfica del 65 porciento, una relación de hallazgos transoperatorios-ecográfica del 59 porciento y una relación de ecográfica y de anatomía patológica de un 54.32 porciento. A la vez se obtuvo una relación de hallazgo transoperatorios y de anatomía patológica de un 90.51 porciento. Se concluyó que el ultrasonido no fué un medio diagnóstico confiable en el período estudiado ya que brindó una sensibilidad del 61 porciento y una especificidad del 16 porciento con una tendencia (+) 0.0713...