An Induced Mutation in Tomato eIF4E Leads to Immunity to Two Potyviruses

BACKGROUND: The characterization of natural recessive resistance genes and Arabidopsis virus-resistant mutants have implicated translation initiation factors of the eIF4E and eIF4G families as susceptibility factors required for virus infection and resistance function. METHODOLOGY/PRINCIPAL FINDINGS: To investigate further the role of translation initiation factors in virus resistance we set up a TILLING platform in tomato, cloned genes encoding for translation initiation factors eIF4E and eIF4G and screened for induced mutations that lead to virus resistance. A splicing mutant of the eukaryotic translation initiation factor, S.l_eIF4E1 G1485A, was identified and characterized with respect to cap binding activity and resistance spectrum. Molecular analysis of the transcript of the mutant form showed that both the second and the third exons were miss-spliced, leading to a truncated mRNA. The resulting truncated eIF4E1 protein is also impaired in cap-binding activity. The mutant line had no growth defect, likely because of functional redundancy with others eIF4E isoforms. When infected with different potyviruses, the mutant line was immune to two strains of Potato virus Y and Pepper mottle virus and susceptible to Tobacco each virus. CONCLUSIONS/SIGNIFICANCE: Mutation analysis of translation initiation factors shows that translation initiation factors of the eIF4E family are determinants of plant susceptibility to RNA viruses and viruses have adopted strategies to use different isoforms. This work also demonstrates the effectiveness of TILLING as a reverse genetics tool to improve crop species. We have also developed a complete tool that can be used for both forward and reverse genetics in tomato, for both basic science and crop improvement. By opening it to the community, we hope to fulfill the expectations of both crop breeders and scientists who are using tomato as their model of study

Development and evaluation of robust molecular markers linked to disease resistance in tomato for distinctness, uniformity and stability testing

Molecular markers linked to phenotypically important traits are of great interest especially when traits are difficult and/or costly to be observed. In tomato where a strong focus on resistance breeding has led to the introgression of several resistance genes, resistance traits have become important characteristics in distinctness, uniformity and stability (DUS) testing for Plant Breeders Rights (PBR) applications. Evaluation of disease traits in biological assays is not always straightforward because assays are often influenced by environmental factors, and difficulties in scoring exist. In this study, we describe the development and/or evaluation of molecular marker assays for the Verticillium genes Ve1 and Ve2, the tomato mosaic virusTm1 (linked marker), the tomato mosaic virus Tm2 and Tm22 genes, the Meloidogyne incognita Mi1-2 gene, the Fusarium I (linked marker) and I2 loci, which are obligatory traits in PBR testing. The marker assays were evaluated for their robustness in a ring test and then evaluated in a set of varieties. Although in general, results between biological assays and marker assays gave highly correlated results, marker assays showed an advantage over biological tests in that the results were clearer, i.e., homozygote/heterozygote presence of the resistance gene can be detected and heterogeneity in seed lots can be identified readily. Within the UPOV framework for granting of PBR, the markers have the potential to fulfil the requirements needed for implementation in DUS testing of candidate varieties and could complement or may be an alternative to the pathogenesis tests that are carried out at present

Neurocognition and quality of life after reinitiating antiretroviral therapy in children randomized to planned treatment interruption

Objective: Understanding the effects of antiretroviral treatment (ART) interruption on neurocognition and quality of life (QoL) are important for managing unplanned interruptions and planned interruptions in HIV cure research. Design: Children previously randomized to continuous (continuous ART, n=41) vs. planned treatment interruption (PTI, n=47) in the Pediatric European Network for Treatment of AIDS (PENTA) 11 study were enrolled. At study end, PTI children resumed ART. At 1 and 2 years following study end, children were assessed by the coding, symbol search and digit span subtests of Wechsler Intelligence Scale for Children (6-16 years old) or Wechsler Adult Intelligence Scale ( 6517 years old) and by Pediatrics QoL questionnaires for physical and psychological QoL. Transformed scaled scores for neurocognition and mean standardized scores for QoL were compared between arms by t-test and Mann-Whitney U test, respectively. Scores indicating clinical concern were compared (<7 for neurocognition and <70 for QoL tests). Results: Characteristics were similar between arms with a median age of 12.6 years, CD4 + of 830 cells/\u3bcl and HIV RNA of 1.7 log 10 copies/ml. The median cumulative ART exposure was 9.6 in continuous ART vs. 7.7 years in PTI (P=0.02). PTI children had a median of 12 months off ART and had resumed ART for 25.2 months at time of first assessment. Neurocognitive scores were similar between arms for all tests. Physical and psychological QoL scores were no different. About 40% had low neurocognitive and QoL scores indicating clinical concern. Conclusion: No differences in information processing speed, sustained attention, short-term memory and QoL functioning were observed between children previously randomized to continuous ART vs. PTI in the PENTA 11 trial

Remedies and administrative review in award procedures for public procurements in selected African countries

International audienc