Variation of morphological descriptors for the evaluation of tomato germplasm and their stability across different growing conditions

[EN] Germplasm and breeding materials are usually characterized using morphological and agronomic descriptors, which should have a high heritability. Despite the widespread use of tomato (Solanum lycopersicum) standardized descriptors, little information exists on environmental effects on descriptor values and their heritability. We have evaluated 12 tomato accessions from seven cultivar groups in three different environments (open-field conventional, open-field organic, and greenhouse) and characterized them with 36 descriptors. A wide range of variation was found for most descriptors, demonstrating their utility for describing tomato materials and their diversity and relationships. The analysis of descriptors variation reveals that while for some descriptors with a simple genetic control the accession effect accounts for 100% of the variation, for others like yield per plant only 10.83% of the variation observed is due to the accession effect. Although significant differences were found among environments for most descriptors, including a much higher yield in the open-field conventional environment than in the two others, the environmental effect was low for most traits. However, the genotype×environment effect generally had an important contribution to the structure of variation for many descriptors, and for three traits it had the highest contribution to the percentage of the sum of squares. As a result of the variation structure, the heritability values are high (> 0.7) for only 10 descriptors, while for five is low (< 0.3). Principal components analysis (PCA) reveals that projections in the PCA graph of a same accession grown in different environments plot together in the same area of the PCA graph. Although cultivar groups are generally clearly separated in the PCA graph, accessions from the same cultivar group in some cases are intermixed. These results have important implications for detecting tomato duplicates and establishing core collections, as well as for analyzing germplasm and breeding results, when using data sets containing data of accessions grown in different environments.This work has been partially funded by the TRADITOM (Traditional tomato varieties and cultural practices: a case for agricultural diversification with impacto n food security and health of European population) and G2P-SOL (Linking genetic resources, genomes and phenotypes of Solanaceous crops) projects. These projects have received funding from the European Union's Horizon 2020 research and innovation programme under grant agreements No 634561 (TRADITOM) and No 677379 (G2P-SOL). Authors are grateful to Mr. Jonatan Cerdan for his technical help.Figás-Moreno, MDR.; Prohens Tomás, J.; Casanova-Calancha, C.; Fernández De Córdova Martínez, PJ.; Soler Aleixandre, S. (2018). Variation of morphological descriptors for the evaluation of tomato germplasm and their stability across different growing conditions. Scientia Horticulturae. 238:107-115. https://doi.org/10.1016/j.scienta.2018.04.039S10711523

The conformation and function of a multimodular glycogen-degrading pneumococcal virulence factor

SpuA is a large multimodular cell wall-attached enzyme involved in the degradation of glycogen by the pathogenic bacterium Streptococcus pneumoniae. The deletion of the gene encoding SpuA from the bacterium resulted in a strain with reduced competitiveness in a mouse model of virulence relative to the parent strain, linking the degradation of host-glycogen to the virulence of the bacterium. Through the combined use of X-ray crystallography, small-angle X-ray scattering, and inhibitor binding, the molecular features involved in substrate recognition by this complex protein are revealed. This uniquely illustrates the complexity of the active site, the conformational changes incurred during carbohydrate binding by this protein, and the interaction and cooperation of its composite modules during this process. New insight into the function of this particular pneumococcal virulence factor is provided along with substantial contributions to the nascent framework for understanding the structural and functional interplay between modules in multimodular carbohydrate-active enzymes.Alicia Lammerts van Bueren, Elizabeth Ficko-Blean, Benjamin Pluvinage, Jan-Hendrik Hehemann, Melanie A. Higgins, Lehua Deng, A. David Ogunniyi, Uwe H. Stroeher, Nahida E Warry, Robert D. Burke, Mirjam Czjzek, James C. Paton, David J. Vocadlo and Alisdair B. Borasto

General support of physical exercise programs in pediatric oncology but differences in perception by childhood cancer care professionals at European and North-African/Arab centers

Purpose: To explore the perception of physical exercise programs for pediatric oncology patients among childhood cancer care professionals. We also aimed at comparing such perceptions between cultures. Healthcare professionals’ endorsement may be essential for initiating and promoting such programs. Methods: An anonymous survey was designed and administered voluntarily to childhood cancer care professionals (including pediatric oncologists, nurses, and physiotherapists) in European, North-African and Arab pediatric oncology centers. Results: Five-hundred-and twenty-eight professionals from 14 sites answered the survey. Most respondents considered physical exercise programs as a suitable therapeutic approach for pediatric cancer patients with a potential positive contribution to survival (81%), wellbeing (82%), quality of life (80%), and self-esteem (75%). 91% of respondents would also support the future introduction of physical exercise programs into standard pediatric oncological care. There was a comparatively higher appreciation of physical exercise programs among European centers compared to North-African / Arab centers. Conclusion: We registered a broad acceptance of physical exercise programs among all European and North-African / Arab childhood cancer care professionals. The positive perception was independent of any pre-existing experience with such programs and seems therefore representative. This finding may encourage the further promotion of physical exercise programs in pediatric oncology