糖心TV

Gwendolyn V. Davis, Jan J. Pavlou, Patrick Li, Marija Smokvarska, Richard S. Smith, Emmanuelle Bayer, George W. Bassel

Cell-to-cell communication underpins pattern formation and organ function in multicellular organisms. Plant cells can communicate directly through cytoplasmic channels called plasmodesmata. The distribution, abundance, and density of plasmodesmata on plant cell interfaces impact the flow of molecules between plant cells; yet the extent to which these properties are genetically and dynamically regulated remains poorly understood at an organ scale. We developed a quantitative approach to map plasmodesmata pit fields across roots in 3D at cell type and cell interface-specific resolution. Multiple parameters are captured simultaneously, including plasmodesmata pit field abundance, density, and spatial distribution, enabling parallel multiscale analyses at cellular resolution across this organ. During root maturation, plasmodesmata abundance increases, with the greatest biogenesis occurring within the inner cell layers. This is coupled with changes in the degree of clustering of the pit fields on these inner cell layers: becoming more dispersed on specific cell interface types and more clustered on others. Significant differences in plasmodesmata pit field spatial patterning were detected at cell type-specific resolution in the BRASSINOSTEROID INSENSITIVE1 mutant, demonstrating a role for this hormone pathway in channel patterning. The ability to quantify pit field abundance and patterning at cell type-specific resolution provides novel insight into the developmental and hormonal regulation of potential symplastic connectivity across plant organs, while providing a powerful tool toward the investigation of quantitative systems-level plasmodesmata distribution and macro-communication between cells in a complex multicellular system.

Boltze J., Fisher M

Recanalization therapies for ischemic stroke, in particular endovascular thrombectomy, have revolutionized acute stroke management. Cytoprotective approaches were unsuccessfully tested in the pre-recanalization era but have seen a renaissance in translational research and early clinical trials as a potential intervention to augment the impact of recanalization therapies. The new clinical trial approaches in which cytoprotective therapies are now being applied require refinement of cytoprotective application strategies. This has a profound impact on both preclinical translational and clinical research. This review summarizes current cytoprotection concepts and explains their rationale based on ischemic stroke pathophysiology and provides an overview of cytoprotection approaches currently under clinical assessment. Preclinical assessment of novel cytoprotective paradigms will require advanced in vivo testing in models resembling human stroke patients as much as possible. The review therefore also describes ways to improve preclinical and translational research with respect to comorbidities and other aspects impacting stroke pathophysiology. Moreover, the role of modern brain imaging approaches is discussed including their use as potential biomarkers or patient selection tools. The review further provides detailed considerations of novel clinical trial design features for cytoprotection trials in the context of recanalization therapies and provides an outlook on potential future research approaches.

Ziyue Zeng, John W. Mansfield, Andrea Vadillo-Dieguez, John Connell, James Irvine, Michelle T. Hulin, Fernando Duarte Frutos, Mojgan Rabiey, Nastasiya F. Grinberg, Richard J. Harrison, Xiangming Xu, Robert W. Jackson

Plant surfaces host diverse microbial communities acting as reservoirs for pathogenic lineages, yet the ecological dynamics and evolutionary consequences of such reservoirs remain underexplored. We conducted landscape-scale genomic surveillance of Pseudomonas syringae on symptomless leaves of cultivated cherry in orchards and wild plant species in adjacent woodlands across the UK, aiming to understand how phyllosphere populations contribute to the emergence of bacterial canker. Whole genome sequencing of 540 isolates collected over two years and across four regions revealed 10 diverse P. syringae phylogroups (PGs) on symptomless leaves. Both orchard and woodland environments harboured a similar range of PGs, but recovery frequency was very different. PG2d strains dominated cherry orchards, whereas PGs 2b and 13a were prevalent in woodlands. Certain PG2d subclades, recovered from both environments, caused disease on cultivated and wild cherry leaves. Additional strains were found to be pathogenic to Phaseolus bean pods. The pathogens of cherry were characterised by the presence of genes encoding the synthesis of the pathotoxin syringolin A and a subset of effector proteins including HopAW1, AvrRpm1 and HopAR1. Resolution of subclades within PG2d provided insights into the emergence of virulent epiphytic strains that have not yet reached the mostly northerly sampling sites but are threats to both cultivated and environmental Prunus spp. Fine-scale analysis of subclade PG2d-3 revealed potential divergence between orchard and woodland populations, with 49 genes exclusive to a woodland lineage. Thirty-eight of these genes were found within prophages, indicating the potential role of bacteriophage-mediated horizontal gene transfer in adaptation to non-agricultural reservoirs.

Andreas Ensslin, Adelaide Clemente, Udayangani Liu, Elke Zippel, Carla Pinto-Cruz, Carolina Sanchez Romero, Simone Schneider, Agust铆 Agut Escrig, Charlotte Allender, K眉lli Annamaa, Marina Antic, Bertille Asset, Gianluigi Bacchetta, Oz Baranzani, Anamaria Barata, Philippe Bardin, Joze Bavcon, Anabela D. F. Belo, Marina Belovarska, Karim Benkhelifa, Christian Berg, Karl-Georg Bernhardt, Marcin Beza, Kristina Bjureke, Sina Bohm, Peter Borgmann, Josep Borrell, St茅phane Buord, Jocelyne Cambecedes, Francesca Carruggio, Angelino Carta, Pedro Casimiro, Ted Chapman, Iveta Cicova, Regis Crisnaire, Antonia Cristaudo, Lucia De la Rosa, Ma卯te Delmas, Gergana Desheva, Valter Di Cecco, Luciano Di Martino, Katia Diadema, Lara Dixon, Denise Dostatny, Marie Duval, Roland K. Eberwein, Mikel Etxeberria-Okariz, Caroline Favier, Nick Fenby, Mariana P. Fernandes, Inmaculada Ferrando-Pardo, Pablo Ferrer, No茅mie Fort, Luigi Forte, Catia F. Freitas, Agnese Gailite, Katarzyna Galej-Ciwis, Rosa Maria Garcia, Ana Irene Garc铆a-del Bao, Catherine Gautier, Bronislovas Gelvonauskis, Gian Petro Giusso del Galdo, Miguel Angel Gonz谩lez P茅rez, Johan Gourvil, Luisa Gouveia, Thierry Helminger, Brais Hermosilla Lorenzo, Laetitia Hugot, Marko Hyv盲rinen, Ignac Jan啪ekovi膷, Andreas K枚nig, Nikos Krigas, Emilio Laguna, Ludivine Lap茅bie, Denis Larpin, Maja Lazarevi膰, Dikla Lifshitz, Vincent Lipa, Carlos Lobo, Ulrike Lohwasser, Sandrine Loriot, Sara Magrini, Francesca Mantino, Mauro Mariotti, Evi Matiatou, Lubomir Mendel, Marine Millet, Mari Miranto, Andrea Mondoni, Santiago Moreno V谩zquez, Valeria Negri, Peter Nick, Maciej Niemczyk, Humberto Nobrega, Pawel Olejniczak, Ma艂gorzata Pa艂ucka, Katerina Papanastasi, Ioanna Papanikolaou, Miguel A. A. Pinheiro de Carvalho, Marco Porceddu, Sotirios Porevis, Peter Poschlod, Lorenzo Raggi, Sarmite Rancane, Leonid Rasran, Blanka Ravnjak, St茅phane Rivi猫re, Axelle Roumier, Anna Ruci艅ska, Felix Schlatti, Marco Schmidt, Guy-Xavier Seznec, Manuela Sim-Sim, Ana Luisa Soares, Nora Stoeckl, Silvia Strajeru, Gitana Stukeniene, Andrej 艩u拧ek, Andreas Titze, , Zlatina Tsvetanova, Theo Van Hintum, Nils Van Rooijen, Magdalena Vicens Forn茅s, Mariacristina Villani, Silvia Villegas, Fiona J. White, Sabine Zachago, Elena Zappa, Vince Zsigmond, Sandrine Godefroid

Ambitious targets have been set to backup seeds of threatened plants by the global strategy for plant conservation (GSPC), but it is unclear in how far these targets have been met and how seed collection should be organized to meet future challenges. Here, we provide an overview of the status of 44 countries in achieving seed conservation targets. We show that progress varies strongly across countries, but in general, targets of the 2011–2020 GSCP have not been reached. By a regional example, we illustrate how seed collection could be organized to safeguard our threatened flora.

Wei Ma, Yuanming Liu, Xiaochun Wei, Xiaomeng Zhang, Xiaonan Li, Zhaokun Liu, Lingyun Yuan, Guangguang Li, Shu Zhang, Qihang Yang, Xiaocong Chang, Zizhuo Han, Hao Liang, Zhaoshui Luan, Qianyun Wang, Yujie Gu, Xinlong Wang, Xianlei Zhao, Qing Liu, Xiaoxue Sun, Mengyang Liu, Daling Feng, Yin Lu, Shuangxia Luo, Lei Yang, Mengyuan Li, Robin Allaby, Kai Wang, Tianzhen Zhang, Shuxing Shen, Yves Van de Peer, Yiguo Hong, Yuxiang Yuan, Jianjun Zhao

Brassica rapa (Br) encompasses many morphotypes and subspecies, so it is a good model with which to investigate plant diversification and subspeciation. Here, we resequenced the genomes of 1720 Br accessions and de novo assembled 11 representative telomere-to-telomere gapless genomes for seven elite subspecies that underwent intensive morphotypification and developed distinct agronomic traits valued to agriculture. We identified 6992 unknown genes, 110 complete (peri)centromeres, and five new satellites associated with Br morphotypes and subspecies and Brassica species evolution. The pangenome, built on 11 gapless and 20 published genomes, reveals structural variations and gene diversities among Br subspecies. Pangenome-wide association studies uncovered that the gene BrLH1 controls leaf-head formation. We show that structural changes have occurred in satellites, (peri)centromeres, and genes, contributing to fast subspeciation and morphotypification during the short history of Br cultivation, providing invaluable resources for Brassica breeding.