Highlights •Intrapopulational and intraindividual genetic diversity of Margalefidinium fulvescens were studied.•2341 LSU rDNA sequences were obtained from clonal cultures and field samplesof M. fulvescens.•The intrapopulational genetic diversity was equivalent to the intraindividual variability in indices of genetic diversity.•The variability among polymorphic copies of LSU rDNA caused genetic diversity of M. fulvescens.

In natural environments, plants often experience different stresses simultaneously, and adverse abiotic conditions can weaken the plant immune system. Interactome mapping revealed that the LOW SULPHUR UPREGULATED (LSU) proteins are hubs in an Arabidopsis protein interaction network that are targeted by virulence effectors from evolutionarily diverse pathogens. Here we show that LSU proteins are up-regulated in several abiotic and biotic stress conditions, such as nutrient depletion or salt stress, by both transcriptional and post-translational mechanisms. Interference with LSU expression prevents chloroplastic reactive oxygen species (ROS) production and proper stomatal closure during sulphur stress. We demonstrate that LSU1 interacts with the chloroplastic superoxide dismutase FSD2 and stimulates its enzymatic activity in vivo and in vitro. Pseudomonas syringae Virulence effectors interfere with this interaction and preclude re-localization of LSU1 to chloroplasts. We demonstrate that reduced LSU levels cause a moderately enhanced disease susceptibility in plants exposed to abiotic stresses such as nutrient deficiency, high salinity, or heavy metal toxicity, whereas LSU1 overexpression confers significant disease resistance in several of these conditions. Our data suggest that the network hub LSU1 plays an important role in co-ordinating plant immune responses across a spectrum of abiotic stress conditions.

The short coiled-coil LSU (RESPONSE TO LOW SULFUR) proteins are linked to sulfur metabolism and have numerous protein partners. However, most of these partners lack direct links to sulfur metabolism, and the role of such interactions remains elusive. Here, we confirmed LSU binding to Arabidopsis catalase (CAT) and revealed that NBR1, a selective autophagy receptor, strongly interacts with LSU1 but not with CAT. Consequently, we observed the involvement of autophagy but not NBR1 in CAT removal. The lsu and nbr1 mutants differed from the wild-type plants in size and the number of yellow fluorescent protein (YFP)-CAT condensates, the number of peroxisomes, and photosynthetic pigments levels in the presence and absence of stress. We conclude that LSU family members and NBR1 contribute directly or indirectly to CAT and peroxisome homeostasis, and the overall fitness of plants. Our structural models of CAT–LSU complexes show at least two regions of interaction in CAT, one of which is at the N-terminus. Indeed, the N-terminally truncated variants of CAT2 and CAT3 interact more weakly with LSU1 than their full-length variants, but the extent of reduction is higher for CAT2, suggesting differences in recognition of CAT2 and CAT3 by LSU1.

Recent work established a backbone reference tree and phylogenetic placement pipeline for identification of arbuscular mycorrhizal fungal (AMF) large subunit (LSU) rDNA environmental sequences. Our previously published pipeline allowed any environmental sequence to be identified as putative AMF or within one of the major families. Despite this contribution, difficulties in implementation of the pipeline remain. Here, we present an updated database and pipeline with (1) an expanded backbone tree to include four newly described genera and (2) several changes to improve ease and consistency of implementation. In particular, packages required for the pipeline are now installed as a single folder (conda environment) and the pipeline has been tested across three university computing clusters. This updated backbone tree and pipeline will enable broadened adoption by the community, advancing our understanding of these ubiquitous and ecologically important fungi.

Science gateways are a mechanism for delivering scientific software as a service, especially when the software requires high performance computing (HPC) resources to run effectively. The existence of a science gateway eliminates the user's need to learn to work with HPC systems and to manage software installations and updates. With well-designed user interfaces, users can more quickly become effective users of scientific applications and can manage information needed for replicating, modifying, and sharing results. All of these efficiency gains enable users to focus more on their research. In addition, science gateways are being identified as an effective educational tool, a tool to be used in classroom environments as a method to get students quickly into research on domain specific questions. In the absence of a science gateway, students are likely to need a considerable time to learn to work with HPC systems, and any time spent on such will reduce their time on the actual science. This poster presents how the Louisiana State University (LSU) gateway for the Computational System Biology Group (CSBG) - (www.brylinski.org) was updated and improved to be a classroom teaching tool. This work makes extensive use of Apache Airavata's group management capabilities.

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