Phosphorus, in its orthophosphate form (P i ), is one of the most limiting macronutrients in soils for plant growth and development. However, the whole-genome molecular mechanisms contributing to plant acclimation to P i deficiency remain largely unknown. White lupin (Lupinus albus) has evolved unique adaptations for growth in P i -deficient soils, including the development of cluster roots to increase root surface area. In this study, we utilized RNA-Seq technology to assess global gene expression in white lupin cluster roots, normal roots, and leaves in response to P i supply. We de novo assembled 277,224,180 Illumina reads from 12 complementary DNA libraries to build what is to our knowledge the first white lupin gene index (LAGI 1.0). This index contains 125,821 unique sequences with an average length of 1,155 bp. Of these sequences, 50,734 were transcriptionally active (reads per kilobase per million reads $ 3), representing approximately 7.8% of the white lupin genome, using the predicted genome size of Lupinus angustifolius as a reference. We identified a total of 2,128 sequences differentially expressed in response to P i deficiency with a 2-fold or greater change and P # 0.05. Twelve sequences were consistently differentially expressed due to P i deficiency stress in three species, Arabidopsis (Arabidopsis thaliana), potato (Solanum tuberosum), and white lupin, making them ideal candidates to monitor the P i status of plants. Additionally, classic physiological experiments were coupled with RNA-Seq data to examine the role of cytokinin and gibberellic acid in P i deficiency-induced cluster root development. This global gene expression analysis provides new insights into the biochemical and molecular mechanisms involved in the acclimation to P i deficiency.

SummaryRoots of phosphorus (P)-deficient white lupin exhibit striking changes in morphology and gene expression. In this report we provide further insight into genetic elements affecting transcription of P-deficiency-induced genes. Moreover, we also show that sugars and photosynthates are integrally related to P-deficiency-induced gene expression. White lupin phosphate transporter (LaPT1) and secreted acid phosphatase (LaSAP1) promoter-reporter genes when transformed into alfalfa, a heterologous legume, showed significant induction in roots specifically in response to P-deficiency. In addition, both promoters were active in nitrogen-fixing root nodules but not in ineffective nodules indicating a link between P-deficiency and factors related to nitrogen fixation/metabolism. As sugars play a role in signal transduction during nitrogen assimilation and are required for effective nitrogen fixation, we tested the relationship of sugars to P-deficiency-induced gene expression. Exogenous sucrose, glucose, and fructose stimulated LaPT1 and LaSAP1 transcript accumulation in darkgrown P-sufficient white lupin seedlings. Furthermore, in intact P-deficient white lupin plants, LaPT1 and LaSAP1 expression in cluster roots was strikingly reduced in dark-adapted plants with expression rapidly restored upon reexposure to light. Likewise, interruption of phloem supply to P-deficient roots resulted in a rapid decline in LaPT1 and LaSAP1 transcript accumulation. Similar results were also obtained with a third lupin P-deficiency-induced gene encoding a putative multidrug and toxin efflux protein (LaMATE). Taken together, our data show that the regulation of P-deficiency-induced genes is conserved across plant species and sugars/photosynthates are crucial for P-deficiency signal transduction.

A series of new amino (NH)-type hydrogen-bonding (H-bonding) compounds comprising 2-(2'-aminophenyl)benzothiazole and its extensive derivatives were designed and synthesized. Unlike in the hydroxyl (OH)-type H-bonding systems, one of the amino hydrogens can be replaced with electron-donating/withdrawing groups. This, together with a versatile capability for modifying the parent moiety, makes feasible the comprehensive spectroscopy and dynamics studies of amino-type excited-state intramolecular proton transfer (ESIPT), which was previously inaccessible in the hydroxyl-type ESIPT systems. Empirical correlations were observed among the hydrogen-bonding strength (the N-H bond distances and proton acidity), ESIPT kinetics, and thermodynamics, demonstrating a trend that the stronger N-H···N hydrogen bond leads to a faster ESIPT, as experimentally observed, and a more exergonic reaction thermodynamics. Accordingly, ESIPT reaction can be harnessed for the first time from a highly endergonic type (i.e., prohibition) toward equilibrium with a measurable ESIPT rate and then to the highly exergonic, ultrafast ESIPT reaction within the same series of amino-type intramolecular H-bond system.

Monitoring systems are expected to play a major role in active distribution grids, and the design of the measurement infrastructure is a critical element for an effective operation. The use of any available and newly installed, though heterogeneous, metering device providing more accurate and real-time measurement data offers a new paradigm for the distribution grid monitoring system. In this paper the authors study the meter placement problem for the measurement infrastructure of an active distribution network, where heterogeneous measurements provided by PhasorMeasurement Units (PMUs) and other advanced measurement systems such as Smart Metering systems are used in addition to measurements that are typical of distribution networks, in particular substation measurements and a-priori knowledge. This work aims at defining a design approach for finding the optimal measurement infrastructure for an active distribution grid. The design problem is posed in terms of a stochastic optimization with the goal of bounding the overall uncertainty of the state estimation using heterogeneous measurements while minimizing the investment cost. The proposedmethod is also designed for computational efficiency so to cover a wide set of scenarios

Summary• White lupin (Lupinus albus) forms specialized cluster roots characterized by exudation of organic anions under phosphorus (P) deficiency. Here, the role of nitric oxide (NO) in P deficiency-induced cluster-root formation and citrate exudation was evaluated.• White lupin plants were treated with the NO donor sodium nitroprusside (SNP) and scavenger or inhibitor of NO synthase under conditions of P deficiency (0 lM) or P sufficiency (50 lM).• Phosphorus deficiency enhanced NO production in primary and lateral root tips, with a greater increase in cluster roots than in noncluster roots. NO concentrations decreased with cluster root development from the pre-emergent stage, through the juvenile stage, to the mature stage. The P deficiency-induced increase in NO production was inhibited by antagonists of NO synthase and xanthine oxidoreductase, suggesting the involvement of these enzymes in NO production. SNP markedly increased the number of cluster roots. Citrate exudation from different root segments in P-deficient roots was positively correlated with endogenous root NO concentrations.• These findings demonstrate differential patterns of NO production in white lupin, depending on root zone, developmental stage and P nutritional status. NO appears to play a regulatory role in the formation of cluster roots and citrate exudation in white lupin under conditions of P deficiency.

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Human-Object Interaction Detection tackles the problem of joint localization and classification of human object interactions. Existing HOI transformers either adopt a single decoder for triplet prediction, or utilize two parallel decoders to detect individual objects and interactions separately, and compose triplets by a matching process. In contrast, we decouple the triplet prediction into human-object pair detection and interaction classification. Our main motivation is that detecting the human-object instances and classifying interactions accurately needs to learn representations that focus on different regions. To this end, we present Disentangled Transformer, where both encoder and decoder are disentangled to facilitate learning of two subtasks. To associate the predictions of disentangled decoders, we first generate a unified representation for HOI triplets with a base decoder, and then utilize it as input feature of each disentangled decoder. Extensive experiments show that our method outperforms prior work on two public HOI benchmarks by a sizeable margin. Code will be available.

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