Mapping the castor bean endosperm proteome revealed a metabolic interaction between plastid, mitochondria, and peroxisomes to optimize seedling growth.

In this work, we studied castor-oil plant Ricinus communis as a classical system for endosperm reserve breakdown. The seeds of castor beans consist of a centrally located embryo with the two thin cotyledons surrounded by the endosperm. The endosperm functions as major storage tissue and is packed with nutritional reserves, such as oil, proteins, and starch. Upon germination, mobilization of the storage reserves requires inter-organellar interplay of plastids, mitochondria, and peroxisomes to optimize growth for the developing seedling. To understand their metabolic interactions, we performed a large-scale organellar proteomic study on castor bean endosperm. Organelles from endosperm of etiolated seedlings were isolated and subjected to liquid chromatography-tandem mass spectrometry (LC-MS/MS). Computer-assisted deconvolution algorithms were applied to reliably assign the identified proteins to their correct subcellular localization and to determine the abundance of the different organelles in the heterogeneous protein samples. The data obtained were used to build a comprehensive metabolic model for plastids, mitochondria, and peroxisomes during storage reserve mobilization in castor bean endosperm.

The Aureochrome Photoreceptor PtAUREO1a Is a Highly Effective Blue Light Switch in Diatoms.

Aureochromes represent a unique type of blue light photoreceptors that possess a blue light sensing flavin-binding LOV-domain and a DNA-binding bZIP domain, thus being light-driven transcription factors. The diatom Phaeodactylum tricornutum, a member of the essential marine primary producers, possesses four aureochromes (PtAUREO1a, 1b, 1c, 2). Here we show a dramatic change in the global gene expression pattern of P. tricornutum wild-type cells after a shift from red to blue light. About 75% of the genes show significantly changed transcript levels already after 10 and 60 min of blue light exposure, which includes genes of major transcription factors as well as other photoreceptors. Very surprisingly, this light-induced regulation of gene expression is almost completely inhibited in independent PtAureo1a knockout lines. Such a massive and fast transcriptional change depending on one single photoreceptor is so far unprecedented. We conclude that PtAUREO1a plays a key role in diatoms upon blue light exposure.

Root exudation of mature beech forests across a nutrient availability gradient: the role of root morphology and fungal activity.

Root exudation is a key plant function with a large influence on soil organic matter dynamics and plant-soil feedbacks in forest ecosystems. Yet despite its importance, the main ecological drivers of root exudation in mature forest trees remain to be identified. During two growing seasons, we analyzed the dependence of in situ collected root exudates on root morphology, soil chemistry and nutrient availability in six mature European beech (Fagus sylvatica L.) forests on a broad range of bedrock types. Root morphology was a major driver of root exudation across the nutrient availability gradient. A doubling of specific root length exponentially increased exudation rates of mature trees by c. 5-fold. Root exudation was also closely negatively related to soil pH and nitrogen (N) availability. At acidic and N-poor sites, where fungal biomass was reduced, exudation rates were c. 3-fold higher than at N- and base-richer sites and correlated negatively with the activity of enzymes degrading less bioavailable carbon (C) and N in the bulk soil. We conclude that root exudation increases on highly acidic, N-poor soils, in which fungal activity is reduced and a greater portion of the assimilated plant C is shifted to the external ecosystem C cycle.

Transcript and metabolite changes during the early phase of abscisic acid-mediated induction of crassulacean acid metabolism in Talinum triangulare.

Crassulacean acid metabolism (CAM) has evolved as a water-saving strategy, and its engineering into crops offers an opportunity to improve their water use efficiency. This requires a comprehensive understanding of the regulation of the CAM pathway. Here, we use the facultative CAM species Talinum triangulare as a model in which CAM can be induced rapidly by exogenous abscisic acid. RNA sequencing and metabolite measurements were employed to analyse the changes underlying CAM induction and identify potential CAM regulators. Non-negative matrix factorization followed by k-means clustering identified an early CAM-specific cluster and a late one, which was specific for the early light phase. Enrichment analysis revealed abscisic acid metabolism, WRKY-regulated transcription, sugar and nutrient transport, and protein degradation in these clusters. Activation of the CAM pathway was supported by up-regulation of phosphoenolpyruvate carboxylase, cytosolic and chloroplastic malic enzymes, and several transport proteins, as well as by increased end-of-night titratable acidity and malate accumulation. The transcription factors HSFA2, NF-YA9, and JMJ27 were identified as candidate regulators of CAM induction. With this study we promote the model species T. triangulare, in which CAM can be induced in a controlled way, enabling further deciphering of CAM regulation.

Transcriptional response of the extremophile red alga Cyanidioschyzon merolae to changes in CO2 concentrations.

Cyanidioschyzon merolae (C. merolae) is an acidophilic red alga growing in a naturally low carbon dioxide (CO2) environment. Although it uses a ribulose 1,5-bisphosphate carboxylase/oxygenase with high affinity for CO2, the survival of C. merolae relies on functional photorespiratory metabolism. In this study, we quantified the transcriptomic response of C. merolae to changes in CO2 conditions. We found distinct changes upon shifts between CO2 conditions, such as a concerted up-regulation of photorespiratory genes and responses to carbon starvation. We used the transcriptome data set to explore a hypothetical CO2 concentrating mechanism in C. merolae, based on the assumption that photorespiratory genes and possible candidate genes involved in a CO2 concentrating mechanism are co-expressed. A putative bicarbonate transport protein and two α-carbonic anhydrases were identified, which showed enhanced transcript levels under reduced CO2 conditions. Genes encoding enzymes of a PEPCK-type C4 pathway were co-regulated with the photorespiratory gene cluster. We propose a model of a hypothetical low CO2 compensation mechanism in C. merolae integrating these low CO2-inducible components.

Comparative transcriptome atlases reveal altered gene expression modules between two Cleomaceae C3 and C4 plant species.

C(4) photosynthesis outperforms the ancestral C(3) state in a wide range of natural and agro-ecosystems by affording higher water-use and nitrogen-use efficiencies. It therefore represents a prime target for engineering novel, high-yielding crops by introducing the trait into C(3) backgrounds. However, the genetic architecture of C(4) photosynthesis remains largely unknown. To define the divergence in gene expression modules between C(3) and C(4) photosynthesis during leaf ontogeny, we generated comprehensive transcriptome atlases of two Cleomaceae species, Gynandropsis gynandra (C(4)) and Tarenaya hassleriana (C(3)), by RNA sequencing. Overall, the gene expression profiles appear remarkably similar between the C(3) and C(4) species. We found that known C(4) genes were recruited to photosynthesis from different expression domains in C(3), including typical housekeeping gene expression patterns in various tissues as well as individual heterotrophic tissues. Furthermore, we identified a structure-related module recruited from the C(3) root. Comparison of gene expression patterns with anatomy during leaf ontogeny provided insight into genetic features of Kranz anatomy. Altered expression of developmental factors and cell cycle genes is associated with a higher degree of endoreduplication in enlarged C(4) bundle sheath cells. A delay in mesophyll differentiation apparent both in the leaf anatomy and the transcriptome allows for extended vein formation in the C(4) leaf.

An engineered plant peroxisome and its application in biotechnology.

Plant metabolic engineering is a promising tool for biotechnological applications. Major goals include enhancing plant fitness for an increased product yield and improving or introducing novel pathways to synthesize industrially relevant products. Plant peroxisomes are favorable targets for metabolic engineering, because they are involved in diverse functions, including primary and secondary metabolism, development, abiotic stress response, and pathogen defense. This review discusses targets for manipulating endogenous peroxisomal pathways, such as fatty acid ß-oxidation, or introducing novel pathways, such as the synthesis of biodegradable polymers. Furthermore, strategies to bypass peroxisomal pathways for improved energy efficiency and detoxification of environmental pollutants are discussed. In sum, we highlight the biotechnological potential of plant peroxisomes and indicate future perspectives to exploit peroxisomes as biofactories.

Synthesis of benzofuran, benzothiophene, and benzothiazole-based thioamides and their evaluation as K(ATP) channel openers.

Several series of benzofurans, benzothiophenes, and benzothiazoles, all featuring the thioamide group, were synthesized and tested as novel K(ATP) channel openers in artificial cell systems: CHO cells transfected with SUR1/Kir6.2, and HEK 293 cells transfected with SUR2B/Kir6.1; these served as model systems for insulin-secreting pancreatic ß cells and smooth muscle cells, respectively. All compounds were investigated with respect to their binding affinity for the SUR2B-type K(ATP) channels using [(3)H]P1075 as radioligand. Selected compounds were also tested as agonists in intact cells using DiBAC(4)(3) and DyeB (R7260) as membrane potential dyes. Remarkable affinity for SUR2B/Kir6.1 channels in the single-digit micromolar range was observed. In addition, benzothiazole-derived thioamides with sterically demanding, lipophilic substituents showed >100-fold selectivity in favor of SUR2B/Kir6.1. A one-carbon spacer between the heterocyclic skeleton and the thioamide moiety was observed to be crucial for affinity and selectivity. Two of the most potent and selective compounds were studied by crystal structure analyses.

Evaluation of the efficacy of pharmacotherapy and psychotherapy in treatment of combat-related post-traumatic stress disorder: a meta-analytic review of outcome studies.

A meta-analysis was conducted to examine the relative effectiveness of the broad-based treatments for combat-related post-traumatic stress disorder (PTSD). The analysis includes 13 pharmacotherapy studies and 12 psychotherapy studies obtained from a PsychINFO database search and a reference search. Studies of pharmacotherapy treatment efficacy demonstrated a significantly greater decrease in reducing PTSD symptoms, t (22) = -2.74, p = 0.01, d = 0.05. A random coefficient analysis supports this finding with significance determined at p < 0.001 for the fixed effects in the models. A limited examination of depression as a frequently comorbid disorder indicated pharmacotherapy also demonstrated a significantly greater decrease than psychotherapy in depression symptoms, t (15.77) = -2.26, p = 0.04, d = 0.16. Differences between treatments are discussed as potentially reflective of assignment to treatments and assessment techniques as well as therapeutic effects.

Maladaptive correlates of the failure to forgive self and others: further evidence for a two-component model of forgiveness.

In a sample composed of 162 young adults, we examined the generalizability of an orthogonal, 2-component model of forgiveness previously reported by Ross, Kendall, Matters, Rye, and Wrobel (2004). Furthermore, we examined the relationship of these two components with maladaptive personality characteristics as measured by the Schedule for Nonadaptive and Adaptive Personality (SNAP; Clark, 1993), with an emphasis on Five-factor model markers of personality. Using multiple measures of forgiveness, principal components analysis supported a 2-component model representing self-forgiveness and other forgiveness. Despite the independence of self-forgiveness and other forgiveness, zero order correlations with SNAP scales supported convergent more than discriminant validity. In contrast, hierarchical multiple regression analyses emphasized the discriminant validity of self-forgiveness and other forgiveness. Among indices of Neuroticism, Extraversion, and Agreeableness, Negative Temperament (+) was the sole predictor of self-forgiveness. In contrast, Positive Temperament (+), Aggression (-), and Histrionic PD (-) were most associated with other forgiveness. Overall, these findings support the validity of these factors and highlight the importance of self-forgiveness in clinical assessment.

Self-report problem scales and subscales and behavioral ratings provided by peers: unique evidence of test validity.

The relationship between children's self-reported problems on the Personality Inventory for Youth (PIY) and peer descriptors derived from the Pupil Evaluation Inventory was examined in a regular education sample of 156 children in fourth through eighth grade. The relative contributions of the PIY scales and subscales to the prediction of peer ratings were compared. Peer ratings of withdrawn, disruptive, and prosocial behaviors were substantially correlated to self-report problem scales made up of logically related content. The addition of more content-specific PIY subscales contributed to the prediction made by PIY scales of peer-reported disruptive behaviors and withdrawal.

A personological examination of self- and other-forgiveness in the five factor model.

In a sample composed of 147 undergraduates (age range 18 to 55 years; M = 22), we conducted an examination of the convergent and discriminant validity of self- and other-forgiveness in the Five-factor model of personality (FFM). Using multiple measures of each construct, principal components analysis (PCA) supported a 2-component model of forgiveness. Findings for the PCA and external correlates with the FFM provided evidence for a largely orthogonal relationship between self- and other-forgiveness. Specifically, self-forgiveness was negatively related to Neuroticism and unrelated to Agreeableness, whereas other-forgiveness was unrelated to Neuroticism and positively related to Agreeableness. Overlap between the constructs was found in which both self- and other-forgiveness were negatively related to the hostility facet of Neuroticism and the order facet from Conscientiousness and positively related to the warmth and positive emotions facet scales from the Extraversion domain of the Revised NEO Personality Inventory (Costa & McCrae, 1992). Overall, these findings suggest that self- and other-forgiveness, although seemingly similar, carry very different motivational underpinnings.