Induction of isoprenyl diphosphate synthases, plant hormones and defense signalling genes correlates with traumatic resin duct formation in Norway spruce (Picea abies)

Norway spruce (Picea abies) defends itself against herbivores and pathogens by formation of traumatic resin ducts filled with terpenoid-based oleoresin. An important group of enzymes in terpenoid biosynthesis are the short-chain isoprenyl diphosphate synthases which produce geranyl diphosphate (C10), farnesyl diphosphate (C15), and geranylgeranyl diphosphate (C20) as precursors of monoterpenes, sesquiterpenes, and diterpene resin acids, respectively. After treatment with methyl jasmonate (MJ) we investigated the expression of all isoprenyl diphosphate synthase genes characterized to date from Norway spruce and correlated this with formation of traumatic resin ducts and terpene accumulation. Formation of traumatic resin ducts correlated with higher amounts of monoterpenes, sesquiterpenes and diterpene resin acids and an upregulation of isoprenyl diphosphate synthase genes producing geranyl diphosphate or geranylgeranyl diphosphate. Among defense hormones, jasmonate and jasmonate-isoleucine conjugate accumulated to higher levels in trees with extensive traumatic resin duct formation, whereas salicylate did not. Jasmonate and ethylene are likely to both be involved in formation of traumatic resin ducts based on elevated transcripts of genes encoding lipoxygenase and 1-aminocyclopropane-1-carboxylic acid oxidase associated with resin duct formation. Other genes involved in defense signalling in other systems, mitogen-activated protein kinase3 and nonexpressor of pathogenesis-related gene1, were also associated with traumatic resin duct formation. These responses were detected not only at the site of MJ treatment, but also systemically up to 60 cm above the site of treatment on the trunk

A dual-fMRI investigation of the iterated Ultimatum Game reveals that reciprocal behaviour is associated with neural alignment

Dyadic interactions often involve a dynamic process of mutual reciprocity; to steer a series of exchanges towards a desired outcome, both interactants must adapt their own behaviour according to that of their interaction partner. Understanding the brain processes behind such bidirectional reciprocity is therefore central to social neuroscience, but this requires measurement of both individuals’ brains during realworld exchanges. We achieved this by performing functional magnetic resonance imaging (fMRI) on pairs of male individuals simultaneously while they interacted in a modifed iterated Ultimatum Game (iUG). In this modifcation, both players could express their intent and maximise their own monetary gain by reciprocating their partner’s behaviour – they could promote generosity through cooperation and/or discourage unfair play with retaliation. By developing a novel model of reciprocity adapted from behavioural economics, we then show that each player’s choices can be predicted accurately by estimating expected utility (EU) not only in terms of immediate payof, but also as a reaction to their opponent’s prior behaviour. Finally, for the frst time we reveal that brain signals implicated in social decision making are modulated by these estimates of EU, and become correlated more strongly between interacting players who reciprocate one another

The Response of Lemna minor to Mixtures of Pesticides That Are Commonly Used in Thailand

In the field, aquatic organisms are exposed to multiple contaminants rather than to single compounds. It is therefore important to understand the toxic interactions of co-occurring substances in the environment. The aim of the study was to assess the effects of individual herbicides (atrazine, 2,4-D, alachlor and paraquat) that are commonly used in Thailand and their mixtures on Lemna minor. Plants were exposed to individual and binary mixtures for 7 days and the effects on plant growth rate were assesed based on frond area measurements. Experimental observations of mixture toxicity were compared with predictions based on single herbicide exposure data using concentration addition and independent action models. The single compound studies showed that paraquat and alachlor were most toxic to L. minor, followed by atrazine and then 2,4-D. For the mixtures, atrazine with 2,4-D appeared to act antagonistically, whereas alachlor and paraquat showed synergism

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Overexpression of a serine alkaline protease gene in Bacillus licheniformis and its impact on the metabolic reaction network

This work reports on cloning of serine alkaline protease (SAP) encoding gene subC to a multi-copy plasmid and its expression in Bacillus licheniformis with the quantitative impact of overexpression of the subC gene on metabolic flux distributions. Bioprocess characteristics of the wild-type and the recombinant B. licheniformis were investigated in a defined simple synthetic medium with glucose as the sole carbon source under well-defined bioreactor-operation conditions. Significant physiological changes were observed in the recombinant B. licheniformis in response to altered bioreactor-operation conditions, i.e. initial glucose concentration, The growth kinetics of microbial cells were investigated prior to the investigation of intracellular reactions and rates within the cell; the unstructured substrate inhibition and Monod models were found valid for the wild-type and recombinant B. licheniformis, respectively. Optimum initial glucose concentration for maximum SAP production and the corresponding cultivation time of the recombinant B. licheniformis shifted respectively from C-G0 = 6 to 8 kg m(-3) and from t = 43 to 67 h. The maximum SAP activity was obtained as 950 U cm(-3) with the recombinant B. licheniformis, which was ca. 2.5-fold higher than that of the wild-type. Carbon fluxes through the central metabolic pathways in the wild-type and recombinant B. licheniformis were calculated, using a mass balance-based mathematical model that contains 105 metabolites and 148 reaction fluxes and the time profiles of glucose. dry cell weight, organic acids, amino acids and SAP obtained in 3.5 dm(3) bioreactor systems at C-G0 = 6 kg m(-3) for the exponential growth phase and the SAP production phase. The bioreaction network flux analyses were first accomplished by using the theoretical data-based approach, and then by using the theoretical data-based capacity analysis approach. During the SAP synthesis period, the actual fluxes of the glycolysis pathway. the pentose phosphate pathway, the tricarboxylic acid cycle, the amino acids biosynthetic pathways (and, consequently, SAP synthesis) are higher in the recombinant B. licheniformis strain than in the wild-type. Further, the normalised relative flux values of all the pathways, except the glycolysis pathway, change considerably in the recombinant bacteria. The effectiveness factor, defined as the SAP synthesis rate per maximum possible SAP synthesis rate was eta = 0.20 for the recombinant B. licheniformis. This indicates the possibility of a further increase in SAP production through metabolic engineering, and potential strategies to achieve this are. also discussed. (C) 2003 Elsevier Science Inc. All rights reserved