Nitrogen Stress Memory in Quinoa: Maternal Effects on Seed Metabolism and Offspring Growth and Physiology.

Plants have developed various strategies to deal with abiotic stresses throughout their lifetimes. However, environmental stresses can have long-lasting effects, positively modifying plant physiological responses to subsequent stress episodes, a phenomenon known as preconditioning or stress memory. Intriguingly, this memory can even be transmitted to offspring, referred to as "inter- or transgenerational memory".

CDK8 of the mediator kinase module connects leaf development to the establishment of correct stomata patterning by regulating the levels of the transcription factor SPEECHLESS (SPCH).

The components of the mediator kinase module are highly conserved across all eukaryotic lineages, and cyclin-dependent kinase 8 (CDK8) is essential for correct cell proliferation and differentiation in diverse eukaryotic systems. We show that CDK8 couples leaf development with the establishment of correct stomata patterning for prevailing CO conditions. In Arabidopsis, the basic helix-loop-helix (bHLH) transcription factor SPEECHLESS (SPCH) controls cellular entry into the stomatal cell lineage, and CDK8 interacts with and phosphorylates SPCH, controlling SPCH protein levels and thereby also expression of the SPCH target genes encoding key regulators of cell fate and asymmetric cell divisions.

Growth-regulated co-occupancy of Mediator and Lsm3 at intronic ribosomal protein genes.

Mediator is a well-known transcriptional co-regulator and serves as an adaptor between gene-specific regulatory proteins and RNA polymerase II. Studies on the chromatin-bound form of Mediator revealed interactions with additional protein complexes involved in various transcription-related processes, such as the Lsm2-8 complex that is part of the spliceosomal U6 small nuclear ribonucleoprotein complex. Here, we employ Chromatin Immunoprecipitation sequencing (ChIP-seq) of chromatin associated with the Lsm3 protein and the Med1 or Med15 Mediator subunits.

Pseudomonas syringae infectivity correlates to altered transcript and metabolite levels of Arabidopsis mediator mutants.

Rapid metabolic responses to pathogens are essential for plant survival and depend on numerous transcription factors. Mediator is the major transcriptional co-regulator for integration and transmission of signals from transcriptional regulators to RNA polymerase II. Using four Arabidopsis Mediator mutants, med16, med18, med25 and cdk8, we studied how differences in regulation of their transcript and metabolite levels correlate to their responses to Pseudomonas syringae infection.

SeedTransNet: a directional translational network revealing regulatory patterns during seed maturation and germination.

Seed maturation is the developmental process that prepares the embryo for the desiccated waiting period before germination. It is associated with a series of physiological changes leading to the establishment of seed dormancy, seed longevity, and desiccation tolerance. We studied translational changes during seed maturation and observed a gradual reduction in global translation during seed maturation.

GENOMES UNCOUPLED1 plays a key role during the de-etiolation process in Arabidopsis.

One of the most dramatic challenges in the life of a plant occurs when the seedling emerges from the soil and exposure to light triggers expression of genes required for establishment of photosynthesis. This process needs to be tightly regulated, as premature accumulation of light-harvesting proteins and photoreactive Chl precursors causes oxidative damage when the seedling is first exposed to light. Photosynthesis genes are encoded by both nuclear and plastid genomes, and to establish the required level of control, plastid-to-nucleus (retrograde) signalling is necessary to ensure correct gene expression.

Norway spruce deploys tissue-specific responses during acclimation to cold.

Climate change in the conifer-dominated boreal forest is expected to lead to warmer but more dynamic winter air temperatures, reducing the depth and duration of snow cover and lowering winter soil temperatures. To gain insight into the mechanisms that have enabled conifers to dominate extreme cold environments, we performed genome-wide RNA-Seq analysis from needles and roots of non-dormant two-year Norway spruce (Picea abies (L.) H.

Candidate regulators and target genes of drought stress in needles and roots of Norway spruce.

Drought stress impacts seedling establishment, survival and whole-plant productivity. Molecular responses to drought stress have been most extensively studied in herbaceous species, mostly considering only aboveground tissues. Coniferous tree species dominate boreal forests, which are predicted to be exposed to more frequent and acute drought as a result of ongoing climate change.

Seed characterization and early nitrogen metabolism performance of seedlings from Altiplano and coastal ecotypes of Quinoa.

Background: Early seed germination and a functional root system development during establishment are crucial attributes contributing to nutrient competence under marginal nutrient soil conditions. Chenopodium quinoa Willd (Chenopodiaceae) is a rustic crop, able to grow in marginal areas. Altiplano and Coastal/Lowlands are two representative zones of quinoa cultivation in South America with contrasting soil fertility and edaphoclimatic conditions.

Stable odor recognition by a neuro-adaptive electronic nose.

Sensitivity, selectivity and stability are decisive properties of sensors. In chemical gas sensors odor recognition can be severely compromised by poor signal stability, particularly in real life applications where the sensors are exposed to unpredictable sequences of odors under changing external conditions. Although olfactory receptor neurons in the nose face similar stimulus sequences under likewise changing conditions, odor recognition is very stable and odorants can be reliably identified independently from past odor perception.

Chemical discrimination in turbulent gas mixtures with MOX sensors validated by gas chromatography-mass spectrometry.

Chemical detection systems based on chemo-resistive sensors usually include a gas chamber to control the sample air flow and to minimize turbulence. However, such a kind of experimental setup does not reproduce the gas concentration fluctuations observed in natural environments and destroys the spatio-temporal information contained in gas plumes. Aiming at reproducing more realistic environments, we utilize a wind tunnel with two independent gas sources that get naturally mixed along a turbulent flow.

Demonstration of fast and accurate discrimination and quantification of chemically similar species utilizing a single cross-selective chemiresistor.

Performance characteristics of gas-phase microsensors will determine the ultimate utility of these devices for a wide range of chemical monitoring applications. Commonly employed chemiresistor elements are quite sensitive to selected analytes, and relatively new methods have increased the selectivity to specific compounds, even in the presence of interfering species. Here, we have focused on determining whether purposefully driven temperature modulation can produce faster sensor-response characteristics, which could enable measurements for a broader range of applications involving dynamic compositional analysis.

Estimation of the limit of detection using information theory measures.

Definitions of the limit of detection (LOD) based on the probability of false positive and/or false negative errors have been proposed over the past years. Although such definitions are straightforward and valid for any kind of analytical system, proposed methodologies to estimate the LOD are usually simplified to signals with Gaussian noise. Additionally, there is a general misconception that two systems with the same LOD provide the same amount of information on the source regardless of the prior probability of presenting a blank/analyte sample.

Two-dimensional wavelet transform feature extraction for porous silicon chemical sensors.

Designing reliable, fast responding, highly sensitive, and low-power consuming chemo-sensory systems has long been a major goal in chemo-sensing. This goal, however, presents a difficult challenge because having a set of chemo-sensory detectors exhibiting all these aforementioned ideal conditions are still largely un-realizable to-date. This paper presents a unique perspective on capturing more in-depth insights into the physicochemical interactions of two distinct, selectively chemically modified porous silicon (pSi) film-based optical gas sensors by implementing an innovative, based on signal processing methodology, namely the two-dimensional discrete wavelet transform.

Multifrequency interrogation of nanostructured gas sensor arrays: a tool for analyzing response kinetics.

This paper presents a unique perspective on enhancing the physicochemical mechanisms of two distinct highly sensitive nanostructured metal oxide micro hot plate gas sensors by utilizing an innovative multifrequency interrogation method. The two types of sensors evaluated here employ an identical silicon transducer geometry but with a different morphological structure of the sensitive film. While the first sensing film consists of self-ordered tungsten oxide nanodots, limiting the response kinetics of the sensor-chemical species pair only to the reaction phenomena occurring at the sensitive film surface, the second modality is a three-dimensional array of tungsten oxide nanotubes, which in turn involves both the diffusion and adsorption of the gas during its reaction kinetics with the sensitive film itself.

Sensor selection and chemo-sensory optimization: toward an adaptable chemo-sensory system.

Over the past two decades, despite the tremendous research on chemical sensors and machine olfaction to develop micro-sensory systems that will accomplish the growing existent needs in personal health (implantable sensors), environment monitoring (widely distributed sensor networks), and security/threat detection (chemo/bio warfare agents), simple, low-cost molecular sensing platforms capable of long-term autonomous operation remain beyond the current state-of-the-art of chemical sensing. A fundamental issue within this context is that most of the chemical sensors depend on interactions between the targeted species and the surfaces functionalized with receptors that bind the target species selectively, and that these binding events are coupled with transduction processes that begin to change when they are exposed to the messy world of real samples. With the advent of fundamental breakthroughs at the intersection of materials science, micro- and nano-technology, and signal processing, hybrid chemo-sensory systems have incorporated tunable, optimizable operating parameters, through which changes in the response characteristics can be modeled and compensated as the environmental conditions or application needs change.

Feature selection versus feature compression in the building of calibration models from FTIR-spectrophotometry datasets.

Undoubtedly, FTIR-spectrophotometry has become a standard in chemical industry for monitoring, on-the-fly, the different concentrations of reagents and by-products. However, representing chemical samples by FTIR spectra, which spectra are characterized by hundreds if not thousands of variables, conveys their own set of particular challenges because they necessitate to be analyzed in a high-dimensional feature space, where many of these features are likely to be highly correlated and many others surely affected by noise. Therefore, identifying a subset of features that preserves the classifier/regressor performance seems imperative prior any attempt to build an appropriate pattern recognition method.

DC information preservation for cardiopulmonary monitor utilizing CW Doppler radar.

Direct conversion RF receivers introduce large DC offsets, reducing the dynamic range of the baseband signal. Coupled with the relatively small time varying signals in human vital sign monitoring using CW Doppler radar, extraction of cardio-pulmonary information becomes difficult. Previous DC offset compensation techniques utilizing AC coupling have proven detrimental to the performance of the system and the integrity of the low-frequency cardiopulmonary signals.

Data acquisition system for Doppler radar vital-sign monitor.

Automatic gain control (AGC) units increase the dynamic range of a system to compensate for the limited dynamic range of analog to digital converters. This problem is compounded in wireless systems in which large changes in signal strength are effects of a changing environment. These issues are evident in the direct-conversion Doppler radar vital-sign monitor.