Regulation of High-Temperature Stress Response by Small RNAs

Temperature extremes constitute one of the most common environmental stresses that adversely affect the growth and development of plants. Transcriptional regulation of temperature stress responses, particularly involving protein-coding gene networks, has been intensively studied in recent years. High-throughput sequencing technologies enabled the detection of a great number of small RNAs that have been found to change during and following temperature stress. The precise molecular action of some of these has been elucidated in detail. In the present chapter, we summarize the current understanding of small RNA-mediated modulation of high- temperature stress-regulatory pathways including basal stress responses, acclimation, and thermo-memory. We gather evidence that suggests that small RNA network changes, involving multiple upregulated and downregulated small RNAs, balance the trade-off between growth/development and stress responses, in order to ensure successful adaptation. We highlight specific characteristics of small RNA-based tem- perature stress regulation in crop plants. Finally, we explore the perspectives of the use of small RNAs in breeding to improve stress tolerance, which may be relevant for agriculture in the near future

Electrochemical synthesis of nanostructured palladium of different morphology directly on gold substrate through a cyclic deposition/dissolution route

Uniform nanostructured palladium (Pd) has been successfully electrodeposited directly on gold substrate through a facile template-free approach, which involved a cyclic electrochemical deposition/dissolution of Pd. Under the regulation of potential scan and surfactant, standing Pd nanoplates and nanotrees were prepared. Improved and superior electrocatalytic activities toward the oxidation of ethanol were observed from these electrodes coated with nanostructured Pd. Furthermore, the uniform Pd nanostructures can be conveniently deposited onto a flexible substrate with a gold precoating, thus allowing fabrication of miniaturized flexible devices. This approach provides a simple route for the synthesis of highly catalytic Pd nanostructures with an excellent electrical contact to a substrate, which is important for the overall device performance. The critical effects exerted by the electrochemical conditions and surfactant will also be discussed

Assembly of carbon nanotubes on a nanoporous gold electrode for acetylcholinesterase biosensor design

An electrochemical sensing platform based on assembly of carbon nanotubes on a nanoporous gold electrode is described for highly sensitive detection of organophosphate pesticides. The nanoporous gold film (NPG) electrode is fabricated by an alloying/dealloying process, which possess high electroactive surface area and is an excellent substrate for sensor design. The NPG functionalized with cysteamine allows the immobilization of carbon nanotubes on the electrode with the self-assembly technique. The carboxylated carbon nanotubes are further linkered with acetylcholinesterase (AChE) for amperometric sensing of pesticides. The immobilized AChE, as a model, shows excellent activity to its substrate and allows a quantitative measurement of organophosphate pesticides. Under the optimal experimental conditions, the inhibition of malathion is proportional to its concentration in the range of 0.001-0.5 mu g mL(-1) with a detection limit of 0.5 ng mL(-1). The proposed method shows good reproducibility and high stability, which provides a new avenue for electrochemical biosensor design. (C) 2014 Elsevier B.V. All rights reserved