Kyungpook National University

About: Kyungpook National University is a education organization based out in Daegu, South Korea. It is known for research contribution in the topics: Population & Catalysis. The organization has 20497 authors who have published 42107 publications receiving 834608 citations.

Fluorescent Actuator Based on Microporous Conjugated Polymer with Intramolecular Stack Structure

Abstract: IO N Artifi cial smart materials that respond to external stimuli, such as heat, light, chemicals, and electric fi elds, have recently attracted considerable attention for applications to actuators and sensors. [ 1 ] An wide range of conjugated polymers have been developed as functional active materials not only for soft actuation but also for optical sensing. [ 1h , 2 ] To our best knowledge, however, there are no reports on conjugated polymers showing a simultaneous optical output signal and actuation behavior. The actuation of soft materials in response to chemical stimuli is based on a reversible expansion/contraction in volume. [ 3 ]

Whitefly infestation of pepper plants elicits defence responses against bacterial pathogens in leaves and roots and changes the below‐ground microflora

Abstract: Summary 1. Upon facing biotic stresses, plants orchestrate defence mechanisms via internal and external mechanisms that are mediated by signalling molecules such as salicylic acid, jasmonic acid, ethylene and various other volatile compounds. Although pathogen- and chemical-induced plant resistance has been studied extensively within the same plant compartment, the effects of above-ground (AG) insect-elicited plant defence on the resistance expression in roots and the below-ground (BG) microbial community are not well understood. 2. We assessed the effect of AG whitefly (Bemisia tabaci) attack on the elicitation of induced resistance against a leaf pathogen, Xanthomonas axonopodis pv. vesicatoria, a soil-borne pathogen, Ralstonia solanacearum, and on BG modifications of the rhizosphere microflora in peppers (Capsicum annuum). 3. Symptom development caused by the two bacterial pathogens on leaves and roots was significantly reduced in whitefly-exposed plants as compared to controls. A combined treatment with benzothiadiazole (BTH) and whitefly caused an additive effect on induced resistance, indicating that whitefly-induced plant defence can utilize salicylic acid (SA)-dependent signalling. To obtain further genetic evidence of this phenomenon, we evaluated the gene expression of Capsicum annuum pathogenesis-related protein (CaPR) 1, CaPR4, CaPR10 and Ca protease inhibitor II, and observed increased expression after BTH and/or whitefly treatment indicating that AG whitefly infestation elicited SA and jasmonic acid signalling in AG and BG. Since the expression pattern of PR genes in the roots differed, we assessed microbial diversity in plants treated with BTH and/or whitefly. 4. In addition to eliciting BG defence responses, a whitefly infestation of the leaves augmented the population of root-associated Gram-positive bacteria and fungi, which may have positively affected plant growth and induced systemic resistance. Whitefly feeding reduced plant size, which usually occurs as a consequence of the high costs of direct resistance induction. 5. Synthesis. Our results demonstrate that whitefly-induced resistance against bacterial pathogens can cross the AG–BG border and may cause further indirect benefits on future plant development, because it can positively affect the association or plant roots with putatively beneficial microorganisms.

Regulation of the chondrocyte phenotype by β-catenin

Abstract: beta-Catenin regulates important biological processes, including embryonic development and tumorigenesis. We have investigated the role of beta-catenin in the regulation of the chondrocyte phenotype. Expression of beta-catenin was high in prechondrogenic mesenchymal cells, but significantly decreased in differentiated chondrocytes both in vivo and in vitro. Accumulation of beta-catenin by the inhibition of glycogen synthase kinase-3beta with LiCl inhibited chondrogenesis by stabilizing cell-cell adhesion. Conversely, the low level of beta-catenin in differentiated articular chondrocytes was increased by post-translational stabilization during phenotypic loss caused by a serial monolayer culture or exposure to retinoic acid or interleukin-1beta. Ectopic expression of beta-catenin or inhibition of beta-catenin degradation with LiCl or proteasome inhibitor caused de-differentiation of chondrocytes. Transcriptional activation of beta-catenin by its nuclear translocation was sufficient to cause phenotypic loss of differentiated chondrocytes. Expression pattern of Jun, a known target gene of beta-catenin, is essentially the same as that of beta-catenin both in vivo and in vitro suggesting that Jun and possibly activator protein 1 is involved in the beta-catenin regulation of the chondrocyte phenotype.