University of Tsukuba

About: University of Tsukuba is a education organization based out in Tsukuba, Ibaraki, Japan. It is known for research contribution in the topics: Population & Gene. The organization has 36352 authors who have published 79483 publications receiving 1934752 citations. The organization is also known as: Tsukuba daigaku & Tsukuba University.

Regulation of water, salinity, and cold stress responses by salicylic acid

Abstract: Salicylic acid (SA) is a naturally occurring phenolic compound. SA plays an important role in the regulation of plant growth, development, ripening, and defense responses. The role of SA in the plant-pathogen relationship has been extensively investigated. In addition to defense responses, SA plays an important role in the response to abiotic stresses, including drought, low temperature, and salinity stresses. It has been suggested that SA has great agronomic potential to improve the stress tolerance of agriculturally important crops. However, the utility of SA is dependent on the concentration of the applied SA, the mode of application, and the state of the plants (e.g., developmental stage and acclimation). Generally, low concentrations of applied SA alleviate the sensitivity to abiotic stresses, and high concentrations of applied induce high levels of oxidative stress, leading to a decreased tolerance to abiotic stresses. In this chapter, the effects of SA on the water stress responses and regulation of stomatal closure are reviewed.

Phosphoinositide phosphatase activity coupled to an intrinsic voltage sensor

Abstract: Changes in membrane potential affect ion channels and transporters, which then alter intracellular chemical conditions. Other signalling pathways coupled to membrane potential have been suggested1,2,3 but their underlying mechanisms are unknown. Here we describe a novel protein from the ascidian Ciona intestinalis that has a transmembrane voltage-sensing domain homologous to the S1–S4 segments of voltage-gated channels and a cytoplasmic domain similar to phosphatase and tensin homologue. This protein, named C. intestinalis voltage-sensor-containing phosphatase (Ci-VSP), displays channel-like ‘gating’ currents and directly translates changes in membrane potential into the turnover of phosphoinositides. The activity of the phosphoinositide phosphatase in Ci-VSP is tuned within a physiological range of membrane potential. Immunocytochemical studies show that Ci-VSP is expressed in Ciona sperm tail membranes, indicating a possible role in sperm function or morphology. Our data demonstrate that voltage sensing can function beyond channel proteins and thus more ubiquitously than previously realized.

Effect of Cyclic Deformation on the Pseudoelasticity Characteristics of Ti-Ni Alloys

Abstract: Change in the pseudoelasticity characteristics of Ti-Ni alloys during tension cycling was investigated. The critical stress for inducing martensites and the hysteresis of a stress-strain curve decreased with increasing number of cyclic loading, while the permanent elongation increased. The degree of the change in these values showed a strong dependence on the maximum applied stress during stress-induced martensitic transformation. However, no change was induced by cyclic elastic deformation even though high stress was applied. It was also found that the stabilization of the pseudoelasticity characteristics during cyclic loading was established using special thermomechanical treatments which are effective to raise the critical stress for slip. Based on these results it is concluded that the cause for the effect of cyclic deformation is the generation of dislocations in the martensitic phase.

A plant vacuolar protease, VPE, mediates, virus-induced hypersensitive cell death

Abstract: Programmed cell death (PCD) in animals depends on caspase protease activity. Plants also exhibit PCD, for example as a response to pathogens, although a plant caspase remains elusive. Here we show that vacuolar processing enzyme (VPE) is a protease essential for a virus-induced hypersensitive response that involves PCD. VPE deficiency prevented virus-induced hypersensitive cell death in tobacco plants. VPE is structurally unrelated to caspases, although VPE has a caspase-1 activity. Thus, plants have evolved a regulated cellular suicide strategy that, unlike PCD of animals, is mediated by VPE and the cellular vacuole.