Potassium and phosphorus transport and signaling in plants

Nitrogen(N), potassium(K), and phosphorus(P) are essential macronutrients for plant growth and development, and their availability affects crop yield. Compared with N, the relatively low availability of K and P in soils limits crop production and thus threatens food security and agricultural sustainability. Improvement of plant nutrient utilization efficiency provides a potential route to overcome the effects of K and P deficiencies. Investigation of the molecular mechanisms underlying how plants sense, absorb, transport, and use K and P is an important prerequisite to improve crop nutrient utilization efficiency. In this review, we summarize current understanding of K and P transport and signaling in plants, mainly taking Arabidopsis thaliana and rice(Oryza sativa) as examples. We also discuss the mechanisms coordinating transport of N and K, as well as P and N.     

Middle Jurassic radiolarians from Jinlang,Zedong, southern Xizang (Tibet), China

Moderately to well-preserved radiolarians have been extracted from nine greyish green and purplish-red bedded cherts in the mud-matrix mélange of the eastern Yarlung-Zangbo Suture Zone (YZSZ) at Jinlang Section, Zedong, southern Xizang (Tibet). Forty-two species belonging to 27 genera, including Middle Jurassic characteristic species such as Laxtorum (?) jurassicum Isozaki and Matsuda, Laxtorum (?) hichisoense Isozaki and Matsuda, Stichocapsa japonica Yao, Stichocapsa robusta Matsuoka, Parahsuum (?) magnum Takemura, Sella chrafatensis (El Kadiri), and Unuma typicus Ichikawa and Yao are recognized and three assemblages, Laxtorum (?) jurassicum Assemblage (Aalenian), Quarticella ovalis Assemblage (late Bajocian), and Stichocapsa robusta Assemblage (middle Bathonian) are established in ascending order. These assemblages can be well correlated to the Middle Jurassic Unitary Association (UA) Zones (Baumgartner et al., 1995) in west Tethys and coeval biozones in Japan and provide reliable age information for the Middle Jurassic stratigraphic correlation of the pelagic sediments along the YZSZ.     

Impact of left atrial appendage location on risk of thrombus formation in patients with atrial fibrillation

Biomechanics and Modeling in Mechanobiology - Most strokes in patients with atrial fibrillation (AF) are thought to arise from thrombus formation in the left atrial appendage (LAA). Assessing the...     

Differential Sensitivities of Normal and Malignant Murine Lymphocytes to Purine Nucleosides

Abstract

Inherited human immunodeficiences associated with loss of adenosine deaminase or purine nucleoside phosphorylase are thought to result from accumulation of the nucleoside substrates. This work attempts to identify lymphocyte subpopulations that are uniquely-sensitive to the endogenous substrates or their analogs.     

Identification of factors that function in Drosophila salivary gland cell death during development using proteomics

Proteasome inhibitors induce cell death and are used in cancer therapy, but little is known about the relationship between proteasome impairment and cell death under normal physiological conditions. Here, we investigate the relationship between proteasome function and larval salivary gland cell death during development in Drosophila. Drosophila larval salivary gland cells undergo synchronized programmed cell death requiring both caspases and autophagy (Atg) genes during development. Here, we show that ubiquitin proteasome system (UPS) function is reduced during normal salivary gland cell death, and that ectopic proteasome impairment in salivary gland cells leads to early DNA fragmentation and salivary gland condensation in vivo. Shotgun proteomic analyses of purified dying salivary glands identified the UPS as the top category of proteins enriched, suggesting a possible compensatory induction of these factors to maintain proteolysis during cell death. We compared the proteome following ectopic proteasome impairment to the proteome during developmental cell death in salivary gland cells. Proteins that were enriched in both populations of cells were screened for their function in salivary gland degradation using RNAi knockdown. We identified several factors, including trol, a novel gene CG11880, and the cop9 signalsome component cop9 signalsome 6, as required for Drosophila larval salivary gland degradation.