Ca2+-Dependent Protein Kinase11 and 24 Modulate the Activity of the Inward Rectifying K+ Channels in Arabidopsis Pollen Tubes

Potassium (K⁺) influx into pollen tubes via K⁺ transporters is essential for pollen tube growth; however, the mechanism by which K⁺ transporters are regulated in pollen tubes remains unknown. Here, we report that Arabidopsis thaliana Ca²⁺-dependent protein kinase11 (CPK11) and CPK24 are involved in Ca²⁺-dependent regulation of the inward K⁺ (K+_in) channels in pollen tubes. Using patch-clamp analysis, we demonstrated that K+_in currents of pollen tube protoplasts were inhibited by elevated [Ca²⁺]_cyt. However, disruption of CPK11 or CPK24 completely impaired the Ca²⁺-dependent inhibition of K+_in currents and enhanced pollen tube growth. Moreover, the cpk11 cpk24 double mutant exhibited similar phenotypes as the corresponding single mutants, suggesting that these two CDPKs function in the same signaling pathway. Bimolecular fluorescence complementation and coimmunoprecipitation experiments showed that CPK11 could interact with CPK24 in vivo. Furthermore, CPK11 phosphorylated the N terminus of CPK24 in vitro, suggesting that these two CDPKs work together as part of a kinase cascade. Electrophysiological assays demonstrated that the Shaker pollen K+_in channel is the main contributor to pollen tube K+_in currents and acts as the downstream target of the CPK11-CPK24 pathway. We conclude that CPK11 and CPK24 together mediate the Ca²⁺-dependent inhibition of K+_in channels and participate in the regulation of pollen tube growth in Arabidopsis.     

An-1 Encodes a Basic Helix-Loop-Helix Protein That Regulates Awn Development,Grain Size,and Grain Number in Rice

Long awns are important for seed dispersal in wild rice (Oryza rufipogon), but are absent in cultivated rice (Oryza sativa). The genetic mechanism involved in loss-of-awn in cultivated rice remains unknown. We report here the molecular cloning of a major quantitative trait locus, An-1, which regulates long awn formation in O. rufipogon. An-1 encodes a basic helix-loop-helix protein, which regulates cell division. The nearly-isogenic line (NIL-An-1) carrying a wild allele An-1 in the genetic background of the awnless indica Guangluai4 produces long awns and longer grains, but significantly fewer grains per panicle compared with Guangluai4. Transgenic studies confirmed that An-1 positively regulates awn elongation, but negatively regulates grain number per panicle. Genetic variations in the An-1 locus were found to be associated with awn loss in cultivated rice. Population genetic analysis of wild and cultivated rice showed a significant reduction in nucleotide diversity of the An-1 locus in rice cultivars, suggesting that the An-1 locus was a major target for artificial selection. Thus, we propose that awn loss was favored and strongly selected by humans, as genetic variations at the An-1 locus that cause awn loss would increase grain numbers and subsequently improve grain yield in cultivated rice.     

An ATP Binding Cassette Transporter Is Required for Cuticular Wax Deposition and Desiccation Tolerance in the Moss Physcomitrella patens

The plant cuticle is thought to be a critical evolutionary adaptation that allowed the first plants to colonize land, because of its key roles in regulating plant water status and providing protection from biotic and abiotic stresses. Much has been learned about cuticle composition and structure through genetic and biochemical studies of angiosperms, as well as underlying genetic pathways, but little is known about the cuticles of early diverging plant lineages. Here, we demonstrate that the moss Physcomitrella patens, an extant relative of the earliest terrestrial plants, has a cuticle that is analogous in both structure and chemical composition to those of angiosperms. To test whether the underlying cuticle biosynthetic pathways were also shared among distant plant lineages, we generated a genetic knockout of the moss ATP binding cassette subfamily G (ABCG) transporter Pp-ABCG7, a putative ortholog of Arabidopsis thaliana ABCG transporters involved in cuticle precursor trafficking. We show that this mutant is severely deficient in cuticular wax accumulation and has a reduced tolerance of desiccation stress compared with the wild type. This work provides evidence that the cuticle was an adaptive feature present in the first terrestrial plants and that the genes involved in their formation have been functionally conserved for over 450 million years.     

TMaCS: A hybrid template matching and classification system for partially-automated particle selection

Selection of particle images from electron micrographs presents a bottleneck in determining the structures of macromolecular assemblies by single particle electron cryomicroscopy (cryo-EM). The problem is particularly important when an experimentalist wants to improve the resolution of a 3D map by increasing by tens or hundreds of thousands of images the size of the dataset used for calculating the map. Although several existing methods for automatic particle image selection work well for large protein complexes that produce high-contrast images, it is well known in the cryo-EM community that small complexes that give low-contrast images are often refractory to existing automated particle image selection schemes. Here we develop a method for partially-automated particle image selection when an initial 3D map of the protein under investigation is already available. Candidate particle images are selected from micrographs by template matching with template images derived from projections of the existing 3D map. The candidate particle images are then used to train a support vector machine, which classifies the candidates as particle images or non-particle images. In a final step in the analysis, the selected particle images are subjected to projection matching against the initial 3D map, with the correlation coefficient between the particle image and the best matching map projection used to assess the reliability of the particle image. We show that this approach is able to rapidly select particle images from micrographs of a rotary ATPase, a type of membrane protein complex involved in many aspects of biology.     

Chinese plasma-derived products supply under the lot release management system in 2007–2011

In 2007, the Chinese State Food and Drug Administration (SFDA) implemented a management system for lot release of all plasma-derived products. Since then, there have been only a few systematic studies of the blood supply, which is a concern when considering the small amount of plasma collected per capita (approximately 3 L/1000 people). As a result, there may be a threat to the safety of the available blood supply. In this study, we examined the characteristics of the supply of Chinese plasma-derived products. We investigated the reports of lot-released biological products derived from all 8 national or regional regulatory authorities in China from 2007 to 2011. The market supply characteristics of Chinese plasma-derived products were analyzed by reviewing the changes in supply varieties, the batches of lot-released plasma-derived products and the actual supply. As a result, the national regulatory authorities can more accurately develop a specific understanding of the production and quality management information provided by Chinese plasma product manufacturers. The implementation of the lot release system further ensures the clinical validity of the plasma-derived products in China and improves the safety of using plasma-derived products. This work provides an assessment of the future Chinese market supply of plasma-derived products and can function as a theoretical basis for the establishment of hemovigilance.     

Morphogenesis and Molecular Phylogeny of a New Freshwater Ciliate,Notohymena apoaustralis n. sp. (Ciliophora,Oxytrichidae)

The live morphology, infraciliature, and morphogenesis of a new oxytrichid ciliate, Notohymena apoaustralis n. sp. collected from a freshwater pond in Qingdao (Tsingtao), China, were studied in vivo and after protargol impregnation. Notohymena apoaustralis n. sp. is characterized as follows: undulating membranes in Notohymena‐pattern; cortical granules yellow‐green, grouped around the marginal cirri and dorsal bristles, and in short irregular rows elsewhere in the cell; single contractile vacuole positioned at anterior 1/3 of the body length; two macronuclear nodules and one micronucleus; about 39 adoral membranelles; 18 frontoventral transverse cirri in typical Oxytricha‐pattern; one right and one left marginal row, almost confluent posteriorly; dorsal ciliature in typical Oxytricha‐pattern; 8–10 caudal cirri arranged in three rows, one each at the posterior end of dorsal kineties 1, 2, and 4, indistinguishable from marginal cirri in life. The morphogenetic process in N. apoaustralis n. sp. is consistent with that of the type species, Notohymena rubescens Blatterer and Foissner, 1988. Phylogenetic analyses based on small subunit rDNA sequence data suggest a sister relationship between N. apoaustralis n. sp. and Paraurostyla weissei, which cluster in a clade with Rubrioxytricha ferruginea.     

A Relationship Between Replication Protein A and Occurrence and Prognosis of Esophageal Carcinoma

Esophageal carcinoma (EC) is an aggressive and the third most common cancer of the digestive tract with poor prognosis. Replication protein A (RPA) is critically required for DNA replication and its elevated expression has been observed in many malignant tumors. In this study, we investigated the expression of RPA1 and RPA2, subunits of RPA, and assessed their prognostic value in EC patients. We analyzed immunohistochemically the expression of RPA1 and RPA2 proteins in 48 EC resection specimens in relation with clinicopathological parameters and survival. We observed a significant elevated (P < 0.001) RPA1 and RPA2 expressions (labeling index) in the tumor than adjacent non-tumor tissues. In addition, both RPA1 and RPA2 labeling index in lymph node metastasis patients was significantly higher (both P = 0.000) than patients without lymph node metastasis. However, RPA1 and RPA2 labeling index in early stage was significantly lower (P = 0.000 and P = 0.002, respectively) than that of late stage EC patients. Importantly, patient’s survival at early stage was significantly higher (P = 0.016) than late stage EC and lymph node metastasis and RPA1 expression was associated with adverse patient’s outcome in multivariate analysis (P < 0.05 and P < 0.00, respectively). In conclusion, RPA1 could be a useful prognostic indicator in patients with esophageal carcinoma and might be a future attractive therapeutic target for regulation by tumor suppressors.     

How to Deal with Resource Productivity

Resource productivity enhancement stands at the center of tackling issues on environmental pollution and resource scarcity. Identifying influential socioeconomic factors should be the first step in establishing and improving resource management policy. This study compares and analyzes data from multiple countries to construct a resource productivity simulation model. The socioeconomic factors and their characteristic patterns are discussed in detail. The results demonstrate that the major factors influencing resource productivity include income level, population density, economic structure, energy structure, and raw material trade. Among these factors, the three most important are income level, population density, and economic structure. The influencing patterns can be summarized as follows: (1) Resource productivity increases with increasing income levels. (2) Countries with high population density are inclined to demonstrate high resource productivity. (3) The economic structure shows a biphase influence on resource productivity, that is, during industrialization, decreased agricultural activity and increased industrial activity lead to higher resource productivity. On the other hand, after industrialization, decreasing industrial activity and an expanding service sector become the major impetus of resource productivity enhancement. (4) Raw material export demonstrates a negative effect on resource productivity. Countries that depend heavily on raw material export show a unique resource productivity evolution pattern. For these countries, relatively high resource productivity in low income phases and relatively low resource productivity in high income phases show only small increases in resource efficiency and economic growth. Finally, insights from the study are transformed into suggestions for sustainable resource management and resource productivity enhancement.     

The gastrointestinal tract: A major site of antioxidant action?

Diets rich in fruits and vegetables delay the onset of many age-related diseases, and contain a complex mixture of antioxidants (including ascorbate, carotenoids, vitamin E and other phenolics such as the flavonoids). However, diet also contains pro-oxidants, including iron, copper, H₂O₂, haem, lipid peroxides and aldehydes. Nitrite is frequently present in diet, leading to generation of reactive nitrogen species in the stomach. In considering the biological importance of dietary antioxidants, attention has usually focussed on those that are absorbed through the gastrointestinal tract into the rest of the body. In the present paper we develop the argument that the high levels of antioxidants present in certain foods (fruits, vegetables, grains) and beverages (e.g. green tea) play an important role in protecting the gastrointestinal tract itself from oxidative damage, and in delaying the development of stomach, colon and rectal cancer. Indeed, carotenoids and flavonoids do not seem to be as well absorbed as vitamins C and E. Hence their concentrations can be much higher in the lumen of the GI tract than are ever achieved in plasma or other body tissues, making an antioxidant action in the GI tract more likely. Additional protective mechanisms of these dietary constituents (e.g. effects on intercellular communication, apoptosis, cyclooxygenases and telomerase) may also be important.