Elevated temperature as a result of global climate warming, either in form of sudden heatwave (heat shock) or prolonged warming, has profound effects on the growth and development of plants. However, ...how plants differentially respond to these two forms of elevated temperatures is largely unknown. Here we have therefore performed a comprehensive comparison of multi-level responses of Arabidopsis leaves to heat shock and prolonged warming.
The plant responded to prolonged warming through decreased stomatal conductance, and to heat shock by increased transpiration. In carbon metabolism, the glycolysis pathway was enhanced while the tricarboxylic acid (TCA) cycle was inhibited under prolonged warming, and heat shock significantly limited the conversion of pyruvate into acetyl coenzyme A. The cellular concentration of hydrogen peroxide (H
O
) and the activities of antioxidant enzymes were increased under both conditions but exhibited a higher induction under heat shock. Interestingly, the transcription factors, class A1 heat shock factors (HSFA1s) and dehydration responsive element-binding proteins (DREBs), were up-regulated under heat shock, whereas with prolonged warming, other abiotic stress response pathways, especially basic leucine zipper factors (bZIPs) were up-regulated instead.
Our findings reveal that Arabidopsis exhibits different response patterns under heat shock versus prolonged warming, and plants employ distinctly different response strategies to combat these two types of thermal stress.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Preparation of anatase TiO2 nanorods from solutions in the absence of surfactants or templates has rarely been reported. The present work has found that hydrothermal treatment of titanate nanotube ...suspensions under an acidic environment resulted in the formation of single-crystalline anatase nanorods with a specific crystal-elongation direction. The nanotube suspensions were prepared by treatment of TiO2 in NaOH, followed by mixing with HNO3 to different pH values. The crystal size of the anatase nanoparticles obtained from the hydrothermal treatment increased with the pH of the suspensions, and nanorods with an aspect ratio up to 6 and a long axis along the anatase 001 were obtained at a pH slightly less than 7. A mechanism for the tube-to-rod transformation has been proposed on the basis of the crystalline structures of the tubes and rods. The local shrinkage of the tube walls to form anatase crystallites and the subsequent oriented attachment of the crystallites have been suggested to be the key steps involved in the nanorod formation.
Electrochemical deposition of p-type Cu2O films on transparent conducting glass from a Cu2SO4 solution was conducted at different temperatures. The films were examined for H2 evolution from ...photoelectrolysis of water under visible light illumination. Using Pt as the counter electrode, photocurrents with corresponding H2 evolution could be observed for the deposited Cu2O films in a Na2SO4 solution under a cathodic bias. The Cu2O films obtained at different deposition temperatures were in the cubic phase, but showed different out-of-plane crystalline orientations. An incident monochromatic photon-to-current conversion efficiency of 26% at 400nm was achieved for a Cu2O film with a 111 out-of-plane orientation, while an efficiency of only 17% was obtained for a film with a 110 orientation. The 111-oriented film exhibited a higher electronic conductivity, which might have led to a higher charge delocalization rate. By coupling with an n-type WO3 film to promote charge transport, the photocurrent for the Cu2O films was significantly improved.
Different p-type Cu2O powders were prepared from electrodeposition and subjected to analysis of their photocatalytic activity in water reduction. The electrodeposited Cu2O powders were obtained by ...scraping the deposited films off the substrate. Under illumination the Cu2O powders alone were not able to catalyze H2 generation from water reduction. However, these Cu2O powders exhibited photocatalytic activity in H2 generation when they were coupled with n-type WO3 in suspensions. The coupling was made to avoid back reactions of the photo-induced charges. The electrodeposited Cu2O powders showed higher photocatalytic activity than a commercially available Cu2O powder. The suspension containing electrodeposited Cu2O with a strong 1 1 1 orientation gave a larger amount of H2 evolution than that containing Cu2O with a 1 1 0 orientation. Appropriate crystalline-texture tuning, as well as charge delocalization promotion, is looked to as the key issue for efficient H2 generation from water reduction over p-type Cu2O photocatalysts.
Background The leaf is an important plant organ, and how it will respond to future global warming is a question that remains unanswered. The effects of experimental warming on leaf photosynthesis and ...respiration acclimation has been well studied so far, but relatively little information exists on the structural and biochemical responses to warming. However, such information is very important to better understand the plant responses to global warming. Therefore, we grew Arabidopsis thaliana at the three day/night temperatures of 23/18°C (ambient temperature), 25.5/20.5°C (elevated by 2.5°C) and 28/23°C (elevated by 5°C) to simulate the middle and the upper projected warming expected within the 21st century for this purpose. Results The 28/23°C treatment significantly reduced the life span, total biomass and total weight of seeds compared with the other two temperatures. Among the three temperature regimes, the concentrations of starch, chlorophyll, and proline were the lowest at 28/23°C, whereas the total weight of seeds, concentrations of chlorophyll and proline, stomatal density (SD), stomatal conductance (gs), net CO2 assimilation rate (A) and transpiration rate (E) were the highest at 25.5/20.5°C. Furthermore, the number of chloroplasts per cell and mitochondrial size were highest at 25.5/20.5°C and lowest at 28/23°C. Conclusions The conditions whereby the temperature was increased by 2.5°C were advantageous for Arabidopsis. However, a rise of 5°C produced negative effects, suggesting that lower levels of warming may benefit plants, especially those which belong to the same functional group as Arabidopsis, whereas higher levels of warming may produce negative affects. In addition, the increase in A under moderately warm conditions may be attributed to the increase in SD, chlorophyll content, and number of chloroplasts. Furthermore, starch accumulation in chloroplasts may be the main factor influencing chloroplast ultrastructure, and elevated temperature regulates plant respiration by probably affecting mitochondrial size. Finally, high SOD and CAT activities may enable plants grown at elevated temperatures to exhibit relatively high tolerance to temperature stress, thus alleviating the harmful effects of superoxide anion radicals and hydrogen peroxide.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In water lily (Nymphaea) hybrid breeding, breeders often encounter non-viable seeds, which make it difficult to transfer desired or targeted genes of different Nymphaea germplasm. We found that ...pre-fertilization barriers were the main factor in the failure of the hybridization of Nymphaea. The mechanism of low compatibility between the pollen and stigma remains unclear; therefore, we studied the differences of stigma transcripts and proteomes at 0, 2, and 6 h after pollination (HAP). Moreover, some regulatory genes and functional proteins that may cause low pollen-pistil compatibility in Nymphaea were identified.
RNA-seq was performed for three comparisons (2 vs 0 HAP, 6 vs 2 HAP, 6 vs 0 HAP), and the number of differentially expressed genes (DEGs) was 8789 (4680 were up-regulated), 6401 (3020 were up-regulated), and 11,284 (6148 were up-regulated), respectively. Using label-free analysis, 75 (2 vs 0 HAP) proteins (43 increased and 32 decreased), nine (6 vs 2 HAP) proteins (three increased and six decreased), and 90 (6 vs 0 HAP) proteins (52 increased and 38 decreased) were defined as differentially expressed proteins (DEPs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that the DEGs and DEPs were mainly involved in cell wall organization or biogenesis, S-adenosylmethionine (SAM) metabolism, hydrogen peroxide decomposition and metabolism, reactive oxygen species (ROS) metabolism, secondary metabolism, secondary metabolite biosynthesis, and phenylpropanoid biosynthesis.
Our transcriptomic and proteomic analysis highlighted specific genes, incuding those in ROS metabolism, biosynthesis of flavonoids, SAM metabolism, cell wall organization or biogenesis and phenylpropanoid biosynthesis that warrant further study in investigations of the pollen-stigma interaction of water lily. This study strengthens our understanding of the mechanism of low pollen-pistil compatibility in Nymphaea at the molecular level, and provides a theoretical basis for overcoming the pre-fertilization barriers in Nymphaea in the future.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Long noncoding RNAs (lncRNAs), with length of more than 200 nucleotides, are not translated into proteins but involved in multiple diverse diseases, especially tumorigenesis. The dysregulation of ...lncRNAs greatly contributes to the progression of various tumors through specific signaling pathways, including Wnt/β-catenin signaling pathway, which is associated with malignant features of tumors. The interactions between lncRNAs, which have specific expression characteristics in diverse cancer tissues, and Wnt/β-catenin signaling pathway, exhibit potential as novel biomarkers and therapeutic targets. In this review, we aim to present research findings on the roles of Wnt pathway-related lncRNAs and their effects on Wnt/β-catenin signaling to regulate tumorigenesis in different cancer types. Results may be used as basis to develop or improve strategies for treatment of different carcinomas.
Hemolymphangiomas are rare malformations composed of both lymphatic and vascular vessels and are located in the pancreas, spleen, mediastinum,
. Small intestinal hemolymphangioma is extremely rare ...and often presents as obscure gastrointestinal bleeding. It is rarely diagnosed correctly before the operation. Endoscopic injection sclerotherapy is usually used as a management of bleeding in esophageal varices and was occasionally reported as a treatment of vascular malformation. The treatment of small intestinal hemolymphangioma with enteroscopic injection sclerotherapy has not been reported.
A 42-year-old male complained of recurrent episodes of melena and dizziness, fatigue and reduced exercise capacity for more than 2 mo. Gastroduodenoscopy and blood test revealed a gastric ulcer and anemia. Treatment with oral proton-pump inhibitors and iron did not improve symptoms. We then performed a capsule endoscopy and anterograde balloon-assisted enteroscopy and revealed a hemolymphangioma. Considering it is a benign tumor without malignant potential, we performed enteroscopic injection sclerotherapy. He was discharged 4 days later. At follow-up 3 mo later, the melena disappeared. Balloon-assisted enteroscopy revealed an atrophied tumor atrophied and no bleeding. Argon plasma coagulation was applied to the surface of the hemolymphangioma to accelerated healing. When he returned for follow-up 1 year later, anemia was resolved and the tumor had been cured.
Balloon-assisted enteroscopy and capsule endoscopy are effective methods for diagnosis of hemolymphangioma. Enteroscopic injection sclerotherapy is an effective treatment.
Copper oxide was deposited on tubular TiO2 via Cu2+ introduction into a titanate nanotube aggregate followed by calcination. The titanate has a layered structure allowing Cu intercalation and can ...readily transform into anatase TiO2 via calcination for condensation of the constituting layers. The activity of the tubular catalysts, with a Cu content of 2 wt %, in selective NO reduction with NH3 was compared with those of other 2 wt % Cu/TiO2 catalysts using TiO2 nanoparticles as the support. The Cu species supported on the nanotubes showed a higher activity than those supported on the nanoparticles. X-ray absorption near-edge structure (XANES) analysis showed that the Cu species on all the TiO2 supports are in the +2 state. Extended X-ray absorption fine structure (EXAFS) investigations of these catalysts reflected higher degrees of CuO dispersion and Cu2+ dissolution into the TiO2 lattice for the tubular Cu/TiO2 catalysts. Absence of CuO bulk detection by a temperature-programmed reduction analysis for the tubular catalysts confirmed the high CuO-dispersion feature of the tubular catalysts. The dissolution of Cu2+ to form a Cu x Ti1- x O2 type of solid solution was improved by using an in-situ ion-intercalation method for Cu deposition on the nanotubes. A fraction as high as 40% for Cu2+ dissolution was obtained for the tubular catalysts while only 20% was obtained for the particulate catalysts. The Cu x Ti1- x O2 species were considered one form of the active sites on the Cu/TiO2 catalysts.
There has been a heated argument over self-incompatibilityof chrysanthemum (Chrysanthemum morifolium) among chrysanthemum breeders. In order to solve the argument, we investigated pistil receptivity, ...seed set, and compatible index of 24 chrysanthemum cultivars. It was found that the 24 cultivars averagely had 3.7–36.3 pollen grains germinating on stigmas at 24 hours after self-pollination through the fluorescence microscope using aniline blue staining method. However, only 10 of them produced self-pollinated seeds, and their seed sets and compatible indexes were 0.03–56.50% and 0.04–87.50, respectively. The cultivar “Q10-33-1” had the highest seed set (56.50%) and compatible index (87.50), but ten of its progeny had a wide range of separation in seed set (0–37.23%) and compatible index (0–68.65). The results indicated that most of chrysanthemum cultivars were self-incompatible, while a small proportion of cultivars were self-compatible. In addition, there is a comprehensive separation of self-incompatibility among progeny from the same self-pollinated self-compatible chrysanthemum cultivar. Therefore, it is better to emasculate inflorescences during chrysanthemum hybridization breeding when no information concerning its self-incompatibility characteristics is available. However, if it is self-incompatible and propagated by vegetative methods, it is unnecessary to carry out emasculation when it is used as a female plant during hybridization breeding.
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