GmFT2a, a Soybean Homolog of FLOWERING LOCUS T, Is Involved in Flowering Transition and Maintenance

BACKGROUND: Flowering reversion can be induced in soybean (Glycine max L. Merr.), a typical short-day (SD) dicot, by switching from SD to long-day (LD) photoperiods. This process may involve florigen, putatively encoded by FLOWERING LOCUS T (FT) in Arabidopsis thaliana. However, little is known about the potential function of soybean FT homologs in flowering reversion. METHODS: A photoperiod-responsive FT homologue GmFT (renamed as GmFT2a hereafter) was cloned from the photoperiod-sensitive cultivar Zigongdongdou. GmFT2a gene expression under different photoperiods was analyzed by real-time quantitative PCR. In situ hybridization showed direct evidence for its expression during flowering-related processes. GmFT2a was shown to promote flowering using transgenic studies in Arabidopsis and soybean. The effects of photoperiod and temperature on GmFT2a expression were also analyzed in two cultivars with different photoperiod-sensitivities. RESULTS: GmFT2a expression is regulated by photoperiod. Analyses of GmFT2a transcripts revealed a strong correlation between GmFT2a expression and flowering maintenance. GmFT2a transcripts were observed continuously within the vascular tissue up to the shoot apex during flowering. By contrast, transcripts decreased to undetectable levels during flowering reversion. In grafting experiments, the early-flowering, photoperiod-insensitive stock Heihe27 promotes the appearance of GmFT2a transcripts in the shoot apex of scion Zigongdongdou under noninductive LD conditions. The photothermal effects of GmFT2a expression diversity in cultivars with different photoperiod-sensitivities and a hypothesis is proposed. CONCLUSION: GmFT2a expression is associated with flowering induction and maintenance. Therefore, GmFT2a is a potential target gene for soybean breeding, with the aim of increasing geographic adaptation of this crop

Dissolution Behavior of Cellulose in IL + DMSO Solvent: Effect of Alkyl Length in Imidazolium Cation on Cellulose Dissolution

Four cellulose solvents including [C2mim][CH3COO] + DMSO, [C4mim][CH3COO] + DMSO, [C6mim][CH3COO] + DMSO, and [C8mim][CH3COO] + DMSO were prepared by adding dimethyl sulfoxide DMSO in 1-ethyl-3-methylimidazolium acetate [C2mim][CH3COO], 1-butyl-3-methylimidazolium acetate [C4mim][CH3COO], 1-hexyl-3-methylimidazolium acetate [C6mim][CH3COO], and 1-octyl-3-methylimidazolium acetate [C8mim][CH3COO], respectively. The solubilities of cellulose in these solvents were determined at 25°C. The effect of the alkyl chain length in imidazolium cation on cellulose solubility was investigated. With increasing alkyl chain length in imidazolium cation, the solubility of cellulose increases, but further increase in alkyl chain length results in decreases in cellulose

LOW CYCLE FATIGUE LIFE PREDICTIONS OF 15CrMoR PARENT MATERIAL AND WELD METAL

Butt-weld specimen has been made for coke drum material 15 Cr MoR. For both parent and weld materials,uniaxial tensile tests and uniaxial ratcheting tests have been conducted under different temperatures. The OW-II kinematic hardening constitutive model has been used to predict the material ratcheting effect using the experimental data obtained. Test results show that the OW-II model can well predict ratcheting strain rates for the stable period. Based on the obtained uniaxial tensile test data,basic parameters for predicting low cycle fatigue life have been obtained. The MSRS model has been used to predict the fatigue lives of the parent material and weld metal. The predicted results are within the 2 times error band and are uniformly distributed on both sides of 45 ° line accurately. Furthermore,the ratcheting strain rate and the strain amplitude for the stable period are obtained for the parent metal and the weld metal respectively by the OW-II kinematic hardening constitutive model under the same conditions. The MSRS model predicts that the fatigue life of the parent material is significantly lower than that of the weld metal and during the stable period the ratcheting strain rate of parent material is significantly higher than that of the weld metal

A FTIR Study of the Acidity of in situ Generated Bronsted Sites on NaY via Displacement Reactions

Extrinsic Bronsted acid sites (BAS) on zeolites are generated on NaY upon exposure to organic acids through an ion exchange process. However, the acid-base chemistry of species adsorbed on the zeolites is largely unexplored. In this work, organic acids with varying acidity are employed to investigate the proton-transfer displacement within the micropores of NaY. The direction and degree of the displacement reactions are monitored by in situ transmission Fourier transform infrared (FTIR) spectroscopy. Two organic acids are sequentially introduced to NaY, and the direction and extent of the displacement reaction are followed by the diagnostic vibrational band of the adsorbed carboxylate species, i. e., nu([O-C-O](-)). Stronger acids are able to displace dissociatively adsorbed weaker acids on NaY, which is analogous to the solution-phase acid-base chemistry favoring the formation of weaker acids by stronger acids. The gas phase deprotonation energy correlates more closely with displacement reaction than pK(a), which is explicitly defined in the aqueous solution of acids. A thermochemical cycle is constructed to rationalize the observation that acid-base reactions in the zeolite pores could be predicted with the gas phase acidity of compounds involved in the displacement reactions

Candle soot: onion-like carbon, an advanced anode material for a potassium-ion hybrid capacitor

Although potassium-ion storage technology has started to receive significant attention, its development is still in its infancy; thus, exploration of suitable electrode materials is critical at this stage. Herein, onion-like carbon (OLC) was obtained from the combustion soot as the candle burnt and used as a promising anode material for potassium-ion storage. This OLC delivered high reversible capacity and exhibited good rate performance and cycling stability. Taking advantage of these features, a potassium-ion hybrid capacitor (PIHC) with OLC as the battery-type anode and activated carbon as the capacitor-type cathode was constructed. The constructed device displayed the high energy density of 142W h kg(-1), the ultrahigh power output of 21 kW kg(-1), and a long cycling life (83% capacity retention after 6000 cycles). Thus, this device may simultaneously cater to the requirements of high power and high energy densities in a wide range of applications

Nature and Catalytic Properties of In-Situ-Generated Bronsted Acid Sites on NaY

Aluminosilicate zeolites are widely used as acid catalysts, and different types of acid sites on these materials have been identified and characterized thoroughly. However, distinct acid sites on zeolites generated during reaction, such as the Bronsted acid sites on NaY upon exposure to organic acids and esters shown in our recent works (referred to as 0 extrinsic sites), remain largely unexplored. In this work, we determine the density of extrinsic Bronsted acid sites generated on NaY by acetic acid and methyl acetate by quantitative Fourier transform infrared (FTIR) spectroscopy. Kinetic investigations using isopropanol dehydration as a model reaction show that the catalytic characteristics of the extrinsic Bronsted acid sites on NaY are not only different from intrinsic Bronsted acid sites on proton-exchanged faujasites, but also are dependent on the precursor molecule (e.g., acetic acid and methyl acetate). The rate of isopropanol dehydration on NaY is found to scale linearly with the square root of the partial pressure of cofed acetic acid, rather than the quantity of spectroscopically measured Bronsted acid sites. We propose that the self-dissociation of acetic acid in the highly ionic zeolite pore network generates protons that are active for the dehydration reaction, and only fraction of these protons, i.e., those that are associated with the zeolite framework, can be identified spectroscopically. When cofeeding methyl acetate, the rate of isopropanol dehydration on NaY increases linearly with the quantity of spectroscopically measured Bronsted acid sites, which is attributed to the fact that the self-dissociation of methyl acetate does not generate active protons within the zeolite pore

Characteristics and Driving Factors of Rhizosphere Bacterial Communities of Chinese Fir Provenances

Rhizosphere bacteria affect the diversity of soil functions, playing important roles in the growth and expansion of Chinese fir. Understanding the driving factors of rhizosphere bacterial distribution is imperative when comparing bacterial diversity and composition under different Chinese fir provenances. We investigated the growth of Chinese fir belts and the effects of climate, geographic location, and soil nutrients. Using 16S rDNA next-generation sequencing analysis, the bacterial communities of 16 Chinese fir provenances were compared. The bacterial compositionsof Dechang, Junlian, Shangrao, Zhenxiong, Yangxin, Xinyang, Luotian, and Tianmushan provenances weredistinct from others. Generally, higher-latitude provenances showed more biomarkers (LDA = 2). Rhizosphere bacterial α-diversity was the highest in Hunan Youxian and lowest in Henan Xinyang (p < 0.05). From south to north, bacterial α-diversity initially increased and then decreased. From east to west in the middle belt, bacterial α-diversity followed a “W” trend, with the eastern middle belt having the highest values, especially near Hunan, Fujian, and Zhejiang provinces. Amongst environmental factors, soil nutrient content (Mg, P and K) and stoichiometric ratio (Ca/Mg, K/Ca and N/P), along with precipitationrate primarily controlled rhizosphere bacterial diversity. Soil pH had a significant impact on the relative abundance of rhizosphere soil bacteria. Our findings offer insight into the evolution of Chinese fir and provide a scientific basis for soil microbial community improvement of Chinese fir provenances