Spin Manipulation by Creation of Single-Molecule Radical Cations

All-trans-retinoic acid (ReA), a closed-shell organic molecule comprising only C, H, and O atoms, is investigated on a Au(111) substrate using scanning tunneling microscopy and spectroscopy. In dense arrays single ReA molecules are switched to a number of states, three of which carry a localized spin as evidenced by conductance spectroscopy in high magnetic fields. The spin of a single molecule may be reversibly switched on and off without affecting its neighbors. We suggest that ReA on Au is readily converted to a radical by the abstraction of an electron.Comment: 5 pages, 3 figures, accepted for publication in Phys. Rev. Let

A Genome-Wide Analysis of StTGA Genes Reveals the Critical Role in Enhanced Bacterial Wilt Tolerance in Potato During Ralstonia solanacearum Infection

TGA is one of the members of TGACG sequence-specific binding protein family, which plays a crucial role in the regulated course of hormone synthesis as a stress-responsive transcription factor (TF). Little is known, however, about its implication in response to bacterial wilt disease in potato (Solanum tuberosum) caused by Ralstonia solanacearum. Here, we performed an in silico identification and analysis of the members of the TGA family based on the whole genome data of potato. In total, 42 StTGAs were predicted to be distributed on four chromosomes in potato genome. Phylogenetic analysis showed that the proteins of StTGAs could be divided into six sub-families. We found that many of these genes have more than one exon according to the conserved motif and gene structure analysis. The heat map inferred that StTGAs are generally expressed in different tissues which are at different stages of development. Genomic collinear analysis showed that there are homologous relationships among potato, tomato, pepper, Arabidopsis, and tobacco TGA genes. Cis-element in silico analysis predicted that there may be many cis-acting elements related to abiotic and biotic stress upstream of StTGA promoter including plant hormone response elements. A representative member StTGA39 was selected to investigate the potential function of the StTGA genes for further analysis. Quantitative real-time polymerase chain reaction (qRT-PCR) assays indicated that the expression of the StTGAs was significantly induced by R. solanacearum infection and upregulated by exogenous salicylic acid (SA), abscisic acid (ABA), gibberellin 3 (GA3), and methyl jasmonate (MeJA). The results of yeast one-hybrid (Y1H) assay showed that StTGA39 regulates S. tuberosum BRI1-associated receptor kinase 1 (StBAK1) expression. Thus, our study provides a theoretical basis for further research of the molecular mechanism of the StTGA gene of potato tolerance to bacterial wilt

Research on Hyperspectral Model for Blacksoil Organic Matter Estimation in Songnen Plain, China

Models of soil reflectance for soil organic matter estimation are needed to quantify soil and vegetation spectral properties. The characteristics of Blacksoil in Songnen Plain, China, fit for quickly estimating organic matter content with hyperspectral reflectance models. Correlation analysis and multivariable statistical methods were used to build hyperspectral models for blacksoil organic matter content estimation, with spectral reflectance and its derivatives as independent variables and the Curvature and Ratio Indices introduced. Finally, the stability and capacity of the models were tested. The results are as follows: 620-810 nm bands are the main response spectrum of blacksoil organic matter, and the maximum is at 710 nm; normalizing spectral data partly eliminates the noises introduced when testing different samples; logtransforming SOM content improve the stability and prediction ability of the linear regression models; compared with other models, the multi-liner regression models are more stable and predictable; Normalized Spectra Derivate Multivariate Stepwise Linear Regression Model is the optimal one, and the Bow-curvature Linear Model is the most feasible one, the hyperspectral model can be used to measure blacksoil organic matter content quickly