Functional analyses of a putative plasma membrane Na+/H+ antiporter gene isolated from salt tolerant Helianthus tuberosus

Jerusalem artichokes (Helianthus tuberosus L.) can tolerate relatively higher salinity, drought and heat stress. In this paper, we report the cloning of a Salt Overly Sensitive 1 (SOS1) gene encoding a plasma membrane Na⁺/H⁺ antiporter from a highly salt-tolerant genotype of H. tuberosus, NY1, named HtSOS1 and characterization of its function in yeast and rice. The amino acid sequence of HtSOS1 showed 83.4 % identity with the previously isolated SOS1 gene from the Chrysanthemum crassum. The mRNA level in the leaves of H. tuberosus was significantly up-regulated by presence of high concentrations of NaCl. Localization analysis using rice protoplast expression showed that the protein encoded by HtSOS1 was located in the plasma membrane. HtSOS1 partially suppressed the salt sensitive phenotypes of a salt sensitive yeast strain. In comparison with wild type (Oryza sativa L., ssp. Japonica. cv. Nipponbare), the transgenic rice expressed with HtSOS1 could exclude more Na⁺ and accumulate more K⁺. Expression of HtSOS1 decreased Na⁺ content much larger in the shoot than in the roots, resulting in more water content in the transgenic rice than WT. These data suggested that HtSOS1 may be useful in transgenic approaches to improving the salinity tolerance of glycophyte.     

Asymmetric reduction of prochiral ketones to chiral alcohols catalyzed by plants tissue

As an important organic compound, chiral alcohols are the key chiral building blocks to many single enantiomer pharmaceuticals. Asymmetric reduction of the corresponding prochiral ketones to produce the chiral alcohols by biocatalysis is one of the most promising routes. Asymmetric reduction of different kinds of non-natural prochiral ketones catalyzed by various plants tissue was studied in this work. Acetophenone, 4'-chloroacetophenone and ethyl 4-chloroacetoacetate were chosen as the model substrates for simple ketone, halogen-containing aromatic ketone and beta-ketoesters, respectively. Apple (Malus pumila), carrot (Daucus carota), cucumber (Cucumis sativus), onion (Allium cepa), potato (Soanum tuberosum), radish (Raphanus sativus) and sweet potato (Ipomoea batatas) were chosen as the biocatalysts. It was found that these kinds of prochiral ketoness could be reduced by these plants tissue with high enantioselectivity. Both R- and S-form configuration chiral alcohols could be obtained. The e.e. and chemical yield could reach about 98 and 80% respectively for acetophenone and 4'-chloroacetophenone reduction reaction with favorable plant tissue. And the e.e. and yield for ethyl 4-chloroacetoacetate reduction reaction was about 91 and 45% respectively.     

Genome Sequence of a Nicotine-Degrading Strain of Arthrobacter

We announce a 4.63-Mb genome assembly of an isolated bacterium that is the first sequenced nicotine-degrading Arthrobacter strain. Nicotine catabolism genes of the nicotine-degrading plasmid pAO1 were predicted, but plasmid function genes were not found. These results will help to better illustrate the molecular mechanism of nicotine degradation by Arthrobacter.     

Production of surfactants by Acinetobacter calcoaceticus K-4 grown on ethanol with organic acids

The effect of fumarate (C₄-dicarboxylic acid, a gluconeogenesis precursor) and citrate (a lipid synthesis regulator) on the production of surfactants by Acinetobacter calcoaceticus K-4 grown on ethanol has been studied. Simultaneous addition of fumarate and citrate to concentrations of 0.01–0.02% at the end of the exponential phase of K-4 growth in a medium with 2 vol % ethanol increases the conditional surfactant concentration by 45–55% in comparison with indices in medium without organic acids. The increased level of surfactant production in the presence of fumarate and citrate is determined by the increase in the activities of enzymes involved in the production of glycolipids (phosphoenolpyruvate synthase and trehalose phosphate synthase) and aminolipids (NADP⁺-dependent glutamate dehydrogenase) in of 1.7–7 times, as well as by the simultaneous functioning of two anaplerotic pathways: the glyoxylate cycle and the reaction catalyzed by phosphoenolpyruvate carboxylase.     

An experiment with a 105-day isolation simulating some conditions of a space flight to mars: the goals, scope, and structure of the research

The article deals with the main goals, objectives, and features of a 105-day experiment simulating some conditions of a manned space flight to Mars. It contains the scope and time patterns of the research program of the 105-day experiment, as well as methodological and organizational recommendations for the preparation for a 520-day experiment based on the analysis of the results of a 105-day experiment.     

Development of Emotion Word Comprehension in Chinese Children from 2 to 13 Years Old: Relationships with Valence and Empathy

Children’s emotion word comprehension (EWC) has constantly received a great deal of attention in developmental science. However, since previous reports focused on only English emotion vocabulary, researchers thus far remained unclear as to the developmental trajectories of EWC (to Chinese emotion words) in Chinese children, let alone the cross-cultural difference of EWC in different languages (i.e., English V.S. Chinese). Furthermore, the influence of valence on EWC, as well as the interaction mechanism between EWC and empathy, has not been fully investigated. Finding answers to these research gaps has become the main motivation of the current study. For this purpose, a Chinese emotion vocabulary was first constructed to estimate EWC of Chinese children (ages 2–13 years old). Then, the valence of each emotion word was evaluated using the standard 9-point scale approach. After that, the Chinese children’s EWC and empathy were measured in terms of parental ratings. Finally, all data collected were statistically analyzed to reveal the influence of the valence of EWC, the relation between EWC and empathy, and the cross-cultural difference of children’s EWC between China and UK from the viewpoint of developmental science. The main results of the current study included the following: (i) EWC in general increased with age for Chinese children ages 2–13 years old, however, there was a dramatic increase during ages 6–8 years old; (ii) EWC of positive emotion words in general developed better than that of negative and neutral ones for Chinese children (ages 2–13 years old); and the disadvantage of EWC to negative emotion words over neutral ones was gradually observed with the increase of age, even though there were no significant differences between them from the beginning; (iii) EWC completely mediated the effect of age on empathy; and (iv) EWC of children in UK developed better than Chinese counterparts during the early childhood period (ages 4–6 years old), then Chinese counterparts developed better during the middle childhood period (ages 7–10 years old), however, there was no significant difference of EWC between both groups during the late childhood period (ages 11–12 years old).