Expression Patterns and Molecular Mechanisms Regulating Drought Tolerance of Soybean [Glycine max (L.) Merr.] Conferred by Transcription Factor Gene GmNAC19.

NAC transcription factors are commonly involved in the plant response to drought stress. A transcriptome analysis of root samples of the soybean variety 'Jiyu47' under drought stress revealed the evidently up-regulated expression of GmNAC19, consistent with the expression pattern revealed by quantitative real-time PCR analysis. The overexpression of GmNAC19 enhanced drought tolerance in Saccharomyces cerevisiae INVSc1. The seed germination percentage and root growth of transgenic Arabidopsis thaliana were improved in comparison with those of the wild type, while the transgenic soybean composite line showed improved chlorophyll content. The altered contents of physiological and biochemical indices (i.e., soluble protein, soluble sugar, proline, and malondialdehyde) related to drought stress and the activities of three antioxidant enzymes (i.e., superoxide dismutase, peroxidase, and catalase) revealed enhanced drought tolerance in both transgenic Arabidopsis and soybean. The expressions of three genes (i.e., P5CS, OAT, and P5CR) involved in proline synthesis were decreased in the transgenic soybean hairy roots, while the expression of ProDH involved in the breakdown of proline was increased. This study revealed the molecular mechanisms underlying drought tolerance enhanced by GmNAC19 via regulation of the contents of soluble protein and soluble sugar and the activities of antioxidant enzymes, providing a candidate gene for the molecular breeding of drought-tolerant crop plants.

Molecular Characterization and Drought Resistance of GmNAC3 Transcription Factor in Glycine max (L.) Merr.

Soybean transcription factor GmNAC plays important roles in plant resistance to environmental stresses. In this study, GmNAC3 was cloned in the drought tolerant soybean variety "Jiyu47", with the molecular properties of GmNAC3 characterized to establish its candidacy as a NAC transcription factor. The yeast self-activation experiments revealed the transcriptional activation activity of GmNAC3, which was localized in the nucleus by the subcellular localization analysis. The highest expression of GmNAC3 was detected in roots in the podding stage of soybean, and in roots of soybean seedlings treated with 20% PEG6000 for 12 h, which was 16 times higher compared with the control. In the transgenic soybean hairy roots obtained by the Agrobacterium-mediated method treated with 20% PEG6000 for 12 h, the activities of superoxide dismutase, peroxidase, and catalase and the content of proline were increased, the malondialdehyde content was decreased, and the expressions of stress resistance-related genes (i.e., APX2, LEA14, 6PGDH, and P5CS) were up-regulated. These expression patterns were confirmed by transgenic Arabidopsis thaliana with the overexpression of GmNAC3. This study provided strong scientific evidence to support further investigation of the regulatory function of GmNAC3 in plant drought resistance and the molecular mechanisms regulating the plant response to environmental stresses.

Mixed potential type sensor based on Gd2Zr2O7 solid electrolyte and BiVO4 sensing electrode for effective detection of triethylamine.

Triethylamine (TEA), as a common and widely used industrial raw material, is extremely hazardous to the environment and human health. Therefore, the development of a portable gas-sensing technology for high-efficiency detection of TEA is of great worth for human health and environmental monitoring. In this work, a mixed potential type TEA sensor was initially developed based on pyrochlore Gd2Zr2O7 solid state electrolyte and BiVO4 sensing electrode. The sensor generates high response values of - 62.2 mV and - 134.4 mV to 5 ppm and 100 ppm TEA at 500 °C, respectively. The response value of the sensor displays a logarithmic linear relationship with the concentration of TEA in the range of 1-100 ppm with the sensitivity of - 50.8 mV/decade. Besides, the sensor shows good response and recovery characteristics, and the response and recovery time to 10 ppm TEA is 10 s and 89 s, respectively. Moreover, the sensor possesses good humidity resistance, reproducibility and stability. The sensing behavior of the sensor is explained by the mixed potential sensing mechanism, which is confirmed by the measurement of the polarization curves. This work provides a good supplement for TEA gas sensor, which holds important application value for the sensitive detection of TEA in the environment.

An investigation of an ergonomics intervention to affect neck biomechanics and pain associated with smartphone use.

BACKGROUND: Neck discomfort and pronounced neck flexion have been associated with smartphone use. OBJECTIVE: Eye glasses with a 90 deg prism in each lens were investigated as a potential intervention to reduce awkward head and neck postures during activities involving viewing the device. METHODS: Sixteen smartphone users with neck pain and 9 asymptomatic users performed a texting task on a smartphone with and without the prism glasses, in sitting and standing postures in a laboratory setting. RESULTS: Cervical erector spinae and upper trapezius muscle activity, head posture and motion, performance, discomfort and other subjective perceptions were assessed. Prism glasses reduced neck extensor muscle activity, neck flexion, and head tilt compared to the direct view. In the symptomatic group, the intervention produced less neck and shoulder discomfort compared to the direct view. CONCLUSIONS: This intervention could offer an alternative way of interacting with a smartphone while texting in stationary postures, by reducing exposure to pronounced flexed neck and head posture commonly seen in users, and thereby could reduce neck discomfort associated with smartphone use.