Integrated ATAC-Seq and RNA-Seq Data Analysis to Reveal OsbZIP14 Function in Rice in Response to Heat Stress.

Transcription factors (TFs) play critical roles in mediating the plant response to various abiotic stresses, particularly heat stress. Plants respond to elevated temperatures by modulating the expression of genes involved in diverse metabolic pathways, a regulatory process primarily governed by multiple TFs in a networked configuration. Many TFs, such as WRKY, MYB, NAC, bZIP, zinc finger protein, AP2/ERF, DREB, ERF, bHLH, and brassinosteroids, are associated with heat shock factor (Hsf) families, and are involved in heat stress tolerance. These TFs hold the potential to control multiple genes, which makes them ideal targets for enhancing the heat stress tolerance of crop plants. Despite their immense importance, only a small number of heat-stress-responsive TFs have been identified in rice. The molecular mechanisms underpinning the role of TFs in rice adaptation to heat stress still need to be researched. This study identified three TF genes, including OsbZIP14, OsMYB2, and OsHSF7, by integrating transcriptomic and epigenetic sequencing data analysis of rice in response to heat stress. Through comprehensive bioinformatics analysis, we demonstrated that OsbZIP14, one of the key heat-responsive TF genes, contained a basic-leucine zipper domain and primarily functioned as a nuclear TF with transcriptional activation capability. By knocking out the OsbZIP14 gene in the rice cultivar Zhonghua 11, we observed that the knockout mutant OsbZIP14 exhibited dwarfism with reduced tiller during the grain-filling stage. Under high-temperature treatment, it was also demonstrated that in the OsbZIP14 mutant, the expression of the OsbZIP58 gene, a key regulator of rice seed storage protein (SSP) accumulation, was upregulated. Furthermore, bimolecular fluorescence complementation (BiFC) experiments uncovered a direct interaction between OsbZIP14 and OsbZIP58. Our results suggested that OsbZIP14 acts as a key TF gene through the concerted action of OsbZIP58 and OsbZIP14 during rice filling under heat stress. These findings provide good candidate genes for genetic improvement of rice but also offer valuable scientific insights into the mechanism of heat tolerance stress in rice.

Development of a high energy resolution and wide dose rate range portable gamma-ray spectrometer.

In this paper, a portable gamma-ray spectrometer for real-time and in-situ gamma-ray detection applications is presented. By combining a quasi-hemispherical CdZnTe (CZT) semiconductor detector and a Geiger-Muller (GM) counter together, a wide dose rate range is achieved, ranging from 0.1 µSv/h to 100 mSv/h with a relative error of less than 10%. The GM counter is used to measure dose rate from 1 mSv/h to 100 mSv/h. With CZT, the spectrometer can provide a high energy resolution spectrum for nuclide identification and a high precision dose rate at low dose rates. The full width half maximum (FWHM) resolution is 2.2% at 662 keV below 70 µSv/h and is better than 3.3% at 3.8 mSv/h. The weight of the spectrometer is 3.2 kg for handheld and the runtime is up to 12 h without charging. For preliminary applications, the spectrometer was used to measure the gamma radiation around the Back-n white neutron beam line at China Spallation Neutron Source and around the steam generator in the nuclear power plant at Daya Bay Nuclear Power Station.

An ultra-low background alpha detection system with a Micromegas-based time projection chamber.

In this paper, a time projection chamber (TPC) system for α radiation detection with ultra-low background is presented, which is based on Micromegas, a type of micro-pattern gaseous detector. Based on multi-dimensional information acquired by the TPC, such as the features of particle energy deposition and 3D track, the system can achieve the purpose of α identification with ultra-low background. A prototype TPC with the volume of 15 × 15 × 6.5 cm3 was developed. It was filled with a gas mixture of 95% neon and 5% isobutene at about 1 bar, and no additional shielding or control of alpha-emitting materials was employed. A low-noise high-integration electronic system based on multi-channel waveform sampling techniques was adopted to read out the anode strip signals. A test with a 241Am α source (5.5 MeV), a 49-h background test, and several other tests with weak radioactive samples in the laboratory environment were conducted. A feature selection method was designed to maximize the suppression of background events while retaining the events of interest. Test results showed that within an assumed 5 × 5 cm2 effective area in the center region of the TPC window, the background count rate of this system was lower than 1.6 × 10-3 counts per minute at 95% confidence level, while retaining the acceptance rate of about 96% for 241Am α particles.

Prototype readout electronics of a double-sided silicon strip detector for space exploration.

Double-sided silicon strip detectors (DSSDs) have been widely used in interplanetary exploration. In this study, the prototype readout electronics of a DSSD for space exploration is presented. It mainly includes a front-end readout module (FEM) and a data acquisition module (DAM). The FEM is responsible for acquiring the charge of the DSSD signals based on an application-specific integrated circuit and polarity inverter circuits. The DAM with a field programmable gate array is employed to perform online calculations of the position and energy as well as data packaging and transfer. Test results show that the electronics has dynamic ranges of 6-2500 and -6 to -2500 fC with an integral nonlinearity of no more than 0.5%, while the root-mean-square noise level is less than 1.9 fC. Joint tests with the DSSD indicate that a full width at half maximum energy resolution of 3.25% at 5.486 MeV and a position resolution of 1.19 mm were achieved.

A compact NaI(Tl) with avalanche photodiode gamma spectrometer for in situ radioactivity measurements in marine environment.

In situ radioactivity measurements in a deep ocean environment are essential for marine environmental pollution monitoring and seabed geological exploration. In the past, the most widely used gamma spectrometers were based on towed instrumentation, which could only be operated underwater at a depth of less than 1500 m. In this study, a compact gamma spectrometer with small-size, light weight, and low power consumption was designed for working in a marine in situ environment. This spectrometer, with two essential parts: detector and electronics, was designed to work on different underwater platforms in the real-time control mode or autonomous operation mode. Multiple small volume avalanche photodiodes were coupled with NaI(Tl), which can significantly reduce the spectrometer volume compared with the option of the photomultiplier tube. Integrated readout electronics were employed to digitize all detector signals for miniaturization and low power consumption. The field programmable gate array (FPGA) was used to obtain the energy spectrum in real-time and an online multi-channel summation with temperature calibration algorithm was employed to improve detection efficiency. Relevant tests were also conducted in the laboratory to evaluate critical techniques and system performance. Results show that the energy resolution (full width at half maximum over the peak position) was ∼7.5% at 662 keV, verifying the online multi-channel summation with temperature calibration based on the FPGA. Moreover, the compact prototype spectrometer worked well in the power-on hydraulic test.

Fe3+ enhanced degradation of oxytetracycline in water by pseudomonas.

The application and fate of antibiotics are closely related to human health and the ecological balance, which has gradually aroused the widespread global concerns. Long-term antibiotic residues can easily induce antibiotic resistance and antibiotic resistance genes (ARGs) in the environment. Although many studies have investigated the metabolic pathways of biosynthesis or degradation of oxytetracycline (OTC) and its influencing factors under laboratory or controlled conditions, the understanding of OTC degradation pathways and influencing factors in the environment is still poor. In the present study, the role of Pseudomonas (T4) in OTC biodegradation were investigated with different carbon sources, metal ions, substrate concentrations, temperatures, and pH values, as well as the temporal changes in the relative abundance of OTC ARGs. It was found that OTC could be degraded by T4 as a sole carbon source. Comparison with Cu2+, the addition of Fe3+ could significantly promote the growth of T4, and then increased the OTC degradation percentage to 65.3%. The initial concentration of OTC, temperature, and pH had significant impacts on OTC degradation. At the initial OTC concentration of 50 mg L-1, the percentage degradation of OTC by T4 could reach 81.0% at the presence of Fe3+, and at 40 °C and pH = 7. Common tetracycline ARGs were not found during the OTC degradation by T4 in the present study. The eight main putative OTC degradation byproducts were identified by ultra-high definition accurate-mass quadrupole time-of-flight tandem mass spectrometry (QTOF/MS). Six different reaction types and seven possible degradation pathways were proposed, including enol-ketone conversion, hydroxylation, dehydration, deamination, demethylation and decarbonylation. Under optimal conditions, the OTC degradation percentages by T4 could reach to 88.2%, 91.6% and 92.0% in pond water, fish wastewater and industrial wastewater, respectively. These results demonstrate the high effectiveness of T4 at the presence of Fe3+ for the enhanced biodegradation of OTC in water environment, without resulting in the occurrence of ARGs. This has important implications for the removal of OTC from aquatic environments by the technology proposed from this study.