Molecular cloning and characterization of a proliferating cell nuclear antigen gene by chemically induced male sterility in wheat (Triticum aestivum L.).

Although a number of studies have shown that chemical hybridizing agents (CHAs) affect anther growth and regulate cell-cycle progression, little is known about the molecular and cellular mechanisms involved. Proliferating cell nuclear antigen (PCNA) is an essential factor in DNA replication, and in many other processes in eukaryotic cells. In this study, the open reading frame of TaPCNA, the PCNA in wheat (Triticum aestivum L.), was cloned by reverse transcription polymerase chain reaction (RT-PCR). Sequence analysis revealed that this gene was 792-bp long and encoded a protein with 234 amino acids. Alignment of the TaPCNA-predicted sequence revealed a high degree of identity with PCNAs from other plant species. A subcellular localization assay indicated that TaPCNA was localized in the nucleus. The TaPCNA was cloned into the prokaryotic expression plasmid pET32a, and the recombinant plasmid was transformed into BL21 (DE3). TaPCNA expression was induced by 0.5 mM isopropyl-beta-D-thiogalactopyranoside and verified using sodium dodecyl sulfate polyacrylamide gel electrophoresis and western blot assays, which indicated that the fusion protein was successfully expressed. The gene involved in the G1-to-S transition, Histone H4, was downregulated by 1376- CIMS, which is a chemically induced male sterility line. However, a semi-quantitative RT-PCR revealed that TaPCNA expression was upregulated in 1376-CIMS. Our results suggest that CHAs (SQ-1) induce DNA damage in wheat anthers. DNA damage results in either the delay or arrest of cell-cycle progression, which affects anther development. This study will help to elucidate the mechanisms of SQ-1-induced male sterility.

Runoff characteristics and non-point source pollution analysis in the Taihu Lake Basin: a case study of the town of Xueyan, China.

Non-point source pollution is a significant environmental issue in small watersheds in China. To study the effects of rainfall on pollutants transported by runoff, rainfall was monitored in Xueyan town in the Taihu Lake Basin (TLB) for over 12 consecutive months. The concentrations of different forms of nitrogen (N) and phosphorus (P), and chemical oxygen demand, were monitored in runoff and river water across different land use types. The results indicated that pollutant loads were highly variable. Most N losses due to runoff were found around industrial areas (printing factories), while residential areas exhibited the lowest nitrogen losses through runoff. Nitrate nitrogen (NO3-N) and ammonia nitrogen (NH4-N) were the dominant forms of soluble N around printing factories and hotels, respectively. The levels of N in river water were stable prior to the generation of runoff from a rainfall event, after which they were positively correlated to rainfall intensity. In addition, three sites with different areas were selected for a case study to analyze trends in pollutant levels during two rainfall events, using the AnnAGNPS model. The modeled results generally agreed with the observed data, which suggests that AnnAGNPS can be used successfully for modeling runoff nutrient loading in this region. The conclusions of this study provide important information on controlling non-point source pollution in TLB.

Effects of plant roots on the hydraulic performance during the clogging process in mesocosm vertical flow constructed wetlands.

The aim of this study was to evaluate the effects of plant roots (Typha angustifolia roots) on the hydraulic performance during the clogging process from the perspective of time and space distributions in mesocosm vertical flow-constructed wetlands with coarse sand matrix. For this purpose, a pair of lab-scale experiments was conducted to compare planted and unplanted systems by measuring the effective porosity and hydraulic conductivity of the substrate within different operation periods. Furthermore, the flow pattern of the clogging process in the planted and unplanted wetland systems were evaluated by their hydraulic performance (e.g., mean residence time, short circuiting, volumetric efficiency, number of continuously stirred tank reactors, and hydraulic efficiency factor) in salt tracer experiments. The results showed that the flow conditions would change in different clogging stages, which indicated that plants played different roles related to time and space. In the early clogging stages, plant roots restricted the flow of water, while in the middle and later clogging stages, especially the later stage, growing roots opened new pore spaces in the substrate. The roots played an important role in affecting the hydraulic performance in the upper layer (0-30 cm) where the sand matrix had a larger root volume fraction. Finally, the causes of the controversy over plant roots' effects on clogging were discussed. The results helped further understand the effects of plant roots on hydraulic performance during the clogging process.

[The pharmacokinetics of SC1001-sodium and SC1001-aminum in human body].

The pharmacokinetics of SC1001-Sodium and SC1001-Aminum in the human body was studied. After 200 mg SC1001-Sodium or SC1001-Aminum by oral administration, plasma concentration-time data were fitted to curves by means of the nonlinear least-square method, employing the program we ourselves compiled. With F-test, comparing gamma 2(1) -value and AIC-value, the linear one compartment open model was available. The mean pharmacokinetic parameters fitted one by one were as follows with the first value given belonging to SC1001-Sodium and the second to SC1001-Aminum: Ka: 0.7248 and 0.5102 h-1; Ke: 0.0597 and 0.1149 h-1; T1/2, a: 1.1437 and 1.8999 h; T1/2, e: 15.7428 and 6.1497 h; AUC: 600.15 and 28.61 micrograms.h/ml; Tm: 4.4798 and 4.3728h.