Comprehensive Analysis of GH3 Gene Family in Potato and Functional Characterization of StGH3.3 under Drought Stress.

As an important hormone response gene, Gretchen Hagen 3 (GH3) maintains hormonal homeostasis by conjugating excess auxin with amino acids during plant stress-related signaling pathways. GH3 genes have been characterized in many plant species, but they are rarely reported in potato. Here, 19 StGH3 genes were isolated and characterized. Phylogenetic analysis indicated that StGH3s were divided into two categories (group I and group III). Analyses of gene structure and motif composition showed that the members of a specific StGH3 subfamily are relatively conserved. Collinearity analysis of StGH3 genes in potato and other plants laid a foundation for further exploring the evolutionary characteristics of the StGH3 genes. Promoter analysis showed that most StGH3 promoters contained hormone and abiotic stress response elements. Multiple transcriptome studies indicated that some StGH3 genes were responsive to ABA, water deficits, and salt treatments. Moreover, qRT-PCR analysis indicated that StGH3 genes could be induced by phytohormones (ABA, SA, and MeJA) and abiotic stresses (water deficit, high salt, and low temperature), although with different patterns. Furthermore, transgenic tobacco with transient overexpression of the StGH3.3 gene showed positive regulation in response to water deficits by increasing proline accumulation and reducing the leaf water loss rate. These results suggested that StGH3 genes may be involved in the response to abiotic stress through hormonal signal pathways. Overall, this study provides useful insights into the evolution and function of StGH3s and lays a foundation for further study on the molecular mechanisms of StGH3s in the regulation of potato drought resistance.

Effects of freeze-thaw cycles on nutrient removal from bioretention cells.

There have been numerous summaries of the runoff purification characteristics of bioretention cells in warm climates. However, little has been done on the effects of freeze-thaw cycles (FTCs) that frequently occur in cold regions on bioretention cell performance. Three experimental columns were constructed to simulate the operation of the bioretention cell under the FTCs. The effects of FTCs on the nutrient removal efficiency of different filling bioretention cells were analyzed. The results showed that the ammonia nitrogen (NH4+-N) concentration in the effluent of the wood chip bioretention cell under the T3 conditions (WBCF) (2.35 mg/L) was significantly higher than that of the wood chip bioretention cell operating at room temperature (WBCR) (0.62 mg/L). The effluent NH4+-N concentration of aluminum sludge bioretention cell (ABCF) (0.096 mg/L) under the FTCs was lower than that of WBCF (0.91 mg/L). Under the T3 condition, the effluent nitrate nitrogen (NO3--N) and total nitrogen (TN) concentrations of WBCF (5.33 mg/L and 8.86 mg/L) were higher than those of WBCR (5 mg/L and 6.11 mg/L) at room temperature. Under FTCs conditions, both WBCF and ABCF had high NO3--N removal efficiency (up to 85.87% and 24.75%) at the initial stage of thawing of the filler, and the efficiency gradually decreased with the thawing of the filler. With the increase of FTCs, the NO3--N removal efficiency of WBCF gradually decreased (always higher than 13.6%), while the removal efficiency of ABCF fluctuated wildly (the removal efficiency was primarily negative). The total phosphorus (TP) concentration in the effluent of WBCF (0.11 mg/L) under the T3 conditions was lower than that of WBCR (0.02 mg/L) at room temperature, and the TP concentration of ABCF (0.021 mg/L) in the effluent under the FTCs was slightly lower than that of WBCF (0.031 mg/L). The FTCs have a more significant impact on removing nitrogen pollutants in runoff, but have little effect on phosphorus. Compared with aluminum sludge, wood chips are more suitable for efficient removal of nitrogen pollutants in runoff under the FTCs. The experimental conclusions can provide a reference for the construction of bioretention cells in cold regions.

Efficacy and mechanism of traditional Chinese medicine in relieving antibiotic-resistant bacterial diarrhea in children: study protocol for a randomized controlled trial.

BACKGROUND: Bacterial infection is an important cause of diarrhea in children, potentially leading to malnutrition, growth and development disorders, and even death. Antibiotic abuse and resistance are widespread problems worldwide, especially in China. We therefore designed a study to evaluate the clinical efficacy and mechanism of traditional Chinese medicine in alleviating the effects of antibiotic resistance in childhood bacterial diarrhea and enhancing the sensitivity of pathogenic bacteria to antibiotics. METHODS: This randomized, double-blind, placebo-controlled clinical trial has completed ChiCTR registration. The trial will randomly divide 120 children who meet the inclusion criteria into three groups: experimental group 1 (basic treatment + Gegen Qinlian decoction granules + Erbai drink placebo), experimental group 2 (basic treatment + Erbai drink granules + Gegen Qinlian decoction placebo), and control group (basic treatment + Gegen Qinlian decoction placebo + Erbai drink placebo). The main efficacy indicators will be antibiotic use rate and clinical cure rate, and the secondary efficacy indicators will be time to antibiotic intervention, effective rate, and course of treatment determined after 5 days. The following physical and chemical indicators will be measured: routine blood parameters, procalcitonin, C-reactive protein, electrocardiogram, liver and kidney function, electrolytes, routine urinalysis, routine stool analysis, and stool culture (including drug sensitivity). DISCUSSION: The results of this study may provide an objective clinical basis for the use of traditional Chinese medicine in managing antibiotic-resistant bacterial diarrhea in children, formulating relevant guidelines, and demonstrating the use of traditional Chinese medicine for reducing the use of antibiotics. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1900027915 . Last refreshed on December 4, 2019.