Research Progress on the Effects of Selenium on the Growth and Quality of Tea Plants.

Selenium (Se) is an essential trace element for humans and animals, and it plays an important role in immune regulation and disease prevention. Tea is one of the top three beverages in the world, and it contains active ingredients such as polyphenols, theanine, flavonoids, and volatile substances, which have important health benefits. The tea tree has suitable Se aggregation ability, which can absorb inorganic Se and transform it into safe and effective organic Se through absorption by the human body, thereby improving human immunity and preventing the occurrence of many diseases. Recent studies have proven that 50~100.0 mg/L exogenous Se can promote photosynthesis and absorption of mineral elements in tea trees and increase their biomass. The content of total Se and organic selenides in tea leaves significantly increases and promotes the accumulation of polyphenols, theanine, flavonoids, and volatile secondary metabolites, thereby improving the nutritional quality of tea leaves. This paper summarizes previous research on the effects of exogenous Se treatment on the growth and quality of tea trees to provide a theoretical basis and technical support for the germplasm selection and exploitation of Se-rich tea.

Genome-wide identification and expression pattern analysis of the TCP transcription factor family in Ginkgo biloba.

Plant-specific TCP transcription factors play an essential role in plant growth and development. They can regulate leaf curvature, flower symmetry and the synthesis of secondary metabolites. The flavonoids in Ginkgo biloba leaf are one of the main medicinally bioactivate compounds, which have pharmacological and beneficial health effects for humans. In this study, a total of 13 TCP genes were identified in G. biloba, and 5 of them belonged to PCF subclades (GbTCP03, GbTCP07, GbTCP05, GbTCP13, GbTCP02) while others belonged to CIN (GbTCP01, GbTCP04, GbTCP06, GbTCP08, GbTCP09, GbTCP10, GbTCP11, GbTCP12) subclades according to phylogenetic analysis. Numerous cis-acting elements related to various biotic and abiotic signals were predicted on the promoters by cis-element analysis, suggesting that the expression of GbTCPs might be co-regulated by multiple signals. Transcript abundance analysis exhibited that most of GbTCPs responded to multiple phytohormones. Among them, the relative expression levels of GbTCP06, GbTCP11, and GbTCP13 were found to be significantly influenced by exogenous ABA, SA and MeJA application. In addition, a total of 126 miRNAs were predicted to target 9 TCPs (including GbTCP01, GbTCP02, GbTCP04, GbTCP05, GbTCP06, GbTCP08, GbTCP11, GbTCP12, GbTCP13). The correlation analysis between the expression level of GbTCPs and the flavonoid contents showed that GbTCP03, GbTCP04, GbTCP07 might involve in flavonoid biosynthesis in G. biloba. In short, this study mainly provided a theoretical foundation for better understanding the potential function of TCPs in G. biloba.

Characterization of a novel levopimaradiene synthase gene responsible for the biosynthesis of terpene trilactones in Ginkgo biloba.

Terpene trilactones (TTLs) are the main medicinal compounds of Ginkgo biloba. Levopimaradiene synthase (LPS) is the crucial enzyme that catalyzes TTLs biosynthesis in G. biloba. In this study, a novel LPS gene (designated as GbLPS2) was cloned from G. biloba leaves. The open reading frame of GbLPS2 gene was 2520 bp in length, encoding a predicted polypeptide of 840 amino acids. Phylogenetic analysis revealed that the GbLPS2 was highly homologous with reported LPS proteins in other plants. On the basis of the genomic DNA (gDNA) template, a 4308 bp gDNA sequence of GbLPS2 and a 913 bp promoter sequence were amplified. Cis-acting elements in promoter analysis indicated that GbLPS2 could be regulated by methyl jasmonate (MeJA) and abscisic acid (ABA). Tissue-specific expression analysis revealed that GbLPS2 was mainly expressed in roots and ovulate strobilus. MeJA treatment could significantly induce the expression level of GbLPS2 and increase the content of TTLs. This study illustrates the structure and the tissue-specific expression pattern of GbLPS2 and demonstrates that exogenous hormones regulated the expression of GbLPS2 and TTL content in G. biloba. Our results provide a target gene for the enhancement of TTL content in G. biloba via genetic engineering.

Application of cystourethroscopy during tracheobronchial foreign body removal in children.

Objective This study aimed to describe preliminary experiences associated with removal of tracheobronchial foreign bodies (TFBs) by cystourethroscopy (CU). Methods We performed a retrospective analysis of 127 paediatric cases of TFB removal by CU at our centre from January 2009 to August 2016. Data that were extracted from the medical records included age, sex, location and nature of the TFBs, operation time, and complications. Results All TFBs were successfully removed by CU. The mean time of the procedure was 3.38 ± 2.86 minutes. A total of 102 (80.31%) patients had successful removal of TFBs by CU during the initial trial, 19 (14.96%) were successfully treated in the second trial, and six (4.72%) required a third trial. Otolaryngologists with 2, 5, and 7 years of professional CU training showed a mean TFB removal time of 3.38 ± 2.13, 3.40 ± 3.60, and 3.37 ± 2.86 minutes, respectively. In the operations, oxygen saturation fell below 90% at an average occurrence of 0.39 times, but no patients showed a decrease below 85%. Only one patient experienced laryngeal oedema after the procedure. Conclusion CU is a useful technique and minimizes complications and operational risks during removal of paediatric TFBs.