The complete chloroplast genome of Asarum heterotropoides Fr. Schmidt var. mandshuricum (Maxim.) Kitag. (Aristolochiaceae), a traditional Chinese medicine herb

The complete chloroplast genome of A. heterotropoides var. mandshuricum reported herein was a circular DNA molecule of 160,262 bp in length. The typical quadripartite structure of the genome consisted of a pair of inverted repeats (IRs) of 27,262 bp separated by a large single-copy (LSC) region of 88,927 bp and a small single-copy region (SSC) of 16,811 bp. The overall GC content of the genome is 38.45%, with 36.7%, 33.1%, and 43.0% in LSC, SSC, IR regions, respectively. The cp genome encoded 125 genes, including 83 protein-coding genes, 34 tRNA genes, and 8 rRNA genes. 138 SSRs were identified in the genome. Phylogenetic anlysis showed the position of A. heterotropoides var. mandshuricum is closely related to A. heterotropoides

Effects of cultivation ages and modes on microbial diversity in the rhizosphere soil of Panax ginseng

Background: Panax ginseng cannot be cultivated on the same land consecutively for an extended period, and the underlying mechanism regarding microorganisms is still being explored. Methods: Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) and BIOLOG methods were used to evaluate the microbial genetic and functional diversity associated with the P. ginseng rhizosphere soil in various cultivation ages and modes. Results: The analysis of microbial diversity using PCR-DGGE showed that microbial communities were significantly variable in composition, of which six bacterial phyla and seven fungal classes were detected in P. ginseng soil. Among them, Proteobacteria and Hypocreales dominated. Fusarium oxysporum, a soilborne pathogen, was found in all P. ginseng soil samples except R0. The results from functional diversity suggested that the microbial metabolic diversity of fallow soil abandoned in 2003 was the maximum and transplanted soil was higher than direct-seeding soil and the forest soil uncultivated P. ginseng, whereas the increase in cultivation ages in the same mode led to decreases in microbial diversity in P. ginseng soil. Carbohydrates, amino acids, and polymers were the main carbon sources utilized. Furthermore, the microbial diversity index and multivariate comparisons indicated that the augmentation of P. ginseng cultivation ages resulted in decreased bacterial diversity and increased fungal diversity, whereas microbial diversity was improved strikingly in transplanted soil and fallow soil abandoned for at least one decade. Conclusion: The key factors for discontinuous P. ginseng cultivation were the lack of balance in rhizosphere microbial communities and the outbreak of soilborne diseases caused by the accumulation of its root exudates

Polyketone-based membrane support improves the organic solvent resistance of laccase catalysis

Enzymes play vital roles in biological transformations due to incomparable selectivity. Enzymatic membrane reactors (EMRs) combine enzymes with membranes, and many researchers have studied the synergistic effect of EMRs exerting on enzyme performance. Before the utility of EMRs can expand from natural aqueous media to organic solvents, robust membranes must be developed to promote enzyme protection from hostile forms of media. For this study, laccase was immobilized on an organic-solvent resistant hydroxylated polyketone (PK-OH) membrane via covalent bonds and served as a model enzyme. Ketone groups facilitated the immobilization via hydrogen bonds, leading to a high immobilization density of 462 mu g/cm(2). In homogeneous aqueous-organic solvents, the activity of immobilized laccase was up to 3.5 times greater than that of free laccase towards 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid). In addition, the results also showed improved activity towards highly concentrated 2,4,6-trichlorophenol and bisphenol A (1.4 g/L). Furthermore, the activity in filtration mode showed a 240% increase over that in batch mode. The immobilized laccase maintained its activity after 40 days of storage, 10 reuse cycles, and 50 h of continuous reaction. These results show that robust polyketone based membrane support will create opportunities for the application of EMRs in aqueous-organic solvents. (C) 2019 Elsevier Inc. All rights reserved

Spatial Distribution and Associated Risk Assessment of Heavy Metal Pollution in Farmland Soil Surrounding the Ganhe Industrial Park in Qinghai Province, China

The farmland around the industrial areas in the Upper Yellow River is crucial for agricultural production but is vulnerable to contamination from the surrounding industries. This research focused on analyzing the spatial distribution and environmental risks of heavy metal pollution in the farmland around the Ganhe Industrial Park in the Qinghai–Tibet Plateau. A total of 138 surface soil samples were collected, and the concentration of seven heavy metals (Cd, As, Pb, Cr, Cu, Ni, and Zn) was analyzed using the random forest (RF) model. Pollution indicators, including the pollution index and Nemero index, were used to evaluate the pollution levels of soil heavy metals. The human health and ecological risks were estimated using the hazard index (HI) and the potential ecological risk index (RI). Cd and Zn were identified as the primary soil pollutants in the study area, with Cd being more concentrated than other heavy metals. Heavy metal contamination was most severe in the central–eastern region of the study area, with a ring-shaped distribution, which correlated with the presence of zinc smelting and chemical plants. Furthermore, the study revealed that soil heavy metal contamination posed a health threat to the local population, with children being particularly vulnerable to non-carcinogenic risks when the HI was 1.21 and to potential carcinogenic risks when the CR was 2.27 × 10−5. Additionally, heavy metal pollution caused a moderate to high ecological risk in 56.4% of the samples. The results highlighted the severe impact of soil heavy metal pollution on the delicate ecosystem of the Upper Yellow River and Qinghai–Tibet Plateau. The government should take action to improve soil environment management and prevent heavy metal pollution to protect the health of the local population and the ecological environment

The complete plastid genome of a drought-tolerant moss, Anomodon attenuatus (Hedw.) hüb

We sequenced the complete plastid genome of Anomodon attenuatus. The genome size is 125,320 bp with two inverted repeat regions of 9,948 bp separated by a large single-copy region of 86,847 bp and a small single-copy region of 18,578 bp. It encodes 114 unique genes including 80 protein-coding genes, 30 tRNA genes and 4 rRNAgenes. The overall GC content is 29.5%, with 26.9, 26.5, and 43.9% in LSC, SSC, IR regions, respectively. 139 SSRs were identified in the genome. Phylogenetic anlysis showed that the position of A.attenuatus is closely related to S.uncinata, another pleurocarpous moss

Root Physiological Changes and Transcription Analysis of <i>Iris domestica</i> in Response to Persistent Drought

Iris domestica is a popular gardening plant. Although the species is considered tolerant to drought, its growth and development are often affected by drought conditions. Therefore, revealing the regulatory mechanisms of drought tolerance in this species will aid in its cultivation and molecular breeding. In this study, morpho-physiological and transcriptome analyses of the roots of I. domestica plants were performed under persistent drought conditions. Peroxidase activity, proline content, and tectoridin content increased under sustained drought conditions. Transcriptome analysis showed that the roots of I. domestica seedlings respond to drought mainly by regulating the expression of drought-resistant genes and biosynthesis of secondary metabolites. This study provides basic data for identifying drought response mechanisms in Iris domestica

Root Physiological Changes and Transcription Analysis of Iris domestica in Response to Persistent Drought

Iris domestica is a popular gardening plant. Although the species is considered tolerant to drought, its growth and development are often affected by drought conditions. Therefore, revealing the regulatory mechanisms of drought tolerance in this species will aid in its cultivation and molecular breeding. In this study, morpho-physiological and transcriptome analyses of the roots of I. domestica plants were performed under persistent drought conditions. Peroxidase activity, proline content, and tectoridin content increased under sustained drought conditions. Transcriptome analysis showed that the roots of I. domestica seedlings respond to drought mainly by regulating the expression of drought-resistant genes and biosynthesis of secondary metabolites. This study provides basic data for identifying drought response mechanisms in Iris domestica