Showing papers by "Bao Yang published in 2019"

Cross-Kingdom Small RNAs among Animals, Plants and Microbes

Abstract: Small RNAs (sRNAs), a class of regulatory non-coding RNAs around 20~30-nt long, including small interfering RNAs (siRNAs) and microRNAs (miRNAs), are critical regulators of gene expression. Recently, accumulating evidence indicates that sRNAs can be transferred not only within cells and tissues of individual organisms, but also across different eukaryotic species, serving as a bond connecting the animal, plant, and microbial worlds. In this review, we summarize the results from recent studies on cross-kingdom sRNA communication. We not only review the horizontal transfer of sRNAs among animals, plants and microbes, but also discuss the mechanism of RNA interference (RNAi) signal transmission via cross-kingdom sRNAs. We also compare the advantages of host-induced gene silencing (HIGS) and spray-induced gene silencing (SIGS) technology and look forward to their applicable prospects in controlling fungal diseases.

Pericarp and seed of litchi and longan fruits: constituent, extraction, bioactive activity, and potential utilization

Abstract: Litchi (Litchi chinensis Sonn.) and longan (Dimocarpus longan Lour.) fruits have a succulent and white aril with a brown seed and are becoming popular worldwide. The two fruits have been used in traditional Chinese medicine as popular herbs in the treatment of neural pain, swelling, and cardiovascular disease. The pericarp and seed portions as the by-products of litchi and longan fruits are estimated to be approximately 30% of the dry weight of the whole fruit and are rich in bioactive constituents. In the recent years, many biological activities, such as tyrosinase inhibitory, antioxidant, anti-inflammatory, immunomodulatory, anti-glycated, and anti-cancer activities, as well as memory-increasing effects, have been reported for the litchi and longan pericarp and seed extracts, indicating a potentially significant contribution to human health. With the increasing production of litchi and longan fruits, enhanced utilization of the two fruit by-products for their inherent bioactive constituents in relation to pharmacological effects is urgently needed. This paper reviews the current advances in the extraction, processing, identification, and biological and pharmacological activities of constituents from litchi and longan by-products. Potential utilization of litchi and longan pericarps and seeds in relation to further research is also discussed.

Natural Estrogen Receptor Modulators and Their Heterologous Biosynthesis.

Abstract: Estrogen receptors (ERs) are transcription factors highly involved in physiological development and metabolism in the human body. They also play important roles in the treatment of cancer and metabolic diseases. Chemicals that interact with ERs can be used to treat diseases and maintain health. Phytoestrogens are natural chemicals that have been documented to possess significant ER modulatory activities. However, since phytoestrogens usually exist at low quantities in nature, heterologous biosynthesis techniques have quickly developed in recent years in order meet the demands for needed therapeutic amounts. In this review, the performance of phytoestrogens as ER modulators is described along with recent advances in biosynthesis techniques.

The Vulnerability of Qilian Juniper to Extreme Drought Events.

Abstract: Identifying which trees are more vulnerable to extreme climatic events is a challenging problem in our understanding of forest and even ecosystem dynamics under climate change scenarios. As one of the most widely distributed tree species across the arid and semi-arid northeastern Tibetan Plateau, Qilian juniper (Juniperus przewalskii Kom.), is the main component of the local forest ecosystem, providing critical insurance for the ecological security of the surrounding areas. However, this species's ability to cope with climate extremes (especially drought) has not been adequately assessed. Here, we apply a dendroecological approach that considers indices of resistance and resilience to quantify the vulnerability of Qilian junipers to the extreme drought events of 1957, 1966, 1979, and 1995. A total of 532 Qilian juniper trees from different age stages (100-1,100 years) and altitudes [3,500-4,000 m above sea level (a.s.l.)] were studied to assess their response characteristics during these four drought extremes. We conclude that drought extremes have a significant negative impact on the growth of Qilian juniper. The oldest Qilian junipers at the lower altitudes constituted the most vulnerable populations across the northeastern Tibetan Plateau and were characterized by the lowest resistance values, the narrowest annual rings, and the highest proportion of missing rings during the four drought years. Tree resilience after droughts was strongly related to the intensity of the drought event and did not change with tree age or elevation. A threshold of tree tolerance to drought may exist, with the more vulnerable tree individuals (e.g., the oldest Qilian junipers from lower altitudes) being exposed to the highest mortality risk when drought intensity exceeds the threshold value. Such a threshold needs further consideration, through the study of trees that have died (or are about to die) due to extreme droughts.

Immunomodulatory mechanism of α-D-(1→6)-glucan isolated from banana

Abstract: Banana is a delicious fruit with potent immunomodulatory function. In this study, α-D-(1→6)-glucan was purified from banana pulp. It could significantly promote pinocytic activity and production of nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). The mRNA expression of nitric oxide synthase (iNOS), IL-6 and TNF-α was increased in RAW264.7 macrophages. α-D-(1→6)-glucan could not only increase the expression levels of p-p65 and p-IκBα, but also induce the translocation of nuclear factor-kappa B (NF-κB) p65 into the nucleus. Moreover, mitogen-activated protein kinases (MAPKs), including p-ERK, p-JNK and p-p38, were upregulated. These results suggested that NF-κB and MAPK signaling pathways were involved in the immunomodulatory mechanisms of α-D-(1→6)-glucan. The results revealed that α-D-(1→6)-glucan might be the critical component responsible for the health benefits of banana.

Identifying teleconnections and multidecadal variability of East Asian surface temperature during the last millennium in CMIP5 simulations

Abstract: . We examine the relationships in models and reconstructions between the multidecadal variability of surface temperature in East Asia and two extratropical modes of variability: the Atlantic Multidecadal Oscillation (AMO) and the Pacific Decadal Oscillation (PDO). We analyse the spatial, temporal and spectral characteristics of the climate modes in the last millennium, historical and pre-industrial control simulations of seven Coupled Model Intercomparison Project phase 5 (CMIP5)/Paleoclimate Model Intercomparison Project phase 3 (PMIP3) global climate models (GCMs) to assess the relative influences of external forcing and unforced variability. These models produce PDO and AMO variability with realistic spatial patterns but widely varying spectral characteristics. AMO internal variability significantly influences East Asian temperature in five models (MPI, HadCM3, MRI, IPSL and CSIRO) but has a weak influence in the other two (BCC and CCSM4). In most models, external forcing greatly strengthens these statistical associations and hence the apparent teleconnection with the AMO. PDO internal variability strongly influences East Asian temperature in two out of seven models, but external forcing makes this apparent teleconnection much weaker. This indicates that the AMO–East Asian temperature relationship is partly driven by external forcing, whereas the PDO–temperature relationship is largely from internal variability within the climate system. Our findings suggest that external forcing confounds attempts to diagnose the teleconnections of internal multidecadal variability. Using AMO and PDO indices that represent internal variability more closely and minimising the influence of external forcing on East Asian temperature can partly ameliorate this confounding effect. Nevertheless, these approaches still yield differences between the forced and control simulations and they cannot always be applied to paleoclimate reconstructions. Thus, we recommend caution when interpreting teleconnections diagnosed from reconstructions that contain both forced and internal variations.

Icariin as a Preservative to Maintain the Fruit Quality of Banana During Postharvest Storage

Abstract: Banana is a tropical fruit with good palatability and multiple health benefits. However, the fruit quality is readily deteriorated during postharvest storage. In this work, icariin was used to treat banana to maintain the fruit quality. NMR spectroscopy was applied to analyze the effect of icariin on the metabolite profiles of banana. It was found that the fruit quality of banana was well maintained after icariin treatment. The data of 1D and 2D NMR spectra revealed the composition of metabolites, whose contents greatly varied during storage. The first principal components included ethanol, acetic acid, saponin b, salsolinol, dopamine, glucose, and linoleic acid. After icariin treatment, the conversion of starch to α-d-glucose and β-d-glucose was delayed, and the production of γ-aminobutyrate, glutamine, and alanine increased. These results indicated that icariin could effectively maintain the fruit quality and delay the senescence of banana.

Elevation-influenced variation in canopy and stem phenology of Qinghai spruce, central Qilian Mountains, northeastern Tibetan Plateau

Abstract: Canopy and stem phenology of Qinghai spruce, central Qilian Mountains, respond to different environmental factors depending on season and elevation. To understand vegetation species response to climate change, much research has been devoted to changes in forest phenology. Results of such studies are not only of scientific interest; they are potentially of great use in forest management. This study focuses on variations in canopy and stem phenology as affected by climate and elevation. We collected data on canopy phenology (as recorded in the Normalized Differential Vegetation Index) and stem phenology [using the Vaganov–Shashkin (V–S) model] in Qinghai spruce (Picea crassifolia) growing at two sites in the central Qilian Mountains, Northeast Tibetan Plateau. One site was at a higher elevation, near the local alpine tree-line, and the other was near the local lower tree-line. At both sites, a significant correlation was found between canopy and stem spring phenology. This would seem to be mainly due to spring temperatures. No such correlation was found between canopy and stem autumn phenology. The study suggests that the main factors affecting stem growth after the beginning of growing season would be temperature and soil moisture, and that these have different effects depending on elevation. At the lower elevation, soil moisture seems to be the main factor limiting growth. At the higher elevation, temperature was the determining factor. Climate change will have different effects depending on elevation.