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The sensory quality and metabolite profiles of the fresh and dried buds and leaves of Lycium from 26 cultivars (lines) were analyzed by sensory evaluation and metabolomics combined with multivariate statistical analysis. The results of sensory evaluation showed that the dried buds and leaves of Lycium had a mellow, fresh and sweet taste, and by liquid chromatography-mass spectrometry (LC-MS), 879 metabolites were identified in Lycium buds and leaves, including amino acids and their derivatives, flavonoids, phenolic acids, saccharides, nucleotides and their derivatives, lignans and coumarins, alkaloids, terpenoids, organic acids, and lipids. Using partial least square discriminant analysis (PLS-DA) model and one-way analysis of variance (ANOVA), 211 differential metabolites were selected, which were mainly enriched in the linoleic acid metabolism, flavonoid biosynthesis, flavonoids and flavanols biosynthesis, phenylpropanol biosynthesis, and galactose metabolism pathways. In addition, it was found that amino acids and their derivatives, flavonoids, sugars, and lipids were important components to discriminate the metabolites of different cultivars (lines). Partial least squares regression (PLSR) analysis showed that 26 metabolites including epicatechin, isoquercitrin, and rutin collectively affected the taste of Lycium tea such as mellow, thick, fresh, sweet and bitter. The results of sensory evaluation and PLSR analysis showed that seven cultivars (lines) of Lycium including ‘Ningqicai No. 1’, ‘Ningqi No. 9’, Z90, Z68, Q3, Q6-13, and Z48 had better sensory quality and rich flavor substances.

To explore the effect of growing altitude on the quality of Zhenghe white tea, the sensory quality and biochemical composition of tea leaves and Zhenghe white tea from different altitudes were evaluated, and multivariate statistical analysis was applied to the obtained data. The results of sensory evaluation showed that there were significant differences in the quality of white tea from different altitudes. The mid- and high-altitude white tea tasted fresh, mellow and clean with a clean and pure aroma, while the low-altitude white tea tasted mellow and thick with a floral aroma. Partial least squares discriminant analysis (PLS-DA) showed that soluble sugars, caffeine, 3-carene, verbenenol, terpene oleene, cis-2-pentenol, 2-ethylfuran and cis-2-hexene-1-alcohol were the key components to distinguish fresh tea leaves from different altitudes. The contents of soluble sugar, cis-2-hexene-1 alcohol and cis-2-pentenol were higher in the mid- and high-altitude samples, while the contents of volatile components such as caffeine, 3-carene, verbenol and terpinolene were higher in the low-altitude samples. Soluble sugar, free amino acid, terpinolene, verbenol, 2-ethyl furan, 2-methylbutyraldehyde, 2-phenylethanol and 3-carene were the key components to distinguish white tea from different altitudes. The contents of soluble sugar and free amino acid were higher in the high-altitude white tea, and the contents of volatile components such as terpinolene, verbenol, phenyl ethanol and 3-carene were higher in the mid- and low-altitude samples, but low in the high-altitude samples. According to odor activity value (OAV) analysis, 2-methyl butyl aldehyde, 3-carene and terpinolene could be used as the characteristic volatile components to identify white tea samples from different altitudes. The results of this study will provide a reference for further exploring the flavor quality of tea from different altitudes.

To explore the effect of storage time on the flavor and quality of white peony tea, sensory evaluation and volatile and non-volatile composition analysis of 12 white peony tea samples made from three different varieties: Fudingdahao (FDDH), Zhenghedabai (ZHDB) and Fujiangshuixian (FJSX) were carried out, and the resulting data were analyzed by multivariate statistical analysis combined with multivariate statistical analysis. The results showed that during the storage process, the content of tea polyphenols and free amino acids decreased, and the ratio of polyphenols to amino and the contents of soluble sugar, flavonoids and thearubigin increased, so that the taste of white peony tea was sweet, mellow, sweet after taste and stale. The large decrease in the content of alcohol substances resulted in a reduction in the refreshing and floral aroma of white peony tea. Totally 12 differential volatiles were key to changing the aroma types of white peony tea. α-Farnesene, linalool oxide II, methyl salicylate, linalool, cis-2-pentene-1-alcohol and hexanal were the key components responsible for the floral, pekoe-like and refreshing aroma. cis-Linalool oxide and neryl oxide were also positively related to the formation of the floral aroma, and the latter was also key to the formation of the pekoe-like aroma. cis-3-Hexen-1-ol and phenethyl alcohol were also positively correlated with the formation of the refreshing aroma. In addition, 4-isopropyltoluene was the key component responsible for the honey-like and herbal aroma. Linalool oxide II and neryl oxide were the key components responsible for the jujube-like aroma. cis-Linalool oxide was the key component responsible for the plum-like aroma. The 4-isopropyltoluene and isobutyraldehyde were the key components contributing to the woody aroma. This study provides scientific insights into the formation of the differences in the flavor and quality of white peony tea of different ages, which could provide a reference for the improvement of tea flavor.

Flame-retardant modified polyurethane (PU) damping layers were prepared using the combination of expandable graphite (EG), aluminum hydroxide, and phosphorus-nitrogen flame-retardant HF600B. The mechanical, thermal, damping, and flame retardancy properties of PU damping layer and the sound insulation, vibration damping, and fire resistance of the deck components were studied systematically. The results revealed that the incorporation of flame retardant depressed the mechanical performance in general, and there was no significant change in damping property. At the same time, the residual char ratio of damping layer increased obviously with the addition of HF600B, the vertical burning rating was upgraded from V-2 to V-0 and passed the low flame test of marine materials. The A60 fire test showed that the floating deck system with damping layer had a maximum temperature rise of 75[degrees]C on the backfire surface during the test, which is much lower than 180[degrees]C required in the A60 grade fire resistance and has good fire resistance. Sound insulation test of the deck components showed that only a 2 mm damping layer increased the average sound insulation by 3 dB, especially in the low-frequency range by about 8 dB. The vibration test showed that the damping effect of the floating damping deck system on the steel plate surface and the dressing surface is increased by 1.1 and 4.0 dB in the range of 10-200 Hz, 9.2, and 4.7 dB in the range of 200-1,500 Hz, respectively., INTRODUCTION In the field of navigation, the vibration and noise problems on ships have become increasingly prominent. First of all, vibration and noise not only affect the comfort of passengers, [...]

The microRNA156 (miR156) family, one of the first miRNA families discovered in plants, plays various important roles in plant growth and resistance to various abiotic stresses. Previously, miR156s were shown to respond to drought stress, but miR156s in tea plants (Camellia sinensis (L.) O. Kuntze) have not been comprehensively identified and analyzed. Herein, we identify 47 mature sequences and 28 precursor sequences in tea plants. Our evolutionary analysis and multiple sequence alignment revealed that csn-miR156s were highly conserved during evolution and that the rates of the csn-miR156 members' evolution were different. The precursor sequences formed typical and stable stem–loop structures. The prediction of cis-acting elements in the CsMIR156s promoter region showed that the CsMIR156s had diverse cis-acting elements; of these, 12 CsMIR156s were found to be drought-responsive elements. The results of reverse transcription quantitative PCR (RT-qPCR) testing showed that csn-miR156 family members respond to drought and demonstrate different expression patterns under the conditions of drought stress. This suggests that csn-miR156 family members may be significantly involved in the response of tea plants to drought stress. Csn-miR156f-2-5p knockdown significantly reduced the Fv/Fm value and chlorophyll content and led to the accumulation of more-reactive oxygen species and proline compared with the control. The results of target gene prediction showed that csn-miR156f-2-5p targeted SQUAMOSA promoter binding protein-like (SPL) genes. Further analyses showed that CsSPL14 was targeted by csn-miR156f-2-5p, as confirmed through RT-qPCR, 5′ RLM-RACE, and antisense oligonucleotide validation. Our results demonstrate that csn-miR156f-2-5p and CsSPL14 are involved in drought response and represent a new strategy for increasing drought tolerance via the breeding of tea plants. [ABSTRACT FROM AUTHOR]

Fujian province, an important tea-producing area in China, has abundant tea cultivars. To investigate the genetic relationships of tea plant cultivars in Fujian province and the characteristics of the tea plant varieties, a total of 70 tea cultivars from Fujian and other 12 provinces in China were subjected to restriction site-associated DNA sequencing (RAD-seq). A total of 60,258,975 single nucleotide polymorphism (SNP) sites were obtained. These 70 tea plant cultivars were divided into three groups based on analyzing the phylogenetic tree, principal component, and population structure. Selection pressure analysis indicated that nucleotide diversity was high in Southern China and genetically distinct from cultivars of Fujian tea plant cultivars, according to selection pressure analysis. The selected genes have significant enrichment in pathways associated with metabolism, photosynthesis, and respiration. There were ten characteristic volatiles screened by gas chromatography–mass spectrometry (GC–MS) coupled with multivariate statistical methods, among which the differences in the contents of methyl salicylate, 3-carene, cis-3-hexen-1-ol, (E)-4-hexen-1-ol, and 3-methylbutyraldehyde can be used as reference indicators of the geographical distribution of tea plants. Furthermore, a metabolome genome-wide association study (mGWAS) revealed that 438 candidate genes were related to the aroma metabolic pathway. Further analysis showed that 31 genes of all the selected genes were screened and revealed the reasons for the genetic differences in aroma among tea plant cultivars in Fujian and Southern China. These results reveal the genetic diversity in the Fujian tea plants as well as a theoretical basis for the conservation, development, and utilization of the Fujian highly aromatic tea plant cultivars. [ABSTRACT FROM AUTHOR]

Polyphosphate ester (PPAE) made from poly(phosphoric acid), pentaerythritol, and 1,3‐butylene glycol has been synthesized. The PPAE reacted with dimethyldichlorosilane (DMDCS) to improve its thermal stability and flame retardancy. Four silane‐modified polyphosphate esters (SiPPAEs) were obtained. FTIR, 31P NMR, and 29Si NMR results showed that the SiCl bond of DMDCS could react with the COH and POH bonds of PPAE, producing SiOC and POSi bond in SiPPAEs. Different transparent coatings were obtained by mixing the PPAE and SiPPAEs with amino resin. The results of TGA showed that the stability of SiPPAEs was higher than that of PPAE. With the increase of silane content, the thermal stability of the coating increased. As the silane content increased within a certain range, the fire resistance and expansion coefficient increased. But too high silane content had adverse effects on the expansion and reduced the overall insulation effect. The digital photos and SEM/EDX microphotographs of coatings after combustion showed that silica segments could enriched in the surface to form a hard protective layer to prevent further degradation of the char layer. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47199. [ABSTRACT FROM AUTHOR]

The heterogeneity of gene expression in plant cells plays a crucial role in determining the functional differences among tissues. Recent advancements in spatial transcriptome (ST) technology have significantly contributed to the study of specific biological questions in plants. This technology has been successfully applied to examine cell development, identification, and stress resistance. This review aims to explore the application of ST technology in plants by reviewing three aspects: the development of ST technology, its current application in plants, and future research directions. The review provides a systematic description of the development process of ST technology, with a focus on analyzing its progress in studying plant cell growth and differentiation, plant cell identification, and stress resistance. In addition, the challenges faced by ST technology in plant applications are summarized, along with proposed future directions for plant research, including the advantages of combining other omics technologies with ST technology to tackle scientific challenges in the field of plants.