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This study explored the relationship between the Big Five personality traits (BFPTs) and the self-regulation strategy of spontaneous mental contrasting (S.MC) among Chinese university students. Study 1 employed a cross-sectional correlational design. We hypothesized that positive relationships exist for conscientiousness, extraversion, and low neuroticism with spontaneous mental contrasting, whereas agreeableness and openness are unrelated to spontaneous mental contrasting regarding the Chinese context. The results did not support the hypotheses. However, Study 1 indicated that two sub-traits (compassion and responsibility) correlated positively with spontaneous mental contrasting. An experimental study (Study 2) was conducted to confirm these results. The results revealed that the two prosocial traits (compassion and responsibility) significantly predict spontaneous mental contrasting compared to neutral condition. These findings support the results of a prior study, which found that those who experienced more social responsibility toward others typically used spontaneous mental contrasting to achieve their social responsibility goals. These findings extended these results, as the participants in this study exhibited increased spontaneous mental contrasting with their academic goals when induced by responsibility and compassion. The results of this study imply that the prosocial traits increased the use of spontaneous mental contrasting and future interventional designs should integrate these traits. [ABSTRACT FROM AUTHOR]

The effects of metal pollution on tea are of great concern to consumers. We apply Geographic information systems technology to study the distribution of heavy metal elements in tea plantation ecosystems in Jiangsu Province, explore the relationships among metals in the soil, tea leaves and tea infusions, and assess the human safety risks of metals. The concentrations of nine metals in a soil–tea leaves–tea infusion system were studied at 100 randomly selected tea plantations in Jiangsu Province, China. Concentrations of selected metals, zinc (Zn), nickel (Ni), manganese (Mn), chromium (Cr) and copper (Cu), were quantified using an inductively coupled plasma-optical emission spectrometer (ICP-OES), and cadmium (Cd), arsenic (As), plumbum (Pb) and mercury (Hg) were quantified using inductively coupled plasma-mass spectrometry (ICP-MS). Arc-Map 10.3 was used for the spatial analysis of metals in soil, tea leaves and tea infusions. We found that the contents of Mn, Ni and Zn are high level in soil, tea leaves and tea infusions. The Mn level showed a spatial distribution pattern with greater concentrations at the junction of Nanjing and Yangzhou, southwest of Changzhou and west of Suzhou. The hazard index (HI) values in north-central Nanjing, southern Suzhou, southwestern Changzhou and northern Lianyungang were relatively greater. The Zn, Ni, Mn, Cr and Cu levels in the soil–tea infusion system were 17.3, 45.5, 54.5, 1.5 and 14.3%, respectively. The order of the leaching rates of the elements was Ni > Cr > Zn > Mn > Cu. The relative contribution ratios of HI were in the order of Mn > Ni > Cu > Zn > Cr > Pb > Cd > As > Hg. In tea infusions, the Mn level has the greatest potential health risks to consumers. Moreover, using Csoil it was inferred that the safety thresholds of Zn, Ni, Mn, Cr and Cu in soil were 27,700, 50, 1230, 493,000 and 16,800 mg L–1, respectively. The content of heavy metals in soil and tea varies greatly in different regions of Jiangsu Province, 92% of the soil has heavy metal content that meets the requirements of pollution-free tea gardens, 91% of tea samples met the requirements of green food tea. The thresholds for Ni (50 mg L−1) and Mn (1230 mg L−1) can be used as maximum limits in tea plantation soils. The consumption of tea infusions did not pose metal-related risks to human health. [ABSTRACT FROM AUTHOR]

Tea plants (Camellia sinensis (L.) Kuntze) can hyperaccumulate fluoride (F−) without any toxic symptom, especially in mature leaves. However, the molecular mechanism of absorption and hyperaccumulation of F− was poorly understood in C. sinensis. Here, a transcriptomic analysis was performed to compare the responses to fluoride stress of tea leaves to understand F− accumulation and its influence on gene expression in C. sinensis leaves. The results indicated that numerous differentially expressed genes involved in ion absorption and transport exist in the process of F− absorption in C. sinensis leaves. The up-regulated expression of genes associated with uptake and transport of Ca2+ and K+ (CNGC, TPC1, CAX, and VHA) increased the intracellular and vacuole cation concentration during F− accumulation in C. sinensis leaves. We also found that some of AQP (PIPs and TIPs) genes may promote F− into the intracellular spaces and vacuoles in C. sinensis leaves, respectively. In addition, F− induced the expression of differential genes related to plant hormone metabolism and signaling pathways (ABA, auxin, and GA). Subsequently, a lot of transcription factors (WRKY, MYB, NAC, bHLH and AP2/ERF) were activated to respond to F− stress in tea leaves by regulating plant hormone signal transduction and other pathways. And ubiquitin systems were involved in the regulation of proteins homeostasis under F− stress indicating that they are responsible for the response of C. sinensis leaves to F−. Overall, these findings provide a comprehensive understanding of the F− absorption mechanism and its influence on gene expression in tea leaves. [ABSTRACT FROM AUTHOR]

Tea plant often suffers from low temperature induced damage during its growth. How to improve the cold resistance of tea plant is an urgent problem to be solved. Nitric oxide (NO), γ-aminobutyric acid (GABA) and proline have been proved that can improve the cold resistance of tea plants, and signal transfer and biosynthesis link between them may enhance their function. NO is an important gas signal material in plant growth, but our understanding of the effects of NO on the GABA shunt, proline and NO biosynthesis are limited. In this study, the tea roots were treated with a NO donor (SNAP), NO scavenger (PTIO), and NO synthase inhibitor (L-NNA). SNAP could improve activities of arginine decarboxylase, ornithine decarboxylase, glutamate decarboxylase, GABA transaminase and Δ1-pyrroline-5-carboxylate synthetase and the expression level of related genes during the treatments. The contents of putrescine and spermidine under SNAP treatment were 45.3% and 37.3% higher compared to control at 24 h, and the spermine content under PTIO treatment were 57.6% lower compare to control at 12 h. Accumulation of proline of SNAP and L-NNA treatments was 52.2% and 43.2% higher than control at 48 h, indicating other pathway of NO biosynthesis in tea roots. In addition, the NO accelerated the consumption of GABA during cold storage. These facts indicate that NO enhanced the cold tolerance of tea, which might regulate the metabolism of the GABA shunt and of proline, associated with NO biosynthesis. [ABSTRACT FROM AUTHOR]

The voltage-gated chloride channel (CLC) superfamily is one of the most important anion channels that is widely distributed in bacteria and plants. CLC is involved in transporting various anions such as chloride (Cl-) and fluoride (F-) in and out of cells. Although Camellia sinensis is a hyper-accumulated F plant, there is no studies on the CLC gene superfamily in the tea plant. Here, 8 CLC genes were identified from C. sinensis and they were named CsCLC1-8. The structure of CsCLC genes and the proteins were not conserved; the number of exons varied from 3 to 24, and the number of transmembrane domains contained 2 to 10. Furthermore, phylogenetic analysis revealed that CsCLC4-8 in subclass I contained the typical conserved domains GxGIPE (I), GKxGPxxH (II) and PxxGxLF (III), and CsCLC1-3 in subclass II did not contain any of the three conserved residues. We measured the expression levels of CsCLCs in roots, stems and leaves to assess the responses to different concentrations of Cl- and F-. The result indicated that CsCLCs participated in subfunctionalization in response to Cl- and F-, and CsCLC1-3 was more sensitive to F- treatments than CsCLC4-8, CsCLC6 and CsCLC7 may participate in absorption and long-distance transport of Cl-. [ABSTRACT FROM AUTHOR]

Intercropping is an important agroforestry practice that can not only increase biodiversity, improve microenvironment and resource utilization, but also improve crop yield and quality. In this paper, the soil environmental characteristics and tea quality of three tea-fruit intercropping patterns (loquat-tea, waxberry-tea, and citrus-tea) and pure tea garden were studied. The soil samples of 0–10 cm, 10–20 cm and 20–30 cm depths in different seasons (spring and autumn) were collected to analyze the physicochemical characteristics of the soil. Corresponding tea bud samples in spring were collected for the determination of the main chemical components. The soil nutrient of the three intercropping patterns was higher than that of the single tea plantation, while the heavy metal content and pH value were opposite. Moreover, the difference in soil nutrient and pH under intercropping patterns were correlated with the sampling period. The tea plantation under intercropping patterns had higher free amino acid content, lower catechins content and the ratio of phenol to amino acids, which is conducive to the formation of green tea quality. Under the patterns of loquat-tea intercropping and citrus-tea intercropping, soil nutrients were higher than that of waxberry-tea intercropping. For the tea plantation soil heavy metals, waxberry-tea intercropping and citrus-tea intercropping had lower concentration than that of loquat-tea intercropping. However, citrus-tea intercropping is superior to the other two intercropping patterns for tea quality. These results may enhance the understanding of tea-fruit intercropping patterns for improving the soil environment of tea plantation and the quality of tea. [ABSTRACT FROM AUTHOR]

Tea plants (Camellia sinensis O. Kuntze) can hyperaccumulate fluoride (F) in leaves. Although, aluminum (Al) can alleviate F toxicity in C. sinensis, the mechanisms driving this process remain unclear. Here, we measured root length, root activity, soluble proteins content, and levels of peroxidase, superoxide dismutase, catalase, malondialdehyde (MDA), and chlorophyll in tea leaves after treatment with different F concentrations. In addition, we focused on the content of organic acids, the gene transcription of malate dehydrogenase (MDH), glycolate oxidase (GO) and citrate synthase (CS) and the relative enzyme activity involved in the tolerance to F in C. sinensis. We also examined the role of Al in this process by analyzing the content of these physiological indicators in tea leaves treated with F and Al. Our results demonstrate that increased MDA content, together with decreased chlorophyll content and soluble proteins are responsible for oxidative damage and metabolism inhibition at high F concentration. Moreover, increased antioxidant enzymes activity regulates ROS damage to protect tea leaves during F stress. Furthermore, exogenous Al alleviated F stress in tea leaves through the regulation of MDA content and antioxidant enzymes activity. In addition, organic acids in exudate stimulated root growth in tea plants exposed to low F concentrations are regulated by MDH, GO, and CS. In addition, Al can stimulate the exudation of organic acids, and may participate in regulating rhizosphere pH of the roots through the interaction with F, eventually leading to the response to F stress in C. sinensis. [ABSTRACT FROM AUTHOR]

Key message: Overexpression of grapevine VvABF2 gene could enhance osmotic stress tolerance in Arabidopsis thaliana but fully required for ABA signaling. The abscisic acid (ABA)-dependent AREB/ABF-SnRK2 pathway has been demonstrated to play a pivotal role in response to osmotic stress in model plants. However, its function in other specific species, for example grapevine, has not been fully characterized. In this study, grapevine (Vitis vinifera L.) ABSCISIC ACID RESPONSE ELEMENT-BINDING FACTOR2 (VvABF2), a homologous gene of AREB/ABFs form Arabidopsis, was isolated and constitutively expressed in Arabidopsis under the control of the cauliflower mosaic virus 35S promoter. The VvABF2 transgenic Arabidopsis plants showed to be more sensitive to exogenous ABA compared to wild type plants and exhibited significant osmotic tolerance, like polyethylene glycol (PEG) and drought but fully required ABA for signaling. This fact was further confirmed by its downstream gene expression assays. In addition, the determination of ROS antioxidant enzymes (including SOD, POD and CAT) and the MDA of transgenic lines indicated that overexpression of VvABF2 in Arabidopsis significantly increased ROS scavenging ability and thereby reduced the cell membrane damage, which might be ABA-independent. Our results provide evidence that VvABF2 has a similar function to the Arabidopsis homolog in response to osmotic stresses, and that there is a similar ancestral function of this gene in ABA-dependent response to stresses in grapevine. [ABSTRACT FROM AUTHOR]

Plant intercropping is increasing in popularity, is conducive to plant growth and development and can improve plant quality and yield. In this study, we intercropped tea (Camellia sinensis) cv. 'Su cha zao' and soybean (Glycine max) cv. 'Lamar' in a tea plantation. The chlorophyll content was higher in intercropped tea leaves than in monoculture, and the different phenotypic characteristics of intercropping and monoculture were correlated with chlorophyll and carotenoid content. Our analyses showed that soybean–tea intercropping not only alleviated cold damage, but also influenced tea plant growth. Furthermore, the soil ammonium nitrogen (N) in intercropping mode increased during soybean flowering and mature periods and was highest in the soybean flowering and podding period. Catechin levels in tea leaves significantly decreased, and the amino acid and soluble sugars increased, for intercropped compared with monoculture tea leaves. The analysis of soil fertility and tea leaf physiological indices also indicated that N fertiliser was significantly positively correlated with free amino acids in tea leaves. In conclusion, soybean–tea intercropping affected the effective N content in soil, especially ammonium N, and the formation of the main physicochemical composition of tea leaves, as well as tea taste and aroma. Thus, intercropping can sustainably improve nutrient management and increase crop yield and quality. [ABSTRACT FROM AUTHOR]