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Cadmium (Cd) is an important environmental heavy metal and one of the main soil pollutants in southwest China and even the Yangtze River Basin because of its toxicity to plants and humans. To clarify the potential of Euryops pectinatus L. and Gardenia jasminoides J. and the mechanism they use to remediate Cd-contaminated soil, a soil pot experiment with 0, 5, 10, 20, and 40 mg kg−1 of Cd was used to investigate the accumulation characteristics, subcellular distribution, chemical forms, and the antioxidative defense systems of the two ornamental plants. When the concentration of Cd was below 40 mg kg−1, it promoted the growth of E. pectinatus shoots, and the tolerance index (TI) was >1. However, 20–40 mg kg−1 Cd significantly inhibited the growth of G. jasminoides, and the TI was <1. The shoots of both varieties accumulated more Cd than the roots, and the E. pectinatus shoots accumulated more Cd (1.45 mg plant−1) than those of G. jasminoides (0.71 mg plant−1). The Cd in E. pectinatus and G. jasminoides was primarily distributed in the soluble fraction (52.83–68.97%) and cell walls (44.62–54.98%), respectively. Higher proportions of Cd bound to NaCl and acetic acid (HAc) in E. pectinatus (55.32–73.44%) than in G. jasminoides (42.94–61.58%), while the inorganic and water-soluble proportions of Cd bound in the opposite manner. E. pectinatus maintained high activities of antioxidant enzymes under Cd treatments, and its levels of malondialdehyde (MDA) and relative electrical conductivity (REC) were comparable to those of the control. Nonetheless, G. jasminoides had low levels of activity of antioxidant enzymes, but its levels of MDA and REC were significantly higher than those of the control under the 20–40 mg kg−1 Cd treatment. Therefore, both types of plants have a strong ability to tolerate and accumulate Cd, which makes them suitable for the remediation of Cd-polluted soil. However, E. pectinatus is more effective at remediating Cd and tolerant to it than G. jasminoides. These plants utilize different mechanisms to detoxify Cd. [ABSTRACT FROM AUTHOR]

Michelia champaca L. (Magnoliaceae) was cultivated in large scale for flowers as cosmetic raw materials, whereas the value of its leaves remains to be discovered. Our chemical study on the leaves yielded four new flavonol diglycosides, champaflavosides A–D (1 – 4), together with twenty-three known flavonoid glycosides (5 – 27). Their structures were determined by spectroscopic and chemical methods. Compounds 5 – 21 and 23 – 27 were not previously reported from the genus Michelia , and kaempferol 3- O -rutinoside (22) was obtained from this species for the first time. All the compounds were evaluated for antioxidant activity by four in vitro assays. Compounds 3 – 12 and 20 showed more potent 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity than l -ascorbic acid (l -AA). Compounds 2 – 23 , 25 , and 27 exhibited 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical cation scavenging activity superior to l -AA. The ferric reducing antioxidant powers (FRAP) of compounds 2 – 13 , 17 , and 19 were higher than l -AA. Further, eighteen compounds demonstrated cellular reactive oxygen species (ROS) scavenging activity, of which champaflavoside D (4), rhamnetin 3- O -neohesperidoside (8), quercetin 3- O -(6- O - E - p -coumaroyl)-neohesperidoside (9), and liquiritin (27) were more potent than curcumin. The results revealed that the renewable leaves of M. champaca are a rich source of flavonoids and antioxidants. [Display omitted] • Michelia champaca has been widely cultivated for flowers as cosmetic raw materials. • The chemical constituents other than volatile oil in the leaves remain unknown. • Four new and 23 known flavonoid glycosides were isolated from the leaves. • Our research results revealed that the leaves are a rich source of antioxidants. [ABSTRACT FROM AUTHOR]

Urbanization has progressively intensified over the past few decades, transforming the structure and function of urban ecosystems and influencing the concentrations and spatial distributions of phosphorus (P) in the soil. This study collected 177 surface soil samples (to a depth of 20 cm) to understand the dynamics of soil P along a gradient of urbanization from a densely urbanized central city to less human-affected suburbs to a new exurban satellite in Chengdu, China. The results showed that concentrations of soil total P (TP) and its fractions (except Water-Po, NaOH-Pi, and Residual-P) in the central city and exurban satellite were significantly higher than in suburban areas ( p  < 0.05). Meanwhile, the concentrations of soil TP and its fractions (except Residual-P) significantly decreased with the increase in distance from the urban center ( p  < 0.05). These concentrations were significantly positively correlated with the densities of built-up areas and roads, and showed significant differences among different green space types. The results of generalized linear models indicated that the most decisive factors contributing to TP accumulation were the distance from urban center and green space type. Generally, green space type and density of built-up area were likely to be more crucial determinants governing soil inorganic P fractions compared with other factors, whereas the key factors affecting soil organic P fractions were varied. To conclude, urbanization is likely to lead to the accumulation of P and, thus, controlling the expansion of built-up areas and road areas is necessary to alleviate soil P accumulation in urban systems. [ABSTRACT FROM AUTHOR]

The flapping of a flag in the wind is a classical fluid-structure problem that concerns the interaction of elastic bodies with ambient fluid. We focus on the desirable experimental results of the flow around the flapping flag. By immersing the elastic yet self-supporting heavy flag into water flow, we use particle image velocimetry (PIV) techniques to obtain the whole flow field around the midspan of the flag interacting with a fluid in periodic state. A unique PIV image processing method is used to measure near-wall flow velocities around a moving elastic flag. There exists a thin flow circulation region on the suction side of the flag in periodic state. This observation suggests that viscous flow models may be needed to improve the theoretical predictions of the flapping flag in periodic state, especially in a large amplitude. [ABSTRACT FROM AUTHOR]

Abstract: We investigated the effects of short-term root-zone hypoxic stress and exogenous calcium application or deficiency in an anoxic nutrient solution on nitrogen metabolism in the roots of the muskmelon cultivar Xiyu No. 1. Seedlings grown in the nutrient solution under hypoxic stress for 6d displayed significantly reduced plant growth and soluble protein concentrations. However, NO3 − uptake rate and activities of nitrate reductase and glutamate synthase were significantly increased. We also found higher amounts of nitrate, ammonium, amino acids, heat-stable proteins, polyamines, H2O2, as well as higher polyamine oxidase activity in the roots. In comparison to the reactions seen under hypoxic stress, exogenous calcium application led to a marked increase in plant weights, photosynthesis parameters, NO3 − uptake rate and contents of nitrate, ammonium, amino acids (e.g., glutamic acid, proline, glycine, cystine, γ-aminobutyric acid), soluble and heat-stable proteins, free spermine, and insoluble bound polyamines. Meanwhile, exogenous calcium application resulted in significantly increased activities for nitrate reductase, glutamine synthetase, and glutamate synthase but decreased activities for diamine and polyamine oxidase, as well as lower H2O2 content in roots during exposure to hypoxia. However, calcium deficiency in the nutrient solution decreased plant weight, photosynthesis parameters, NO3 − reduction, amino acids (e.g., alanine, aspartic acid, glutamic acid, γ-aminobutyric acid), protein, all polyamines except for free putrescine, and the activities of glutamate synthase and glutamine synthetase. Additionally, there was an increase in the NO3 − uptake rate, polyamine oxidase activity and H2O2 contents under hypoxia–Ca. Simultaneously, exogenous calcium had little effect on nitrate absorption and transformation, photosynthetic parameters, and plant growth under normoxic conditions. These results suggest that calcium confers short-term hypoxia tolerance in muskmelon, most likely by promoting nitrate uptake and accelerating its transformation into amino acids, heat-stable proteins or polyamines, as well as by decreasing polyamine degradation in muskmelon seedlings. [Copyright &y& Elsevier]

Herbivore‐induced plant volatiles (HIPVs) are critical compounds that directly or indirectly regulate the tritrophic interactions among herbivores, natural enemies and plants. The synthesis and release of HIPVs are regulated by many biotic and abiotic factors. However, the mechanism by which multiple factors synergistically affect HIPVs release remains unclear. Tea plant (Camellia sinensis) is the object of this study because of its rich and varied volatile metabolites. In this study, benzyl nitrile was released from herbivore‐attacked tea plants more in the daytime than at night, which was consistent with the feeding behaviour of tea geometrid (Ectropis grisescens Warren) larvae. The Y‐tube olfactometer assay and insect resistance analysis revealed that benzyl nitrile can repel tea geometrid larvae and inhibit their growth. On the basis of enzyme activities in transiently transformed Nicotiana benthamiana plants, CsCYP79 was identified as a crucial regulator in the benzyl nitrile biosynthetic pathway. Light signalling‐related transcription factor CsPIF1‐like and the jasmonic acid (JA) signalling‐related transcription factor CsMYC2 serve as the activator of CsCYP79 under light and damage conditions. Our study revealed that light (abiotic factor) and herbivore‐induced damage (biotic stress) synergistically regulate the synthesis and release of benzyl nitrile to protect plants from diurnal herbivorous tea geometrid larvae. Summary statement: Tea geometrid‐induced volatile benzyl nitrile (BN) emission has a diurnal pattern, which is consistent with the feeding of tea geometrids. Light and damage induce the emission of BN and the CsCYP79 expression which is promote by the CsMYC2 and CsPIFs‐like. [ABSTRACT FROM AUTHOR]

Some members of the CYP51G subfamily has been shown to be obtusifoliol 14α‐demethylase, key enzyme of the sterol and brassinosteroid (BR) biosynthesis, which mediate plant development and response to stresses. However, little is known about the functions of CYP51H subfamily in rice. Here, OsCYP51H3, an ortholog of rice OsCYP51G1 was identified. Compared with wild type, the mutants oscyp51H3 and OsCYP51H3‐RNAi showed dwarf phenotype, late flowering, erected leaves, lower seed‐setting rate, and smaller and shorter seeds. In contrast, the phenotypic changes of OsCYP51H3‐OE plants are not obvious. Metabolomic analysis of oscyp51H3 mutant indicated that OsCYP51H3 may also encode an obtusifoliol 14α‐demethylase involved in phytosterol and BR biosynthesis, but possibly not that of triterpenes. The RNA‐seq results showed that OsCYP51H3 may affect the expression of a lot of genes related to rice development. These findings showed that OsCYP51H3 codes for a putative obtusifoliol 14α‐demethylase involved in phytosterol and BR biosynthesis, and mediates rice development. [ABSTRACT FROM AUTHOR]

Soil heavy metal speciation has received much attention for their different ecological and environmental effects. However, the effects of climate and soil geochemical properties on them in uncontaminated soils at macroscale were still unclear. Therefore, a transect more than 4000 km was chosen to study the effects of these factors on soil Cd, Pb and Cr forms. The results revealed that mean annual temperature and precipitation showed significant positive relations with the exchangeable and Fe-Mn oxide bound states of Cd, Pb and Cr, and residual Cr. And humidity and drought indexes were significantly positively correlated with their organic and carbonate bound forms, respectively. As for soil geochemical properties, pH displayed significant negative relationships with exchangeable, Fe-Mn oxide and organic bound Pb and Cr, and exchangeable Cd. Fe 2 O 3 was significantly positively with the exchangeable and Fe-Mn oxide bound Cd, Pb and Cr, and residual Cr. And soil organic matter showed positive relations with organic bound Pb and Cr, and residual Cd and Cr, displayed negative relationships with carbonated bound Pb and Cr. Overall, climate and soil geochemical properties together affect the transformation and transport of heavy metals between different forms in uncontaminated soils. [Display omitted] • MAT and MAP positively relate with exchangeable and Fe-Mn oxide bound metals. • HI and DI positively relate with organic and carbonate bound metals respectively. • pH displayed significant negative relationships with Fe-Mn oxide bound Pb and Cr. • Soil organic matter showed negative relationship with carbonated bound Pb and Cr. [ABSTRACT FROM AUTHOR]

Background: The obligate mutualism between fig trees (Ficus, Moraceae) and pollinating fig wasps (Agaonidae) is a model system for studying co-evolution due to its perceived extreme specificity, but recent studies have reported a number of examples of trees pollinated by more than one fig wasp or sharing pollinators with other trees. This will make the potential of pollen flow between species and hybridization more likely though only few fig hybrids in nature have been found. We reared pollinator fig wasps from figs of 13 Chinese fig tree species and established their identity using genetic methods in order to investigate the extent to which they were supporting more than one species of pollinator (co-pollinator). Results: Our results showed (1) pollinator sharing was frequent among closely-related dioecious species (where pollinator offspring and seeds develop on different trees); (2) that where two pollinator species were developing in figs of one host species there was usually one fig wasp with prominent rate than the other. An exception was F. triloba, where its two pollinators were equally abundant; (3) the extent of co-pollinator within one fig species is related to the dispersal ability of them which is stronger in dioecious figs, especially in small species. Conclusions: Our results gave more examples to the breakdown of extreme specificity, which suggest that host expansion events where pollinators reproduce in figs other than those of their usual hosts are not uncommon among fig wasps associated with dioecious hosts. Because closely related trees typically have closely related pollinators that have a very similar appearance, the extent of pollinator-sharing has probably been underestimated. Any pollinators that enter female figs carrying heterospecific pollen could potentially generate hybrid seed, and the extent of hybridization and its significance may also have been underestimated. [ABSTRACT FROM AUTHOR]

• Metabolic dynamics of L. ruthenicum fruit was monitored using UHPLC-MS/MS. • A total of 49 compounds were tentatively identified in the fruits. • Four developmental stages can be easily distinguished by PCA. • Positive correlation between anthocyanin and spermidine derivative hexoses was found. • The positive correlation was attributed to a glycosyltransferase HG27071. The Lycium ruthenicum (Lr) fruit is a widely used nutritional food that contains various bioactive components such as anthocyanin and spermidine derivatives. In the present study, ultra-high-performance liquid chromatography with tandem mass spectrometry was utilized to profile the metabolic dynamics of four developmental stages of Lr fruit. A total of 49 compounds, including anthocyanin, alkaloids, hydroxycinnamic acid derivatives, flavonoids, and amino acids, were tentatively identified. Principal component analysis distinguished the fruit at four developmental stages using 15 (9 were tentatively identified) potential marker compounds. Pearson correlation analysis suggested that anthocyanin and spermidine derivative hexoses had a strong positive correlation coefficient. A glucosyltransferase (HG27071) was confirmed to glucosylate both anthocyanidin and spermidine derivative in vitro. Our results provide insight into the metabolic linkages among bioactive components in Lr fruits. The glucosyltransferase identified in this study will promote its potential use in functional foods and natural pigment resources. [ABSTRACT FROM AUTHOR]

The second recovery of rare earth elements from the bastnaesite-rich slags can effectively alleviate their industry demand and achieve cleaner production, but it still remains unclear and difficult to remove impurities from the leachate by hydrochloric acid. In this study, NaOH and NH 4 HCO 3 as precipitants were used to remove impurities and explore the optimal precipitation conditions and the mechanism by the D-optimal mixture design. The results showed that among the factors of temperature, pH and concentration, pH was the key affecting factor in impurity removal by the two reagents. The synergistic effect between the temperature and concentration promoted the impurity removal for NaOH and NH 4 HCO 3 , and the antagonism of pH with temperature inhabited the removal in the NH 4 HCO 3 group. At the optimal conditions of 35.7–70.0 °C, 2.0–6.0 solution pH and 2.0–6.0 mol L−1 concentrations, the removal rates of Fe3+, Al3+, and Cu2+ by the NaOH were about 100, 64.9, and 58.4%, respectively, and those were about 100, 36.1, and 26.6% under the optimal conditions of 25.9–60.0 °C, 3.0–5.0 solution pH and 0.5–2.5 mol L−1 concentrations by NH 4 HCO 3 , respectively. Therefore, NaOH and NH 4 HCO 3 are two feasible reagents for impurity removal in rare earth leachate for cleaner production. [Display omitted] • Impurity ions were effectively removed by NaOH and NH 4 HCO 3. • D-optimal mixture design was first employed for impurity removal optimization. • Interaction between temperature and concentration lifted the impurity removal. • The REEs recovery efficiencies are 99.6 and 94.4% in optimized conditions. [ABSTRACT FROM AUTHOR]

Siegesbeckia orientalis L. is a promising species for cadmium (Cd) phytoextraction with large biomass and fast growth rate, while little information about their intracellular mechanisms involved in Cd tolerance and detoxification has been explored. A soil pot experiment with total target Cd concentrations of 0, 10, 50, 100, and 150 mg kg−1 were designed to investigate the subcellular distribution, chemical forms and thiol synthesis characteristics of Cd in S. orientalis. More than 90% of Cd was bound to the soluble fractions (48.4-76.5%) and cell walls (19.9-46.3%). Increasing soil Cd concentrations enhanced Cd sequestration into the cell walls. Most of the Cd (69.8-82.7%) in the plant organ was mainly in the forms of pectate and protein integrated Cd and undissolved Cd phosphate, while a minor portion (6.8-20.9%) was in the forms of the inorganic Cd and the water soluble Cd. Nonprotein thiols and phytochelatins significantly increased with increasing soil Cd treatment levels, while glutathione concentrations had no obvious change trends. Therefore, intracellular detoxification mechanisms of Cd in S. orientalis mainly rely on formation of less toxic Cd chemical forms, store of a large amount of Cd in cell wall and synthesis of thiol compounds. [ABSTRACT FROM AUTHOR]

Soil washing with chelators is a promising and efficient method of remediating metals-contaminated soils. However, the toxicity of residual metals and the effects on soil microbial properties have remained largely unknown after washing. In this study, we employed four biodegradable chelators for removal of metals from contaminated soils: iminodisuccinic acid (ISA), glutamate-N,N-diacetic acid (GLDA), glucomonocarbonic acid (GCA), and polyaspartic acid (PASP). The maximum removal efficiencies for Cd, Pb, and Zn of 85, 55, and 64% and 45, 53, and 32% were achieved from farmland soil and mine soil using biodegradable chelators, respectively. It was found that the capacity of ISA and GLDA to reduce the labile fraction of Cd, Pb, and Zn was similar to that of the conventional non-biodegradable chelator ethylenediaminetetraacetic acid (EDTA). The leachability, mobility, and bioaccessibility of residual metals after washing decreased notably in comparison to the original soils, thus mitigating the estimated environmental and human health risks. Soil β-glucosidase activity, urease activity, acid phosphatase activity, microbial biomass nitrogen, and microbial biomass phosphorus decreased in the treated soils. However, compared with EDTA treatment, soil enzyme activities distinctly increased by 5–94% and overall microbial biomass slightly improved in the remediated soils, which would facilitate reuse of the washed soils. Based on soil toxicity tests that employed wheat seed germination as the endpoint of assessment, the washed soils exhibited only slight effects especially after ISA and GLDA treatments, following high-efficiency metal removal. Hence, ISA and GLDA appear to possess the greatest potential to rehabilitate polluted soils with limited toxicity remaining. [ABSTRACT FROM AUTHOR]

Banana is a tropical fruit widely accepted by people over the world. Its chemical composition is critical for its organoleptic properties and nutritional value. In this work, the metabolite changes during postharvest senescence were investigated using NMR spectroscopy. The 1D and 2D NMR spectroscopic information revealed the primary and secondary metabolites in banana fruit, including organic acids, amino acids, carbohydrates and phenolics. Bananas at five senescence stages showed similar chemical profiles, but the levels of the individual compounds varied to a large extent. The principal metabolites responsible for postharvest senescence of banana were valine, alanine, aspartic acid, choline, acetate, glucose, malic acid, gallic acid and dopamine. At stage V, ethanol was present due to the conversion of glucose. Salsolinol was generated due to the conversion of dopamine. This was a characteristic marker for the postharvest senescence of banana fruit. [ABSTRACT FROM AUTHOR]

The global tea (Camellia sinensis L.) output has been in decline despite the continued increases in global tea consumption amount and cultivation area. Application of potassium (K) fertilizer is a common way to enhance tea yield and quality, given the widespread deficiency of soil-available K in tea plantations. However, the specific effects of K fertilizer application upon tea yield and quality and its differential effects among varied K fertilizer application amount, soil-available K amount and tea types remain unknown. In this study, 518 pairwise comparisons between tea productivity after non-application and application of K fertilizers were obtained through a literature review, and then analyzed. The results showed that K application had a significant positive effect on tea yield and overall quality, enhancing the amount of tea yield, the content of amino acid, tea polyphenol, water extract, and catechin by 7.83 %, 7.84 %, 26.79 %, 1.57 % and 6.47 %, respectively. Furthermore, a K application rate of 90–120 kg ha−1 maximized the tea yield and quality. However, K application showed varied effects on tea yield and quality in soils with different available K levels. In terms of tea types, the yield and quality of black and green tea were enhanced under K application. The results of a mixed-effects model indicated that the main factors affecting tea quality were the amount of K fertilizer applied and the soil-available K content, whereas the variation in tea yield results mainly from the tea types. Therefore, to develop high-quality tea plantations and address the contradiction between low tea yield and high tea consumption, efforts should be made to enhance the soil-available K content by optimizing the amount of K applied on tea plantations. [Display omitted] • K application significantly increases tea yield and overall quality. • K application rate of 90–120 kg ha−1 generally maximize tea yield and quality. • Tea quality mainly depends on K fertilizer amount and soil-available K content. • The variation in tea yield mainly results from the tea types. • Optimizing potassium application is crucial for tea quality improvement. [ABSTRACT FROM AUTHOR]

Soil washing, an emerging method for treating soils contaminated by heavy metals, requires an evaluation of its efficiency in simultaneously removing different metals, the quality of the soil following remediation, and the reusability of the recycled washing agent. In this study, we employed N , N -bis (carboxymethyl)- l -glutamic acid (GLDA), a novel and readily biodegradable chelator to remove Cd, Pb, and Zn from polluted soils. We investigated the influence of washing conditions, including GLDA concentration, pH, and contact time on their removal efficiencies. The single factor experiments showed that Cd, Pb, and Zn removal efficiencies reached 70.62, 74.45, and 34.43% in mine soil at a GLDA concentration of 75 mM, a pH of 4.0, and a contact time of 60 min, and in polluted farmland soil, removal efficiencies were 69.12, 78.30, and 39.50%, respectively. We then employed response surface methodology to optimize the washing parameters. The optimization process showed that the removal efficiencies were 69.50, 88.09, and 40.45% in mine soil and 71.34, 81.02, and 50.95% in polluted farmland soil for Cd, Pb, and Zn, respectively. Moreover, the overall highly effective removal of Cd and Pb was connected mainly to their highly effective removal from the water-soluble, exchangeable, and carbonate fractions. GLDA-washing eliminated the same amount of metals as EDTA-washing, while simultaneously retaining most of the soil nutrients. Removal efficiencies of recycled GLDA were no > 5% lower than those of the fresh GLDA. Therefore, GLDA could potentially be used for the rehabilitation of soil contaminated by heavy metals. [ABSTRACT FROM AUTHOR]

The cost–effective removal and recovery of phosphate from wastewater is of great importance to controlling eutrophication and alleviating the phosphorus resource exhaustion crisis. Herein, chitosan (Cs) encapsulated bimetallic lanthanum (La) and iron (Fe) metal(hydro) oxides (La/Fe–Cs) composites were fabricated using a co–precipitated method for enhanced phosphate removal and recovery. The La/Fe–Cs composites had rough and raised spongy–like surfaces coated with La/Fe (hydr)oxide particles with a high specific surface area of 109.84 m2 g−1, providing more potential binding sites for phosphate capture. The La/Fe–Cs composites with a 1:2 La–to–Fe molar ratio exhibited a maximum adsorption capacity of 67.52 mg g−1 for phosphate at 308 K, calculated using the Langmuir model, which was 211% higher than that of monometallic Fe–Cs composites. Meanwhile, this composite also showed a high phosphate removal rate (63–95%) in an extensive applicable pH range (3.00–10.00) and rapid adsorption within 10 min (up to 94%). Moreover, the adsorption of phosphate by La/Fe–Cs composites was mildly disturbed against co–existing ions of NO 3 −, Cl−, and humic acid, while adsorption capacities were reduced by almost 13–45% with the existence of SO 4 2−, HCO 3 −, and CO 3 2−. The FTIR, XPS, and DFT results suggested that La–doped facilitated phosphate removal and the predominant mechanisms involved electrostatic interaction, surface precipitation, and inner–sphere complexation processes. Additionally, La/Fe–Cs composites also illustrated excellent efficiencies in simultaneous scavenging phosphate and ammonia from eutrophication and poultry wastewater. These results highlight bimetallic La/Fe–Cs composites are promising candidates for efficient elimination and recovery of phosphate from real wastewater, and subsequently could be used as slow–release fertilizers or soil amendments. [Display omitted] •Bimetallic La/Fe–Cs composites were synthesized for phosphate removal. • The derived bimetallic La/Fe–Cs composites showed excellent phosphate adsorption capacity of 67.52 mg g−1 • Mechanisms driving phosphates adsorbed onto the La/Fe–Cs composites were elucidated by FTIR, XPS, and DFT. • High efficiency in scavenging phosphate from eutrophication wastewater and poultry wastewater. • The phosphate–loden La/Fe–Cs composites can be used as slow–release fertilizers or soil amendments. [ABSTRACT FROM AUTHOR]

The cost–effective removal and recovery of phosphate from wastewater is of great importance to controlling eutrophication and alleviating the phosphorus resource exhaustion crisis. Herein, chitosan (Cs) encapsulated bimetallic lanthanum (La) and iron (Fe) metal(hydro) oxides (La/Fe–Cs) composites were fabricated using a co–precipitated method for enhanced phosphate removal and recovery. The La/Fe–Cs composites had rough and raised spongy–like surfaces coated with La/Fe (hydr)oxide particles with a high specific surface area of 109.84 m2 g−1, providing more potential binding sites for phosphate capture. The La/Fe–Cs composites with a 1:2 La–to–Fe molar ratio exhibited a maximum adsorption capacity of 67.52 mg g−1 for phosphate at 308 K, calculated using the Langmuir model, which was 211% higher than that of monometallic Fe–Cs composites. Meanwhile, this composite also showed a high phosphate removal rate (63–95%) in an extensive applicable pH range (3.00–10.00) and rapid adsorption within 10 min (up to 94%). Moreover, the adsorption of phosphate by La/Fe–Cs composites was mildly disturbed against co–existing ions of NO 3 −, Cl−, and humic acid, while adsorption capacities were reduced by almost 13–45% with the existence of SO 4 2−, HCO 3 −, and CO 3 2−. The FTIR, XPS, and DFT results suggested that La–doped facilitated phosphate removal and the predominant mechanisms involved electrostatic interaction, surface precipitation, and inner–sphere complexation processes. Additionally, La/Fe–Cs composites also illustrated excellent efficiencies in simultaneous scavenging phosphate and ammonia from eutrophication and poultry wastewater. These results highlight bimetallic La/Fe–Cs composites are promising candidates for efficient elimination and recovery of phosphate from real wastewater, and subsequently could be used as slow–release fertilizers or soil amendments. [Display omitted] •Bimetallic La/Fe–Cs composites were synthesized for phosphate removal. • The derived bimetallic La/Fe–Cs composites showed excellent phosphate adsorption capacity of 67.52 mg g−1 • Mechanisms driving phosphates adsorbed onto the La/Fe–Cs composites were elucidated by FTIR, XPS, and DFT. • High efficiency in scavenging phosphate from eutrophication wastewater and poultry wastewater. • The phosphate–loden La/Fe–Cs composites can be used as slow–release fertilizers or soil amendments. [ABSTRACT FROM AUTHOR]

Estimating the spatial distribution of soil nitrogen at different scales is crucial for improving soil nitrogen use efficiency and controlling nitrogen pollution. We evaluated the spatial variability of soil total nitrogen (TN) and available nitrogen (AN) in the Fujiang River Valley, a typical hilly region composed of low, medium and high hills in the central Sichuan Basin, China. We considered the two N forms at single hill, landscape and valley scales using a combined method of classical statistics, geostatistics and a geographic information system. The spatial patterns and grading areas of soil TN and AN were different among hill types and different scales. The percentages of higher grades of the two nitrogen forms decreased from low, medium to high hills. Hill type was a major factor determining the spatial variability of the two nitrogen forms across multiple scales in the valley. The main effects of general linear models indicated that the key affecting factors of soil TN and AN were hill type and fertilization at the single hill scale, hill type and soil type at the landscape scale, and hill type, slope position, parent material, soil type, land use and fertilization at the valley scale. Thus, the effects of these key factors on the two soil nitrogen forms became more significant with upscaling. [ABSTRACT FROM AUTHOR]

Soil labile organic carbon fractions (LOCF) are valuable indicators of changes in soil quality and soil total organic carbon (TOC), and they are easily influenced by changes in soil management practice. To explore the sensitivity of LOCF and their enzymatic conversion under straw mulch for scientific management of crop straw use on the Chengdu plain, a straw mulch field experiment was conducted to observe the LOCF changes and explore their relationships with C-cycle enzymes during wheat growth. The treatments included no fertilizer or straw (Control), only mineral fertilizer (MF), 10% rice straw nitrogen (N) plus 90% fertilizer N (RS1), 20% rice straw N plus 80% fertilizer N (RS2), 30% rice straw N plus 70% fertilizer N (RS3), 100% rice straw (RS). The water-soluble organic carbon (WSOC) and microbial biomass carbon (MBC) under straw treatments in the 0–20 cm soil layer were significantly higher than those of Control and MF treatments from the seedling stage, and showed significant differences among straw treatments from the tillering stage. Correspondingly, the dissolved organic carbon (DOC) and permanganate oxidized carbon (POXC) showed no obvious differences among straw treatments in most growth stages. Therefore, WSOC and MBC were the most sensitive indicators for assessing soil organic carbon (SOC) change under straw mulch. Moreover, stepwise multiple linear regression revealed that cellulase and β-glucosidase were significantly positive impact factors for LOCF in the two soil layers, while polyphenol oxidase had both positive and negative impacts on WSOC at different soil layers, and peroxidase was a negative factor for LOCF. [ABSTRACT FROM AUTHOR]

The water-soluble bioactive polysaccharides can contribute to the health benefits of Lycium barbarium fruit. However, the structure characteristics of these polysaccharides remain unclear yet. An important polysaccharide (LBPA) was isolated and purified from L. barbarium in this work. It was identified by chemical and spectroscopic methods as arabinogalactan with β- d -(1 → 6)-galactan as backbone, which was different to any reported polysaccharides from this species before. This arabinogalactan was comprised of Ara f , Gal p , Glc p A and Rha p with a molar ratio of 9.2:6.6:1.0:0.9. The side chains, including α- l -Ara f -(1→, α- l -Ara f -(1 → 5)-α- l -Ara f -(1→, β- l -Ara f -(1 → 5)-α- l -Ara f -(1→ and α- l -Rha p -(1 → 4)-β- d -Glc p A-(1 → 6)-β- d -Gal p -(1→, were linked to β- d -(1 → 6)-galactan at O-3. The putative structure was drawn as below. The molecular weight was determined to be 470,000 g/mol by gel permeation chromatography. [ABSTRACT FROM AUTHOR]

Cuticular wax forms a hydrophobic layer covering aerial plant organs and acting as a protective barrier against biotic and abiotic stresses. Compared with well-known wax biosynthetic pathway, molecular regulation of wax biosynthesis is less known. Here, we show that rice O s WS 1, a member of the membrane-bound O-acyl transferase gene family, involved in wax biosynthesis and was regulated by an osa-mi R 1848. Os WS 1-tagged green fluorescent protein localized to the endoplasmic reticulum (ER). Compared with wild-type rice, O s WS 1 overexpression plants displayed a 3% increase in total wax, especially a 35% increase in very long-chain fatty acids, denser wax papillae around the stoma, more cuticular wax crystals formed on leaf and stem surfaces, pollen coats were thicker and more seedlings survived after water-deficit treatment. In contrast, O s WS 1-RNAi and osa-mi R 1848 overexpression plants exhibited opposing changes. Gene expression analysis showed that overexpression of osa-mi R 1848 down-regulated O s WS 1 transcripts; furthermore, expression profiles of O s WS 1 and osa-mi R 1848 were inversely correlated in the leaf, panicle and stem, and upon water-deficit treatment. These results suggest that O s WS 1 is regulated by osa-mi R 1848 and participates in cuticular wax formation. [ABSTRACT FROM AUTHOR]

Phytosterols are membrane components or precursors for brassinosteroid ( BR) biosynthesis. As they cannot be transported long distances, their homeostasis is tightly controlled through their biosynthesis and metabolism. However, it is unknown whether micro RNAs are involved in their homeostatic regulation., Rice ( Oryza sativa) plants transformed with microRNA osa-miR1848 and its target, the obtusifoliol 14α-demethylase gene, Os CYP51G3, were used to investigate the role of osa-miR1848 in the regulation of phytosterol biosynthesis., osa-miR1848 directs Os CYP51G3 mRNA cleavage to regulate phytosterol and BR biosynthesis in rice. The role of Os CYP51G3 as one of the osa-miR1848 targets is supported by the opposite expression patterns of osa-miR1848 and Os CYP51G3 in transgenic rice plants, and by the identification of Os CYP51G3 mRNA cleavage sites. Increased osa-miR1848 and decreased Os CYP51G3 expression reduced phytosterol and BR concentrations, and caused typical phenotypic changes related to phytosterol and BR deficiency, including dwarf plants, erect leaves, semi-sterile pollen grains, and shorter cells. Circadian expression of osa-miR1848 regulated the diurnal abundance of Os CYP51G3 transcript in developing organs, and the response of Os CYP51G3 to salt stress., We propose that osa-miR1848 regulates Os CYP51G3 expression posttranscriptionally, and mediates phytosterol and BR biosynthesis. osa-miR1848 and OsCYP51G3 might have potential applications in rice breeding to modulate leaf angle, and the size and quality of seeds. [ABSTRACT FROM AUTHOR]

Fruit of two different papaya cultivars (‘Sui huang’, yellow flesh, and ‘Sui hong’, red flesh) were characterized in terms of carotenoid and volatile profiles throughout storage at 25 °C. The results showed that ‘Sui huang’ cultivar exhibited significantly lower carotenoid contents than ‘Sui hong’, which accounted for the different color characteristic. The analyses of HPLC coupled to mass spectrometry showed that zeaxanthin, β-cryptoxanthin and and β-carotene were identified as the most abundant carotenoids in ‘Sui huang’ fruit while the most abundant carotenoids were lycopene, followed by β-carotene, zeaxanthin and β-cryptoxant hin in ‘Sui hong’ fruit. The high expression of carotenoid cleavage dioxygenase gene ( CpCCD1 ) in ‘Sui hong’ papaya fruit might stimulate the degradation of β-carotene and lycopene and then form the specific volatiles of 6-methyl-5-hepten-2-one and β-ionone. [ABSTRACT FROM AUTHOR]

Guanglin 9 ( Eucalyptus grandis × Eucalyptus urophlla ) and Eucalyptus grandis 5 are two eucalyptus species which have been found to grow normally in soils contaminated with lanthanum and cerium, but the tolerance mechanisms are not clear yet. In this study, a pot experiment was conducted to investigate the tolerance mechanisms of the eucalyptus to lanthanum and cerium. Cell walls stored 45.40–63.44% of the metals under lanthanum or cerium stress. Peroxidase and catalase activities enhanced with increasing soil La or Ce concentrations up to 200 mg kg −1 , while there were no obvious changes in glutathione and ascorbate concentrations. Non-protein thiols concentrations increased with increasing treatment levels up to 200 mg kg −1 , and then decreased. Phytochelatins concentrations continued to increase under La or Ce stress. Therefore, the two eucalyptus species are La and Ce tolerant plants, and the tolerance mechanisms include cell wall deposition, antioxidant system response, and thiol compound synthesis. [ABSTRACT FROM AUTHOR]

ABSTRACT With-leaf (WL) storage and selling are becoming increasingly popular with consumers for its attractiveness and freshness. To better understand the changes of quality attributes in fruit stored WL, quality, antioxidant properties and volatile in 'Shatangju' mandarin were determined during the 9-week storage at 5C. WL storage decreased titratable acidity, flavonoid content and antioxidant activity determined by 1-diphenyl-2-picrylhydrazyl but increased ethanol content significantly, whereas WL storage had no significant effects on the content of total soluble solids, acetaldehyde and total phenolics, and reducing power. Furthermore, WL storage decreased the diversity of volatile compounds quickly. Based on the study, 'Shatangju' mandarin fruit WL (packed with polyethylene film and fungicide-treated) could be stored at 5C for up to 7 weeks. To the best of our knowledge, this is the first study thoroughly describing the quality profile of fruit stored WL. PRACTICAL APPLICATIONS This paper reports on the changes of quality, antioxidant activity and volatile compositions of 'Shatangju' mandarin fruit stored with leaves (WLs) attached to the remaining pedicle at a temperature commonly encountered in the industry. From the results obtained, 'Shatangju' mandarin stored WL deteriorates much quicker than without leaf because of faster accumulation of acetaldehyde and ethanol, and decrease in total soluble solids, titratable acidity, total phenolics, flavonoids, 1-diphenyl-2-picrylhydrazyl radical scavenging activity, reducing power and the volatile components. The results of the study suggest that a storage life of 7 weeks at 5C is recommended for commercial usage. [ABSTRACT FROM AUTHOR]

• Marsh degradation reduced large-aggregate ratio and SOC content in aggregates. • Dominant aggregate size of SOC preservation decreased under marsh degradation. • SOC active functional groups in aggregates increased along degraded marsh gradient. • Marsh degradation weaken organic C stability and sequestration in soil aggregates. Alpine marsh wetlands in the Qinghai-Tibetan Plateau are ecological hotspots for global carbon (C) cycling in Central Asia; however, the soil C sinks are increasingly limited by marsh degradation. To assess the physical mechanisms by which changes in the soil C sequestration occur, the distribution and functional groups of soil organic C (SOC) in aggregates along a marsh degradation gradient on the Zoige Plateau in China were investigated using soil samples collected from differently degraded marshes. Our results showed that, beyond the state of light degradation, the large aggregate content decreased significantly by 31.1–55.2%, while the micro-aggregate content increased significantly by 23.1–93.1%. The SOC content in the aggregates decreased significantly by 39.1–84.8% and the dominant aggregate size for SOC preservation decreased to small or micro-aggregate. Marsh degradation also decreased the relative ratio of aliphatic-C while increasing that of alcohol and phenolic-C, and polysaccharide-C. Index I (relative decomposition of SOC in aggregates) was 73.5–429.0% higher for degraded marshes than for relatively pristine marsh (RPM), while Index Ⅱ (relative recalcitrance of SOC in aggregates) was 13.8–79.5% lower in comparison. Therefore, we concluded that marsh degradation probably reduces the organic C sequestration capacity of soil by increasing the decomposition of SOC in aggregates after both the dominant aggregate size for SOC preservation and aggregate stability decreased. This result represents the physical mechanism by which the decrease in SOC content occurs in response to marsh degradation in alpine regions. [ABSTRACT FROM AUTHOR]

• Marsh degradation reduced large-aggregate ratio and SOC content in aggregates. • Dominant aggregate size of SOC preservation decreased under marsh degradation. • SOC active functional groups in aggregates increased along degraded marsh gradient. • Marsh degradation weaken organic C stability and sequestration in soil aggregates. Alpine marsh wetlands in the Qinghai-Tibetan Plateau are ecological hotspots for global carbon (C) cycling in Central Asia; however, the soil C sinks are increasingly limited by marsh degradation. To assess the physical mechanisms by which changes in the soil C sequestration occur, the distribution and functional groups of soil organic C (SOC) in aggregates along a marsh degradation gradient on the Zoige Plateau in China were investigated using soil samples collected from differently degraded marshes. Our results showed that, beyond the state of light degradation, the large aggregate content decreased significantly by 31.1–55.2%, while the micro-aggregate content increased significantly by 23.1–93.1%. The SOC content in the aggregates decreased significantly by 39.1–84.8% and the dominant aggregate size for SOC preservation decreased to small or micro-aggregate. Marsh degradation also decreased the relative ratio of aliphatic-C while increasing that of alcohol and phenolic-C, and polysaccharide-C. Index I (relative decomposition of SOC in aggregates) was 73.5–429.0% higher for degraded marshes than for relatively pristine marsh (RPM), while Index Ⅱ (relative recalcitrance of SOC in aggregates) was 13.8–79.5% lower in comparison. Therefore, we concluded that marsh degradation probably reduces the organic C sequestration capacity of soil by increasing the decomposition of SOC in aggregates after both the dominant aggregate size for SOC preservation and aggregate stability decreased. This result represents the physical mechanism by which the decrease in SOC content occurs in response to marsh degradation in alpine regions. [ABSTRACT FROM AUTHOR]

Longan is a delicious subtropicalfruit with great health-beneficialeffects. It has been utilized for disease prevention and health caresince ancient age. To explore the chemicals responsible for the healthbenefits, water-soluble polysaccharides were extracted from longanflesh in this work. A pure polysaccharide (LPS1) was obtained throughcolumn purification. Analysis by gas chromatography showed LPS1 wasa homopolysaccharide of glucose with glycosidic linkage of →6)-d-Glc-(1→. Nuclear magnetic resonance (NMR) spectra indicatedthat the configuration of anomeric carbon in glucose residual wasα-form. The polysaccharide structure was further confirmed tobe (1→6)-α-d-glucan by chemcial shift of C6.The molecular weight of LPS1 was calculated to be 108 kDa, which had661 glucose residuals. Anticancer assay showed that LPS1 had anticanceractivity against the growth of HepG2 cells to a certain extent. However,it did not show any cytotoxicity against MCF-7 breast cancer cells. [ABSTRACT FROM AUTHOR]

Abstract: Chelant assisted phytoextraction has been proposed to enhance the efficiency of remediation. This study evaluated the effects of biodegradable ethylene diamine tetraacetate (EDDS), nitrilotriacetic (NTA) and anionic polyacrylamide (APAM) on the tolerance and uptake of Siegesbeckia orientalis L. at 10 and 100mgkg−1 Cd-contaminated soils. On the 80th and 90th days of transplanting, pots were treated with EDDS and NTA at 0 (control), 1 and 2mmolkg−1 soils, and APAM at 0 (control), 0.07 and 0.14gkg−1. Generally, the root and shoot biomass of S. orientalis in all treatments reduced not significantly compared with the control, and the activities of peroxidase and catalase in leaves generally increased by the application of chelants (P <0.05). The concentrations of Cd in the shoots were increased significantly by addition of all chelants. As a result, the Cd accumulation of S. orientalis under treatments with higher dosages of the three chelants on the 80th day were 1.40–2.10-fold and 1.12–1.25-fold compared to control at 10 and 100mgkg−1 Cd, respectively. Under the addition of 2mmolkg−1 NTA on the 80th day, the highest metal extraction ratio reached 1.2% and 0.4% at 10 and 100mgkg−1 Cd soils, respectively. Therefore, the applications of EDDS, NTA and APAM may provide more efficient choices in chemical-enhanced phytoextraction. [Copyright &y& Elsevier]

Abstract: Identification of new higher yield cadmium (Cd)-hyperaccumulating cultivars from native species is key to the phytoremediation of Cd contaminated soils. A pot experiment with different soil Cd concentrations and a plot experiment at 28.44mgCdkg−1 were conducted to investigate Cd tolerance and accumulation by Siegesbeckia orientalis following a field survey. In the pot experiment, at Cd concentration of 150mgkg−1, S. orientalis grew normally and shoot biomass was not reduced significantly compared with the no Cd control. The activities of superoxide dismutase and catalase in roots and leaves, and peroxidase in leaves significantly increased with increasing soil Cd (P <0.05). The highest shoot Cd concentrations were 117.48, 192.92 and 77.10mgkg−1, in the field survey, pot and plot experiments, respectively and their corresponding accumulations were 6.762mgplant−1, 4.134mgpot−1 and 18.45mgm−2. All Cd bioconcentration factors and translocation factors were more than 1.0. Therefore, S. orientalis is a Cd-accumulator with hyperaccumulating ability. [Copyright &y& Elsevier]

Abstract: Because of its toxicity to animals and humans, cadmium (Cd) is an environmentally important heavy metal. Consequently, researchers are interested in using hyperaccumulator and accumulator plants to decontaminate Cd polluted soils. To investigate Cd tolerance, uptake and accumulation by Amaranthus hybridus L., Cd concentration gradients were applied to a soil (at rates of 0, 30, 60, 90, 120, 150 and 180mgkg−1) and hydroponics solutions (at rates of 0, 5, 10, 15, 20, 30, and 40mgL−1) following a field survey. A. hybridus grew normally at added Cd concentrations≤90mgkg−1 and≤20mgL−1 in the soil culture and in the hydroponics solutions, respectively. In the hydroponics solutions, peroxidase activity showed a quadratic relationship and catalase activity changed irregularly with increasing Cd concentrations. The highest Cd concentration and accumulation in shoots were 241.56mgkg−1 and 1006.95μgpot−1 in the soil culture, and 354.56mgkg−1 and 668.42μgpot−1 in the hydroponics experiment. Bioconcentration factors in soil culture and hydroponics solutions were 0.58–1.22 and 5.18–17.55, and translocation factors were 0.64–1.50 and 0.33–0.92, respectively. A. hybridus has potential phytoremediation capability in Cd polluted soils. [Copyright &y& Elsevier]

Abstract: Two alkali-soluble polysaccharide fractions (ASPs I and II) were extracted from longan fruit pericarp in this work. The results of chemical composition indicated that ASP I and II fractions comprised mainly of polysaccharides, proteins and lignins. Four monosaccharides, namely Xyl, Ara, Glc and Gal, were identified for both ASPs I and II. Xyl was the dominant monosaccharide in the two alkali-soluble polysaccharides with relative molar percentages of >60%. It constructed the backbone in combination with Ara for both ASPs I and II. The analysis of glycosidic linkage indicated that Xyl had two linkages,→3)-Xyl-(1→ and →3, 4)-Xyl-(1→. The substitution at C-4 position indicated that Xyl was of pyranose structure. The infrared spectra of ASPs I and II showed the characteristic bands at approximate 897cm−1 which indicated the β-linkage configuration of Xyl. Industrial relevance: Hemicellulose has been suggested as an important polysaccharide with good pharmaceutical properties, including immune modulation and anti-cardiovascular diseases. In this work, alkali-soluble polysaccharides were extracted from longan fruit pericarp and fractionated. The structural characteristics were identified by gas chromatography/mass spectrometry and infrared spectrophotometry. The results will be helpful for application of hemicellulose in functional food industry. [Copyright &y& Elsevier]

Excessive ammonium (NH 4 +) and phosphate (PO 4 3−) in aquatic environments can cause serious eutrophication. Agricultural waste is an efficient adsorbent for nutrients removal and has good potential for comprehensive utilisation of resources. In this study, two Chinese medicinal herbal residues, Rhizoma Typhonium Gigantei (ZB) and Radix Glycyrrhizae Preparata (ZG), were implemented to simultaneously remove NH 4 + and PO 4 3− from water. Parameters such as adsorbent dosage, solution pH, contact time and initial concentration that influenced the adsorption process onto adsorbents, along with removal mechanism and practical performance were investigated. The microstructure of ZB was irregular with numerous spherical particles, while ZG displayed an uneven flaky structure with few rough grooves. The nutrients adsorption was significantly influenced by pH. The maximum adsorption capacity by ZB was 91.84 N mg g−1 and 71.81 P mg g−1. In addition, the maximum adsorption capacity recorded by ZG was 100.86 N mg g−1 and 89.51 P mg g−1 (pH, 8.0; dosage, 0.2 g L−1; initial concentration, 60 mg L−1; and contact time, 180 min, for both the herbal residues). The adsorption of NH 4 + and PO 4 3− was well described by the pseudo-second-order and intra-particle diffusion models, respectively. The Langmuir isotherm model is the best fit model for the adsorption equilibrium data, suggesting monolayer adsorption of NH 4 + and PO 4 3− by the two adsorbents. In addition, NH 4 + was predominantly adsorbed by electrostatic attraction, ion exchange and complexation, whereas PO 4 3− was predominantly adsorbed by intra-particle diffusion and ligand exchange. Practical application analysis demonstrated that ZG could remove and recover more NH 4 + and PO 4 3− from swine wastewater than ZB. Therefore, ZG exhibited a more significant potential to simultaneously remove and recover NH 4 + and PO 4 3− from wastewater. [Display omitted] • Ammonium and phosphate can be effectively and simultaneously adsorbed. • Ammonium was removed by electrostatic attraction, ion exchange and complexation. • Phosphate was removed mainly by intra-particle diffusion and ligand exchange. • Chinese herbal medicine residues show great application potential in wastewater. • About 80% adsorbed ammonium and phosphate could be successfully recovered. [ABSTRACT FROM AUTHOR]

Background: It is well known that aromatic essential oils extracted from the heartwood of Santalum album L. have wide economic value. However, little is known about the role of terpenoids in response to various adverse environmental stresses as other plants do in the form of signals during plant-environment interactions. Results: In this study, trace amounts of volatiles consisting of α-santalene, epi-β-santalene, β-santalene, α-santalol, β-santalol, (E)-α-bergamotene, (E)-β-farnesene and β-bisabolene were found in the leaves of mature S. album trees. We identified more than 40 candidate terpene synthase (TPS) unigenes by mining publicly-available RNA-seq data and characterized the enzymes encoded by three cDNAs: one mono-TPS catalyzes the formation of mostly α-terpineol, and two multifunctional sesqui-TPSs, one of which produces (E)-α-bergamotene and sesquisabinene as major products and another which catalyzes the formation of (E)-β-farnesene, (E)-nerolidol and (E,E)-farnesol as main products. Metabolite signatures and gene expression studies confirmed that santalol content is closely related with santalene synthase (SaSSY) transcripts in heartwood, which is key enzyme responsible for santalol biosynthesis. However, the expression of three new SaTPS genes differed significantly from SaSSY in the essential oil-producing heartwood. Increased activities of antioxidant enzymes, superoxide dismutase, catalase, peroxidase and ascorbate peroxidase, were detected in different tissues of S. album plants after applying 1 mM methyl jasmonate (MeJA) and 1 mM salicylic acid (SA), or exposure to 4°C, 38°C and high light intensity. MeJA and SA dramatically induced the expression of SaTPS1 and SaTPS2 in leaves. SaTPS1 to 3 transcripts were differentially activated among different tissues under adverse temperature and light stresses. In contrast, almost all SaSSY transcripts decreased in response to these environmental stresses, unlike SaTPS1 to 3. Conclusions: Multifunctional enzymes were biochemically characterized, including one chloroplastic mono-TPS and two cytosolic sesqui-TPSs in sandalwood. Our results suggest the ecological importance of these three new SaTPS genes in defensive response to biotic attack and abiotic stresses in S. album. [ABSTRACT FROM AUTHOR]

Jasmonic acid (JA) is reportedly involved in the interaction between insects and the vegetative parts of horticultural crops; less attention has, however, been paid to its involvement in the interaction between insects and the floral parts of horticultural crops. Previously, we investigated the allene oxide synthase 2 (AOS2) gene that was found to be the only JA synthesis gene upregulated in tea (Camellia sinensis) flowers exposed to insect (Thrips hawaiiensis (Morgan)) attacks. In our present study, transient expression analysis in Nicotiana benthamiana plants confirmed that CsAOS2 functioned in JA synthesis and was located in the chloroplast membrane. In contrast to tea leaves, the metabolite profiles of tea flowers were not significantly affected by 10 h JA (2.5 mM) treatment as determined using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry, and gas chromatography-mass spectrometry. Moreover, JA treatment did not significantly influence ethylene formation in tea flowers. These results suggest that JA in tea flowers may have different functions from JA in tea leaves and other flowers. [ABSTRACT FROM AUTHOR]