查看更多>>摘要：Phytophthora capsici is a notorious pathogen capable of infecting various host plants and causing serious threats to agriculture worldwide. Tetradium glabrifolium fruit essential oil (TFO) is widely utilized in traditional Chinese medicine treatment, but its antimicrobial activity is unknown. In this study, we first investigated the inhibitory efficacy of TFO against P. capsici and found TFO strongly inhibited the development of phytophthora blight on pepper by in vivo inoculation assay. Second, we found TFO could significantly suppress vegetative and reproductive growth of P. capsici in vitro. Microscope observations indicated that TFO destroyed the mycelial morphology and cellular ultrastructure of P. capsici. Additionally, TFO could damage the cell membrane integrity of the pathogen, leading to cellular leakages of intercellular contents of P. capsici. Third, TFO could enhance the activities of defence-related enzymes in pepper fruits during pathogen infection. Finally, we identified the chemical composition of TFO by GC-MS analysis and demonstrated three abundant components (D-limonene, beta-elemene, and 2-tridecanone) contributed to the antifungal activity of TFO. Together, out results revealed that TFO had outstanding inhibitory efficacy against P. capsici, and uncovered its potential antifungal mechanism. This study would propose the application of TFO as an efficient alternative approach for controlling phytophthora blight.
查看更多>>摘要：Bamboo is mainly composed of fiber and parenchyma cells, and the gradient fiber distribution structure endows bamboo with excellent mechanical properties and improves its heterogeneity. Little is known about the real-time distribution and distribution mechanism of water on the gradient structure. In this study, the real-time moisture content of primeval bamboo with different density and proportions of fiber cells was tested. The mathematical models were used to calculate the content and distribution of adsorbed water in monolayered and multilayered bamboo and the differences in hygroscopicity of gradient structures were analyzed at cell level, sub-cellular level and molecular scale The results showed that microfibrillar aggregates of parenchyma cells differ at the subcellular scale, and parenchyma cells were more sensitive to changes in ambient humidity than fibers. When the humidity was higher than 40%, the moisture content of the different parts of bamboo differed considerably. When the humidity was 90%, the moisture content of the Inner, Middle, and Outer were 28.81%, 25.57%, and 18.55% respectively. And the adsorption isotherm were analyzed using the Hailwood-Horrobin (H-H) models. The monolayer moisture content in Inner was between 3.00% -3.50%. Under a high humidity, the multilayer adsorbed water content of Inner, Middle, and Outer reached 20.40-23.30%, 17.50-20.40%, and 14.60-17.00%.
查看更多>>摘要：Climate change and human activities in recent years have led to habitat narrowing or migration of medicinal plants and may result in quality changes. However, Panax notoginseng (Burkill) F. H. Chen (P. notoginseng), a valuable traditional medicine in China, has been included in a few studies to address climate challenges. With the increasing demand for this medicinal herb, the sustainable supply of high-quality P. notoginseng has become particularly important. Therefore, this study integrated the habitat and quality of P. notoginseng to assess its potential distribution in China under climate change conditions. To achieve this, occurrence records and samples of P. notoginseng were collected using online and field surveys. Suitable habitats of P. notoginseng were predicted for different periods using the parameter-optimized MaxEnt model, and the saponin content of the samples was determined by high-performance liquid chromatography (HPLC). The results suggested that the current highly suitable habitats (105277.78 km2) were predicted to be mainly distributed in the central and eastern parts of Yunnan Province. However, under future climate change scenarios, the suitable habitat was predicted to gradually decrease and move to high-altitude areas in the central-eastern part of Yunnan province. Furthermore, the saponin content in highly suitable habitats was relatively low. Temperature and precipitation play a key role in the distribution of P. notoginseng. Overall, the findings of the present study serve as references for the identification of suitable areas for P. notoginseng cultivation in China.
Dias, Maria CelesteFerreira de Oliveira, Jose Miguel P.Marum, LilianaPereira, Vanessa...
12页
查看更多>>摘要：Extreme climate change events, such as long periods of drought and heat waves, are predicted to increase throughout this century. Pinus species are important economic resources. However, it remains unknown the vulnerability of most species to climate change-related stresses. We aimed to compare the performance reconfiguration of two resin/timber important species [Pinus elliottii var. elliottii (PE) and the hybrid Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis (PE x PCH)] to face combined stress of drought+heat. Young PE and PE x PCH plants were grown at optimal conditions, then exposed to water deficit for 5 days, and in the last day of water deficit, plants were additionally exposed to a heat shock. The physiological responses, antioxidant capacity and oxidative stress were evaluated immediately and 5 days (recovery) after drought+heat treatment. Under control conditions, the hybrid displayed higher photosynthetic and biochemical performance (e.g. higher net CO2 assimilation rate, transpiration rate, photosynthetic pigments and anthocyanins levels, carbohydrates and antioxidant enzyme activities). Immediately after the drought+heat episode, plant water status decreased in both species, as well as the PSII photosynthetic parameters (CYRILLIC CAPITAL LETTER EFPSII and Fv'/Fm'), while non-photochemical quenching increased. However, the gas-exchange parameters of PE and the hybrid responded differently to the combined stress. The hybrid suffered a stronger reduction on the net CO2 assimilation rate and transpiration rate, and presented higher levels of lipid peroxidation, but with no cell membrane permeability injuries. Principal component analysis supports that the different profile of both species is possibly associated to the stronger antioxidant capacity of PE under stress conditions. Moreover, these differences were still observed during recovery and photosynthesis was re-established totally only in PE. The hybrid clearly demonstrated less ability to restore the gas-exchange in the same period, possibly due to stomata re-opening limitations. The low net CO2 assimilation rates in the hybrid after stress relief could also result in the necessity to use the starch reserves to maintain TSS pools available for stress recovery. We conclude that the hybrid perform better under control conditions, and the PE seems better prepared to cope with the predictable global climate change scenarios forecast for the next decades. The hybrid is more affected by drought+heat, but is able to keep a photosynthetic performance close to the PE under stress, although less efficient during recovery.
查看更多>>摘要：Crop wastes are advantaged feedstocks for low-cost erythritol production via Yarrowia procedure, whereas a high amount of cellulose remains in the fermentative medium due to the lack of cellulase. The present study proposed a one-step solid-state fermentation (SSF) for erythritol production from oil crop waste that was simultaneous saccharified by the incorporated exogenous cellulase. Cellulase was immobilized in alginate-chitosan beads, and the outstanding performance of the immobilized cellulase in erythritol cultivation was proven based on its tolerance to pH and osmotic pressure, with high stability and reusability (83% of activity maintained after five cycles of utilization). Under the optimal condition of pH 6.0 and 0.01 g/g dry substrate with the immobilized cellulase addition of 1.5% (w/w), persistent cellulase activity accompanied by the efficient consumption of total sugar was detected during the cultivation. Enhanced erythritol production was achieved with the highest titer of 226.8 mg/g dry substrate in scale-up batch fermentation, when the fed-batch cultivation contributed to a considerable total amount of erythritol. Cost analysis suggests that the present process leads toward the development of eco-friendly and economically feasible erythritol production.
查看更多>>摘要：Globe artichoke [Cynara cardunculus var. scolymus (L.) Fiori] is a proven source of nutraceutical compounds with high bioavailability. However, different pre- and post-harvest variables may affect plant secondary metabolism. In this view, the present study investigated the influence of irrigation frequency and drying temperature on the yield of dry leaf biomass and its pharmacological value in terms of polyphenol content. The field treatments included three irrigation frequencies (7, 14 and 21-day intervals) with a single dose of 10 mm water, and control (not irrigated). Artichoke biomass leaves were collected from 120-day plants and dehydrated using different air temperatures (30 degrees C, 40 degrees C, and 50 degrees C). The samples were analyzed for polyphenolic compounds by HPLC method. Antioxidant activity was also studied by ABTS, DPPH, and FRAP assays. Irrigation frequency significantly influenced the yield of dry leaf biomass with a greater increase in the case of irrigation frequency every 7 and 14 days than every 21 days. The content of caffeoylquinic acids (TCQA) was higher under soil water deficit conditions than in the raw material obtained from plants irrigated with different frequencies. The drought stress caused by the lack of additional irrigation increased the content of chlorogenic and ferulic acids in the biomass leaves. Higher drying temperatures (40 and 50 degrees C) increased the content of cynarine by 100% and 132% and ferulic acid by 100% and 172%, respectively, compared to biomass leaves dried at 30 degrees C. Irrigation frequency influenced the content of flavonoids, and frequency every 7 and 14 days than 21 days reduced apigenin and increased luteolin content. A high correlation between the content of TCQA and the frequency of irrigation and drying temperature was reported.
查看更多>>摘要：Drying is a crucial step in processing for enhancing the storability of yam (Dioscorea hispida) slices. In this present work, the drying of yam slices was carried out in a lab-scale auto weighing forced convective hot air drier at a temperature span of 50-70 0C after 30 min of boiling. The study focused on drying behavior, fitting mathematical models to drying and color kinetics, examining the texture and rehydration ratio of dries yam slices. To exhibit the mass and color change characteristics, experimental data were fitted to seven drying kinetics and two color kinetics models. Model fitness was compared and selected based on chi-square (X2), goodness of fit (R2), residual sum of squares (RSS), and root mean square error (RMSE). Moisture diffusivity ranged from 4.5133 x 10-10- 7.522 x 10-10 m2/s and increased with temperature. The activation energy of 23.53 kJ/mol was obtained. Midilli-kucuk model confirmed the superior fitting to experimental data followed by two-term model. Color kinetics was determined using L, a, b values, total color change (Delta E), chroma, hue and browning index. L value reduced with drying time, while b and a value increased. Zero order kinetics fitted a and Delta E values adequately while first order kinetics described the changes in L and b values. It can be concluded that the Midilli-kucuk model can be used for predicting drying process behavor, system design of convective hot air drying of Dioscorea hispida for industrial scale up.
查看更多>>摘要：Drought stress is one of the important abiotic stresses that restrict the growth of plants. Plants acclimatize themselves to the stress by reprogramming their metabolic pathways. Therefore, understanding the metabolic mechanisms of plants is of great importance to meet the challenge of water shortage. Licorice (Glycyrrhiza uralensis Fisch.) is a commonly used herb that is widely distributed around the world. Nevertheless, the variation of integrated metabolites in licorice under drought stress are still unclear. In this study, the non-targeted metabolomic technology was applied for the first time to comparatively investigate the metabolites changes under different degree of drought stress (slight, moderate, and intense) of two morphologically distinct genotypes of licorice from Gansu (G1) and Xinjiang (G2) provinces. Under the drought conditions, the length and dry weight of the roots of licorice were affected. Different degrees of drought caused antioxidant enzyme activities in both of the two genotypes to increase first and then decrease, and the increase in the G1 genotype was greater than that of the G2 genotype. The amino acid metabolism, flavonoid metabolism and other metabolic pathways were disrupted by drought stress. Additionally, a higher amount of amino acids such as tryptophan and tyrosine was observed in the root of the G2 genotype, and the increase of phospholipid content in the G2 genotype depended on the deepening of drought stress. Slight or moderate drought stress was beneficial to the accumulation of flavonoids. The glycosylation modification of flavonoids and accumulation patterns of jasmonic acid and abscisic acid had differences between genotypes. Collectively, this study provided new insights into the potential biochemical pathways of licorice or other legumes in response to drought and a fundamental framework to improvement the medicinal value of licorice.
查看更多>>摘要：Xylanase and laccase are now used more frequently in biomass biorefinery. Different operational conditions of the two enzymes reflect their limitations for enzyme cocktails. Xylanase and laccase bleaching efficiencies were studied to reveal evidence of their synergistic action on energy cane (EC) structural features. Temperature and pH of both enzymes were optimized to a one-step treatment of mixing enzymes after alkaline pretreatment. Results showed that a single pretreatment of 50 Ug-1 xylanase and 100 Ug-1 laccase significantly enhanced the whiteness index of pretreated fibers by 85%. Whiteness index increased to 95% when biobleaching synergistic xylanase/laccase treatment was applied. Synergistic xylanase/laccase-treated fibers showed 70% xylan removal, with enhanced crystallinity index at 59% compared to single xylanase and laccase-treated fibers. Synergistic xylanase/laccase treatment increased the specific surface area (2.8 m2g-1) and surface roughness (81.83 mu m) of the fibers, indicating partial xylan hydrolysis and lignin depolymerization. NMR spectroscopy exhibited bond cleavage of lignin-xylan and lignin inter-unit linkages due to enzyme synergistic actions. Results increase the understanding of synergistic action mechanisms between xylanase and laccase to improve biobleaching efficiency and can be implemented to enhance biorefinery production of various lignocellulosic biomass.
NSTL
Elsevier