Food grade lingonberry extract: polyphenolic composition and in vivo protective effect against oxidative stress

Fractionation of the polyphenols constituting a food grade lingonberry extract (Vaccinium vitis-idaea) highlighted a composition more complex than described until now in the berry. Procyanidins B1, B2, and A2 were identified by UPLC/ESI-MS(2) along with the presence of other flavanol oligomers. Processing induced the release of large amounts of aglycones for ferulic acid, p-coumaric acid, and quercetin. The described anthocyanic composition of lingonberry was completed with hexoside derivatives of peonidin, petunidin, malvidin, and delphinidin. Besides confirmation of in vitro antioxidant activity, in vivo study was performed on rats fed a diet inducing oxidative stress. Supplementation with lingonberry extract significantly decreased the total oxidant status and favorably affected antioxidant defense enzymes in red blood cells and liver. A drop in the serum reduced glutathione level was also prevented, and uric acid was maintained at low level, confirming the antioxidant activity of the extract (5% proanthocyanidins) from a dosage of 23 mg/kg of body weight.     

Antagonistic effect of gibberellic acid and boron on protein and carbohydrate metabolism of soybean germinating seeds

Lots of soybean seeds (Glycine max L. Merr. cv MG 13 G2) were pretreated with solutions of boron (1 or 2 μg/ml) or/and gibberellic acid (GA₃) (0.1 μg/ml) during three hours, and germinated in a culture chamber at 24°±1°C. Germination and seedling growth were inhibited by boron. GA₃ activated both processes and partially reversed the inhibitory effect of the microelement. This protective effect of GA₃ against the negative action of boron is particularly due to the antagonism GA₃ /boron on protein and carbohydrate metabolism during the seed germination process.     

钼酸钠浸种对花生种子萌芽及幼苗生长的影响

本文研究不同浓度钼酸钠浸种对花生种子萌发和幼苗生长的影响。试验结果表明,一定浓度的钼酸钠溶液浸种,对花生种子萌发具有促进作用,可以提高花生种子的发芽率,促进种子胚根的生长。在花生幼苗生长阶段,它能增加叶片叶绿素含量和可溶性蛋白质含量,提高了过氧化氢酶活性和硝酸还原酶活性。实验结果显示,钼酸钠溶液浸种是促进花生种子萌发和幼苗植株生长的重要措施。     

Effects of postharvest treatment and heat stress on availability of wheat antioxidants

This research evaluated the effects of postharvest treatment and heat stress on the availability of wheat antioxidants using Ankor and Trego wheat varieties. The grain, bran, and 40-mesh bran samples of both Ankor and Trego wheat were kept at 25, 60, and 100 degrees C for 9 days. Samples taken at day 0, 1, 2, 3, 5, and 9 were extracted with pure ethanol and examined for antioxidant properties including the scavenging activity against peroxyl (ORAC), cation ABTS, and 2,2-diphenyl-1-picryhydrazyl (DPPH.) radicals, as well as total phenolic content (TPC) and phenolic acid composition. Both heat stress and postharvest treatment significantly altered the antioxidant properties of wheat grain fractions. The ORAC values of Ankor bran and corresponding 40-mesh bran samples kept at 100 degrees C for 9 days reduced to 61 and 40% of that at day 0 on a per dry weight basis, respectively, while the ORAC values of the grain samples showed no significant change. The overall loss of DPPH. scavenging capacity was 38 and 100% for the bran and 40-mesh Ankor bran samples, respectively, and was 47 and 60% in the bran and 40-mesh Trego bran samples, respectively, whereas no reduction was detected in the grain samples under the same heat stress. Heat stress and postharvest treatment had similar effects on ABTS.+ scavenging capacities and TPC values of grain and fractions of both varieties. These data suggest that whole grain as opposed to its fractions is a preferred form of long-term storage for better preserving natural antioxidants and that the reduction of the particle size may accelerate the loss of natural antioxidants in wheat bran during storage and thermal processing but may enhance the releasable amount of wheat antioxidants from bran.     

Salicylic acid alleviates the toxicity of cadmium on seedling growth,amylases and phosphatases activity in germinating barley seeds

The present study investigated the possible mediator role of salicylic acid (SA) in alleviating cadmium (Cd) toxicity during the germination stage of barley. The exposure of barley seedling to increasing Cd concentrations (25, 50 and 100 µM) during early stages of their establishment, caused a gradual decrease in vigour index, root length, α-amylase, acid phosphatase, alkaline phosphatase activities in endosperms and mitotic index of the root tip. Seed pretreatment with 600 µM SA partially alleviated the negative effects of Cd on germination parameters and increased the hydrolytic enzyme activities and mitotic index. Cadmium treatment increased Cd accumulation in roots. Furthermore, results showed that compared to the cadmium treatment applied alone, SA pretreatment of the seeds did not influenced the Cd concentration in the roots. These results suggest that SA plays a positive role in barley-seed germination and early seedling growth by protecting it against Cd toxicity by moderating its toxic effect on the mobilization of organic reserves.     

Effect of light conditions on the contents of glucosinolates in germinating seeds of white mustard, red radish, white radish, and rapeseed

The study was aimed at determining the effect of light conditions on contents of glucosinolates (GLS) in germinating seeds of white mustard, red radish, white radish, and rapeseed. The seeds were germinated in light and dark, at 25 degrees C, for up to 7 days. As compared to the nongerminated seeds, in seeds exposed to light and germinated for 4, 5, 6, and 7 days the content of total GLS was observed to decrease by 30 to 70% depending on the species. Germination in conducted the dark for the respective periods of time resulted in decreases of total GLS not exceeding 25%. The changes in the concentration of total GLS were attributed to aliphatic GLS predominating in seeds, yet in the case of white mustard to sinalbin belonging to aralkyl glucosinolates. Although seeds germinated in the dark, as compared to those exposed to light, were characterized by a higher total content of indole GLS, the percentage contribution of that group of compounds in white mustard, red radish, and white radish remained at a similar level, irrespective of germination time. Only in the case of rapeseed was the percentage of the sum of indole GLS observed to increase from 17 to up to 45% once the seeds were exposed to light and to 50% once they were germinated in the dark.     

盐胁迫对发芽水稻种子质膜透性及物质转化的影响

盐（NaCl）胁迫下水稻发芽种子的细胞膜透性增加，细胞伤害率加大，胞内K^ 、Na^ 外渗量增加：淀粉酶活性下降，尤其是α-淀粉酶活性迅速降低，使淀粉水解速率减慢，可溶性糖含量降低，淀粉贮藏组织中淀粉粒形象较密致；同时蛋白酶活性降低，蛋白质转化速率下降，糊粉层胞质中蛋白质残留量增多，干物质消耗减少。耐盐品种“119”水解酶活性受抑程度小于不耐盐品种“78130”，而贮存物质转化速率高于不耐盐品种“78130”，这表明水稻品种耐盐性与上述指标有密切相关关系。     

Silicon effect on growth,nutrient uptake,and yield of peanut (Arachis hypogaea L.) under aluminum stress

Abstract

The objective of this study was to investigate the effect of silicon (Si) on growth, nutrient uptake, and yield of peanut under aluminum (Al) stress. Peanut (Arachis hypogaea L. cv. Zhonghua 4) raised with or without Si (1.5?mM) in the growth chamber under 0 and toxic Al (0.3?mM) levels. Aluminum stress significantly decreased the biomass and root dry weight by 12.9% and 10.7%, and the pod yield, number of mature pod per plant and seed number of per pod by 16.7%, 10.7%, and 13.9%. The content of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) was significantly decreased, but that of Al increased markedly in shoots and roots of peanut after Al exposure at seedling, flower-needle and pod-setting stage. Under Al stress condition, Si application protected peanut by improving nutrient uptake at different growth stages and favoring the partitioning of dry mass to pod and the allocation of tissue N, P, K, Ca, and Mg to shoots and pod and decreasing Al uptake and accumulation.     

缺氮胁迫下含Na+叶面肥对花生生长的抑制及补氮后的恢复效应

【目的】叶面肥中的钠离子（Na+）大多为伴随离子,其对作物的影响通常被忽视。实践中,Na+对作物的作用包括促进和抑制两方面,取决于作物营养生理状况。研究Na+对花生的抑制与缺氮（N）胁迫的关系,探索补施氮素对上述抑制作用的恢复效应,可为花生高效合理施肥提供理论依据。【方法】盆栽试验在山东省花生研究所人工气候室内进行,设喷施肥料中含Na+0、2.0、10.0 mg/pot 3个水平,依次记为T0、T1和T2。测定了花生叶片光合作用、茎叶及根干物质累积、根系形态特性和养分吸收,比较了缺氮胁迫（T0、T1、T2）和后期补施尿素态N（T0-N、T1-N、T2-N）条件下Na+对花生影响的差异,并深入分析花生Na吸收与干物质累积和氮（N）、磷（P）、钾（K）养分吸收的相关关系。【结果】1）缺氮胁迫条件下,叶面喷施Na+显著抑制了花生的光合作用,净光合速率由CO₂ 11.4 μM/（m2·s）下降到CO₂ 6.7~7.5 μM/（m2·s）。茎叶和根干重T0（6.4和2.4 g/pot）>T1（5.7和1.9 g/pot）>T2（5.3和1.5 g/pot）。与T0相比,根总长度、总表面积和总体积T1处理下降了7.8%~10.5%,T2处理显著下降了27.5%~31.8%。植株Na与N、K含量呈显著负相关关系（P < 0.05）,花生Na吸收量每增加1.0 mg/pot,植株总的N、K吸收量分别下降26.6和20.9 mg/pot。2）后期补充喷施氮素条件下,施Na+处理花生茎叶干物重比不施Na+处理增加了20.3%~25.8%。补施氮素后,施Na+促进了茎叶对N、P、K的吸收,N的吸收量增加了9.2%~19.2%,P增加了20.0%~42.3%,K增加了21.4%~24.0%。相关性分析表明,花生植株总干物重及P、K含量在补施氮素后与Na含量呈显著正相关关系（P < 0.05）。【结论】Na+对花生生长及养分吸收的影响与氮素营养有关。在缺氮胁迫下,Na+对花生的生长为抑制作用,抑制程度随喷施量增加而加重,高浓度Na+显著抑制根茎叶干物质的累积和N、K养分的吸收。补施氮肥提高了花生植株对Na+的适应性,恢复了光合作用及养分吸收能力,消除了Na胁迫的危害作用,产生“N-Na”协同促进效应。     

Influence of soil moisture stress and soil bulk density on the imbibition of corn seeds in a sandy soil

The imbibition of corn seeds (Zea mays L.) was examined in a sandy soil compacted to simulate the effect that might be expected from pressure wheels behind a planting machine.Water uptake was found to be exponential and to be the only factor contributing to the increase in volume of the seed during imbibition. Changes in bulk density of the soil over the range from 0.90 to 1.31 Mg cm^?3 produced no significant effects on water uptake.It was therefore concluded that the degree of contact between seed coat and soil particles is not an important factor in influencing the rate of imbibition of corn seeds under the specific conditions which were examined.Water flux into the seeds was calculated to be several orders of magnitude lower than bulk soil water flux at all soil water potentials tested. Estimates of seed coat permeability suggest that, for corn, this factor is the major restriction on entry of water into the seed during imbibition.At a field level, the widespread use of pressure wheels behind corn planters as a means of increasing seed/soil contact appears not to be necessary in sandy soils.     

一株动性球菌对苜蓿的促生和缓解 NaHCO3胁迫作用

为改良和利用盐碱地,以大庆草原盐碱土为材料,筛选耐盐碱细菌,对筛选纯化后的细菌用 16S rRNA基因序列对其进行分子生物学鉴定,并对其能力进行分析;设置 2种处理(CK1:无菌蒸馏水;S1:菌液),对苜蓿种子进行发芽实验,比较不同处理下种子的发芽率、苗长和鲜重;同样,设置 2种处理(CK2:无菌蒸馏水;S2:菌液),采用蛭石浇灌营养液的培养方式进行试验,分析不同处理下的 NaHCO 3胁迫苜蓿生长特性及其抗氧化活性变化。结果表明,实验共分离获得 43株菌,其中,一株编号为 38的菌株(S38),基于 16S rRNA基因序列鉴定发现,该菌为动性球菌( Planococcus)属的菌株,具有固氮和产 ACC脱氨酶的能力;S1相比 CK1处理,显著提高了苜蓿种子的萌发率、苗长和鲜重;S2相比 CK2处理,地上部和地下部生物量分别提高 32%和 50%,Chla、Chlb和 Chla+Chlb含量分别增加了1.33、1.15和 1.28倍,而可溶性糖含量、抗氧化酶(SOD、POD、CAT)活性均有所降低,同时也影响了 K +吸收和分布。由此可见,S38对苜蓿种子有促生的作用,可影响 NaCO 3胁迫下苜蓿幼苗生长形态、根形态建成、光合作用等,降低苜蓿对盐的吸收,从而促进幼苗生长。综上,S38在缓解 NaHCO 3对植物的伤害方面有着重要的作用。     

Plants as biofactories: physiological role of reactive oxygen species on the accumulation of phenolic antioxidants in carrot tissue under wounding and hyperoxia stress

Plants subjected to postharvest abiotic stresses synthesize secondary metabolites with health-promoting properties. Here, we report the potential use of carrots (Daucus carota) as biofactories of caffeoylquinic acids when subjected to wounding and hyperoxia stresses. Wounding stress induced an increase of ～287% in total phenolic content (PC) in carrots stored for 48 h at 20 °C. This increase was higher (～349%) in the wounded tissue treated with hyperoxia stress. To further understand the physiological role of reactive oxygen species (ROS) as a signaling molecule for the stress-induced accumulation of phenolics in carrots, the respiration rate as well as the enzymatic activities of NADPH oxidase, superoxide dismutase, ascorbate peroxidase, and catalase were evaluated. Likewise, shredded carrots were treated with diphenyleneiodonium chloride solution to block NADPH oxidase ROS productions, and the phenylalanine ammonia lyase activity and total PC were evaluated. Results demonstrated that ROS play a key role as a signaling molecule for the stress-induced accumulation of PC in carrots.     

Effects of environmental stress on forest crown condition in Europe. Part II: Estimation of stress induced by meteorology and air pollutants

In order to assess the relationship betweenenvironmental stress and crown condition of foresttrees monitored since 1986 in Europe, estimates ofstress factors, including temperature stress, droughtstress and air pollution stress, were derived with thebest data, methods and models currently available.This paper presents information on the methods used toderive such stress factors, and on the overall ranges,the temporal trends, the spatial distribution and thereliability of the calculated stress factors. Thetemperature stress indices did not show much temporalvariation between 1985 to 1995. As expected spatialpatterns were north-south orientated, going fromcolder northern regions to warmer southern regions.The calculated relative transpiration showed a morecomplex pattern, coinciding to a large extend withpatterns of rainfall and temperature. Potential aciddeposition decreased between 1986 and 1992, butremained fairly constant after 1992. The strongdecrease was mainly the result of the decrease inSO_x deposition, and to a small decrease inNO_y deposition. Highest levels of the S and Ndeposition were calculated in Central and WesternEurope. Base cation deposition was largest in coastalareas and in southern Europe. This is mainly due tosoil dust, Sahara dust and sea salt. Base cationdeposition can compensate almost entirely for thepotential inputs in the south of Europe, whereas incentral Europe it equalled about 25% of thepotential acid input. A comparison between sitespecific modelled deposition and deposition derivedfrom throughfall data showed that the total aciddeposition is usually overestimated by the model,whereas the total nitrogen deposition isunderestimated, especially at plots with high nitrogenloads. There is, however, a significant correlationbetween measured and modelled data for all S and Ndeposition, thus allowing their use in a statistical analyses.