Using tree leaves and barks collected from contaminated and uncontaminated areas as indicators of air metallic pollution

Abstract

The aim of this study was to show the usefulness of woody species in assessing air pollution by cadmium, copper, lead, and zinc. For this, washed leaves, unwashed leaves, and barks of a coniferous species (Cupressus sempervirens var. fastigiata) and a broadleaved one (Eucalyptus cladocalyx F. Muell) were analyzed for cadmium, copper, lead and zinc contents. A transect sampling approach was carried out during spring 2016. Fifty stations were selected along an intensive traffic road, and three in a control area. The results showed that the highest concentrations were recorded in barks for copper (21.86?µg/g, 23.33?µg/g) and lead (14.53?µg/g, 63.33?µg/g), and in unwashed leaves for cadmium (0.57?µg/g, 1.19?µg/g) and zinc (48.94?µg/g, 47.6?µg/g) for E. cladocalyx F. Muell, and C. sempervirens var. fastigiata, respectively. Lead and zinc are the most accumulated metals compared to cadmium and copper in all samples. The studied metal contents in urban area were significantly higher than that of the control one. This represents that traffic road has influenced the metals contamination of the surrounding area. Results of the bioconcentration factor (BCF) for both species indicate that the studied species could be used as biomonitors to identify ecological problems and to predict effect on wildlife habitats. The highest values of metal accumulation index (MAI) indicate the effectiveness of these trees for controlling the air metals in the polluted areas. Result shows too that the studied species could be used for phytoextraction of heavy metals from the polluted soils and/or air.     

Size fractions of dust and amount of associated metals on leaf surface and inner wax of 15 plant species at Beijing roadside

To provide more insight into the removal ability of urban air dust and associated metals by plant leaves, and thus guide urban green planning to improve air quality, 15 plant species leaves collected from Beijing roadside were analyzed for size fractions of leaf surface dust (SD) and inner wax dust (WD). Seven associated metals Cd, Cr, Cu, Fe, Mn, Pb and Zn were also measured. Metal Accumulation Index (MAI) was calculated for different species leaves at various dust sizes and soluble forms, respectively. Cluster analysis was used for the plant species and correlations between dust and metal concentrations and for inter-metal concentrations were calculated for both surface and inner wax dust. Mean leaf total dust TD (SD?+?WD), SD and WD were measured as 1159, 817 and 342?mg m^?2, respectively, with the highest values observed all in Euonymus japonicus. Most species leaves collected larger ratios of SD than WD except Salix babylonica and Robinia pseudoacacia. While SD was presented at all particle size fractions for all plants, nearly all species leaves collected higher proportions of WD >10?µm. Mean metal levels of leaf TD of all species ranged from high to low as Fe?>?Cr?>?Zn?>?Pb?>?Cu?>?Mn?>?Cd, but with different orders for individual species. Metals were observed in all sizes of SD/WD, although the size distributions were various for certain metals. Intercorrelations of metal concentrations in leaf SD/WD were positively significant except Pb, which may have different emission sources. Species Prunus cerasifera f. atropurpurea, Syringa oblata, Malus micromalu, Koelreuteria paniculata and Robinia pseudoacacia may possess better overall metal collection ability due to their relatively higher MAI values, but species Euonymus japonicus, Malus micromalu, Ligustrum x vicaryi and Koelreuteria paniculata were identified as the best choices in removing air dust based on cluster analysis and suggested to be planted at heavy trafficked road site for air quality improvement.     

Enzymatic acylation of flavone isolated from extractive of bamboo leaves with oleic acid and antioxidant activity of acylated product

This present study aims to establish a relatively cheap and effective method for preparation of ester of flavone isolated from bamboo‐leaf extracts. According to this method, the solubility of bamboo leaf extract in a lipid medium could be improved, which would expand the utilization of bamboo leaf extract. Acylation of flavone with oleic acid was efficient in a system containing dried tert‐amyl‐alcohol and molecular sieves. The bioconversion yield ranged from 24 to 63% in different conditions. the type of fatty acids, the amount of the lipase, water content and temperature of the system were investigated in detail to influence on the performance of the acylation reaction. High purity of ester (>95%) was obtained by a two‐step solvent purification procedure and chromatographic separation. Followed by the 1H and 13C nuclear magnetic resonance spectroscopy analysis, single product of 6′′‐O‐oleate isoorientin ester was detected. Introducing an acyl group into isoorientin significantly improved its lipophilicity yet slightly reduced their antioxidant activity, while its antioxidant activity still significantly better than VE.     

西藏高原硬叶柳叶片结构对寒旱环境的适应机制

为探究硬叶柳叶片结构对高寒高海拔环境的适应机制,以西藏那曲嘉黎县硬叶柳叶片为试验材料,应用石蜡切片技术和植物显微技术,分析硬叶柳叶片结构对寒旱环境的适应特征。结果显示:(1)硬叶柳叶片为异面叶,叶片背面有表皮毛,叶片主叶脉在叶片下部凸起,呈现不规则半圆形;栅栏组织呈柱状紧密排列,有2～3层,海绵组织形状多为短柱状或者短球形,细胞间隙较大。(2)随着海拔的不断升高,硬叶柳叶片厚度从最低海拔(4 000 m)的40.4μm增加到最高海拔(4 700 m)的68.04μm,其中叶片下表皮厚度在海拔4 400 m～4 700 m之间呈显著增加的趋势,而上表皮厚度在4 000～4 400 m之间变化不显著;海绵组织和栅栏组织厚度变化分别在9.34～24.84μm、25.63～40.36μm之间,且随海拔梯度的升高海绵组织和栅栏组织的厚度均呈不显著的增加趋势。(3)硬叶柳叶片上表皮无气孔分布,下表皮散生着大量气孔,且气孔器小而密集,其密度为17.87～28.37个·mm~(-2),单位面积的气孔总周长为0.13～0.25 mm,但气孔密度和单位面积的气孔周长在海拔梯度上没有明显变化。研究表明,硬叶柳叶片主要通过增加叶片厚度来适应高海拔地区的寒旱环境。     

山杏叶乙酸乙酯提取物调控乳腺癌MCF7细胞增殖和凋亡的机制研究

为探究山杏叶乙酸乙酯提取物对乳腺癌MCF7细胞株增殖和凋亡的影响,本研究采用CCK8法检测山杏叶提取物对MCF7细胞增殖的抑制作用,流式细胞仪检测细胞凋亡率,倒置荧光显微镜和流式细胞仪分别检测胞内活性氧(ROS)的水平变化,RT-PCR检测细胞周期及凋亡相关基因的表达情况,试剂盒检测caspase-3的活性。实验表明,山杏叶提取物可降低MCF7细胞存活率,促进细胞凋亡,增加胞内ROS水平。同时上调和Bax,下调Bcl-2,增强caspase-3活性,并降低CDK4、CyclinE和CyclinD1的表达。综上说明山杏叶提取物可通过调控周期蛋白的表达来抑制MCF7细胞的增殖,并通过caspase途径和提升ROS水平来诱导MCF7细胞的凋亡。     

荷叶总生物碱激活肝脏AMPK/Nrf2通路缓解对乙酰氨基酚诱导的小鼠急性肝损伤

为探讨荷叶总生物碱(TAL)对对乙酰氨基酚(APAP)所致小鼠急性肝损伤的保护作用及可能机制,小鼠被随机分为正常组,模型组和TAL低、高剂量组(30、100 mg/kg),连续灌胃给药七天后,除正常组外,其余各组腹腔注射300 mg/kg的APAP诱导急性肝损伤。12小时后,收集各组小鼠的血清与肝脏样本,进行后续实验。结果显示,与模型组相比,TAL可显著降低血清中的ALT和AST活性,下调肝组织中TNF-α、IL-1β、IL-6和MDA含量,上调肝组织中SOD、CAT、GSH-Px和GSH的水平。此外,TAL还明显改善了APAP诱导的小鼠肝组织病变。在TAL的作用下,肝内AMPK磷酸化水平提高,Nrf2蛋白入核,HO-1和GCLC基因表达上调。综上所述,TAL对APAP诱导的急性肝损伤具有保护作用,其机制可能与激活AMPK/Nrf2通路相关。     

银杏叶萜内酯含量的变化及其与叶绿素荧光特性的关系

为探究银杏(Ginkgo biloba)叶萜类内酯含量和光合同化作用的关系,对其内酯含量和叶绿素荧光特性进行了研究。结果表明,不同采收时间银杏叶中白果内酯和银杏内酯含量有显著差异,总体上,5月份含量较低,此后逐渐升高,8月份达到高峰,然后快速下降,10月底最低;与此同时,银杏叶片的光合色素以及叶绿素荧光参数也呈现周期性变化。白果内酯以及萜内酯含量与叶绿素荧光参数Y(NPQ)之间呈极显著正相关关系,因此,可以通过银杏叶片的叶绿素荧光参数预测白果内酯和萜内酯含量。     

邳州银杏内生放线菌分离、筛选及活性菌株鉴定

【目的】从银杏中分离、筛选得到具有抑菌作用的内生放线菌,为放线菌在生物防治上的应用提供新的菌种资源。【方法】采用组织贴片培养法进行分离,生长对峙法进行筛选。【结果】从银杏的根、茎、叶中分离得到98株、50株、8株内生放线菌(共计156株),47株放线菌具有拮抗植物病原真菌活性。菌株KLBMP 5501抗菌活性最好且具有广谱性,基于形态特征、培养特征、生理生化特征和16S rRNA基因序列的相似性分析等多项分类特征表明,菌株KLBMP 5501是一株浅紫链霉菌(Streptomyces violascens)。【结论】筛选得到了具有应用潜力的高活性菌株,并进行了菌种鉴定。     

水杨酸对牡丹叶片耐冷性的影响

为了探索低温胁迫下,水杨酸(salicylic acid,SA)提高牡丹叶片耐冷性的生理机制,以8年生牡丹品种‘胡红’20 d叶龄的叶片为试材,将其浸入0、0.5、1.0、1.5、2.0 mmol·L-1的SA水溶液,置于4℃光照培养箱进行暗培养,经0、4、8、12 h的低温处理后取样测定其活性氧水平和保护酶活性,MDA、可溶性糖和可溶性蛋白含量及细胞膜透性。结果表明:施用低于2.0 mmol·L-1的SA可减轻低温对牡丹叶片的伤害程度,降低O-2·、H2O2和MDA含量以及细胞膜透性,但能使可溶性糖、可溶性蛋白含量升高,POD、SOD和CAT活性增加。其中1.0 mmol·L-1的SA能显著降低叶片组织中O-2·和MDA的含量,明显降低低温引起的叶片水渍化程度,随着低温处理时间的增加,这种效果更加明显。施用2.0 mmol·L-1的SA并不能明显减轻低温引起的叶片水渍化程度,当低温处理12 h后,叶片受到的低温伤害程度和没有施用SA时没有明显区别。总之,SA是否能明显提高牡丹叶片的耐冷性与其浓度有关,1.0 mmol·L-1的SA最能提高牡丹叶片的抗寒性,过低和过高浓度的SA则不能明显增加叶片的抗寒性。该研究成果能快速应用于牡丹的提早生产,并为增强其它作物的抗寒性提供理论参考。     

云南近光滑小檗(小檗科)主要分类学性状特征的变异式样

通过野外居群取样,结合实验室观察、标本检查及统计分析方法,研究了云南省腾冲县近光滑小檗主要分类学性状特征的变异式样。结果显示:(1)近光滑小檗叶片长度为1.95~12.91(5.54±2.15)cm,宽度为0.45~1.94(0.97±0.32)cm;单个簇生花序中花数目为2~14(5.1±2.2)个,花黄色,花被片数目为13~20(15.36±1.34)个;具蜜腺花被片为狭倒卵形至宽倒卵形,先端常缺裂,偶全缘,长3.18~5.94(4.82±0.52)mm,宽1.45~4.41(2.65±0.54)mm。(2)子房内胚珠数目及果实内种子数目都是1个;浆果椭圆形至卵状椭圆形,紫黑色,长3.37~8.36(6.91±0.82)mm,宽2.85~5.13(4.02±0.46)mm;果柄长0.47~2.20(1.10±0.32)cm。(3)在变异系数方面,簇生花序中花数目(0.37)叶长(0.21)叶宽(0.18)果柄长度(0.17)具蜜腺花被片宽度(0.14)具蜜腺花被片长度(0.08)=花被片数目(0.08)果长(0.07)=果宽(0.07)。(4)对《中国植物志》中近光滑小檗空缺的绘图补充了叶、花和果实等图片资料;并讨论了生境条件对近光滑小檗居群间变异的影响,及其与同域种卷叶小檗的种间关系。