Effect of Copper and Zinc on Accumulation of Vitamin E in Wheat Embryo-derived Callus

[Objective] The aim was to study the effect of the content of copper and zinc on in medium the vitamin E accumulation in wheat embryo-dreived callus.[Method] The mathematical models were established to describe the growth kinetics and the vitamin E accumulation in wheat embryo callus cells.With the aim of getting the highest accumulation of the secondary metabolite Vitamin E,the optimal combination of copper and zinc in medium was confirmed by testing.[Result] The results showed that the production of vitamin E in B5 medium reached the highest value with 2.0 mg/mL ZnSO4·7H2O and 0.1 mg/mL CuSO4·5H2O.The fitting degrees of kinetic models of vitamin E accumulation and cell growth were 97.53% and 95.60%,respectively,which indicated good nonlinear relationships.[Conclusion] Both copper and zinc could affect the accumulation of vitamin E in wheat germ callus,and Copper showed more prominent effect than Zn.Synergism existed in low copper and zinc concentration,and the inhibitive effect enhanced with the increase of the concentrations.

In vitro demonstration of interactions among zinc-binding domains of cellulose synthases in Arabidopsis and aspen

Plant cellulose synthases (CesAs) are the key enzymes necessary for cellulose biosynthesis. In Arabidopsis, two distinct groups of three CesAs each are necessary for cellulose synthesis during primary and secondary cell wall formation. It has also been suggested that such three CesAs interact with each other to form plasma-membrane bound rosette complexes that are functional during cellulose production. However, in vivo demonstration of such assemblies of three CesAs into rosettes has not been possible. We used yeast two-hybrid assays to demonstrate the possible interactions among several CesAs from Arabidopsis and aspen via their N-terminal zinc-binding domains (ZnBDs). While strong positive interactions were detected among ZnBDs from secondary wall associated CesAs of both Arabidopsis and aspen, the intergeneric interactions between Arabidopsis and aspen CesAs were weak. Moreover, in aspen, three primary wall associated CesA ZnBDs positively interacted with each other as well as with secondary CesAs. These results suggest that ZnBDs from either primary or secondary CesAs, and even from different plant species could interact but are perhaps insufficient for specificities of such interactions among CesAs. These observations suggest that some other more specific interacting regions might exist within CesAs. It is also possible that some hitherto unknown mechanism exists in plants for assembling the rosette complexes with different compositions of CesAs. Understanding how cellulose is synthesized will have a direct impact on utilization of lignocellulosic biomass for bioenergy production.

THE INFLUENCE OF ZINC ON THE MUTAGENICITY OF CADMIUM

The mutagenicity of two kinds of heavy metal:Cadmium and Zincand the influence of Zinc on the mutagenicity of Cadmium werestudied with miotic gene conversion of yeast saccharomces ce-revisiae strain D7,and with sister chromotid exchang（SCE）,chromosome aberration （CA） of human lymphocytes.The resultsshowed:

Absorption,Accumulation and Distribution of Zinc in Highly-Yielding Winter Wheat

Zinc（Zn） is an important essential microelement for wheat.In order to study the characteristics of Zn absorption,accumulation and distribution in highly-yielding winter wheat（with a grain yield of 9 000 kg ha-1）,field experiments were conducted in Gaocheng County of Hebei Province,China.Four winter wheat cultivars,i.e.,Shimai 14,Jifeng 703,Shimai 12,and Shixin 828,and four cultivars,i.e.,Temai 1,Shimai 12,Shixin 531,and Shixin 828,were used in the experiment,during 2004-2005 and 2005-2006,respectively.Plant samples were taken from the plots at each growing stage for Zn concentration analysis.The main results showed that the concentration of Zn in various above-ground organs of wheat was 9.5-112.5 mg kg-1 at different growing stages.The organ with the highest Zn concentration differed with the change of growth center at different growing stages.Accumulation of Zn in leaf blades was the highest among all the organs during early growing period,and more than 50% of the Zn accumulation was distributed to leaf blades before jointing,and higher than that to other organs.In late growing period,however,the accumulation of Zn in grains was the highest,and 58.1% of the Zn accumulation was distributed in grains at maturity.The total accumulation of Zn in wheat plant during its life span ranged from 384.9 to 475.9 g ha-1.The amount of Zn required for the formation of 100 kg grain yield ranged from 4.3 to 5.2 g.All the organs were ordered in such a sequence that leaf blades 〉 spikes 〉 leaf sheaths 〉 stems according to their net absorption and transportation of Zn as well as their contribution to Zn accumulation in grains.58.2-60.3% of the Zn accumulated in grains was redistributed from other organs,mostly from leaf blades.Concentration and accumulation of Zn in all the organs of wheat was high during early and middle growing periods,while accumulation of Zn in grains during late growing period mainly depended on the redistribution from other organs.According to these characteristics of Zn absorption and accumulation,Zn should be applied as seed dressing or basal fertilizer,so as to accelerate the early growth and Zn absorption of wheat.

Knocking-Out OsPDR7 Triggers Up-Regulation of OsZIP9 Expression and Enhances Zinc Accumulation in Rice

Zinc(Zn) is an essential trace mineral that is required for plant growth and development. A number of protein transporters, which are involved in Zn uptake, translocation and distribution, are finely regulated to maintain Zn homeostasis in plant. In this study, we functionally characterized an ATP-binding cassette(ABC) transporter gene, OsPDR7, which is involved in Zn homeostasis. Os PDR7 encodes a plasma membrane-localized protein that is expressed mainly in the exodermis and xylem in the rice root.ospdr7 mutants resulted in higher Zn accumulation compared with the wild type. Heterogeneous expression of OsPDR7 in a yeast mutant rescued the Zn-deficiency phenotype, implying transport activity of OsPDR7 to Zn in yeast. However, no ZIP genes except for OsZIP9 showed change in expression profile in the ospdr7 mutants, which suggested that OsPDR7 maintains cellular Zn homeostasis through regulating Os ZIP9 expression. RNA-Seq analysis further revealed a set of differentially expressed genes between the wild type and ospdr7 mutants that allowed us to propose a possible OsPDR7-associated signaling network involving transporters, hormone responsive genes, and transcription factors. Our results revealed a novel transporter involved in the regulation of Zn homeostasis and will pave the way toward a better understanding of the fine-tuning of gene expression in the network of transporter genes.

A novel cell-impermeable fluorescent zinc sensor containing poly(ethylene glycol) chain

A novel cell-impermeable zinc sensor was synthesized by incorporating poly（ethylene glycol） （PEG） to N-（8-quinolyl）-p- aminobenzenesulfonamide （HQAS） group. The polymeric zinc sensor combines both valuable features of HQAS and PEG. The HQAS of the sensor has the similar functions to TSQ, and exhibits a good fluorescence response to Zn^2＋ but poor fluorescence responses to other metal ions. The PEG chain can prevent the sensor to permeate healthy cell membrane. The stained experirnents with the yeast cells as model showed that the sensor cannot stain the healthy yeast cells, but only the damaged or died yeast cells. These results indicated the novel zinc probe was a typical cell-impermeable zinc sensor.

Variation in copper and zinc tolerance and accumulation in 12 willow clones： implications for phytoextraction

Willows （Salix spp.） have shown high potential for the phytoextraction of heavy metals. This study com- pares variations in copper （Cu） and zinc （Zn） tolerance and accumulation potential among 12 willow clones grown in a nutrient solution treated with 50 pmol/L of Cu or Zn, respectively. The results showed differences in the tolerance and accumulation of Cu and Zn with respect to different species/clones. The biomass variation among clones in response to Cu or Zn exposure ranged from the stimulation of growth to inhibition, and all of the clones tested showed higher tolerance to Cu than to Zn. The clones exhibited less variation in Cu accumulation but larger variation in Zn accumulation. Based on translocation factors, it was found that most of the Cu was retained in the roots and that Zn was more mobile than Cu for all clones. It is concluded that most willow clones are good accumulators of Zn and Cu.

Zinc Accumulation Characteristics of Two Exophiala Strains and Their Antioxidant Response to Zn²⁺Stress

Zinc is an essential element, which is toxic for organisms in their natural environments in excessive amounts. The zinc accumulation characteristics of a Zn-tolerant strain (H93, EC50 = 1010 mg·L–1 Zn2+) and a Zn-sensitive strain (B40-3, EC50 = 26 mg·L–1 Zn2+), Exophiala spp. and their antioxidant response to Zn2+ stress were comparatively characterized. Under their respective Zn2+ median effective concentrations, H93 absorbed 2.5-fold and accumulated 5.2-fold more Zn than B40-3. An elution experiment using CaCl2 revealed that Zn mainly accumulated intracellularly in the mycelia of the two fungal strains. The modulation of antioxidant components and antioxidant enzyme activities of the two fungal strains were comparatively analyzed under different Zn2+ concentrations. The activity of the total superoxide dismutase, peroxidase, and glutathione of H93 was always higher than that of B40-3, and the malondialdehyde content in H93 was also higher than that of B40-3. The current results suggested that the Zn tolerance of Exophiala strain may be attributed to their various instinctive behaviors with different rates of Zn accumulation and modulation of antioxidant components.

氮锌配施对不同锌效率玉米品种植株矿质元素累积、分配的影响

以锌高效玉米品种郑单958和锌不敏感品种隆平638为试验材料,设置90 kg/hm^(2)(LN)、180kg/hm^(2)(MN)、225 kg/hm^(2)(HN)3个施氮量和不喷施锌肥(F0)、拔节期和大口期1∶1喷锌4.5 kg/hm^(2)(F1)2个喷锌处理,分析氮锌配施对不同锌效率玉米品种植株矿质元素含量、累积量、分配和籽粒产量的影响,为玉米生产上氮锌合理配施提供依据。结果表明,玉米籽粒中铜、锌含量以MN处理最高,分别为1.82、16.23 mg/kg。F1处理能够提高籽粒中氮、锌含量和锌有效性。植株中氮、磷、钾累积量以MNF1处理隆平638最高,籽粒中铜和锌、锰和铁累积量分别以LNF1、HNF1处理郑单958最高。籽粒中氮、磷、铜的占比以隆平638 HNF1处理最高,籽粒中锌占比以郑单958 HNF0和LNF0处理较高。HN处理籽粒产量最高,平均为10.31 t/hm^(2),其次是MN处理,LN处理最低。2个品种籽粒磷含量与锰含量均呈极显著正相关,隆平638籽粒钾含量与铁、锌含量均呈显著正相关,与铜含量呈显著负相关。总体来看,施氮量180 kg/hm^(2)配合拔节期和大口期1∶1叶面喷施锌肥能够提高玉米籽粒中锌生物有效性和矿质元素累积量,促进玉米籽粒产量和矿质元素营养同步提高,可在大田中进行推广应用。

水稻泛素连接酶D3与抗病相关蛋白VOZ2的互作分析

多蘖矮秆基因dwarf-3(D3)是水稻独脚金内酯信号转导过程中的重要节点基因,拟南芥中的MAX2基因与D3同源,且MAX2参与拟南芥的抗病防卫反应。本研究以水稻泛素连接酶D3为诱饵进行酵母双杂筛库,发现水稻抗病相关蛋白维管植物单锌指蛋白VOZ2与D3存在潜在的相互作用。通过酵母双杂交试验证实,D3与VOZ2存在互作。通过荧光定量PCR证实,接种水稻白叶枯病菌后,VOZ2基因在转录水平上的表达受到显著诱导。利用水稻原生质体开展的亚细胞共定位实验发现,D3与VOZ2共定位于细胞核。双分子荧光互补实验发现,D3与VOZ2在烟草叶肉细胞的细胞核和细胞质均产生较强的荧光,进一步证实了D3与VOZ2的相互作用。研究结果为进一步探究D3和VOZ2在水稻抗病防卫反应中的功能与分子机理奠定了基础。

HOG1基因缺失对酵母细胞锌耐受的影响

以酿酒酵母(ΔHOG1突变株和野生株BY4741)为材料,检测了酵母细胞在硫酸锌胁迫下生长、凋亡、ROS水平和线粒体膜电位的变化.结果显示,高浓度硫酸锌可抑制酵母细胞生长,引起胞内ROS水平升高和线粒体膜电位下降,进而诱导细胞发生凋亡.在3 mmol/L的硫酸锌处理组中,ΔHOG1突变株的锌耐受性和线粒体膜电位显著低于野生株BY4741,而胞内ROS水平和细胞凋亡率显著高于野生株BY4741.结果表明,HOG1 MAPK可通过影响胞内ROS水平调控酵母细胞对硫酸锌的耐受性.

基于人5α还原酶活性试验对化妆品控油原料的筛选

本文通过测试样品对人5α还原酶活性的抑制率来评估筛选化妆品原料的控油作用,在1%的测试浓度下,柠檬巴豪提取物、柳兰提取物、红车轴草提取物、苦参提取物和富锌酵母都对5α还原酶有一定的抑制作用,抑制率在22.29%~55.28%,其中富锌酵母效果最好,抑制率为55.28%。在5%样品浓度条件下,茶树纯露、马鞭草迷迭香纯露、薰衣草提取物、迷迭香提取物和金缕梅提取物对5α还原酶的抑制率在48.24%~68.34%,其中金缕梅提取物和薰衣草提取物效果相对较好,抑制率分别为68.34%和60.00%。在0.5%浓度测试下,壬二酸和一水柠檬酸效果非常好,对5α还原酶的抑制率达到90%以上,分别为95.29%和92.36%。植物复合单宁酸、乳糖酸和葡萄糖酸内酯对5α还原酶的抑制相对弱一些,抑制率分别为51.38%、65.33%和44.27%。

小麦富锌育种的发展现状及研究趋势

本文总结分析了农田土壤锌含量分布现状、锌对小麦籽粒营养品质的影响、小麦对锌的吸收积累特性以及小麦籽粒锌营养强化途径等。土壤中锌含量的分布特征与地形地貌、地质构造和生态环境等密切相关,部分小麦主产区的土壤中锌含量较低。锌是一种重要的微量元素,对小麦籽粒淀粉和蛋白质含量均有影响,一般被植物根系吸收后,在根部压力或蒸腾作用下被输送到地上部,或者被横向输送到韧皮部,由韧皮部进行向上或向下的运输,再被运输到各组织和器官中。小麦锌强化途径包括遗传改良育种、农艺改良和生物技术应用等。研究结果为小麦富锌育种提供了一些新的思路。

酵母菌/锌发酵产物在头皮护理中的功效研究

从人体安全性、控油去屑功效、毛囊养护等方面初步认识酵母菌/锌发酵产物在头皮护理方面的功效。通过人体斑贴试验测试酵母菌/锌发酵产物的人体安全性;使用体外SZ95细胞模型研究酵母菌/锌发酵产物的控油功效,并使用qRT-PCR法验证油脂分泌相关基因SREBP-1c,PPARG和PI3K的表达;采用分光光度法测试酵母菌/锌发酵产物对5α-还原酶的抑制率;通过人体功效测试和离体毛囊模型分别研究酵母菌/锌发酵产物对头皮油脂的抑制效果和对毛囊的养护作用。结果表明:5%含量的酵母菌/锌发酵产物对人体安全隐患较小;0.8%~1.5%含量的酵母菌/锌发酵产物均可显著抑制5α-还原酶的活性;0.5%~2.0%含量的酵母菌/锌发酵产物均可显著抑制体外SZ95细胞油脂的分泌,并显著下调与油脂分泌相关基因SREBP-1c和PPARG的表达,1.0%、2.0%含量的酵母菌/锌发酵产物可显著抑制PI3K的表达;5%含量的酵母菌/锌发酵可显著降低头皮油脂分泌量,并具有改善毛囊周期和促进毛干增长的作用。因此,酵母菌/锌发酵产物具有一定头皮护理功效,在控油、改善毛囊健康、促进毛干生长等方面具有积极作用。

脂肪酸代谢紊乱通过上调ZNF143促进胰腺癌进展的机制研究

目的·通过肿瘤转录组学筛选,明确在胰腺癌中因脂肪酸代谢紊乱引起上调的关键基因,并探究其中的锌指蛋白143(zinc finger protein 143,ZNF143)在胰腺癌中的表达及其对胰腺癌细胞迁移、侵袭能力的影响。方法·运用R语言整合Gene Expression Omnibus(GEO)数据库中GSE164760数据集、癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据库中179例胰腺癌组织和4例癌旁组织及GTEx(Genotype-Tissue Expression)数据库中167例胰腺正常组织的转录组数据;筛选分析胰腺癌中脂肪酸紊乱可能会诱导表达的潜在差异基因;qRT-PCR检测使用棕榈酸(palmitic acid,PA)或油酸(oleic acid,OA)处理24 h后胰腺癌细胞中筛选基因的mRNA水平变化。按照筛选基因ZNF143表达水平的中位数,将TCGA数据库中胰腺癌患者分为高低表达2组,并将2组分析所得的差异基因进行京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)通路和基因本体论(Gene Ontology,GO)富集分析;通过细胞划痕实验、侵袭实验检测使用siRNA敲低ZNF143对胰腺癌细胞的迁移、侵袭能力的影响;使用蛋白质印迹法(Western blotting)检测敲低ZNF143对上皮-间质转化(epithelial-mesenchymal transition,EMT)相关蛋白及Wnt/β-catenin通路的影响。结果·分析了胰腺癌和肝癌中脂质代谢紊乱上调的关键基因,其中ZNF143是胰腺癌脂肪酸蓄积诱导的潜在基因之一;体外实验验证棕榈酸或油酸处理胰腺癌细胞后,ZNF143的mRNA水平均明显上调;KEGG和GO富集分析均显示ZNF143相关差异基因主要富集于细胞黏附相关通路;功能实验表明,转染ZNF143 siRNA的胰腺癌细胞迁移与侵袭能力均被下调,且EMT相关蛋白的表达也降低,可能与Wnt/β-catenin通路激活有关。结论·脂肪酸蓄积上调ZNF143在胰腺癌细胞中的mRNA表达含量,且ZNF143可能通过激活Wnt/β-catenin通路介导EMT,进而增强胰腺癌细胞的迁移和侵袭能力。

酵母对无机锌的富集及其影响因素研究

在培养基中添加无机锌，利用生物转化技术，通过酵母的生命活动，将无机锌有效地富集到细胞内，研究锌离子浓度对酵母生长繁殖、细胞含锌量、锌富集率及酵母发酵力的影响，并通过控制锌离子浓度，使酵母细胞既能富集锌，又对其发酵力不产生显著的影响，以便将仍具有发酵活力的富锌酵母用于食品加工之中。研究结果表明，锌离子浓度对酵母的生长繁殖和富集能力影响较大，浓度越高，酵母细胞含锌量越大。但无机锌对酵母细胞有显著的损伤，且这种损伤是非遗传性的，当无机锌去掉后，酵母细胞形态又恢复正常。

东南景天对锌镉复合污染的反应及其对锌镉吸收和积累特性的研究

比较和分析了锌镉复合处理对东南景天(SedumalfrediiHance,景天科景天属,一种生长在浙江某一古老铅锌矿区土壤上的新锌超积累植物)的生长及其对锌和镉的吸收积累特性的影响。结果表明,Zn/Cd=500/100μmol·L-1下,植物生长最佳。镉、锌在东南景天体内的含量随着镉、锌处理浓度的提高而提高。锌在植物体内的分布为茎>叶片>根系,在Zn/Cd=1000/50μmol·L-1处理水平植株体内锌含量达到最大,其中茎中锌含量为23.2mg·g-1;而镉在植株体内分布则为叶片>茎>根系,在Zn/Cd=50/400μmol·L-1处理水平镉含量达到最大,其中叶片中镉含量为12.1mg·g-1。在一定处理范围内,锌的加入促进了植物对镉的吸收和积累,但镉的加入对植物体内锌的积累没有显著影响。高锌或高镉处理均抑制了植物对锌和镉的吸收和积累。表明东南景天不仅可以忍耐锌镉复合污染,还具有一定的超量积累锌和镉的能力。

汉源铅锌矿区植物对Pb和Zn的积累及耐性研究

采取野外调查与实验分析相结合的方法,对汉源3个典型矿区内17种优势植物中Pb和Zn的吸收富集特点进行了分析。结果表明,17种植物对Pb和Zn的吸收有较大差异,其中:星毛角柱花、籽粒苋的地上部分和曼陀罗的地下部分对Pb的积累较好,积累含量分别为331.63、226.44和253.13mg·kg-1;新樟的地下部分和银柳的地上部分对Zn的积累能力较强,积累含量分别达到1068.40和823.32mg·kg-1;蔗茅的地下部分以及大乌泡的地上部分对Pb和Zn均表现出较强的富集能力,其Pb积累含量分别达到455.75和673.52mg·kg-1,其Zn含量为1317.62和893.34mg·kg-1。同时,籽粒苋、卷柏、蜈蚣草、冬青对Pb和Zn以及新樟对Pb的生物迁移系数均大于1,尤以新樟对Pb和卷柏对Zn的生物迁移系数最为突出,分别高达15.88和8.44。虽然所有植物均未达到超富集植物临界含量要求,但其部分体内已形成耐性,成为Pb和Zn耐性植物,其中蔗茅、大乌泡、新樟、籽粒苋和曼陀罗5种植物,可以作为潜在的Pb和Zn污染修复物种。

不同锌肥对旱作马铃薯植株锌的吸收、积累与分配的影响

通过大田试验,研究了施用不同锌肥(无机硫酸锌和有机螯合态糖醇锌)对马铃薯"新大坪"植株锌的吸收、积累和分配以及对块茎产量的影响。结果表明:出苗后35 d即可观察到马铃薯植株各器官锌浓度的明显差异;在生育期进行的3次喷施显著提高了各器官的锌浓度和积累量,以叶片的增幅最大;硫酸锌处理(T2)和糖醇锌处理(T3)叶片的锌浓度分别于出苗后85 d和75 d达到峰值;出苗后85 d时,T2和T3处理叶片的锌浓度分别比对照(T1)提高了47.88 mg·kg-1和72.24 mg·kg-1,T3比T2提高了24.36 mg·kg-1。至块茎增长末期,T2和T3处理叶片的锌积累量分别比T1增加了1.5倍和4倍,块茎锌素积累量比T1增加37.5%和49.4%。施用锌肥后通过提高马铃薯叶片的锌浓度,促进了叶片的光合作用,进而促进了其它器官的生长发育,最终提高了块茎产量和锌产量,T2和T3处理的块茎产量分别比T1增加了10.6%和22.5%,锌产量分别增加了26.9%和46.0%。"拌种+喷施"的锌肥施用技术法提高了锌向根和茎叶的分配率,降低了向块茎的分配率;施用锌肥提高了地上器官中向地下器官的转运系数。马铃薯种薯和叶片对小分子有机螯合态锌肥糖醇锌的吸收明显优于无机锌肥硫酸锌。

施锌对小麦开花后氮、磷、钾、锌积累和运转的影响

为明确大田条件下施锌对小麦地上部器官氮、磷、钾、锌的积累量和转移量的影响,2001～2002年开展了田间试验.试验以专用强筋小麦（8901-11）和普通小麦（4185）两个冬小麦品种为材料,包括4个施锌水平（分别为施ZnSO4·7H2O 0、11.25、22.5和33.75 kg/hm^2）.结果表明,各器官中Zn的含量变化在4.14～54.18 mg/kg,刚开花时及灌浆前期的含量以子粒＞穗壳＞叶片＞茎秆,至接近成熟时则以子粒＞叶片＞穗壳＞茎秆.每生产100kg小麦子粒需要吸收Zn的范围在4.40～5.20g之间.小麦成熟时吸收的Zn约为N或K2O的1/800～1/700,为P2O5的1/500～1/300.施锌后小麦各器官氮、磷、钾、锌的积累量及开花后向子粒的运转量增加,但施锌过多,这些营养元素的吸收、积累和运转反而受到抑制.4185开花前吸收氮和磷的能力较强,而8901-11开花后吸收氮和磷的能力较强;而吸收钾和锌的能力与吸收氮和磷的情况相反.8901-11氮、磷、钾、锌的积累量基本随施锌量增加而提高,以施硫酸锌22.5～33.75 kg/hm^2的积累量最高;而4185以施硫酸锌11.25 kg/hm^2的积累量最高.因此,在施用大量元素的基础上,普通小麦以施硫酸锌11.25 kg/hm^2为宜,而强筋小麦以施硫酸锌22.5～33.75 kg/hm^2为宜.