土荆芥挥发性化感物质诱导蚕豆保卫细胞死亡及信号调节

为了探讨入侵植物土荆芥的化感作用机制,以其入侵地广泛种植的农作物蚕豆叶片下表皮为受试材料,通过对保卫细胞的活性分析,研究了土荆芥挥发油及其两种主要成分α-萜品烯和对伞花素诱导保卫细胞死亡及其信号调节的机制。结果表明:土荆芥挥发油、α-萜品烯、对伞花素具有显著的细胞毒性,随着处理剂量增加,保卫细胞存活率显著下降,细胞核出现了畸形、碎裂和降解等程序性细胞死亡的典型特征;活性氧(Reactive oxygen species,ROS)、一氧化氮合酶(Nitric oxide synthetase,NOS)和Ca~(2+)的组织化学定位显示,在土芥挥发油、α-萜品烯和对伞花素作用下,保卫细胞内ROS、NOS和Ca~(2+)的水平明显高于对照组;活性氧清除剂(AsA)、Ca~(2+)螯合剂(EGTA)和硝酸还原酶抑制剂(NaN——3)均可有效缓解土荆芥挥发油、α-萜品烯和对伞花素的细胞毒性,显著提高了保卫细胞的存活率(P0.05)。上述结果表明,ROS、NO和Ca~(2+)参与了土荆芥挥发油、α-萜品烯和对伞花素诱导蚕豆保卫细胞死亡的信号调节过程。土荆芥挥发油、α-萜品烯和对伞花素诱导的保卫细胞死亡,可能是通过ROS和NO调控保卫细胞内Ca~(2+)水平的变化而引起的。     

六种农作物叶保卫细胞形态特征对不同入侵地土荆芥挥发物胁迫的响应

选择两个环境条件差异明显的土荆芥(Chenopodium ambrosioides L.)入侵地(四川成都和贵州安顺)为对象,以其入侵农田中6种农作物为受体,分析了两地土荆芥挥发油及其主要成分α-萜品烯和对伞花素对叶表皮保卫细胞活性和核结构的影响差异。结果表明:两地挥发油成分中,含量最多的成分均为α-萜品烯和对伞花素,成都植株二者的含量分别为21.07%和25.88%,安顺的分别为42.11%和24.04%;经挥发油、对伞花素、α-萜品烯、对伞花素+α-萜品烯处理后,保卫细胞活性下降,细胞核形态发生变化,除个别低剂量组(2μL)对保卫细胞无显著毒性外,各处理组毒性效应随处理浓度增加而显著升高(P0.05),当剂量为10μL时毒性效应最大,保卫细胞的最高死亡率达到93.85%,最高核畸变率达到81.16%;6种农作物保卫细胞对土荆芥挥发物的敏感程度由大到小依次为荞麦(Fagopyrum esculentum Moench.)、豌豆(Pisum sativum Linn.)、蚕豆(Vicia faba L.)、韭(Allium tuberosum Rottl.ex Spreng.)、花生(Arachis hypogaea Linn.)、白菜(Brassica campestris L.);细胞毒性表现为安顺挥发油大于成都挥发油、α-萜品烯大于对伞花素,对伞花素+α-萜品烯混合物的细胞毒性与α-萜品烯所占比例呈正相关。上述结果表明,土荆芥挥发物破坏了保卫细胞结构。入侵地环境较差时,土荆芥增加释放细胞毒性较大的化感物质。     

信号分子活性氧和NO在土荆芥化感胁迫诱导蚕豆根边缘细胞死亡中的调控

为了探讨入侵植物土荆芥(Chenopodium ambrosioides L.)化感作用如何干扰受体植物的防御功能,以蚕豆(Vicia faba L.)为受体,研究了土荆芥挥发油及其主要成分ρ-对伞花素和α-萜品烯对根边缘细胞活性及其胞外诱捕网厚度的影响,并测定了细胞内信号分子活性氧(Reactive oxygen species, ROS)和NO水平的变化。结果表明:在土荆芥挥发油、ρ-对伞花素和α-萜品烯作用下,蚕豆根边缘细胞粘胶层厚度增加,细胞活性下降,而ROS和NO水平升高,且表现为浓度依赖效应,细胞死亡率、ROS水平和NO水平三者之间存在着显著的正相关(P<0.05)。ROS清除剂抗坏血酸(AsA)、硝酸还原酶抑制剂(NaN₃)和泛Caspase抑制剂Z-VAD-FMK均可有效缓解挥发性物质的细胞致死效应,表明ROS和NO诱导根边缘细胞发生了Caspase依赖性细胞凋亡。上述结果表明土荆芥挥发性化感物质诱导蚕豆根边缘细胞内NO和ROS的水平上升,二者协同作用导致细胞凋亡,引起受体防御功能障碍,从而抑制了植物根系的生长。     

蚕豆幼苗光合特性对土荆芥挥发性物质胁迫的响应

以蚕豆(Vicia faba)为受体,采用盆栽试验评价了入侵植物土荆芥(Chenopodium ambrosioides)挥发油及其两个主要成分α-萜品烯和对伞花素对受体光合特性的影响。结果表明:土荆芥挥发油及其两个主要成分不同程度地影响了蚕豆叶片的特性。挥发油处理显著降低了净光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)、最大光化学效率(F_v/F_m)、实际光化学效率(ΦPSⅡ)和叶绿素含量,但增加了胞间CO₂浓度(C_i),这种效应表现为剂量和时间双重效应,高剂量挥发油处理的这种效应是不可逆的; 与对照相比,α-萜品烯处理组的P_n、F_v/F_m和ΦPSⅡ降低,C_i、G_s和T_r上升,停止处理后,各参数均趋于对照水平; 整体来看,对伞花素对蚕豆幼苗的光合特性影响不大。上述研究结果说明,土荆芥化感胁迫对受体光合特性的影响是诸多化感物质协同作用的结果,并非由单一组分决定。     

佛手挥发油特征化学成分群GC-MS研究

目的:分析6个不同产地佛手挥发油的化学成分,确定其特征化学指标成分群.方法:采用水蒸气蒸馏法提取佛手挥发油.运用气相色谱质谱联用技术(GC-MS),结合计算机检索对其化学成分进行分离和鉴定,得到其共有的特征性化学成分群,用色谱峰面积归一化法计算各组分的相对含量.结果:从广东、四川、金华、广西、安徽佛手的挥发油中鉴定16种共有特征成分,按保留时间的先后顺序分别为:α-水芹烯、α-蒎烯、β-蒎烯、β-月桂烯、α-萜品油烯、邻伞花烃、柠檬烯、顺式-β-罗勒烯、反式-β-罗勒烯、γ-萜品烯、γ-萜品油烯、乙酸芳樟酯、顺式-水合桧烯、α-萜品醇、β-柠檬醛、α-柠檬醛,其占总峰面积的的比例大于82.9%;其中柠檬烯和γ-萜品烯是主要成分,两者峰面积占总峰面积的比例大于65%.结论:所建立的特征成分群能充分地袁征佛手挥发油化学组成,可以为佛手挥发油的质量评价提供参考.     

土荆芥挥发油对蚕豆根尖细胞的氧化损伤

土荆芥是一种入侵植物,对周围植物具有较强的化感潜力.采用培养皿土培法和培养皿滤纸法,分别模拟土荆芥挥发油通过淋溶和挥发两条途径对蚕豆根尖细胞膜脂过氧化和抗氧化酶活性的影响,并分析了挥发油诱导的细胞凋亡.结果表明:在培养皿土培和培养皿滤纸处理中,在处理前期(24 h),蚕豆根尖细胞超氧化物歧化酶、过氧化物酶和过氧化氢酶的活性均随土荆芥挥发油剂量的增大呈先升高后降低的趋势;根尖丙二醛含量随处理时间的延长和处理剂量的增大呈上升趋势.在处理中期(48 h)和处理后期(72 h),出现了典型的DNALadder条带,表明土荆芥挥发油可诱导蚕豆根尖细胞凋亡,并且随着挥发油剂量的增大和处理时间的延长,细胞凋亡程度加剧.土荆芥挥发油可以通过淋溶和挥发两种途径作用于周围植物,使受体植物的膜脂过氧化程度加剧,抗氧化酶活性受到抑制,诱导根尖细胞发生氧化损伤和细胞凋亡,从而抑制周围植物生长.而且,当挥发油以淋溶途径进入土壤时,蚕豆根尖抗氧化酶活性整体较高,DNA损伤程度较小,土荆芥挥发油通过挥发途径的化感作用大于通过淋溶途径.     

大叶桉挥发物对蚕豆细胞毒性效应及信号调节

为探讨大叶桉(Eucalyptus robusta)化感作用的细胞学机制，该研究以大叶桉挥发油及其主要成分α-蒎烯和桉油精为供体，以蚕豆(Vicia faba)的根细胞和叶保卫细胞为靶标，运用显微技术、细胞化学技术和qRT-PCR技术，研究了大叶桉挥发物的毒性效应。结果表明：(1)在大叶桉挥发物作用下，蚕豆幼根生长受抑制并表现为时间-浓度依赖效应，其化感效应强弱由大到小依次为挥发油、α-蒎烯和桉油精。(2)蚕豆根边缘细胞活性降低，分生区细胞微核率升高，有丝分裂指数下降且大部分细胞的细胞周期被阻滞在分裂前期。(3)蚕豆叶保卫细胞内NADPH氧化酶活性升高，活性氧(reactive oxygen species, ROS)爆发，微丝聚合，气孔开度下降；叶保卫细胞的核畸变率升高，细胞活性降低甚至发生caspase依赖性细胞凋亡，而Ca²⁺通道阻断剂(LaCl₃)、活性氧清除剂(AsA)和硝酸还原酶抑制剂(NaN₃)均可显著提高保卫细胞存活率，说明大叶桉挥发物改变了信号分子Ca²⁺、ROS和NO的信号调节。...     

杜香植物资源开发利用的基础研究——Ⅰ.杜香油化学成分的研究

应用气相色谱-质谱联用技术,对杜香挥发油的化学成分进行分析,共鉴定出桧烯、α-萜品烯、γ-萜品烯、萜品烯-[4]-醇、桃金娘烯醛等18个化合物,并测定了各成分在挥发油中的含量。     

NO体外供体硝普钠诱导蚕豆气孔保卫细胞死亡机理研究

为分析NO在植物细胞死亡过程中的作用,以蚕豆表皮条和NO体外供体硝普钠(SNP)及NO信号途径抑制剂为材料,采用表皮条生物法,探讨SNP对蚕豆叶面保卫细胞的毒性机理.结果表明:(1)0.5～9 mmol· L-1的SNP可使蚕豆气孔保卫细胞活性降低,部分细胞死亡,且随着SNP浓度的增高细胞死亡率增高.(2)凋亡抑制剂Z-Asp-CH2-DCB或TLCK可显著降低SNP诱发的保卫细胞死亡率.(3)抗坏血酸(AsA)、过氧化氢酶(CAT)、Ca2+螯合剂EGTA或Ca2+通道抑制剂LaCl3与SNP共同作用时,细胞死亡率显著降低.(4)NO清除剂c-PTIO、MAPK激酶抑制剂PD98059和鸟苷酸环化酶抑制荆ODQ亦能有效阻止SNP诱发的细胞死亡.研究发现,较高浓度的SNP可诱导蚕豆保卫细胞程序性死亡,SNP诱发植物细胞死亡与胁迫组保卫细胞内NO、ROS和Ca2+水平升高有关,cGMP和MAPK参与了SNP诱发的细胞死亡.     

园柏挥发油化学成分的GC—MS分析

利用毛细管气相色谱保留指数定性、标准样品叠加和色谱－质谱－计算机联用技术,对园柏挥发油的化学成分进行了分离和鉴定,共鉴定出单萜烃１６个、倍半萜烃１８个,并测得了各化合物的相对含量。其主要成分是：香桧烯、α－蒎烯、萜品醇－４、柠檬烯、γ－萜品烯和对一花烃。     

内生真菌对油樟悬浮细胞培养的影响

该文研究了内生真菌YG42、YG71、YY11和YY26发酵液,对油樟悬浮细胞的生长量及挥发性代谢产物积累量的影响。结果表明：4种内生真菌对油樟悬浮细胞的生长均有抑制作用,抑制强度随发酵液添加量的增加而加强。4种内生真菌对油樟悬浮细胞挥发性代谢产物积累总量及1,8-桉叶油素、γ-叶松油烯和α-油松油醇3种油樟油组分物质积累量的影响多表现为低浓度促进高浓度抑制的趋势。其中,1％添加量的YG42和YY26及0.25％添加量的YY11对悬浮细胞总挥发性代谢产物积累的促进作用相当且最强,其积累量分别是空白组的2.00、1.95、2.01倍;0.25％添加量的YG71对1,8-桉叶油素积累的促进作用最强,其积累量为空白组的11.03倍;0.25％添加量的YG71和YY26对α-松油醇积累的促进作用相当且最强,其积累量分别为空白组的1.72和1.81倍;对于γ-松油烯的积累,在空白组中未检测到其峰值,4种真菌诱导子对γ-松油烯的产生有诱导作用,诱导的最大峰面积为0.19,诱导菌是0.25％添加量的YG71。该研究结果为充实内生菌影响香料植物挥发性代谢产物合成理论奠定了基础,也为生产上内生真菌提高油樟油中有用物质组分含量措施的采用提供了依据。     

UV-B辐射对蚕豆叶片气孔运动的间接效应与NO和H2O2有关

0.2 W.m-2的UV-B辐射不仅能诱导整体蚕豆叶片气孔导度和开度的显著降低,而且能明显降低蚕豆叶肉光合活性,但该强度的UV-B辐射却不能明显影响离体表皮条的气孔开度.说明0.2W.m-2的UV-B主要通过间接途径调控了蚕豆叶片气孔运动.借助药理学试验和激光扫描共聚焦显微镜技术,进一步对该间接效应过程中是否有NO和H2O2的参与进行了探讨.结果显示:NO专一性清除剂cPT IO和一氧化氮合酶(NO S)抑制剂L-NAM E均能有效地抑制UV-B辐射诱导的叶片气孔关闭和保卫细胞内源NO水平的升高;H2O2清除剂抗坏血酸(A SC)和过氧化氢酶(CAT)也能有效地逆转UV-B辐射诱导的气孔关闭和保卫细胞内源H2O2含量的升高.另外,外源NO或H2O2处理也能有效地诱导叶片气孔关闭.结果说明0.2W.m-2的UV-B辐射对蚕豆叶片气孔关闭的间接诱导与NO和H2O2有关.     

Volatile allelochemicals of Chenopodium ambrosioides L. induced mitochondrion-mediated Ca2+-dependent and Caspase-dependent apoptosis signaling pathways in receptor plant cells

Plant and Soil - This study aims to explain the mechanism of action of allelochemical effect of Chenopodium ambrosioides L. volatile oil on mitochondrial characteristics of receptor plants. This...     

The responses of guard and mesophyll cell photosynthesis to CO2, O2, light,and water stress in a range of species are similar

High resolution chlorophyll a fluorescence imaging was used to compare the photosynthetic efficiency of PSII electron transport (estimated by Fq'/Fm') in guard cell chloroplasts and the underlying mesophyll in intact leaves of six different species: Commelina communis, Vicia faba, Amaranthus caudatus, Polypodium vulgare, Nicotiana tabacum, and Tradescantia albifora. While photosynthetic efficiency varied between the species, the efficiencies of guard cells and mesophyll cells were always closely matched. As measurement light intensity was increased, guard cells from the lower leaf surfaces of C. communis and V. faba showed larger reductions in photosynthetic efficiency than those from the upper surfaces. In these two species, guard cell photosynthetic efficiency responded similarly to that of the mesophyll when either light intensity or CO2 concentration during either measurement or growth was changed. In all six species, reducing the O2 concentration from 21% to 2% reduced guard cell photosynthetic efficiency, even for the C4 species A. caudatus, although the mesophyll of the C4 species did not show any O2 modulation of photosynthetic efficiency. This suggests that Rubisco activity is significant in the guard cells of these six species. When C. communis plants were water-stressed, the guard cell photosynthetic efficiency declined in parallel with that of the mesophyll. It was concluded that the photosynthetic efficiency in guard cells is determined by the same factors that determine it in the mesophyll.     

石山巴豆与毛果巴豆叶中挥发油成分分析

采用水蒸气蒸馏法提取石山巴豆和毛果巴豆叶中的挥发油,利用GC-MS联用仪对其化学成分进行分析和鉴定,以归一化法计算各个化学成分的相对含量。结果表明:从石山巴豆叶鉴定出39种化合物,占总量的95.96%,主要成分是α-松油醇(17.57%)、桉树醇(11.13%)、乙酸松油酯(9.07%)、倍半水芹烯(8.52%)等;从毛果巴豆叶鉴定出55种化合物,占总量的97.8%,以反式-橙花叔醇(9.48%)、α-松油醇(7.51%)、桉树醇(6.43%)、乙酸松油酯(6.72%)为主要成分。两种植物叶中的挥发油成分均以萜醇、倍半萜烯为主,并且其中多种成分具有生物活性,因此研究结果可为石山巴豆和毛果巴豆的开发利用提供科学依据。     

Detection of Alfalfa mosaic virus (AMV) in pea field in Iran

During the spring and summer, in 2003-2004, pea viruses were identified in twenty pea fields of Tehran. Some leaf samples were collected randomly from pea fields of Tehran. Samples were tested by Double Antibody Sandwich Enzyme Linked Immunosorbent Assay (DAS-ELISA) technique using polyclonal antiserum of Alfalfa mosaic virus (AMV), AS-0001, DSMZ, Braunschweig, Germany). The samples were extracted in 0.1 M Phosphate buffer pH 7 to 7.5 and inoculated on Chenopodium amaranticolor, Chenopodium quina, Phaseolus valgaris, Vicia faba, Vignia unguiculata. Pea cultivars were infected by AMV, causing mild mosaic, translucent veins and a diffuse green-yellow of tender parts and spots may also was involved necrosis of tissue. Infected plants grow slowly and malformed pods produce fewer ovules. In Chenopodium amranticolor, C. quina chlorotic and necrotic flecks, and Vicia faba systemic mosaic had produced. Phaselous vulgaris and Viginia unguiculata are good assay hosts for strains that produce local lesions after 3-5 days in these plants. Back inoculated on Pisum sativum and Vicia faba and tested with DAS-ELISA that had been confirmed the results. This is the first report of AMV on pea from Iran.     

Ascitic and solid Ehrlich tumor inhibition by Chenopodium ambrosioides L. treatment

The leaves of Chenopodium ambrosioides L. [Chenopodiaceae] ('mastruz') have been indicated for the treatment of several diseases, among which the cancer. There are no results focusing the effect of C. ambrosioides treatment on tumor development in vivo. The aim of this study was to investigate the effect of treatment with C. ambrosioides on Ehrlich tumor development. Swiss mice were treated by intraperitoneal route (i.p.) with hydroalcoholic extract from leaves of C. ambrosioides (5 mg/kg) or with PBS (control group) 48 h before or 48 h later the Ehrlich tumor implantation. The tumor cells were implanted on the left footpad (solid tumor) or in the peritoneal cavity (ascitic tumor). To determine the solid tumor growth, footpad was measured each 2 days until the fourteenth day, when the feet were weighed. Ascitic tumor development was evaluated after 8 days of tumor implantation by quantification of the ascitic fluid volume and tumor cell number. The i.p. administration of C. ambrosioides extract before or after the tumor implantation significantly inhibited the solid and ascitic Ehrlich tumor forms. This inhibition was observed in ascitic tumor cell number, in the ascitic volume, in the tumor-bearing foot size and foot weight when compared to control mice. The treatments also increased the survival of tumor-bearing mice. In conclusion, C. ambrosioides has a potent anti-tumoral effect which was evident with a small dose and even when the treatment was given two days after the tumor implantation. This effect is probably related with anti-oxidant properties of C. ambrosioides.     

乌榄叶挥发油化学成分分析

采用气相色谱-质谱联用(GC-MS)方法首次对乌榄叶挥发油成分进行了测试分析,并应用色谱峰面积归一化法计算各成分的相对含量。分离出19个峰,确认了19种化合物,所鉴定的组分占挥发油总量的100%,主要成分是石竹烯(33.47)、α-蒎烯(18.03%)、d-柠檬烯(16.82%)、α-侧柏烯(11.74%)和α-水芹烯(6.51%)。