外来入侵植物小飞蓬化感物质的释放途径

在室内以滤纸为载体用离体生测方法测定了小飞蓬(Conyza canadesiL.)全株水浸提物、茎叶淋溶物、根系分泌物及残体土壤分解物对萝卜(Raphanussativus L.)、黄瓜(Cucumis sativus L.)、马唐(Digitarias anguinalis(L.)Scop.)油菜(Brassica campestris L.)和小麦(Triticuma estivum L.)的化感效应,同时在温室内以土壤为载体通过盆栽植物浇灌的方法测定了小飞蓬茎叶淋溶物和根系分泌物对盆栽植物生长的影响。室内生测实验结果表明,小飞蓬全株水浸提物对5种受体种子的萌发和幼苗生长均有较强的抑制作用;根系分泌物、茎叶淋溶物和残体土壤分解物对受体种子的生长抑制作用不同,根系分泌物的活性高于茎叶淋溶物和残体土壤分解物。温室盆栽实验结果也表明,小飞蓬根系分泌物对受体生长的影响高于茎叶淋溶物。这些结果说明根系分泌是小飞蓬化感物质释放的主要途径之一。     

防御活性氧保护系统在黑豆抗旱生理中的响应

以黑豆幼苗为材料,研究了水分胁迫下其非酶促保护物质和保护酶系对活性氧的清除作用。结果显示:黑豆皮红色素(17.36%)对DPPH.的清除率高达93.6%,可溶性糖(7.227%)对O2-与.OH的清除率分别为47.71%与68.16%,谷胱甘肽(0.8033mg/g)对O2-与.OH有较明显的清除作用,三种非酶促保护物质随着浓度的升高其清除能力呈逐渐增强的趋势;在水分胁迫下,黑豆幼苗超氧化物歧化酶(33~14 U.mg-1.min-1.2~6d-1),过氧化氢酶(2.87~2.01 mg.mg-1.min-1.3~6d-1)与过氧化物酶(31~14 mg.mg-1.min-1.3~6d-1)三种保护酶活性呈现先升高后降低的变化趋势。研究表明:黑豆体内清除活性氧防御系统作用十分明显,且具有较强的抗氧化、抗衰老、抗逆能力。     

外源5-氨基乙酰丙酸对干旱胁迫下甘草种子萌发及幼苗生理特性的影响

以药用植物甘草种子和幼苗为材料,在20%PEG-6000模拟干旱胁迫条件下,测定了不同浓度外源5-氨基乙酰丙酸(ALA)处理甘草种子的发芽势(Gv)、发芽率(Gr)、发芽指数(Gi)和活力指数(Vi)的变化,以及ALA处理幼苗叶片的质膜透性、丙二醛(MDA)含量、可溶性糖含量、游离脯氨酸含量和超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性。结果显示:(1)在20%PEG-6000胁迫下,甘草种子萌发受到显著抑制,而各项萌发指标经过不同浓度的ALA进行恢复处理后均有明显提高,且均以10 mg.L-1ALA处理的各项指标值最大,其种子发芽势(75%)、发芽率(91%)比干旱胁迫对照显著提高了35%和30%,发芽指数(36.2)和活力指数(709.7)分别提高至干旱胁迫的2.6和3.5倍。(2)各ALA处理较对照均显著提高了干旱胁迫下甘草幼苗总生物量、可溶性糖的含量及脯氨酸含量,却显著降低了甘草叶片的MDA含量和质膜透性,同时显著提高了干旱胁迫下甘草叶片中的SOD、POD和CAT的活性,且以10 mg.L-1ALA处理后的酶活性最强。研究表明,适宜浓度(10 mg.L-1)的ALA能显著提高干旱胁迫下甘草种子的萌发能力,通过调节渗透调节物质含量和保护酶活性来有效减缓干旱胁迫对甘草幼苗的伤害,提高甘草种子及幼苗的抗旱能力。     

Droserone from cell cultures of Triphyophyllum peltatum (Dioncophyllaceae) and its biosynthetic origin

The growth and droserone content of callus cultures of Triphyophyllum peltatum grown in liquid 1/5 Linsmaier and Skoog medium was studied. During a lag phase in growth, droserone concentrations in the medium reached a value of 2.1 mg g-1 fr. wt. After this maximum value the concentration decreased slightly to 1.8 mg g-1 fr. wt., while the growth of the calli was enhanced (25% increase in fr. wt. within 7 days). Plumbagin and isoshinanolone were likewise present in the medium. By feeding 13C2-labelled acetate to the cultures the biosynthesis of droserone was elucidated. The incorporation of whole C2-units unambiguously shows its acetogenic origin and fits well in the biosynthetic scheme suggested for the structurally--and biogenetically--related naphthylisoquinoline alkaloids.     

Effects of Riyadh cement industry pollutions on some physiological and morphological factors of Datura innoxia Mill. plant

Cement factory emissions into air cause serious air pollution and affect the plant and animal life in the environment. Herein, we report the effects of cement industry emissions (O₃, SO₂ and NO₂) in air, as pollutants, at Riyadh City on Datura innoxia Mill. plant. Morphological characters including plant height, leaves area and number, fresh and dry weight of shoot and root systems of D. innoxia showed a significant reduction from their normal control plants as a response to exposure to pollutant emissions. Chlorophyll and carotenoid contents recorded reductions in values compared to control plant, and the lowest values of chlorophyll A, B, total chlorophyll, carotenoids and total pigments were 0.431, 0.169, 0.60, 0.343 and 0.943 mg/g respectively at a distance of 1–5 m from the cement factory in fruiting stage. These changes in values may be attributed to a probable deceleration of the biosynthetic process rather than degradation of pigments. Further D. innoxia showed a significant (P < 0.01) reduction in non-reducing and total sugars, protein and total lipid contents compared with the control plant. The root system recorded the lowest values of reducing sugars (0.350 mg/g f. wt.), non-reducing sugars (0.116 mg/g f. wt.), total sugars (0.466 mg/g f. wt.), protein content (0.931 mg/g f. wt.) and total lipids content (0.669 mg/g f. wt.) in fruiting stage at a distance of 1–5 m from the cement factory. The peroxidase activity of shoot and root systems of the studied plant was also significantly higher than those of control plant. Thus a highest value of (29.616 units/g f. wt.) peroxidase activity was recorded in vegetative stage of shoot system at a distance 1–5 m from the cement factory. Results of the study indicated that cement industry emission strongly influence the physiology and morphology of date palm D. innoxia which contribute date fruits, a staple food in the Arab world.     

Transformation of opium poppy (Papaver somniferum L.) with Agrobacterium rhizogenes MAFF 03-01724

Summary Transformed cultures of opium poppy (Papaver somniferum L.) were established by infecting hypocotyl segments with Agrobacterium rhizogenes MAFF 03-01724. Undifferentiated calli formed on the infected site grew satisfactorily on phytohormone-free solid medium in the dark and produced opine, mikimopine, which could not be detected in a normal culture. Numerous adventitious shoots developed from transformed calli during subculture. The transformed shoots separated individually were cultured on phytohormone-free MS solid medium at 22 ° C under 14 h/day light. They displayed wider leaves and longer internodes than shoots established from seeds or non-transformed root culture. The content of morphinan alkaloids in the cultures and regenerated shoots were quantitatively analyzed by enzyme-linked immunosorbent assay and high performance liquid chromatography. HPLC analysis revealed that non-transformed shoots contained much more codeine (1310 gmg/g dry wt.) than morphine (50 g/g dry wt.), while the transformed shoot cultures did not contain morphine, although the level of morphinan alkaloids in the transformed shoots (213 g morphine equivalents/g fr. wt.) was comparable to that in non-transformed shoots (182 g morphine equivalents/g fr. wt.) by ELISA.Abbreviations MS Murashige-Skoog (Murashige and Skoog 1962) - 1/2 MS half strength MS - HF phytohormone-free - NAA 1-naphthaleneacetic acid - ELISA enzyme-linked immunosorbent assay - HPLC high performance liquid chromatography     

不同栽培措施对凤丹容器苗生长及生理的影响

分别采用不同基质配比(即泥炭和珍珠岩体积比分别为1：0、2：1和3：1)、不同促侧根措施(包括主根截短和200 mg·L-1 IBA溶液灌根单一措施以及上述2种单一措施的复合措施)和不同栽培容器(包括穴盘、营养钵和无纺布育苗袋)对凤丹( Paeonia ostii T. Hong et J. X. Zhang)容器苗进行培育,分析了容器苗的形态指标、单株质量、根冠比及部分生理指标的差异,并在此基础上筛选出适宜凤丹容器苗培育的栽培措施。分析结果表明：在泥炭-珍珠岩(体积比3：1)混合基质中,凤丹容器苗的单株侧根数、单株地下部鲜质量和干质量、根冠比以及叶片的总叶绿素含量、可溶性糖含量和含水量均显著高于其他基质。采取主根截短单一措施或复合措施后,容器苗的单株叶面积、单株侧根数、单株地下部鲜质量和干质量、根冠比及叶片含水量均显著高于对照(不做任何处理)和采取200 mg·L-1 IBA溶液灌根单一措施的容器苗,其中,采取复合措施的容器苗大部分指标最高。在无纺布育苗袋和营养钵中栽培的容器苗的株高、根颈直径、单株侧根数以及叶片的总叶绿素含量、可溶性糖含量和含水量显著高于在穴盘中栽培的容器苗;其中,在无纺布育苗袋中栽培的容器苗的单株侧根数以及叶片的总叶绿素含量和含水量均最高,且这3个指标显著高于在营养钵中栽培的容器苗。研究结果显示：不同栽培措施对凤丹容器苗的生长及生理均有一定影响,总体上看,对根系的单株侧根数、主根长、地下部质量和根冠比以及叶片的叶面积、总叶绿素含量、可溶性糖含量和含水量的影响均较大。根据实验结果,初步筛选出适宜凤丹容器苗培育的栽培措施,即用无纺布育苗袋,以泥炭-珍珠岩(体积比3：1)混合基质为栽培基质,实施主根截短和200 mg·L-1 IBA溶液灌根复合措施。     

Variation in Concentration of Ribulose-1, 5-bisphosphate Carboxylase in Leaves of Barley, Wheat and Hybrids of Crested Wheatgrasses

Amounts of the enzyme ribulose-1,5-bisphosphate carboxylasewere estimated in seedling leaves of barley (Hordewn vulgareL.) and flag leaves of wheat (Triticum aestitum L.) by radialimmuno diffusion. A fourfold variation among barley varietiesfor amount of RuBPCase at the seedling stage was observed (c.3.5–15mg g^–1 fr. wt). Range in variation for amountof flag leaf RuBPCase among wheat varieties was 6-09-9.39 mgRuBPCase g^–1 fr. wt. F₁ hybrids from interspecific andintergeneric crosses of crested wheatgrasses (Agropyron andElymus spp.) and their amphidiploid analogues were comparedfor amount of RuBPCase in the most recent fully expanded leavesharvested before seed set. Amount of enzyme varied from 3.4to 77.6 mg g^–1 fr. wt among the hybrids. No effect chromosomenumber on enzyme concentration was observed among 13 hybridsand their amphidiploid counterparts. Key words: RuBPCase, wheatgrasses     

多裂骆驼蓬中生物碱类物质对小麦种子萌发和幼苗生长的影响

室内培养和盆栽试验结果表明,多裂骆驼蓬生物碱提取液浸种的小麦萌发种子呼吸速率、淀粉酶和蛋白酶活性受抑,种子萌发率下降并随处理浓度提高而降低。幼苗根系活性和叶绿素含量提高,叶片硝酸还原酶（NR）、超氧化物歧化酶（SOD）和过氧化物酶（POD）活性增强,过氧化氢酶（CAT）活性下降;幼苗根体积,株高、根系和地上部干重增加。多裂骆驼蓬生物碱提取液浸种对小麦种子萌发和幼苗生长作用的大小顺序为：总生物碱〉水溶性生物碱〉脂溶性生物碱。     

NaCl胁迫过程中喷施ALA对菘蓝幼苗生长及主要活性成分含量的影响

以来源于安徽亳州和山西运城的菘蓝（Isatis indigotica Fort.）幼苗为实验材料,对100 mmol·L-1NaCl胁迫条件下喷施50.0、25.0、16.7、12.5和0.0 mg·L-15-氨基乙酰丙酸（ALA）后幼苗部分生长指标、叶片中靛蓝和靛玉红含量以及根中表告依春含量的变化进行了研究。结果表明：在100 mmol·L-1NaCl单一胁迫条件下,来源于安徽亳州的幼苗单株叶鲜质量和叶片中靛蓝和靛玉红含量均低于对照,单株根鲜质量、根冠比以及根中表告依春含量均高于对照;来源于山西运城的幼苗单株叶和根鲜质量、叶片中靛玉红含量和根中表告依春含量均低于对照,根冠比和叶片中靛蓝含量均高于对照。在NaCl胁迫过程中喷施ALA对菘蓝幼苗生长和有效成分的积累均有不同效应。其中,喷施25.0 mg·L-1ALA后安徽亳州产幼苗单株叶和根鲜质量均最高且显著高于NaCl单一胁迫处理组;喷施16.7 mg·L-1ALA后山西运城产幼苗单株叶和根鲜质量均较高但与NaCl单一胁迫处理组无显著差异。喷施50.0 mg·L-1ALA后安徽亳州产幼苗叶片中靛蓝含量最高（0.376 mg·g-1）,喷施25.0 mg·L-1ALA后其叶片中靛玉红含量最高（9.977 mg·g-1）,喷施16.7 mg·L-1ALA后其根中表告依春含量最高（0.229 mg·g-1）,且均显著高于NaCl单一胁迫处理组;喷施16.7 mg·L-1ALA后山西运城产幼苗叶片中靛蓝含量最高（0.282 mg·g-1）,喷施12.5 mg·L-1ALA后其叶片中靛玉红含量和根中表告依春含量均最高（分别为4.526和0.301 mg·g-1）,且均显著高于NaCl单一胁迫处理组。研究结果表明：喷施适宜浓度ALA能够有效减轻NaCl胁迫对菘蓝幼苗生长的影响、提高其体内药用活性成分的含量;总体上看,产自安徽亳州的菘蓝幼苗的耐盐性较强,且不同种源适宜的ALA浓度也有一定差异。     

Cysteine sulfoxide derivatives in Petiveria alliacea.

Two diastereomers of S-benzyl-L-cysteine sulfoxide have been isolated from fresh roots of Petiveria alliacea. Their structures and absolute configurations have been determined by NMR, MALDI-HRMS, IR and CD spectroscopy and confirmed by comparison with authentic compounds. Both the R(S) and S(S) diastereomers of the sulfoxide are present in all parts of the plant (root, stem, and leaves) with the latter diastereomer being predominant. Their total content greatly varied in different parts of the plant between 0.07 and 2.97 mg g(-1) fr. wt, being by far the highest in the root. S-Benzylcysteine has also been detected in trace amounts (<10 microg g(-1) fr. wt) in all parts of the plant. This represents the first report of the presence of S-benzylcysteine derivatives in nature.     

小麦幼苗根系形态与反复干旱存活率的关系

以35个不同栽培类型的小麦品种（系）作为试验材料,根据其6叶幼苗的根系形态性状进行聚类分析,供试材料的根系类型分为3种：大根系、小根系和中间型根系。具有中间型根系的材料反复干旱存活率最高,这些材料的根系特点是单株根数7－8．5条,最大根长20-22cm,根总干重44－48mg,其中10cm以下根干重占36％－45％,根冠比范围在0.22-0.24。一些水地栽培的育成品种苗期抗旱性较强,旱地栽培的育成品种苗期抗旱性差异较大,个别旱地栽培的地方品种在土壤水分胁迫条件下反而比在正常水分条件下的根系发育更好,可能是长期适用干旱条件的结果。     

燕山山脉不同居群豆茶决明的种子形态及营养成分比较

豆茶决明也Cassia nomame ( Sieb.) Kitag.页为云实科( Caesalpiniaceae)决明属( Cassia Linn.)一年生草本植物[1],其地上部分及种子可入药,主治水肿、肾炎、慢性便秘、咳嗽和痰多等,并具有驱虫、健胃之功效,也可代茶饮用[2],在药理和保健方面具有多重功效,是极具开发潜力的野生植物资源。目前仅燕山山脉的河北省青龙满族自治县每年就有近1000 t的豆茶决明全草出口,而且燕山山脉民间还有用豆茶决明种子做酱的习惯,致使豆茶决明野生资源面临枯竭的境地。目前,对豆茶决明的研究还非常有限,尤其在资源调查、引种、栽培和开发等方面。     

高温高湿胁迫下茉莉酸甲酯对紫苏种子萌发及生理特性的影响

以紫苏品系GS011种子为材料,在温度为50℃、空气相对湿度为95%、时间为12h的胁迫条件下,研究不同浓度(0.05、0.10、0.15、0.20和0.25mmol.L-1)茉莉酸甲酯(MeJA)对紫苏种子萌发、幼苗生长、叶片氧化损伤和抗氧化酶活性的影响。结果表明:0.15mmol.L-1 MeJA处理能显著缓解高温高湿对紫苏种子生长发育造成的胁迫伤害,使紫苏种子发芽率、发芽势、发芽指数、活力指数均达到最大值,分别为40.84%、31.83%、8.83和1.35;同时使其叶片MDA含量最低(0.15μmol.g-1),SOD、CAT、LOX、POD和APX活性均达到最大值,分别为0.27U.mg-1及4.7、5.7、4.9和8.9U.g-1.min-1。研究发现,MeJA在一定程度上能提高SOD等保护酶的活性,缓解高温高湿造成的氧化损伤,有效促进高温高湿胁迫下紫苏种子的萌发和幼苗生长。     

多裂骆驼蓬提取物对黄瓜种子萌发和幼苗生理特性的影响

通过室内培养和盆栽土培试验研究了多裂骆驼蓬提取物对黄瓜种子萌发和幼苗生长及生理特性的影响。结果表明,多裂骆驼蓬总生物碱提取液、水溶性生物碱提取液和脂溶性生物碱提取液浸种均抑制黄瓜种子萌发过程中淀粉酶、蛋白酶和脂肪酶活性,种子活力和萌发速率降低,呼吸速率减慢;幼苗生长过程中根系活力、硝酸还原酶活性升高,叶绿素含量增加,超氧化物歧化酶（SOD）和过氧化物酶（POD）活性提高。说明用多裂骆驼蓬提取液浸种能够促进黄瓜幼苗生长,有利于培育壮苗。     

Seedling vigour and the early growth of transplanted rice (Oryza sativa)

Previous studies suggest that the positive response of transplanted rice (Oryza sativa L.) to nursery fertiliser application was due to increased seedling vigour or possibly to increased nutrient content. This paper presents results of two glasshouse experiments designed to test the hypothesis that seedling vigour was responsible for the response of transplanted seedlings to nursery treatments. The aim of the present study was to explore the concept of seedling vigour of transplanted rice and to determine what plant attributes conferred vigour on the seedlings. Seedling vigour treatments were established by subjecting seedlings to short-term submergence (0, 1 and 2 days/week) in one experiment and to leaf clipping or root pruning and water stress in another to determine their effect on plant growth after transplanting. Submerging seedlings increased plant height but depressed shoot and root dry matter and root:shoot ratio of the seedling at 28 days after sowing. After transplanting these seedlings, prior submergence depressed shoot dry matter at 40 days. Nursery nutrient application increased plant height, increased root and shoot dry matter, but generally decreased root:shoot ratio. Pruning up to 60% of the roots at transplanting decreased shoot and root dry matter, P concentration in leaves at panicle initiation (PI) and straw dry matter and grain yield at maturity. By contrast, pruning 30% of leaves depressed shoot and root dry matter by 30% at PI, and root dry matter and straw and grain yield by 20% at maturity. The combined effects of leaf clipping and root pruning on shoot, root and straw dry matter were largely additive. It is concluded that the response of rice yield to nursery treatments is largely due to increased seedling vigour and can be effected by a range of nutritional as well as non-nutritional treatments of seedlings that increase seedling dry matter, nutrient content, and nutrient concentration. Impairment of leaf growth and to a lesser extent root growth in the nursery depressed seedling vigour after transplanting. However, rather than increasing stress tolerance, seedling vigour was more beneficial when post transplant growth was not limited by nutrient or water stresses.     

紫茎泽兰生长发育过程中糖、激素、单宁、黄酮的变化

采用高效液相和分光光度法对紫茎泽兰不同发育阶段（种子,芽,幼苗和成株）糖、激素、单宁及总黄酮含量差异进行了研究。结果表明：不同糖类的变化。紫茎泽兰的葡萄糖含量以芽最高,为6.93%;而种子（0.16%）、幼苗（1.27%）、成株(1.07%)均明显低于芽阶段;同样,紫茎泽兰中蔗糖含量芽较高,为2.68%,而种子（0.32%）、幼苗（0.52%）、成株(0.09%)均明显低于芽阶段。果糖含量的变化,最大值也是在芽阶段（3.28%）,其次为种子阶段（2.56%）,而种子和成株阶段均很低（0.14%和0.55%）。测定中,海藻糖、棉子糖、甘露糖的含量差别很大,仅种子阶段测定出3种糖的含量,结果表明差别不大,依次为0.04%、0.04%、0.03%。激素类的变化。在不同发育阶段,紫茎泽兰芽阶段吲哚乙酸（IAA）含量较高,达到14.20μg·g^-1 Dw ,比种子阶段高1.25μg·g^-1 Dw,是幼苗的1.63倍,成株阶段的5.55倍。紫茎泽兰赤霉素（GA）含量在不同发育阶段存在着明显的差异,而且种子的GA含量（901.11μg·g^-1 Dw）明显高于芽、幼苗和成株阶段,而以芽和幼苗阶段含量最低,分别为97.35和84.29μg·g^-1 Dw,成株阶段略高于芽和幼苗阶段,为280.50μg·g^-1 Dw。单宁类的变化：紫茎泽兰单宁变化差异明显,紫茎泽兰种子中单宁含量为1.98%,明显高于芽、幼苗和成株阶段（<0.30%）;总黄酮类的变化：紫茎泽兰总黄酮含量在发育过程中呈不断上升趋势。紫茎泽兰种子中总黄酮含量很微弱,为0.04%,而芽、幼苗和成株阶段的紫茎泽兰总黄酮含量均明显高于种子阶段,并且这3个阶段之间含量差别不大,分别为（0.60%、0.64%、0.62%）。这些结果说明,糖、激素、单宁及总黄酮含量与植物生长发育的基本规律和代谢过程的调控密切相关。     

Allelopathy and the allelothathic activity of a phenylpropanol from cucumber plants

The growth inhibitory effect of cucumber (Cucumis sativus L.) plants after crop harvested was investigated. Aqueous methanol extracts of the cucumber plants inhibited the growth of roots and shoots of cress (Lepidium sativum L.), lettuce (Lactuca sativa L.), alfalfa (Medicago sativa L.), ryegrass (Lolium multiflorum L.), timothy (Pheleum pratense L.), crabgrass (Digitaria sanguinalis L.), Echinochloa crus-galli (L.) Beauv and Echinochloa colonum (L.) Link, and increasing the extract concentration increased the inhibition. These results suggest that cucumber plants may possess allelopathic activity. The aqueous methanol extract of cucumber plants was divided into ethyl acetate and aqueous fractions, and the growth inhibitory activity of ethyl acetate fraction was greater than that of aqueous fraction. Thus, ethyl acetate fraction was further purified and a main allopathically active substance in the fraction was isolated and determined as (S)-2-benzoyloxy-3-phenyl-1-propanol by spectral data. This substance inhibited root and shoot growth of cress seedlings at concentrations greater than 10 μM, and the concentration required for 50% inhibition of root and shoot growth was 21 and 23 μM, respectively. These results suggest that (S)-2-benzoyloxy-3-phenyl-1-propanol may contribute to the growth inhibitory effect of cucumber plants and may play an important role in cucumber allelopathy. Thus, cucumber plants may be potentially useful for weed management in a field setting. An erratum to this article can be found at     

Dihydroquercetin protects barley seeds against mold and increases seedling adaptive potential under soil flooding

Barley (Hordeum vulgare L.) seeds were soaked in aqueous 10⁻⁴ M dihydroquercetin (DHQ) to examine its influence on seed germination and further growth of seedlings under optimal soil watering and flooding conditions. The adaptive potential of the plants was estimated by the content of thiobarbituric acid reactive substances (TBARs) and the activity of ascorbate peroxidase (AsP). High-grade seeds were germinated evenly under (−DHQ)- and (+DHQ)-treatments. Low-grade seeds soaked in DHQ, showed no mold and twofold germination rate in comparison with the same seeds soaked in water. The seedlings grown from the similarly germinated seeds did not differ from each other in the shoot growth, independent of the DHQ-pretreatment. The root growth was higher in DHQ-pretreated plants. Soil flooding suppressed the shoot and root growth rates in non-pretreated and DHQ-pretreated plants, however TBARs content was lower in the roots and leaves of (+DHQ)-seedlings as compared to the (−DHQ)-ones. The activity of AsP increased more significantly in the (+DHQ)-plants. The ratio between TBARs content and the AsP activity was lower in the leaves of (+DHQ)-plants both under optimal soil conditions and flooding. Thus, the treatment of low-grade barley seeds with DHQ protects the seeds against mold and increases adaptive potential of the seedlings.     

Solanum paniculatum L. (Jurubeba): potent inhibitor of gastric acid secretion in mice.

Solanum paniculatum L. is used commonly in Brazilian folk medicine for the treatment of liver and gastrointestinal disorders. The freeze-dried aqueous extracts (WEs) obtained from distinct parts of the plant (flowers, fruits, leaves, stems and roots) were tested to determine their antiulcer and antisecretory gastric acid activities using mice. The aqueous extracts of roots, stems and flowers inhibited gastric acid secretion in pylorus-ligated mice with ED50 values of 418, 777 and 820 mg/kg body wt. (i.d.), respectively. Extracts of leaves (0.5-2 g/kg body wt., i.d.) did not affect gastric secretion, whereas fruit extracts (0.5-2 g/kg body wt., i.d.) stimulated gastric acid secretion. The stimulatory effect of the fruit extract was inhibited by pretreatment with atropine (5 mg/kg body wt., i.m.) but not with ranitidine (80 mg/kg body wt., i.p.) suggesting that the fruit extract activates the muscarinic pathway of gastric acid secretion. In contrast, administration of the root extract into the duodenal lumen inhibited histamine- and bethanechol-induced gastric secretion in pylorus-ligated mice. In addition, the aqueous extract of roots (ED50 value, 1.2 g/kg body wt., p.o.) protected the animals against production of gastric lesions subsequent to the hypersecretion induced in mice by stress following cold restraint. This effect was not reproduced when the lesions were induced by blockade of prostaglandins synthesis via subcutaneous injection of indomethacin. Thus, antiulcer activity of the plant extracts appears to be related directly to a potent anti-secretory activity. No toxic signs were observed following administration of different extracts up to 2 g/kg body wt., p.o. Collectively, the results validate folk use of Solanum paniculatum L. plant to treat gastric disorders.