酚酸类物质的抑草效应分析

运用正交旋转回归试验设计分析5种常见的化感物质替代物水饧酸、对羟基苯甲酸、肉桂酸、香草酸和阿魏酸对田间伴生杂草稗草的抑制效应．结果表明,肉桂酸对稗草根长抑制率的影响最显著。其关系函数的二次项系数为-6．18,达极显著水平,水杨酸、对羟基苯甲酸和阿魏酸对稗草根长的抑制效应趋势与肉桂酸相同,效应曲线均为“n”形抛物线;而香草酸的效应曲线则为“U”形抛物线．当水饧酸、对羟基苯甲酸、肉桂酸、香草酸和阿魏酸浓度水平分别为0．06、0．60、0．24、0．02和0．02mmol·L^-1时,混合物对稗草根长的抑制率最大,达到78．65％。     

三七重茬根际土壤中化感物质的测定及其对 三七根腐菌的生长作用

目的研究三七重茬根际土壤中化感物质的组成及其对病原微生物的化感作用。方法采用乙酸乙酯提取三七重茬根际土壤中的化感物质,利用GC-MS对萃取液进行物质组成分析,并研究检测中出现的特征性化感物质对羟基苯甲酸、邻苯二甲酸二异丁酯对三七根腐病菌(F.oxysporum Schlecht)的化感作用。结果采集的三七重茬土壤中共检测到29种化感物质,其中2种特征性化感物质对羟基苯甲酸、邻苯二甲酸二异丁酯对三七病原菌的生长呈现低促高抑的现象,且当对羟基苯甲酸浓度为5mmol/L时能促进病菌小孢子的产生。结论检测到的化感物质组分为苯甲酸及其衍生物类、酚类、酯类、饱和烃类等物质。这些物质在低浓度时有利于病原菌的生长,对病害的发生具有促进作用。     

有机酸类化感物质对甜瓜的化感效应

以甜瓜种质“新银辉”为材料,用苹果酸、柠檬酸、对羟基苯甲酸、肉桂酸、阿魏酸、水杨酸和香豆酸等7种有机酸类化感物质处理甜瓜种子和幼苗,探讨其对甜瓜的化感效应及作用机理.结果表明:苹果酸可以促进甜瓜种子发芽和幼苗胚根生长,抑制植株鲜重增加和胚轴生长;柠檬酸促进发芽,对羟基苯甲酸和肉桂酸抑制发芽,但三者均抑制胚根生长,且对鲜重和胚轴生长表现为低促高抑效应,高浓度肉桂酸对种子发芽和胚轴生长的抑制效应最强,可能是甜瓜重要的化感物质;阿魏酸和香豆酸对发芽表现为低促高抑效应,抑制鲜重、胚根和胚轴生长;水杨酸对发芽和胚轴生长表现为低促高抑效应、抑制鲜重和胚根生长.7种有机酸处理后过氧化物酶活性均增强,有机酸类物质对甜瓜的化感效应可能和其体内的过氧化氢水平有较高的相关性;苹果酸、肉桂酸、对羟基苯甲酸和水杨酸处理后甜瓜幼苗体内超氧化物歧化酶的活性基本呈下降趋势,柠檬酸、阿魏酸和香豆酸则表现为低促高抑效应;过氧化物酶活性变化较复杂,但基本随处理浓度升高而上升;丙二醛含量大多低于对照.     

化感物质对枯草芽孢杆菌（Bacillus subtilis）在厌氧条件下和生长？…

研究由秸秆腐解产生的化感物质：阿魏酸（ｔ－ＦＡ）、对羟基苯甲酸（ｐ－ＨＡ）和苯甲酸（ＢＡ）在不同浓度下对厌氧培养的枯草芽孢杆菌（Ｂａｃｉｌｌｕｓ ｓｕｂｔｉｌｉｓ）的生长及其反硝化活性的影响。结果表明,３种浓度的阿魏酸（５．１５、２．５８、０．２６ｍｍｏｌ／Ｌ）均表现出对枯草芽孢杆菌的生长有抑制作用。对羟基苯甲酸（０;．３６、３．６２、７．２４ｍｍｏｌ／Ｌ）对生长影响不明显。８．１９ｍｍｏｌ／Ｌ和     

杂交鹅掌楸不同无性系对Pb胁迫的生理响应及抗性比较

采用盆栽法研究了4个杂交鹅掌楸(Liriodendron chinense×L.tulipifera)无性系扦插苗对土壤Pb胁迫的生理响应与抗性差异。研究结果表明,Pb胁迫能抑制杂交鹅掌楸无性系扦插苗生长,使叶片失绿变黄、根系活力下降,且1.0mg·g-1Pb胁迫的抑制效果更明显。随Pb胁迫时间的延长,4个杂交鹅掌楸无性系扦插苗叶片的相对电导率和MDA含量均持续增加,胁迫结束时,相对电导率和MDA含量分别是对照的1.45~1.92倍和2.23~3.23倍。叶片的POD活性和游离脯氨酸含量在整个Pb胁迫过程中呈先升后降的变化趋势;不同无性系的SOD活性变化存在一定差异。随着Pb浓度的增加,杂交鹅掌楸不同无性系扦插苗各生理指标的变化幅度各异。比较发现,无性系NE60对Pb胁迫的抗性最强。     

六价铬对水绵生长的毒性效应

为研究六价铬（Cr^6＋）对水绵（Spirogyrasp．）的毒性效应和水绵对六价铬的毒性响应,实验设置5个暴露组（4、6、8、10和12mg／L）和1个对照组。结果表明：96h后各暴露组对水绵的生长均有抑制作用,铬浓度越高,藻细胞叶绿素a越低,显示出较明显的剂量一效应关系;六价铬对水绵的96h的Ec。值为7．25mg／L。细胞浸出液电导率在低浓度（4～6mg／L）组上升较缓慢,在高浓度组（8～12mg／L）上升显著;丙二醛（MDA）累积含量在Cr6＋≥4mg／L时,累计含量上升较高（P〈0．01）,当Cr^6＋≥8mg／L时,累积含量上升较少。水绵细胞浸出液电导率与MDA存在显著正相关（P〈0．05,r=0．891）。水绵细胞浸出液电导率和MDA含量与六价铬浓度分别存在显著（P〈0．05,r=0．951）和极显著（P〈0．01,r=0．977）的非线性的毒性响应关系。     

磷胁迫对不同杉木无性系酸性磷酸酶活性的影响

 缺磷是限制目前农林业产量的一个重要因子,传统的农林业生产主要通过施肥和土壤改良来满足植物对磷的需求,近年来人们开始发掘磷高效利用植物来替代传统方法提高磷的利用效率。杉木(Cunninghamia lanceolata)是我国亚热带地区最重要的造林树种之一,生长快、材质好、产量高,在中国人工林经营中占有重要地位。为揭示磷素胁迫条件下杉木无性系酸性磷酸酶的变化规律和筛选磷高效利用杉木无性系,通过土培试验,设计4种磷素处理水平(正常供磷16 mg•kg－1、轻度磷胁迫8 mg•kg－1、中度磷胁迫4 mg•kg－1、重度磷胁迫0 mg•kg－1),进行磷素胁迫条件下不同杉木无性系酸性磷酸酶(APA)活性的比较研究。结果表明：缺磷条件下1年生杉木叶片和根际的APA活性明显高于正常供磷处理。随缺磷时间的延长、不同杉木无性系酸性磷酸酶的变化规律不同,其中8号、24号、37号无性系叶片和根际的APA活性明显高于正常供磷处理;5号、9号无性系根际APA活性虽然增幅较大,但其叶片酶活性变化较小;3号、23号、34号无性系整体而言对磷胁迫不敏感,缺磷条件不对其叶片APA及根系APA活性造成显著影响。在磷胁迫条件下,杉木无性系可通过叶片及根际酸性磷酸酶活性的增强来适应环境磷缺乏,但不同杉木无性系对磷缺乏的适应性存在明显差异,因此能否将APA活性作为杉木无性系磷效率的评价指标之一仍需作进一步研究。     

化感物质对植物根系形态属性影响的meta分析

植物化感作用是通过释放到环境中的化感物质直接或间接影响受试植物生长而实现的。化感物质主要作用于根系,所以植物根系属性是化感作用研究的重要指标之一。目前,关于受试植物形态属性对外源化感物质的响应模式尚缺乏整体的认识。为此,本文对61篇有关纯化感物质(包括酚类、萜类和含氮化合物等)对植物根系形态属性(尤其是根长)影响的文献进行整合分析。结果发现: 整体上化感物质处理显著抑制根长,而对根生物量、根表面积和根体积等形态属性影响较小;酚类对根长的抑制效应最大,且化感物质对草本植物根长的抑制率高于木本、作物和其他植物;酚类与根长抑制效应呈显著的线性相关。进一步量化了4种典型酚酸——阿魏酸、对羟基苯甲酸、香草酸和肉桂酸的浓度-效应关系,证实了黄酮对受试植物根长的抑制效应显著高于酚酸类化感物质。受试植物根系属性对化感物质的响应主要受化感物质类型和添加浓度、植物种类与培养条件等多因素影响,建议未来研究在土壤环境条件下综合评价化感物质对受试植物根系形态和生理属性以及根系构型等参数的影响机制。     

外源亚精胺对棉花幼苗抗冷性的生理生态特征影响

以棉花幼苗为试材,分析不同浓度的亚精胺（Spermidine,Spd）（0．01mmol／L、0．10mmol／L、0．50mmol／L和1．00mmol／L）处理对棉花幼苗生长、生理生态特性的影响,以弄清Spd增强棉花抗冷性的效果及其生理机制。结果表明,Spd预处理棉花叶片可提高冷胁迫条件下棉花幼苗抗冷性,具体表现为Spd处理棉花幼苗可增加幼苗体内干物质和含水量,降低叶片冷害指数、电解质渗漏率和丙二醛（MDA）含量,增强超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性,提高抗坏血酸、脯氨酸和可溶性糖含量。表明Spd可以改变冷胁迫条件下棉花幼苗体内生理生化指标,从而缓解冷胁迫对棉花的伤害,其中以0．50mmol／L的Spd处理效果较理想。     

邻株竞争对低磷环境杉木幼苗光合特性及生物量分配的影响

选择同一杉木(Cunninghamia lanceolata)无性系幼苗为研究对象,通过设计邻株竞争处理和3个供磷水平的室内沙培模拟试验,采用破坏性收获方式,分别于试验初期、中期和末期测定不同竞争与供磷水平条件下杉木幼苗光合特性和生物量分配的变化规律,综合分析邻株竞争对低磷环境杉木响应行为的影响。结果表明:竞争处理、供磷水平和胁迫时期三者对杉木幼苗4个光合特性指标的影响均存在明显的交互作用(p0.05),而对生物量分配的交互作用未达显著水平(p0.05)。低磷和不供磷处理条件下杉木幼苗叶片的净光合速率、蒸腾速率和气孔导度均明显较低,其中缺磷胁迫和邻株竞争对叶片气孔导度的降低具有叠加效应。随着竞争和低磷处理时间的延长,杉木幼苗叶片蒸腾速率逐渐降低,但气孔导度和胞间CO2浓度呈先下降后上升的趋势,而根系生物量和根冠比均显著增加。     

Some physiological and biochemical responses to nickel in salicylic acid applied chickpea (Cicer arietinum L.) seedlings

The present study examined the effects of salicylic acid pre-application on the responses of seven-day-old chickpea (Cicer arietinum L.) seedlings to nickel. For this purpose, the plants were treated with 1 mM salicylic acid solution for 6 and 10 hours and then treated with 0.75, 1.5 and 3 mM nickel solutions for 48 hours hydroponically. Following the treatment, changes in seedling length, seedling fresh weight and leaf dry weight (after 10 hours), as well as MDA, proline, protein and pigment contents (after 6 and 10 hours) were examined. Salicylic acid pre-application was found to significantly alleviate the typical harmful effects caused by nickel and 3 mM nickel concentration in particular, on the parameters associated with toxic stress. However, pre-application of salicylic acid for 6 and 10 hours without nickel treatment did not produce any stimulatory or inhibitory effect on the seedlings as compared to the controls.     

Salicylic acid-induced adaptive response to copper stress in sunflower (Helianthus annuus L.)

The ameliorative effect of salicylic acid (SA: 0.5 mM) on sunflower (Helianthus annuus L.) under Cu stress (5 mg l⁻¹) was studied. Excess Cu reduced the fresh and dry weights of different organs (roots, stems and leaves) and photosynthetic pigments (chlorophyll a, b and carotenoids) in four-week-old plants. There was a considerable increase in Chl a/b ratio and lipid peroxidation in both the roots and leaves of plants under excess Cu. Soluble sugars and free amino acids in the roots also decreased under Cu stress. However, soluble sugars in the leaves, free amino acids in the stems and leaves, and proline content in all plant organs increased in response to Cu toxicity. Salicylic acid (SA) significantly reduced the Chl a/b ratio and the level of lipid peroxidation in Cu-stressed plants. Under excess Cu, a higher accumulation of soluble sugars, soluble proteins and free amino acids including proline occurred in plants treated with 0.5 mM SA. Exogenous application of SA appeared to induce an adaptive response to Cu toxicity including the accumulation of organic solutes leading to protective reactions to the photosynthetic pigments and a reduction in membrane damage in sunflower.     

Salicylic acid-induced salinity tolerance in corn grown under NaCl stress

Effects of salicylic acid on some physiological and biochemical characteristics of maize ( Zea mays L.) seedlings under NaCl stress were studied. Pre-soaking treatments of NaCl (0, 50, 100 and 200 mM) were given to maize seeds in the presence as well as in the absence of 0.5 mM salicylic acid. Two-week-old maize seedlings exhibited significant decrease in dry weight, root length, shoot length and leaf area on 6 h exposure of 100 and 200 mM NaCl stress. Photosynthetic pigments and NR activity in leaves decreased sharply with increasing stress levels. Both proline content and lipid peroxidation (measured in terms of MDA) levels increased significantly under saline conditions. However, seedlings pretreated with 0.5 mM salicylic acid along with the salinity levels showed enhancement in growth parameters, photosynthetic pigments, NR activity while, free proline and MDA levels decreased. The results showed that salt-induced deleterious effects in maize seedlings were significantly encountered by the pretreatment of salicylic acid. It is concluded that 0.5 mM salicylic acid improves the adaptabilities of maize plants to NaCl stress.     

化学诱抗剂诱导黄瓜抗盐性及其机理

在200 mmol·L^-1 NaCl胁迫条件下,采用根际注射结合叶面喷洒的诱导方法探讨了不同浓度水杨酸、油菜素内酯、壳聚糖、亚精胺4种化学诱抗剂对黄瓜幼苗生长及其生理生化特性的影响.结果表明,4种化学诱抗剂在适宜浓度范围内,显著地降低了黄瓜幼苗的盐害指数和死苗率,以油菜素内酯0.01 mg·L^-1降低幅度最大,比对照分别降低了63.0%和75.0%;显著地促进了超氧化物歧化酶、过氧化物酶、过氧化氢酶等保护酶活性,从而显著降低了丙二醛含量和电解质渗出率,干重含水量显著升高;促进了幼苗的形态建成,植株茎粗、展开叶数及壮苗指数显著提高,壮苗指数以壳聚糖150 mg·L^-1最大,比对照提高了30.9%.说明施用适宜浓度的化学诱抗剂可以诱导黄瓜幼苗的抗盐能力,减缓盐害症状.综合作用效果依次为：油菜素内酯0.005～0.05 mg·L^-1、亚精胺150～200 mg·L^-1、壳聚糖100～200 mg·L^-1和水杨酸50～150 mg·L^-1.     

水杨酸对镉胁迫下玉米幼苗质膜透性和保护酶活性的影响

在Cd^2＋胁迫下,添加外源水杨酸（SA）的培养液中生长的玉米幼苗叶中超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）的活性均提高,质膜透性降低,丙二醛（MDA）的积累减少,显示SA对Cd^2＋胁迫具有一定的缓解效应。     

几种化感物质替代物间的互作效应分析

运用正交旋转回归试验设计分析5种常见的化感物质替代物水杨酸、对羟基苯甲酸、肉桂酸、香草酸和阿魏酸间对稗草根长的互作效应,以探明化感物质抑草作用机理.结果表明,水杨酸和对羟基苯甲酸、水杨酸和肉桂酸间增效或拮抗的互作效应与各因子在化合物中浓度水平密切相关.水杨酸在浓度＜0.14 mmol·L^-1时,对对羟基苯甲酸表现为增效作用;当浓度＞0.14 mmol·L^-1时,则表现为拮抗作用.而对羟基苯甲酸在浓度为0.425 mmol·L^-1时,对水杨酸表现为拮抗作用.在所考察的浓度范围内,水杨酸对肉桂酸都具有拮抗作用,而肉桂酸在浓度为0.14 mmol·L^-1时对水杨酸表现出拮抗作用.在所考察的浓度范围中,香草酸与肉桂酸的作用效果都是增效的.     

Salicylic acid induces amelioration of chromium toxicity and affects antioxidant enzyme activity in Sorghum bicolor L.

Aim: Chromium (Cr(VI)) would inflict serious morphological, metabolic, and physiological anomalies in plants ranging from chlorosis of shoot to lipid peroxidation and protein degradation. Cr(VI) toxicity is often associated with oxidative stress, caused by the excessive formation of reactive oxygen species (ROS). In response, plants are equipped with a repertoire of mechanisms to counteract heavy metal (HM) toxicity. Salicylic acid (SA) plays a key role in the signal transduction pathways of various stress responses, demonstrating the protective effect of SA against abiotic stress factors. So, the present investigation was carried out to study the amelioration of pernicious effects of different concentration of Cr(VI) (0.0, 2.0, and 4.0?mg Cr(VI) kg^?1 soil in the form of potassium dichromate) by treatments of salicylic acid solution viz. pretreatment and foliar spray via antioxidative enzymes and their metabolites.

Results: With different treatments of salicylic acid solution, the reinstatement from ill effects of Cr(VI) toxicity was contemplated but the most conspicuous effect was observed when salicylic acid solution was supplied through the foliar spray (0.50?mM). This was accompanied with an increase in ascorbate peroxidase activity and hydrogen peroxide content and decrease in peroxidase activity and ascorbic acid content.

Significance of the study: This study suggests that salicylic acid when applied through pre-treatment of seeds or through a foliar spray can be used to ameliorate the toxic effects of chromium (VI). Salicylic acid has the great potential for reducing the toxicity of heavy metals without negatively impacting the growth of the plants.     

水杨酸对植物光合作用影响的研究进展

水杨酸作为一种信号分子,对植物呼吸代谢、种子萌发、成花诱导、衰老及抗逆等生理过程都有调节作用,近年来有关水杨酸对植物光合作用影响的研究取得了很大进展。水杨酸能够调节植物叶片气孔运动、光合色素含量、光合机构性能、光合碳同化酶活性等各方面,其效果因浓度、植物种类、环境条件等不同而表现出差异。该文就近年来国内外有关水杨酸对植物光合作用的影响(主要从植物叶片气孔运动、光合色素含量、光合机构性能和光合碳同化酶活性等方面)研究进展进行综述。     

喷施黄腐酸对干旱胁迫下甘蔗苗期叶绿素荧光参数及丙二醛的影响

分别对具4～5张完全叶桶栽甘蔗品种ROC22#和园林6#叶面喷施黄腐酸,分别为正常供水0(CK1)、0(CK2)、200、400、800、1200mg/L黄腐酸,研究在不同胁迫程度下不同浓度黄腐酸对甘蔗叶片叶绿素荧光参数、丙二醛(MDA)含量变化的影响。结果表明,经过黄腐酸处理后甘蔗叶片的PSⅡ原初光能转换效率(Fv/Fm)、光合量子产额(Yield)、光化学淬灭系数(qP)数值在中度和重度水分胁迫下都高于干旱对照CK2,品种和处理间参数的变化有差异;非光化学淬灭系数(qN)值则与正常供水对照比较没有大的差异。黄腐酸处理后甘蔗叶片MDA含量随处理浓度增大而降低,且明显低于干旱对照CK2。从2个参试品种6个处理浓度综合分析,水分胁迫下喷施黄腐酸可提高ROC22#和园林6#甘蔗苗期的抗旱性,以200、400mg/L处理效果较好。     

Cadmium stimulates the accumulation of salicylic acid and its putative precursors in maize (Zea mays) plants

The effect of 10, 25 and 50 µ M Cd(NO₃)₂ on the salicylic acid (SA) metabolism was investigated in young maize seedlings ( Zea mays L., hybrid Norma). Cadmium (Cd) was translocated into the leaves and induced oxidative damage, as indicated by the reduced chlorophyll content, the decreased quantum efficiency of photosystem II and the enhanced malondialdehyde (MDA) content, especially after 7 days. The activity of glutathione reductase (EC 1.6.4.2) increased from the fourth day and that of guaiacol peroxidase (EC 1.11.1.7) after 7 days of Cd stress compared with the control leaves. These effects of Cd exhibited a correlation with the concentration. Under these conditions, Cd did not affect the MDA content or the antioxidant enzyme activities in the roots. After 7 days, Cd increased the levels of free and bound forms of benzoic acid (BA), O -coumaric acid ( O -hydroxy-cinnamic) ( O- HCA) and SA in the leaves, but in the roots, only the 50 µ M rate of Cd caused changes in the free O -HCA acid and bound BA content.