水杨酸诱导对玉米大斑病抗性的影响

外施水杨酸(SA)可以显著减轻玉米(Zea mays)大斑病的病害症状.外施SA后玉米叶片的病斑数目和病斑大小明显降低和缩小,诱抗效果超过56%.SA诱导玉米抗病机制研究发现,SA预处理减缓了玉米大斑病菌侵染速度,表现为由侵入钉长出新菌丝,菌丝充满侵染细胞以及向邻近细胞扩展的时间延迟;SA预处理加速了病菌侵染过程中侵染点及周围玉米细胞的死亡.SA处理或SA预处理后接菌,明显增强了玉米叶片中苯丙氨酸解氨酶、几丁质酶、β-1,3-葡聚糖酶的活性;增加了玉米叶片内木质素、丁布的含量;SA处理后接菌,增加了玉米叶片内H2O2含量;而单独接菌,这些酶活性及物质含量均无明显改变.     

玉米大斑病的发病原因及防治策略

玉米栽培种植期间,病害属于引起减产的关键因素,大斑病属于重要的病害.玉米大斑病不但对植物产生不利影响,而且对种子造成为害,病害的出现和传播均同玉米抗病能力、耕作栽培制度以及气候等存在紧密联系.所以,务必对玉米大斑病加以重点关注,对发病原因进行科学准确的分析,并运用科学可行的防治策略,为玉米栽培种植提供可靠保障.基于此,...     

AM 菌根真菌诱导对提高玉米纹枯病抗性的初步研究

试验研究玉米接种摩西球囊霉后对纹枯病抗性反应的结果表明,接种摩西球囊霉能明显减轻玉米纹枯病的发病率和病情指数,减轻病害。接种摩西球囊霉还能促进玉米营养生长,但立枯丝核菌侵袭会降低菌根的侵染率,表明摩西球囊霉与立枯丝核菌间存在相互作用。     

玉米内生芽胞杆菌的抗菌活性物质及其拮抗玉米大斑病菌机理的初步研究

为了研究生防菌株对玉米大斑病菌的抑菌作用,深化对生防菌抗菌机制的认识,本研究从玉米(Zea mays)植株体内分离拮抗玉米大斑病菌(Setosphaeria turcica)的内生细菌,对其抗菌物质及其抑菌机理进行初步研究。结果表明,所分离的内生菌株YY1经形态学观察、生理生化测定及16SrDNA序列分析,鉴定为枯草芽胞杆菌(Bacillus subtilis)。菌株YY1发酵液的硫酸铵沉淀物具有抑菌活性,且在硫酸铵50%饱和度时抑菌活性最强,说明YY1菌株产生的抗菌活性物质可能是蛋白类物质。该菌株及其蛋白粗提液均对禾谷镰刀菌(Fusarium graminearum)、苹果轮纹病菌(Botryosphaeria dothidea)、灰霉病菌(Botrytis cinerea)、玉米弯孢霉叶斑病菌(Curvularia lunata)等7种植物病原真菌有较强的拮抗作用。用蛋白粗提液处理菌丝、分生孢子、原生质体后经显微观察发现,大斑病菌的基内菌丝由丝状畸变为串珠状,当蛋白粗提液浓度为0.78μg/μL时,可完全抑制分生孢子萌发,并导致原生质体裂解。通过抑制孢子萌发过程中信号途径相关基因的半定量RT-PCR分析和玉米大斑病菌不同信号途径相关基因突变体的抑制率统计,初步判定该抑菌过程主要通过cAMP信号转导途径发挥作用。本研究为寻找玉米大斑病菌新的防治方法和途径提供基础资料。     

转兔防御素基因（NP-1）玉米植株的获得及其抗病性分析*

首次报道了采用基因枪法将兔防御素基因(NP-1)导入玉米(Zea mays L．)不同杂交组合胚性愈伤组织中获得了T0再生植株。分别通过PCR和DNA点杂交证实．NP-1基因已经整合到部分T0代玉米基因组中。PCR和Southern杂交证实NP-1基因已经稳定遗传至部分T1代玉米植株中。RNA点杂交结果表明部分T1代转基因玉米中NP-1基因能够进行正常转录。在Tl代玉米5～7叶期接种玉米大斑病菌(Helminthosporium turcicum Pass)0号生理小种，发现转兔防御素基因玉米能有效抵抗玉米大斑病的侵袭。     

东兰县鲜食玉米大斑病流行原因及绿色防控措施探析

鲜食玉米是广西东兰县农村脱贫攻坚的特色产业,其果穗是现代餐桌的新兴食品,其茎叶是优质的农牧饲料,种植效益高于普通玉米2～3倍,深受广大农民欢迎.随着高端鲜食玉米的大面积推广与连年复种,大斑病呈明显的偏重发生趋势,果穗减产率达15％～50％,对鲜食玉米产业构成重大的威胁.通过对东兰县鲜食玉米大斑病的流行调查,并结合多年有...     

诱导模式对真菌激发子的影响

选择抗（耐）黄萎病的豫8号和感黄萎病的豫棉6两个棉花（Gossypium hirsutum L.)品种作为细胞系，选择高毒的V44和低毒的V64两种大丽轮枝菌9Verticillium dahlium Kle.b)为黄萎病原菌。设计不同毒力的病原菌分别直接诱导不同抗性的棉花细胞，不同毒力的病原菌和不同抗性的棉花细胞互相诱导的几种互作模式。发现棉花过氧化物酶（POD），超氧化物歧化酶（SOD）和多酚氧化酶（PPO）的比活经病原菌激发子直接诱导后有不同程度的提高；经交互诱导3种酶比活有进一步的变化，豫棉6号细胞交互诱导后3种酶的比活有了进一步的升高，而豫棉8号细胞交互诱导后3种酶的比活基本保持不变，并探讨了这些变化与棉花抗病性之间的关系。     

玉米大斑病菌G蛋白β亚基编码基因的克隆与表达

玉米大斑病菌（Setosphearia turcica）属半知菌亚门丝状真菌，是严重威胁玉米生产的重要植物病原真菌。本研究克隆了玉米大斑病菌G蛋白β亚基编码基因Stgb-1。Stgb-1基因全长1296bp，由5个外显子和4个内含子组成；开放阅读框（ORF）为1056bp，编码351个氨基酸，蛋白质计算分子量为39.081kDa。STGB1蛋白推导氨基酸序列与Cochliobolus heterostrophus（100%）、Cryphonectria parasitica（80%）、Aspergillus fumigatus（81%）等丝状真菌的G蛋白β亚基编码基因均具有较高的同源性。同时，利用RACE技术和Genomic Walking技术获得了Stgb-1基因3’-末端cDNA和DNA的3’端侧翼序列，BlastN结果表明其cDNA 3’-UTR为136bp，poly(A)由9个A构成。此外，构建了pET28a-Stgb-1原核表达载体，SDS-PAGE检测和Western blot鉴定结果表明，目的蛋白在E.coli BL21菌株中已成功实现了诱导表达，为进一步研究蛋白结构与功能的关系奠定了基础。     

水杨酸诱导下人参培养物差异表达基因片段的克隆

本研究以人参愈伤悬浮细胞为材料,在其生长的第28天添加1×10^-3mg／L水杨酸,测定水杨酸添加后,过氧化物酶、多酚氧化酶和苯丙氨酸解氨酶等3种酶在72h内的变化及皂苷含量,结果表明：水杨酸添加后对过氧化物酶和苯丙氨酸解氨酶的活力影响最大,分别在24h和48h达到最大峰值,在18h开始影响多酚氧化酶的活力,培养物生长的第28天添加水杨酸可以明显提高人参愈伤组织中皂苷的合成。确定添加水杨酸后24h提取总RNA,进行cDNA-RDA分析,筛选差异片段。确定差异基因并在GenBank中注册,注册号为FE900130。为探讨水杨酸作为诱导子对人参次生代谢的影响奠定基础。     

玉米大斑病菌GPCRs超家族的基因鉴定及其在孢子发育过程中的转录模式

G蛋白偶联受体(G protein-coupled receptors,GPCRs)广泛存在于动物、植物以及微生物中,是最大的涉及信号转导的膜受体家族.本研究通过基于隐马尔科夫模型的HMMER 3.0软件搜索玉米大斑病菌(Setosphaeria turcica)基因组数据库,鉴定并获得GPCRs超家族基因及其基因组定位;采用MEGA 6.0软件进行系统进化分析;通过通用样品数据系统(generalized sample data system,GSDS)工具进行基因结构分析;利用InterPro和SMART工具分析GPCRs的保守结构域.进一步利用qRT-PCR技术,对所确定的GPCR基因在分生孢子发育形成侵染结构的过程中不同阶段的相对表达量进行分析.结果表明,在玉米大斑病菌基因组中至少有9个典型的GPCR,其中3个属氮源感应因子类,信息素受体和碳源感应因子类各2个,类环磷酸腺苷受体和真菌视蛋白类各1个.这些基因散布在玉米大斑病菌基因组中,且结构复杂多样,但所有成员编码产物均由N端、7个跨膜结构域、3个胞内环、3个胞外环及C端组成.每个跨膜结构域包含20～25个氨基酸.以分生孢子为对照,所有基因在附着胞成熟时期接种后12 h(12 hours post inoculation,12 hpi)均显著下调(P＜0.05);除基因StRtc1和Stfdd123以外,全部基因整体变化趋势均呈现上调/持平(3 hpi)-上调(6 hpi)-下调(12 hpi)-上调(24 hpi)的规律,尤其在侵入丝形成时期(24 hpi)显著上调(P＜0.05).在附着胞形成时期(6 hpi),仅StSte2p和StRtc2表达显著上调.St Rtc1和Stfdd123在各阶段中的表达量与对照差异不显著或显著降低.本研究为深入解析植物病原真菌GPCR超家族的功能提供了理论依据.     

水杨酸对高温胁迫下水稻幼苗抗热性的影响

以"西农优1号"水稻品种为材料,研究了水杨酸(SA)预处理对高温胁迫下水稻幼苗抗热性的影响,结果表明:0.5 mmol·L-1 SA预处理可减缓水稻幼苗的电解质渗出,降低MDA含量和超氧阴离子产生速率,提高高温胁迫下水稻幼苗体内过氧化氢、脯氨酸、可溶性糖、可溶性蛋白质、抗坏血酸和GSH的含量.表明SA预处理可提高高温胁迫下水稻幼苗的抗热性.     

Physiological and biochemical effects of salicylic acid on Pisum sativum exposed to isoproturon

In the present study, attenuation of isoproturon (IPU) toxicity by salicylic acid (SA) was observed. Seven-day-old seedlings of pea (Pisum sativum L. cv. Azad P-1) were treated with 10 mM IPU. IPU influenced physiological and biochemical parameters. IPU significantly inhibited growth variables like shoot and root height, fresh and dry biomass of the pea. The contents of carotenoids, chlorophylls, protein and activity of nitrate reductase were inhibited significantly. IPU enhanced the accumulation of H₂O₂, ion leakage and lipid peroxidation due to induction of oxidative stress in pea. The activities of antioxidant enzymes, namely superoxide dismutase, catalase and ascorbate peroxidase increased while the activities of guaiacol peroxidase decreased. However, exogenous SA regulated the toxic effects of IPU. The indices of oxidative stress appeared to be alleviated by SA. Pigment content and activities of enzymes increased approximately up to the level of control. IPU caused non-target phytotoxicity to P. sativum. The natural growth regulator/allelochemical has potential to overcome the adverse effects caused by IPU.

Abbreviations: CAT: catalase; EL: electrolyte leakage; IPU: isoproturon; LP: lipid peroxidation; MDA: malondialdehyde; NR: nitrate reductase; POD: guaiacol peroxidase; SOD: superoxide dismutase; TCA: trichloroacetic acid     

Relationships between salicylic acid content,phenylalanine ammonia-lyase (PAL) activity,and resistance of barley to aphid infestation

It has been suggested that salicylic acid (SA) is a signal in acquired resistance to pathogens in several plants. Also, it has been suggested that infestation of plants causes an increase in the activity of phenylalanine ammonia-lyase (PAL), a key phenolic biosynthesis enzyme. The purpose of this work was to investigate whether the induction of SA and PAL activity is related to the susceptibility of barley to aphid infestation. The induction of free and conjugated SA in two barley cultivars that differ in susceptibility to aphids was analyzed. Analyses of several physiological parameters showed that cv. UNA-80 was more susceptible to the aphid Schizaphis graminum than cv. LM-109. Salicylic acid was not detected in noninfested plants. Levels of free and conjugated SA in cv. LM-109 and of conjugated SA in cv. UNA-80 increased with aphid infestation, whereas the levels of free SA in cv. UNA-80 remained high under all infestation degrees. Maximum values reached in both cultivars were not significantly different. With respect to PAL activity, cv. LM-109 showed a significantly higher specific activity than cv. UNA-80, the more susceptible cultivar. The relationship between the susceptibility of a plant to aphid and SA induction and PAL activity is discussed.     

Effect of salicylic acid and salt on wheat seed germination

Abstract

The effects of pretreatment with salicylic acid on wheat seed germination (Triticum aestivum L. cv. Roshan), lipid peroxidation, and superoxide dismutase, catalase, polyphenol oxidase, and peroxidase activity were studied under conditions of salt stress. Seeds treated with different concentrations of salicylic acid were used for measuring germination traits. Salt stress was induced by sodium chloride solution. Seeds were soaked in salicylic acid solution for 24 h, dried with sterile paper, transferred to sterile Petri dishes, and treated with 10 ml NaCl solution at different concentrations. After 1 week, the number of germinated seeds, root length, seedling length, and dry weight were recorded. Antioxidant enzyme activity and lipid peroxidation were also assayed. Salinity decreased seed germination. Thus, a high concentration of NaCl (200 mM) decreased germination by 17.6% compared with control treatment. Salicylic acid significantly increased germination in stressed and control seeds. Salicylic acid increased the level of cell division of seedlings and roots, which increased plant growth. Salt stress significantly increased the activity of the antioxidative enzymes catalase, superoxide dismutase, peroxidase, and polyphenol oxidase in wheat seedlings, and salicylic acid reduced the activity of antioxidant enzymes as stress signal molecules. Our results indicated that scavenging of reactive oxygen species was effective, especially by salicylic acid, and that membrane damage was limited. The aim of the present work was to study the character of changes in enzymatic systems induced by NaCl and salicylic acid in wheat seedlings under conditions of salt stress. In brief, salicylic acid treatment reduced the damaging action of salinity on embryo growth and accelerated a restoration of growth processes; thereupon it may be effective for the improvement of seed germination in arid and semi-arid regions.     

Modulation of oxidative damage due to salt stress using salicylic acid in Hordeum vulgare

Oxidative status of salicylic acid (SA) treated barley (Hordeum vulgare) plants grown under saline conditions was examined in a two-year field study during 2012–2013 and 2013–2014 growing seasons. Salinity caused a marked oxidative stress which was manifested as increased concentration of hydrogen peroxide (H₂O₂) and reduced grain yield of barley. Barley plants induced antioxidant system to tolerate salt stress, so that activities of four antioxidant enzymes: peroxidase, catalase, superoxide dismutase and glutathione reductase were enhanced by 22%, 28%, 57% and 44% in the first and by 33%, 20%, 45% and 68% in the second year, respectively. Foliar application of SA in concentration over 0.5 mM enhanced the activities of all four antioxidant enzymes and reduced H₂O₂ content and so enhanced yield. However, higher concentrations of SA reduced grain yield in salt stressed plants in both years, which could be attributed to the negative interaction of antioxidant enzymes with higher concentrations of SA as a non-enzymatic antioxidant. Furthermore, SA is in benzoic acid group and at very higher concentrations can act as an herbicide. It was concluded that SA modulated the oxidative stress through enhanced activities of antioxidant enzymes and reduced the salt-induced adverse effect thereby improving grain yield.     

邻羟基苯甲酸对干旱胁迫下杉木幼苗保护酶的影响

为研究干旱胁迫下杉木自毒物质邻羟基苯甲酸(SA)对杉木幼苗的毒害作用,采用不同浓度的聚乙二醇(PEG-6000)模拟干旱处理,通过水培方法研究干旱胁迫下不同浓度杉木自毒物质邻羟基苯甲酸(SA)对杉木幼苗保护酶的影响.结果表明:在轻度(-0.3MPa)、中度(-0.5MPa)干旱胁迫下,随SA浓度增加超氧化物歧化酶(SOD)活性先降后升再下降,但重度(-0.7MPa)干旱胁迫下,SOD活性直线下降;过氧化物酶(POD)活性则表现为在轻度干旱胁迫下先降后升,中度和重度干旱胁迫下总体呈下降趋势.     

稻瘟菌细胞壁热解物诱导水稻抗稻瘟病的研究

以水稻近等基因系和广东省稻瘟病菌优势小种ZC13的细胞壁热解物(HDS)为材料进行诱导抗病性的研究。HDS通过细胞壁121°C 20 m in热解获得。HDS中葡萄糖质量浓度为176.83 m g/mL。HDS在体外对稻瘟病菌的孢子萌发和菌丝生长均无抑制作用,但处理水稻后可以显著提高水稻对稻瘟病菌的抗病性。在亲和性品系中,诱导抗病效果最高可达82.47%,且浓度与活性间存在正相关趋势;在非亲和品系中,热解物处理引起HR反应。HDS处理后,水稻过氧化物酶(POD)和苯丙氨酸解氨酶(PAL)活力明显升高。     

邻羟基苯甲酸对不同化感型杉木无性系内源激素含量的化感效应

以筛选的自毒物质忍耐型(01 号)和自毒物质敏感型(02 号)杉木无性系为试验材料, 采用胁迫试验分析邻羟基苯甲酸对2 个不同化感型杉木无性系内源激素含量的化感效应。研究结果表明, 邻羟基苯甲酸对不同化感型杉木无性系ABA 含量表现为促进效应, 其中对01 号杉木无性系的促进效应大于02 号; 邻羟基苯甲酸对不同化感型杉木无性系IAA、GA₃ 含量表现为抑制效应, 胁迫后期邻羟基苯甲酸对02 号无性系GA₃ 含量的抑制效应较01 号强, 2 个无性系间IAA 含量的抑制效应差异不明显; 邻羟基苯甲酸对不同化感型杉木无性系ZR 含量的化感效应表现为胁迫第20 d 达到抑制效应高峰期, 随后抑制作用下降, 邻羟基苯甲酸对02 号无性系ZR 含量的抑制效应强于01 号无性系。     

Determination of aspirin and salicylic acid by reverse-phase liquid chromatography

Buffered solid dosage forms containing aspirin, magnesium hydroxide, and aluminum hydroxide are blended with acidic ethanol to extract the aspirin and salicylic acid rapidly. The resulting preparation is then immediately injected onto a 4.6 mm x 3 cm 5 micron reverse-phase column. Aspirin and free salicylic acid are determined simultaneously. The run time is less than 2 min. The total time from the initiation of sample extraction to completion of the separation is less than 5 min.