苯丙噻二唑诱导辣椒抗白粉病机制研究

以花溪辣椒、遵义辣椒为试材,辣椒白粉病菌为供试菌,苯丙噻二唑(BTH)为诱导剂,采用喷施接种法,研究了BTH诱导辣椒对白粉病产生抗性的作用机制.结果表明:不同浓度BTH均可以诱导辣椒对白粉病产生抗性,浓度为0.20 mmol·L-1时诱导效果最佳,防治效果为81.82％;BTH-接菌处理的辣椒叶片过氧化物酶(POD)、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)活性明显增加;BTH-接菌、BTH-未接菌和CK-接菌处理都能诱导辣椒叶片几丁质酶和β-1,3-葡聚糖酶活性的升高,但CK-接菌处理增加幅度较小.BTH不影响白粉病菌孢子萌发和附着胞子的产生,却能有效抑制菌丝的生长,表现为菌丝生长缓慢和菌丝的侧枝数减少.通过扫描电镜观察,发现CK-接菌处理在24 h后,辣椒叶片保护层开始被溶解,BTH-接菌处理的辣椒在接菌48 h后才出现该现象,说明BTH能产生阻碍或延迟菌丝破坏的保护层物质.     

BTH诱导的一种黄瓜叶片胞间隙病程相关蛋白的纯化及鉴定

 对苯并噻二唑(BTH) 处理和接种霜霉病菌后的黄瓜幼苗叶片胞间隙液中病程相关蛋白的诱导积累及纯化鉴定进行了研究。结果表明, BTH处理和接种霜霉病菌均可诱导黄瓜叶片胞间隙液产生分子量为27 kD的新蛋白, 利用SDS-PAGE结合电洗脱的方法纯化了该蛋白。通过基体辅助激光解析电离飞行时间质谱(MALDI-TOFMS) 分析, 将所得的肽指纹图谱( PMF) 在NCBInr蛋白质数据库中比对, 发现该蛋白是一种酸性几丁质酶。酶活性测定及Western blotting分析进一步证实了上述结果。     

四种化学诱抗剂防治黄瓜绿斑驳花叶病毒病的试验初报

为了筛选出能够诱导瓠瓜产生黄瓜绿斑驳花叶病毒(Cucumber green mottle mosaic virus,CGMMV)病抗性的化学诱抗剂,在瓠瓜幼苗上分别喷施不同浓度的2,1,3-苯并噻二唑(2,1,3-Benzothiodiazole,BTH)、芸薹素内酯(Brassinolide,BL)、壳聚糖(Chitosan Oligosaccharide,CTS)、水杨酸(Salicylic Acid,SA)后,人工摩擦接种CGMMV,评价它们的相对防治效果。结果表明:接种前3 d用0.050 g·L-1 BTH、5.0×10-5 g·L-1 BL、1.0 g·L-1 CTS、0.138 g·L-1 SA处理均可使瓠瓜CGMMV的病情指数降低,其中5.0×10-5 g·L-1 BL防效最佳,达70.38%。进一步研究表明,BL、CTS、SA以喷药后3 d为最佳诱导时间,而BTH为喷药后1 d。4种化学物质均能诱导瓠瓜对CGMMV产生抗性,其抗性差异与诱抗剂种类、浓度及诱导时间相关。     

促生菌CH1诱导黄瓜对猝倒病抗性的研究

 采用分根法研究了植物生长促生菌CH1诱导黄瓜对猝倒病的抗性以及黄瓜植株经CH1处理后根部与叶部组织的超氧化物歧化酶( SOD) 、过氧化物酶( POD) 、过氧化氢酶(CAT) 、多酚氧化酶( PPO) 和苯丙氨酸解氨酶( PAL) 的活性变化。结果表明, 促生菌CH1提高了黄瓜的成苗率, 处理后的28 d, 猝倒病相对防效高达78.64% , 推测促生菌CH1使黄瓜产生的诱导抗性是其防病的主要原因。黄瓜经CH1处理并同时接种腐霉菌后, 处理根部与未处理叶部组织中SOD、POD、CAT、PPO和PAL活性都明显高于其它处理, 其根部这些酶的活性分别在处理后3、3、5、5和5 d时出现高峰, 叶部酶活性变化基本与根部的相吻合。表明这些酶活性的提高与CH1诱导的黄瓜对猝倒病抗性可能有一定的相关性, 而且CH1对这些酶活性的诱导具有系统性。     

脱落酸诱导黄瓜对霜霉病的抗性研究

以"新泰密刺"黄瓜为试材,选用5、10、20、30、40mg/L的脱落酸(ABA)处理黄瓜幼苗,研究外源ABA对黄瓜抗霜霉病的影响。结果表明:适当浓度ABA处理可诱导黄瓜抗霜霉病,降低病情指数,诱导叶片防御酶POD、SOD、PAL、PPO活性升高。其中10mg/L浓度处理表现效果最好;诱导抗性可持续8d以上,第4天防御酶活性均高于第8天。     

外源壳聚糖对霜霉病胁迫下黄瓜幼苗抗性指标的影响

为研究外源壳聚糖(CTS)对黄瓜幼苗抗霜霉病的诱导作用,采用菌悬液叶面喷洒的方法,测定了黄瓜幼苗在白粉病菌侵染下叶绿素含量,过氧化氢酶(CAT)活性,丙二醛(MDA)含量,脯氨酸含量,可溶性糖和蛋白含量的变化。结果表明:CTS处理增加了黄瓜幼苗的叶绿素、可溶性糖和蛋白的含量,提高了CAT的活性,降低了MDA和游离脯氨酸的含量,说明CTS有利于提高黄瓜幼苗对霜霉病菌的抗性,其最适浓度为150 mg/L。     

BTH处理对不同生育期甜瓜抗白粉病的诱导效应

以幼苗期、伸蔓期和幼果期的黄河蜜甜瓜为试材,研究了苯并噻二唑(BTH)处理对3个生育期甜瓜植株抗白粉病的诱导效应。结果显示:0.25mmol·mL-1BTH对幼苗期和伸蔓期甜瓜植株的诱导效果显著高于幼果期甜瓜植株,而伸蔓期和幼苗期植株之间病情指数差异不显著;0.25mmol·mL-1BTH处理后,幼苗期甜瓜植株叶片中β-1,3-葡聚糖酶(GLU)活性在接种白粉菌后增幅最大,伸蔓期次之,幼果期最小;无论是诱导+接种的植株,还是只接种的植株,叶片中的苯丙氨酸解氨酶(PAL)活性高峰都随着苗龄增大呈现出不断推迟的现象。     

不同浓度维生素诱导处理对黄瓜幼苗防御酶活性的影响分析

为了研究不同维生素处理对黄瓜幼苗防御酶活性的影响,分别用维生素B1、B2、B6和抗坏血酸(VC)对黄瓜幼苗进行诱导处理,以蒸馏水为空白对照,对黄瓜幼苗的防御酶活性进行测定和分析。结果表明:经过维生素诱导处理的黄瓜幼苗,体内的多酚氧化酶(PPO)和过氧化物酶(POD)的活性基本呈现先升高后降低的趋势,而超氧化物歧化酶(SOD)的活性整体呈现升高的趋势,其中经过2.0%维生素B2诱导处理的黄瓜幼苗体内的SOD活性增强最为显著,可诱导黄瓜植株产生对霜霉病的抗性,增强植株抵抗病虫害的能力。     

茉莉酸甲酯诱导辣椒抗青枯病与活性氧代谢的关系

为探究茉莉酸甲酯(Methyl Jasmonate,Me JA)诱导辣椒抗青枯病效应与活性氧代谢相关酶的关系,以辣椒易感青枯病品种‘粤红1号’和抗青枯病品种‘辛香8号’幼苗为试验材料,在0.1mmol·L-1 Me JA喷雾处理后12、24、48、72和96 h接种青枯劳尔氏菌(Ralstonia solanacearum),对其进行青枯病病情指数与活性氧代谢相关酶——超氧化酶歧化酶(Superoxide Dismutase,SOD)、过氧化氢酶(Catalase,CAT)、过氧化物酶(Peroxidase,POD)和抗坏血酸过氧化物酶(Ascorbate Peroxidase,APX)活性以及丙二醛(Malondialdehyde,MDA)含量测定及相互关系的分析。结果表明:‘粤红1号’和‘辛香8号’的病情指数随喷Me JA处理时间的推移表现为先降后升,但都低于对照;而诱导效果则相反,Me JA处理对两个辣椒品种幼苗抗性的最适诱导时间均为接种前48 h。接种后0~96 h,Me JA喷雾处理的辣椒幼苗叶片SOD、CAT、POD和APX酶活性均显示先升后降的趋势,且明显高于对照,接种后24~48 h达到最高,而MDA含量则明显低于对照。因此,Me JA可诱导辣椒幼苗抗青枯病,其实现途径可能与提高活性氧代谢相关酶活性和缓解膜脂过氧化有关。     

哈茨木霉β-葡聚糖酶诱导、纯化及对黄瓜幼苗的促生防病作用

在实验室条件下分别以β-葡聚糖、麦麸和黄瓜枯萎病菌(Fusarium oxysporum)细胞壁作为唯一碳源诱导哈茨木霉菌(Trichoderma harzianum)Th-30发酵产生β-葡聚糖酶,采用硫酸铵盐析和琼脂糖凝胶色谱柱层析法对β-葡聚糖酶进行分离纯化,以津研4号黄瓜为试验材料,探究β-葡聚糖酶对黄瓜幼苗抗性生理指标、形态指标的影响及黄瓜常见土传病害的防控作用。结果表明：不同诱导条件下木霉Th-30发酵产β-葡聚糖酶活性差异显著,经β-葡聚糖诱导发酵的粗酶液酶活性最高,发酵72 h时达75.63 U·mL^-1;纯化的β-葡聚糖酶比活力为783.56 U·mg^-1,是粗酶液的45.32倍;5倍液和10倍液β-葡聚糖酶可显著提高黄瓜幼苗的根系活力、游离脯氨酸含量、苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)活性以及根冠比和壮苗指数;β-葡聚糖酶10倍液处理对黄瓜立枯病、黄瓜枯萎病、黄瓜疫病、黄瓜猝倒病、黄瓜菌核病的防效为50.36%～80.63%。     

诱抗处理对甜瓜叶片酚类物质代谢的影响

以甜瓜抗白粉病品种‘银帝’和感白粉病品种‘卡拉克赛’为材料,研究诱导抗性处理对其叶片酚类物质代谢的影响及其与抗病性的关系。结果表明：苯丙噻重氮（BTH）和水杨酸（SA）处理以及接种白粉菌均可显著诱导甜瓜叶片苯丙氨酸解氨酶（PAL）、过氧化物酶（POD）、多酚氧化酶（PPO）活性和绿原酸、总酚、类黄酮含量升高,但纳米硅（SiO2）诱导无效。经诱导和接菌后,甜瓜抗病品种叶片PAL、POD、PPO活性和总酚、绿原酸、类黄酮含量高于感病品种。BTH和SA诱导甜瓜抗病性增强的原因之一是提高了叶片次生代谢相关酶的活性,增加了叶组织次生代谢物质的含量。     

BTH-mediated antioxidant system responses in apple leaf tissues

BTH (S-methylbenzo-1,2,3-thiadiazole-7-carbothiate), an active compound of the commercial preparation Bion, has been studied as an elicitor of resistance to fire blight (Erwinia amylovora) in apple. However, the biochemical mechanisms of its action are not fully elucidated. Our study indicated that BTH at the best time of its protection activity (2–14 days after application) induced changes in prooxidant–antioxidant balance in the leaves of apple trees, but in different ways in the enzymatic and nonenzymatic antioxidants. Glutathione as low molecular antioxidant as well as superoxide anion radical and lipid peroxides as oxidants exhibited changes at the early phase of BTH action. Glutathione-dependent enzymes were strongly affected by the elicitor used. On the 2nd day glutathione transferase (GST) and glutathione peroxidase (GSH-Px) activities increased by about 70% and 30% above the control, respectively. GST activity normalized about the 14th day but GSH-Px at the same time showed 27% of the control value. Among enzymes utilising hydrogen peroxide only catalase showed increase (37%) at the early phase of experiment. Compared with the control, BTH-treated plants did not show changes in ascorbate peroxidase and phenylalanine ammonia-lyase activities. Tocopherol (TOC) level diminished starting from the 7th day after BTH treatment and on the 14th day it was only 28% of the control. It is proposed that extinguishing of BTH-mediated signal resulted from TOC and glutathione action. The diminished ascorbate level at all examined times may play a crucial role in BTH-mediated cell growth regulation. The direct influence of BTH on lipid metabolism should be also taken into consideration.     

苯并噻二唑处理提高采后沙糖橘对指状青霉菌的抗性

对沙糖橘(Citrus reticulata Blancdo‘Shiyueju’)果实进行苯并噻二唑(S-methyl benzo thiadiazole-7-carbothioate,BTH)渗透处理后接种指状青霉菌孢子,12h后即可明显诱导果皮中抗病相关蛋白CR-CT1和CR-BG3基因表达并在贮藏期间维持较高水平;不同浓度BTH处理果实的发病率和病斑面积均比对照低,其中以0.025g·L-1BTH处理的效果最好;BTH处理提高了果皮几丁质酶(CT)、β–1,3–葡聚糖酶(GUN)、苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、过氧化物酶(POD)活性和H2O2含量,表明BTH诱导的沙糖橘果实抗病性与果实CR-CT1和CR-BG3基因的表达增强,CT、GUN、PAL、PPO和POD等相关酶活性和H2O2含量提高密切相关。     

BTH和水杨酸(SA)对甜瓜抗白粉病的诱导作用

研究了BTH和水杨酸(SA)作为诱导剂在不同浓度,不同时期对甜瓜抗白粉病的诱导作用。采用盆栽甜瓜植株,喷施诱导剂,然后接种甜瓜白粉菌的方法测定这2种诱导剂对甜瓜的诱导效果。结果表明2种诱导剂均对甜瓜有明显的诱导作用。BTH最佳诱导浓度为50μg／mL,SA为25μg/mL,平均诱导效果分别为86,6％和83．7％。在最佳诱导浓度下,2种诱导剂诱抗的持效期至少可达17 d。在2—8叶期,BTH和SA处理均有良好的诱导效果,且差异不显著。诱导剂本身对甜瓜白粉病菌分生孢子萌发及菌丝生长无明显影响。     

BTH诱导西瓜甜瓜抗病毒病研究

为了考察S-甲基苯基(1,2,3)噻二唑-7-硫代羧酸酯(benzothiodiazole,BTH)诱导西瓜对小西葫芦黄花叶病毒(Zuccini yellow mosaic virus,ZYMV)、西瓜花叶病毒(Watermelon mosaic virus,WMV)与甜瓜对黄瓜花叶病毒(Cucumber mosaic virus,CMV)的抗病效果,分别在接种ZYMV、WMV、CMV前喷施BTH。结果表明:在接种ZYMV、WMV、CMV前3d用25μg/mLBTH处理西、甜瓜,4周后植株的病情指数减少,相对防效分别为55.6%、56.8%、78.2%;进一步研究发现,经BTH处理后,诱导时间的长短对病情指数有一定的影响;BTH对病毒病的防治效果优于病毒A、病毒K、宁南霉素、芸薹素内酯。     

Pre-harvest application of 2, 6-dichloroisonicotinic acid, -aminobutyric acid or benzothiadiazole to control post-harvest storage diseases of melons by inducing systemic acquired resistance (SAR)

Summary

Field-grown rockmelon plants were treated with -aminobutyric acid (BABA), 2,6-dichloroisonicotinic acid (INA), benzothiadiazole (BTH) or water during fruit development and evaluated for increased resistance against plant diseases or post-harvest pathogens. One experiment was conducted at Camden, NSW, Australia (INA, BABA or water). Two experiments were at Griffith, NSW, Australia (INA, BTH or water). Growing plants and harvested fruits were assessed for disease symptoms from natural infections and assayed for the accumulation of chitinase and peroxidase, two major pathogenesis-related (PR) proteins induced as a result of systemic acquired resistance (SAR). Harvested fruit from both BTH- or INA-treated plants showed a significant (P < 0.05) reduction in the severity and incidence of post-harvest storage diseases mainly caused by Fusarium, Alternaria and Rhizopus. However, there were no differences in disease severity and the incidence of rots between using four fortnightly foliar sprays of INA or BTH during flowering and fruit development, or a single spray of BTH, 2 weeks before harvest. Each approach showed an equivalent reduction in storage diseases. Plants treated with BABA showed less resistance against powdery mildew in the field and storage rots from natural inoculum, and lower increases in chitinase and peroxidase activities than those treated with INA. In all trials, an additional post-harvest dip with guazatine [0.05% (w/v)] gave a substantial reduction in melon storage rots. Pre-harvest application of INA or BTH reduced the occurrence of powdery mildew and downy mildew on the leaves. Over the three field-experiments, INA had a small phytotoxic effect causing lesion-like symptoms on leaves and affected plant growth, but not yield, at Camden, when applied during flowering and 2 weeks after flowering. However, INA did not produce any phytotoxic effects in the two experiments at Griffith when applied serially, four times to plants after flowering.     

黄瓜抗霜霉病相关基因cDNA片段的克隆与分析

 以抗霜霉病黄瓜‘东农129’为试材, 利用基因差异显示技术(DDRT-PCR) 研究了黄瓜接种霜霉病菌前后基因表达的差异。共分离出4个接菌后在叶片中特异表达的cDNA片段, 分别命名为49-2、 50-5、50-7和52-14。同源性比对发现, 50-7号片段与黄瓜脂氧合酶基因部分同源, 其余为未知新基因序列。表达分析显示, 所筛选的4个差异表达基因片段与黄瓜感染霜霉病菌有密切关系。49-2号片段在所检 测的整个感染过程都有很强的表达; 50-5号片段与病菌侵染也有较密切的关系, 但相对49-2表达延迟; 50-7和52-14仅在接种24 h有一定表达, 显示出与病菌诱导之间的特殊关系。     

低温胁迫对嫁接黄瓜叶片抗坏血酸-谷胱甘肽循环的影响

 为了探讨嫁接增强黄瓜抗冷性的分子机制,本试验以黑籽南瓜为砧木,‘津绿3号’黄瓜为接穗,对低温胁迫下嫁接和自嫁黄瓜幼苗叶片抗坏血酸-谷胱甘肽循环中抗氧化酶基因的表达和相关酶活性及AsA、GSH和 H₂0₂含量变化进行了研究。结果表明: 低温胁迫下, 嫁接黄瓜叶片DHAR mRNA和GR mRNA相对表达量均大于自嫁黄瓜,GalLDH mRNA和APX mRNA相对表达量均与自嫁黄瓜差异无显著差异; DHAR、GR、GalLDH和APX活性均高于自嫁黄瓜;AsA和GSH含量与AsA/DHA和GSH/GSSG比值均高于自嫁黄瓜, DHA、GSSG和H₂O₂含量均低于自嫁黄瓜。嫁接黄瓜叶片DHAR和GR较高的转录水平维持的较高DHAR和GR活性是AsA和GSH含量明显高于自嫁黄瓜的重要原因, 而嫁接黄瓜叶片较高的GalLDH和APX活性与GalLDH mRNA和APX mRNA相对表达量无关。     

Improving disease resistance in peach fruit during storage using benzo-(1,2,3)-thiodiazole-7-carbothioic acid S-methyl ester (BTH)

Summary

The compound benzo-(1, 2, 3)-thiodiazole-7-carbothioic acid S-methyl ester (BTH) effectively induces a systemic acquired resistance (SAR) response in plants and increases plant resistance to disease. To learn how BTH may affect post-harvest quality and disease resistance in peach, (Prunus persica L. cv. ‘Jiubao’) peach fruit were treated with 200 mg l^–1 BTH for 5 min immediately after harvest, then incubated for 60 h at 20°C, 85–95% RH. Sixty h after treatment, fruit were inoculated with spore suspensions of Penicillium expansum at 1.2 10⁴ CFU ml^–1. The incidence of disease and lesion areas on peach fruit were significantly reduced by BTH-treatment (P < 0.05). In addition, chitinase and -1,3-glucanase activities in peach fruit were significantly enhanced by BTH-treatment (P < 0.05). Moreover, the total levels of phenolic compounds and chlorogenic acid, and the lignin content of BTH-treated fruit were significant higher than in control fruit (P < 0.05). The effects of BTH on fruit quality were also analysed. Soluble solids content, soluble pectin, titratable acidity and ascorbic acid levels in peach fruit were not significantly affected by treatment with BTH. Our results suggest that the application of BTH may control post-harvest diseases in peach fruit during commercial production.