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1.
Invertase Activities in Sheath-blight Infected Rice Selection Lines and Fungus Culture Filtrates 总被引：2，自引：0，他引：2
Infection of rice plants with Rhizoctonia solani, the sheath blight fungus, at the flowering stage resulted in an increase in acid invertase activity. Activity of the invertase(s)
with optimum pH at 3.5 and 4.5 was higher in the susceptible plants compared to resistant plants. Healthy control plants had
no change in invertase activity. An invertase of fungal origin produced in sheath blight fungus culture filtrates had an optimum
acidic pH of 3.5. The increase in invertase activity observed in the later stages of infection in the susceptible plants compared
to the resistant plants demonstrated a relation to fungal growth. These results suggested that the fungus produced an invertase
for the hydrolysis of sucrose that resulted in alterations of source-sink relationships in the colonized cells. Thus, the
increased invertase activity in the susceptible plants regulated the ratio of hexose to sucrose. This observation is further
supported by the lack of a significant invertase increase in the resistant plants.
Received 14 July 1999/ Accepted in revised form 9 December 1999 相似文献
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水稻叶鞘3种氧化还原酶活性在褐飞虱胁迫中的变化 总被引：1，自引：0，他引：1
为阐明水稻抗褐飞虱的机制,分析了褐飞虱为害对感、抗虫水稻品种叶鞘中3种保护酶活性的影响。采用苗期群体接虫方法对水稻品种进行抗性鉴定,在此基础上测定了褐飞虱为害前后水稻叶鞘中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)的活性。受褐飞虱为害后,抗虫和感虫品种叶鞘中SOD活性均上升,表明无论是抗性植株还是感性植株在清除超氧阴离子自由基方面都具有较强的能力;POD活性在抗虫品种中下降,而在感虫品种中增加,表明抗性品种较感性品种具有更强的酶促抗氧化性能,从而对褐飞虱胁迫具有更强的适应能力。CAT活性在抗虫品种中增加,而在感虫品种中大幅下降,这与其对褐飞虱抗性弱密切相关。 相似文献
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Wheat plants infected with wheat streak mosaic virus were studied for their physiological response to infection. Previous histological data suggest that wheat streak mosaic virus-induced deposits of phenolic nature are present along the bundle sheath and mesophyll cell walls. In this study, we examined this phenomenon further by analysis of phenolic compounds and enzymes involved in their synthesis. In infected plants, the amounts of free and wall-bound phenolic compounds increased slightly, and chromatography showed that the type of free phenolic compounds present had changed. The amount of lignin did not change due to infection. Enzyme assays showed that while phenylalanine ammonia lyase and tyrosine ammonia lyase activities decreased as they do in healthy plants, cinnamyl alcohol dehydrogenase activity stayed high throughout infection. In addition, peroxidase activities in infected plants decreased around the time that the leaves ceased to expand. These results suggest that the general phenylpropanoid pathway is stimulated upon infection, but that lignification is not. 相似文献
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蜡质芽孢杆菌AR156防治水稻纹枯病机理初探 总被引：3，自引：0，他引：3
蜡质芽孢杆菌AR156是一种防治多种土传病害的生物制剂,对水稻纹枯病具有较好的防治效果。本研究通过温室试验方面验证菌株 AR156的防病效果和促生作用,从细胞水平和基因水平初步揭示了菌株AR156防治水稻纹枯病的机理。结果表明,菌株AR156对水稻纹枯病的温室防效达73.06%,同时促进水稻生物量增加14.45%。菌株AR156处理提高了水稻植株SOD、PAL、POD和CAT等防御酶活性,增强了OsPR1b、OsPR10、OsNPR1和ZB8等防卫相关基因的表达。接种立枯丝核菌Rhizoctonia solani HNW-21之前用菌株AR156预处理的水稻植株,SOD和PAL分别提前4、2 d出现活性峰;防卫相关基因均提前表达,且表达时间延长,从而提高水稻对纹枯病的抗性。 相似文献
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J.M. MutukuA. Nose 《Physiological and Molecular Plant Pathology》2012,77(1):41-51
Rice sheath blight disease caused by Rhizoctonia solani Kuhn results in significant yield and quality losses in rice growing areas worldwide. The glycolytic pathway is important in the resistance response to R. solani infection in rice. This study examined one of the regulatory steps in this pathway catalyzed by pyrophosphate-fructose-6-phosphate-phosphotransferase (PFP) and 6-phosphofructokinase (PFK). PFP and PFK activity in R. solani-infected rice plants increased. The mRNA expression of PFP/PFK isozymes showed that PFK 1, 2, 4 and 5 in the resistant line at 1 dpi were high as compared to the gradual increase observed in the expression of all PFP isozymes. Also PFK 1, PFK 3, PFK 4, PFK 5, PFP 2 and PFP 5 were adaptive to sheath blight disease infection and linked to defence response while, the expressions of PFK 2, PFP 1, PFP 3 and PFP 4 although adaptive, were not specific to R. solani infection. These observations provide evidence that (a) both PFP and PFK have isozymes that play an adaptive role after R. solani infection but while those of PFK are expressed at higher levels within a short time after infection those of PFP are expressed gradually, (b) the adaptive activation of PFP in R. solani-infected rice plants is correlated with the paired expression of its α- and β-subunits as shown by PFP 2 and PFP 5, and (c) the expression of some α-subunits is not specific to R. solani infection as shown by PFP 1, PFP 3 and PFP 4. 相似文献
7.
转抗真菌基因水稻对纹枯病的抗性表达分析 总被引：1，自引：0，他引：1
采用人工接种和酶活性测定的方法,研究转入几丁质酶基因等1～4个抗真菌基因的13个转基因水稻株系对纹枯病的抗性和几丁质酶活性变化规律.结果表明:13个转基因水稻株系的抗性均显著高于非转基因亲本.母本抗性水平不同或者导入单个及多个抗真菌基因的转基因水稻中均可筛选出抗性优良的株系;转基因水稻病情指数的变异系数为21.93～69.32,高于非转基因亲本的14.37～47.00,表明转基因水稻的抗病性更容易变异.对转基因水稻几丁质酶的活性分析结果表明,除1个转基因水稻株系的酶活性与非转基因亲本相同外,其它转基因水稻酶活性均高于非转基因亲本,但酶活力高低与转基因水稻株系间抗病性的高低无显著的相关性. 相似文献
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寒地水稻纹枯病初步研究 总被引：2，自引：0，他引：2
1990～2000年首次对寒地水稻纹枯病进行了初步研究 ,明确佳木斯地区水稻纹枯病始发期为 6月下旬至7月上旬、盛发期为7月中旬至8月上旬、停止蔓延期为8月中、下旬。病害水平扩展高峰期为7月中旬至8月上旬 ,垂直扩展高峰期为7月下旬至8月中旬 ,防治最佳时期为分蘖末期。采用人工接种和自然感病两种方法对486份材料进行鉴定 ,筛选出抗源材料11份 ;鉴定耐病品种 5份 :牡丹江21、品鉴1、品鉴 3、松 94-7、龙粳5号 ;在自然感病条件下 ,病害级别与空秕率、千粒重、产量损失率成显著相关 相似文献
12.
W. Wu L. Nie F. Shah Y. Liao K. Cui D. Jiang J. Xie Y. Chen J. Huang 《Plant pathology》2014,63(1):98-108
Sheath blight (caused by Rhizoctonia solani) is one of the most important constraints in achieving high grain yield in intensive rice production systems. Canopy structure can influence the development of sheath blight epidemics. The objective of this study was to determine the effect of canopy structure parameters such as shoot number, leaf area index, biomass production, contact frequency, light transmittance and plant height on the development of sheath blight epidemics in commercial fields. Field experiments were conducted in both early and late seasons of 2009 and 2010 in Wuxue, Hubei province, China. The effects of nitrogen (N) rate and hill density on structure and production parameters and sheath blight severity were investigated. Sheath blight severity was recorded as a sheath blight index or relative lesion height on inoculated and uninoculated plants in each crop. Lesion length was measured on inoculated plants in 2010. The results showed that the sheath blight index increased with an increase of N rate and hill density in uninoculated plots in each trial. Stepwise multiple regression analysis demonstrated that contact frequency was consistently related to sheath blight. Lesion length on inoculated plants was not correlated with canopy structure. These results indicate that canopy structure influences sheath blight epidemics. A ‘healthy’ canopy resulting from appropriate crop management practices can be used to suppress sheath blight epidemics in rice. 相似文献
13.
Regulation of defense-related enzymes associated with bacterial spot resistance in Tomato 总被引：1，自引：0，他引：1
Twenty tomato (Solanum lycopersicon) cultivars were screened for resistance against bacterial spot disease incited byXanthomonas axonopodis pv.vesicatoria under field conditions with and without pathogen infection. Screening was done by artificially inoculating aX. axonopodis pv.vesicatoria suspension to 4-week-old tomato seedlings and observing them for typical symptoms of the disease. Seedlings were categorized
into highly resistant, resistant, susceptible and highly susceptible cultivars on the basis of disease incidence. Tomato cultivars
were screened for defense-related enzymes, total phenols and lignin contents. The temporal patterns of all these enzymes were
estimated with a moderately susceptible tomato cultivar. Native PAGE analysis of both peroxidase (POX) and polyphenol oxidase
(PPO) was carried out for the time course of enzyme activities and also by selecting three different tomato cultivars, following
infection with the pathogen. Based on the inducible amounts of these enzymes upon pathogen infection, the tomato cultivars
were correlated with the disease incidence under field conditions. A significant (P≤0.05) correlation was observed between the degree of host resistance and the enzyme levels. In highly resistant tomato cultivars
the enzyme levels, total phenols and lignin contents were increased in comparison with highly susceptible tomato cultivars.
Isoform analysis of POX and PPO enzymes indicated a clear difference between resistant and susceptible tomato cultivars in
the number of isoforms and also in the intensity of each isoform in the presence of pathogen infection. The possible regulation
of defense-related enzymes in imparting host resistance is discussed.
http://www.phytoparasitica.org posting March 11, 2008. 相似文献
14.
Pathogen development and host responses in wheat spikes of resistant and susceptible cultivars infected by Fusarium culmorum causing Fusarium head blight (FHB), were investigated by means of electron microscopy as well as immunogold labelling techniques. The studies revealed similarities in the infection process and the initial spreading of the pathogen in wheat spikes between resistant and susceptible cultivars. However, the pathogen’s development was obviously more slow in the resistant cultivars as in comparison to a susceptible one. The structural defence reactions such as the formation of thick layered appositions and large papillae were essentially more pronounced in the infected host tissues of the resistant cultivars, than in the susceptible one. β -1,3-glucan was detected in the appositions and papillae. Furthermore, immunogold labelling of lignin demonstrated that there were no differences in the lignin contents of the wheat spikes between susceptible and resistant cultivars regarding the uninoculated healthy tissue, but densities of lignin in host cell walls of the infected wheat spikes differed distinctly between resistant and susceptible cultivars. The lignin content in the cell walls of the infected tissues of the susceptible wheat cultivar increased slightly, while the lignin accumulated intensely in the host cell walls of the infected wheat spikes of the resistant cultivars. These findings indicate that lignin accumulation in the infected wheat spikes may play an important role in resistance to the spreading of the pathogen in the host tissues. Immunogold labelling of the Fusarium toxin DON in the infected lemma showed the same labelling patterns in the host tissues of resistant and susceptible cultivars. However, there were distinct differences in the toxin concentration between the tissues of the susceptible and resistant cultivars. At the early stage of infection, the labelling densities for DON in resistant cultivars were significantly lower than those in the susceptible one. The present study indicates that the FHB resistant cultivars are able to develop active defence reactions during infection and spreading of the pathogen in the host tissues. The lower accumulation of the toxin DON in the tissues of the infected spikes of resistant cultivars which results from the host’s defence mechanisms may allow more intensive defence responses to the pathogen by the host. 相似文献
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为明确抗感褐飞虱Nilaparvata lugens水稻遗传群体在细胞水平的生理变化差异,通过蛋白质组学法对抗褐飞虱水稻遗传群体16W19-1-1和感稻飞虱水稻遗传群体16W45水稻叶片的差异蛋白质组进行研究,采用串联质谱标签标记和液相色谱-串联质谱联用仪进行差异蛋白质谱分析,利用Mascot search results软件进行搜库以确定差异表达蛋白,应用qPCR技术对差异蛋白关联基因在抗感褐飞虱遗传群体中的表达情况进行验证分析。结果表明,从抗感褐飞虱遗传群体中共鉴定出7 625个蛋白,其中差异蛋白229个,涉及上调蛋白156个,下调蛋白73个,主要集中在代谢蛋白、氧化还原蛋白和应激蛋白,主要参与了氰胺基酸代谢、牛磺酸代谢、聚糖降解、脂肪酸链伸长等通路。最终找到9个关键蛋白,关联6种酶,分别为γ-谷氨酰基转移酶、β-葡糖苷酶、β-N-乙酰-D-氨基葡萄糖酶、谷氨酸脱羧酶、甚长链烯酰-CoA还原酶和甚长链3-氧酰辅酶,对应8个基因。表明以上6种酶与植物抗虫性关系密切,可能在上述水稻品系抗褐飞虱中起着重要作用。 相似文献
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茉莉酸甲酯对水稻白叶枯病的诱导抗性及相关防御酶活性的影响 总被引：7，自引：5，他引：2
为探索茉莉酸甲酯(methyl jasmonate,MeJA)诱导水稻抗白叶枯病的效应,采用MeJA喷雾处理剪叶接种法,测定MeJA对水稻幼苗的白叶枯病病情指数、白叶枯病病菌Xanthomonas oryzae pv.oryzae的抑菌效果及对叶片过氧化物酶(peroridase,POD)、过氧化氢酶(catalase,CAT)、超氧化物歧化酶(superoxide dismutase,SOD)、多酚氧化酶(polyphenol oxidase,PPO)和苯丙氨酸解氨酶(phenylalnaine ammonialyase,PAL)等相关防御酶活性的影响.0.05 ～ 2.0 mmol/L的MeJA能降低水稻幼苗白叶枯病的病情指数,但对水稻白叶枯病菌无直接抑菌活性;0.1 mmol/L MeJA的诱导效果最好,处理48h后,感病品种温229和抗病品种嘉早312的诱导效果分别为73.18％和70.43％;0.05 ～2.0mmol/L的MeJA处理水稻叶片中POD、CAT、SOD、PPO和PAL活性呈上升趋势.研究表明MeJA能诱导水稻幼苗对白叶枯病的抗性,且诱导抗性的产生与MeJA提高水稻相关防御酶的活性有关. 相似文献
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Effects of Elevated Atmospheric CO(2) Concentration on the Infection of Rice Blast and Sheath Blight
ABSTRACT The effect of elevated atmospheric CO(2) concentration on rice blast and sheath blight disease severity was studied in the field in northern Japan for 3 years. With free-air CO(2) enrichment (FACE), rice plants were grown in ambient and elevated ( approximately 200 to 280 mumol mol(-1) above ambient) CO(2) concentrations, and were artificially inoculated with consist of Magnaporthe oryzae. Rice plants grown in an elevated CO(2) concentration were more susceptible to leaf blast than those in ambient CO(2) as indicated by the increased number of leaf blast lesions. Plants grown under elevated CO(2) concentration had lower leaf silicon content, which may have contributed to the increased susceptibility to leaf blast under elevated CO(2) concentrations. In contrast to leaf blast, panicle blast severity was unchanged by the CO(2) enrichment under artificial inoculation, whereas it was slightly but significantly higher under elevated CO(2) concentrations in a spontaneous rice blast epidemic. For naturally occurring epidemics of the sheath blight development in rice plants, the percentage of diseased plants was higher under elevated as opposed to ambient CO(2) concentrations. However, the average height of lesions above the soil surface was similar between the treatments. One hypothesis is that the higher number of tillers observed under elevated CO(2) concentrations may have increased the chance for fungal sclerotia to adhere to the leaf sheath at the water surface. Consequently, the potential risks for infection of leaf blast and epidemics of sheath blight would increase in rice grown under elevated CO(2) concentration. 相似文献
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感染白叶枯病后水稻叶片光合同化物对病害的补偿作用 总被引：1，自引：1，他引：1
水稻抗白叶枯病品种ＩＲ２６和感病品种金刚３０在拔节期接种白叶枯病菌后，接种叶片净光合速率均下降，而与病叶相邻的健叶的净光合速率则明显增加，在穗期，ＩＲ２６接种叶片的＾１４Ｃ同化物累积率和运输到穗的百分率均高于金刚３０；ＩＲ２６与病叶相邻的健叶，＾１４Ｃ同化物输向接种病叶和穗的百分率高于金刚３０。这表明抗病品种ＩＲ２６接种病叶和健康叶片光合同化物对病菌侵染和产量损失的补偿作用较强，相反，金刚３０则不 相似文献
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C. L. Shrestha I. Oña S. Muthukrishnan T. W. Mew 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(1):69-77
Various rice cultivars were selected and screened for their reaction to sheath blight in the greenhouse. Cluster analysis
of percent relative lesion height (% RLH) generated four groups of cultivars with a coefficient of similarity of 3.27. Chitinase
activities were detected 24 h after inoculation of moderately resistant cvs Betichikon, Dudruchi, Khatochalani, Padi Pulut
Malat, Kakua, IR72, Khakibinni. But in the susceptible cv. IR58, chitinase activity was detected only 36 h after inoculation.
Western blot analysis showed that class 1 and class 2 chitinases were induced following Rhizoctonia
solani infection of these cultivars. The % RLH and the number of infection cushions were negatively correlated with the level of
chitinase activity. Moderately resistant rice cultivars had higher levels of chitinase activity and lower disease severity
and numbers of infection cushions formed compared to IR58. 相似文献