Comparison of the gene expression profiles of resistant and non‐resistant Japanese black pine inoculated with pine wood nematode using a modified LongSAGE technique

The Japanese black pine (Pinus thunbergii) is highly susceptible to pine wilt disease caused by the pine wood nematode (PWN; Bursaphelenchus xylophilus). To cope with this disease, researchers and tree breeders selected PWN‐resistant individuals in a previous breeding program. In an attempt to understand the mechanisms of resistance in the Japanese black pine, we created four LongSAGE (serial analysis of gene expression) libraries. A total of 20 818 tags were studied, including 5194 tags from a PWN inoculated resistant pine, 5218 a non‐inoculated resistant pine, 5194 an inoculated non‐resistant pine, and 5212 a non‐inoculated non‐resistant pine. The analysis of the libraries indicated that 14 tag species were significantly up‐regulated (e.g., pathogenesis‐related proteins 2 and 4, osmotin, lipoxygenase, and chalcone synthase), and nine were down‐regulated (eukaryotic translation initiation factor SUI1, translationally controlled tumor protein, and xyloglucan endotransglycosylase) by the PWN inoculation in both the resistant and non‐resistant pines. On the other hand, 38 tag species were significantly expressed at a higher level only in the resistant pine (catalase, dienelactone hydrolase family protein) and 25 were expressed at a higher level in the non‐resistant pine (pathogenesis‐related proteins 1, 2, and 3, and leucoanthocyanidin dioxygenase). These differentially expressed genes are presumed to reflect some of the differences between the resistant and non‐resistant pines. Our results provide valuable information on the complex responses induced in the resistant and non‐resistant pine trees in response to PWN invasion.     

抗枣疯病枣树品系选育及抗病机理初探

通过野外嫁接病枝病皮和室内PCR检测的方法,测定了不同枣树品种和单株对枣疯病的抗性,历经12 a的时间,筛选出了抗病性较强的壶瓶枣和婆枣单株。建立了总面积24 hm2的6个试验示范园,观测了林间生长表现,证明选择的枣树品系抗病性稳定。通过与感病枣树品种进行对比分析,初步研究了抗病品系的抗病机理。抗病和感病品系间在酚类物质含量、绿原酸含量和蛋白质含量间都存在显著差异。在抗病品种中发现一种感病品种中没有的酚类物质,经提取测定,该物质的提取液可对过氧化物酶、吲哚乙酸氧化酶的活性产生显著影响。     

Variation among Italian and French elm clones in their response to Ophiostoma novo‐ulmi inoculation

In 1995 a clone bank of elms from across Italy was created at Antella (Florence, I) under a European Union project. In 1998 an experimental planting of some clones from this source was established in Antella together with material from a similar clone bank in France and two reference clones: Commelin (relatively susceptible) and Lobel (relatively resistant). In May 2001, the elms were inoculated with Ophiostoma novo‐ulmi and disease development was assessed throughout that summer and the next. Significant differences in susceptibility were found between taxonomic groups, with putative natural hybrids between Ulmus minor and Ulmus pumila being the most resistant and Ulmus glabra the most susceptible. Significant differences were also found within U. minor, some clones being as resistant as Lobel. For U. minor, a statistically significant relation was found with latitude, southerly clones showing less disease than more northerly ones. Relationships were also found between disease severity and times to bud burst, these relationships applying both to the different taxonomic groups and within U. minor. Relationships between growth increment and disease severity were inconsistent. These results are discussed in relation to the intrinsic genetically‐controlled differences that exist between elms and to differences in susceptibility that occur as the growing season proceeds and as a consequence of environmental influences.     

侧柏抗病单株对叶枯病抗性机制研究

本文比较测定了对叶枯病具有高度抗性的侧柏单株叶片中木质素和纤维素含量、苯丙氨酸解氨酶（ＰＡＬ）和超氧化物歧化酶（ＳＯＤ）、以及细胞含水量和肉质化程度。结果表明,抗病单株叶片细胞中木质素和纤维素的含量显著地高于普通的感病侧柏;抗病单株的ＰＡＬ活性和ＳＯＤ活性也明显高于感病株。并且发现ＰＡＬ活性和木质素含量之间具有高度相关性。抗病单株的细胞含水量和肉质化程度则显著地低于感病株。综上指标说明,抗病单株在生理生化和遗传上,明显地区别于普通感病株。     

榆属树种的叶子结构与抗虫性的关系

榆树是我国重要的造林树种，在全国各地尤其是“三北”地区有大面积栽植。但最近几年来，榆树一直遭受着严重的虫害，特别是食叶害虫榆蓝叶甲，使榆树的生长发育和木材产量受到严重的影响。因此，选育抗虫品种和进行科学管理已成为当务之急。据观察，榆树在遭受虫害后，不同的树种或同一树种的不同无性系间的受害程度差别很大，是什么原因引起受害程度的不同呢？现有的研究己清楚指出，物理因素和化学因素共同构成了植物抵御害虫的防御体系。植物可以利用存在于它们组织的，经长期进化而形成的物理因素（形态结构）来阻止或破坏害虫的为害。本研究采用了电镜扫描和石蜡切片法，结合生物测定和田间调查，分析了榆属树种的叶子结构与其抗虫性之间的关系。结果表明，①榆属树种的气孔以大密度分布在叶子的下表面，气孔的保卫细胞具有角质层和木质化的壁。这种特点使幼虫不易从叶子下表面取食到叶肉，所以它们往往转移到叶子上表面取食，从而造成叶子上表面的结构特点与抗虫性的强弱直接相关；②抗虫性强的树种或无性系的叶子表面有很厚的蜡质层，而易感虫的树种或无性系的叶子上表面蜡质较薄。下表面无此规律；③叶子上表面的表皮毛密度（Ｘ１）和角质层厚度（Ｘ２）与叶面积受害指数（Ｙ）呈高度负相关（     

磷酸葡萄糖脱氢酶和苯丙氨酸解氨酶与抗松针褐斑病的关系

松针褐斑病（Ｌｅｃａｎｏｓｔｉｃｔａａｃｉｃｏｌａ）是我国南方重要病害。在湿地松（Ｐｉｎｕｓｅｌｌｉｏｔｔｉｉ）抗褐斑病选育研究的基础上对湿地松针叶中的６－磷酸葡萄糖脱氢酶和苯丙氨酸解氨酶与抗病性的关系进行了研究分析。结果表明二年生健康针叶的６－磷酸葡萄糖脱氢酶的活性水平与针叶的抗病性有密切关系。在测定的１３个无性系和单株中，４个易感株的酶活性较低，９个抗病无性系中除个别酶活性与易感株相近外，其余无性系的酶活性和比活性都明显比易感株高。苯丙氨酸解氨酶的株间差异相对较小，但在总体水平上，抗病无性系的酶活性和比活性也比易感株略高。用松针褐斑病菌毒素液处理后，无论是抗病针叶还是易感针叶，６－磷酸葡萄糖脱氢酶的活性均呈上升趋势，升幅为０．５—１倍，但苯丙氨酸解氨酶的活性在用毒素处理后无明显变化。     

油用樟树无性系炭疽病抗性测定

采用室内人工接种法,对前期筛选出的25个油用樟树无性系进行炭疽病抗性测定,为抗病无性系的选育和应用提供理论基础。结果表明,不同油用樟树无性系对炭疽病存在一定抗性差异。其中高抗无性系有3个,分别为LL002(芳樟醇型)、BL508(龙脑型)和711(邻伞花烃型);抗病无性系有GLC95(芳樟醇型)、LL001(芳樟醇型)和LL004(芳樟醇型)等14个;中抗无性系有LLT11(芳樟醇型)、CN001(柠檬醛型)和SA001(黄樟油素型)等5个;中感、感病和高感无性系均为1个,分别是CA627-1(桉叶素型)、LR201(右旋芳樟)和SA002(黄樟油素型)。     

Changes in host chitinase isoforms in relation to wounding and colonization by Heterobasidion annosum: early and strong defense response in 33-year-old resistant Norway spruce clone

We studied the defense reactions of 33-year-old susceptible and resistant clones of Norway spruce (Picea abies (L.) Karst.) to the major root-rot fungus Heterobasidion annosum (Fr.) Bref. and determined if tissue cultures can be used as a model system for studying defense responses of mature trees at the molecular level. Quantitative PCR analysis of genomic DNA obtained from samples taken at different times along the lesion length in living bark indicated that the fungus was present in higher amounts and extended further into the host tissue in the susceptible clone than in the resistant clone. In protein extracts from the same lesion samples, there were differences in temporal and spatial changes in host chitinase isoform profiles between the resistant and susceptible clones. Host chitinase isoforms with pI values approximately 4.8, 4.4 and 3.7 increased more during the first 7 days after wounding and inoculation and extended further along the lesion length in the resistant clone than in the susceptible clone. These results suggest that the time from wounding and infection to induction of defense-related expression is shorter in the resistant clone indicating a more efficient host defense response than in the susceptible clone. Tissue cultures from the same clones were not resistant to H. annosum and showed no difference in the timing of the increase in chitinase isoforms in response to the pathogen. However, tissue cultures from both clones showed an increase in chitinase isoforms within 6 to 24 h past inoculation, indicating that increased chitinase expression in response to the pathogen is part of a general defense response common to both mature clones and tissue cultures.     

Fourier transform-infrared spectroscopy as a new method for evaluating host resistance in the Dutch elm disease complex

Resistance of elms (Ulmus spp.) to the pathogenic fungus Ophiostoma novo-ulmi Brasier depends on chemical and anatomical factors that confine the spread of the pathogen in the vascular system of the host. This study focused on detecting chemical differences in 4-year-old Ulmus minor Mill. seedlings before and after inoculation with a virulent O. novo-ulmi isolate. According to symptom development over 60 days, the trees were divided into resistant (0-33% wilting) and susceptible (67-100% wilting) groups. Histochemical tests and Fourier transform-infrared (FT-IR) spectroscopy analysis were performed on transverse sections of 2-year-old twigs, 2 days before and 40 days after inoculation. Although histochemical tests did not clearly discriminate susceptible from resistant elms, chemical differences between resistant, susceptible and control trees were detected by FT-IR. The average spectrum for resistant tree samples had higher absorbance peaks than the spectra from the susceptible and control samples, indicating increased formation of lignin and suberin. The roles of lignin and suberin in the resistance of the elms against O. novo-ulmi and the usefulness and sensitivity of the FT-IR technique for analyzing metabolic changes caused by pathogens in plants are discussed.     

Multiplex real-time PCR detection of pathogen colonization in the bark and wood of Picea sitchensis clones differing in resistance to Heterobasidion annosum

A quantitative multiplex real-time polymerase chain reaction (PCR) procedure was developed to assess the extent of Heterobasidion annosum (Fr.) Bref. growth in Sitka spruce (Picea sitchensis (Bong.) Carr.) bark and wood and to determine correlations between lesion length and fungal colonization. Based on lesion length and real-time PCR, the responses of four 3-year-old Sitka spruce clones to inoculation with H. annosum were characterized as showing either resistance or susceptibility to the pathogen. In susceptible clones, the extent of bark colonization did not differ from the visible length of the bark lesion, whereas lesions were longer than the extent of fungal colonization in resistant clones. The resistant clones contained considerably less fungal DNA than the susceptible clones, relative to the amount of host DNA in both the bark and the wood, indicating less resistance and more host cell death in the susceptible clones following inoculation. In both resistant and susceptible clones, fungal colonization in the wood extended beyond the visible necrotic lesion in the bark, indicating that host defense responses are weaker in wood than in bark. The spread of the pathogen in both bark and wood was less in the resistant clones than in the susceptible clones, indicating that defenses in both bark and wood of the resistant clones were superior to those in the susceptible clones.     

杨树溃疡病菌毒素对杨树树皮愈伤组织超微结构的影响

用２种浓度的杨树溃疡病病菌毒素处理具有不同抗生的杨树愈僵组织,引起了显著的超微结构变化。其变化包括：细胞壁变形消解,中胶层分解;质壁分离,质膜破裂,线粒体局部破裂、分解成颗粒甚至空胞化;细胞核在处理的后期核膜破裂,核仁亦部分分解,损害发生得最早、最严重的是细胞膜、杨树未处理的愈伤组织具有健康组织细胞所具有的完整结构。经过毒素处理,抗病品种比感病品种膜系列受因轻,对细胞损伤高浓度毒素处理比低度的要大     

Purification of the toxin protein PC from Arthrinium phaeospermum and its effect on the defence enzymes of Bambusa pervariabilis × Dendrocalamopsis grandis varieties

Bamboo blight in hybrid Bambusa pervariabilis × Dendrocalamopsis grandis is caused by the fungus Arthrinium phaeospermum. One component designated as P_C with pathogenic activity and a molecular weight of about 27 kDa was obtained from this fungus by ammonium sulphate precipitation, polyethylene glycol concentration, Sephadex G‐100 gel chromatography and Q‐Sepharose Fast Flow anion exchange resin. The toxin P_C was shown to cause the same typical symptoms caused by the pathogen itself, although the reaction of the toxin was quicker than the pathogen in all four hybrid bamboo varieties. A threshold toxic dose of 10–20 μg/ml was observed for two resistant varieties, while only 5–10 μg/ml was observed for two susceptible varieties. Moreover, effects of the purified toxic protein on the activities of superoxide dismutase, peroxidase, phenylalanine amonnialyase, polyphenol oxidase, chitinase and β‐1,3 glucanase in the different bamboo varieties were analysed using the impregnation and leaf disc methods. The results showed a positive correlation between the resistance of bamboo and the activities of all six enzymes. The activities of all enzymes except β‐1,3 glucanase decreased over the time course of investigation. These results proved the important role played by toxic proteins in the pathogenicity of A. phaeospermum and their potential for selecting resistant varieties or identify the resistance of this bamboo.     

Study on Isozyme Electrophoresis of Martes zibellina L.

IntroductionM8rtssZibelliDaL.,belongingtoCarnivoraodder,MuStelidaefsmily,Martesgenus,isakindofrarefurbearinganimal.itsfuristhetreasureoffursorpeltsofwildlif6,andmartencoatsmadewithitareconsideredas"TheFurChampion"andarewellknownathomesndabroad.M8deszibelliDaL.ismainlydistributedinRussia,Mongolia,Korea,JapanandXinjiangProvinceandNortheastareaofChina.Foralongtime,duetotheenvironmentaldeteriorationandoverhunting,theamountofthepopulationsofwildM8desZibelliDaL.hasbeendroppingoff.Forthisre…     

Relationship between field resistance to Phytophthora ramorum and constitutive phenolic chemistry of coast live oak

Sudden oak death, caused by Phytophthora ramorum, has resulted in high levels of coast live oak (CLO) mortality. However, some CLO survive in areas with high disease pressure and may thus be resistant. We tested the hypothesis that such field‐resistant trees contain constitutively higher levels of phenolics than susceptible trees. Phloem was sampled from the trunks of two groups of trees (one previously inoculated, one naturally infected with P. ramorum) categorized over the course of several years as putatively resistant (PR, no symptoms), in remission (IR, showed symptoms but then recovered) and symptomatic (S). Individual and total soluble phenolics from these trees were quantified. There were no significant differences in individual or total soluble phenolics between groups of naturally infected trees. However, inoculated PR and IR trees were characterized by higher constitutive levels of ellagic acid, a tyrosol derivative, and an unidentified phenolic than S trees. Ellagic acid and tyrosol‐like compounds in CLO phloem are promising resistance biomarker candidates.     

Histological response of resistant and susceptible white spruce to simulated white pine weevil damage

The traumatic wound response of families of white spruce, Picea glauca (Moench) Voss, resistant or susceptible to the white pine weevil, Pissodes strobi (Peck), were compared after simulated weevil damage. Leaders from 331 trees were wounded just below the apical bud in the spring, coinciding with the natural time of weevil oviposition. A portable 1-mm diameter drill was used to drill 24 holes per leader. Leaders were removed in the fall and examined for evidence of traumatic resin canal formation. Drilled trees had a traumatic wound response 8 times greater than that of undrilled trees; however, undrilled trees also formed some resin canals in response to unknown causes. In the drilled trees, the traumatic wound response extended into the lower part of the leader, where it could possibly affect older larvae. Trees from resistant families responded with greater intensity than trees from susceptible families, by producing multiple rings of traumatic resin canals. Trees from resistant families also responded more rapidly than trees from susceptible families based on number of cells to the first ring of traumatic resin canals. Trees from some resistant families exhibited no traumatic resin canal formation, showing considerable within-family variation and suggesting that other resistance mechanisms might be important. In the year after drilling, there was a reduction in tree diameter growth and trees suffered a reduction in constitutive resin canals in the bark, which suggests some energetic cost of traumatic resin production. There was no indication that the extent of constitutive defenses, as measured by density of cortical resin canals before wounding, was related to the ability to produce traumatic resin canals. Screening trees based on their capacity to produce traumatic resin canals may be useful in selecting genotypes resistant to white pine weevil.     

Volatile components of Japanese cedar cultivars as repellents related to resistance to Cryptomeria bark borer

The response of the essential oils and their components toCryptomeria bark borer has been studied. The oils of inner bark and sapwood of resistant cultivars acted as a repellent toCryptomeria bark borer rather than as an attractant, whereas those of susceptible cultivars acted as an attractant.-Terpineol, nerolidol,-cadinene,-eudesmol, terpinolene, and cedrol showed high repellent activity. The relative contents of the former four compounds were larger in resistant cultivars than in sensitive cultivars. It suggests that these four compounds might be one of the causes of resistance toCryptomeria bark borer. The contents of terpinolene and cedrol were small, and these two compounds may have no or a small influence on resistance. Although some of compounds acted as attractants forCryptomeria bark borer, it was not attributable to the difference in the bark borer response of Japanese cedar because of the relatively low ratio of these compounds in each essential oil and the small differences in the ratios between resistant and susceptible cultivars.     

白桦木材中总酚含量与抗木材腐朽菌的关系

腐朽是木材最严重的生物破坏,它能引起木材结构损坏,造成经济上的巨大损失.白桦(Betula platyphylla)是极易腐朽的树种(李坚,2002).本文利用5种木材腐朽菌对白桦进行生物降解,根据质量损失率筛选出易腐和抗腐植株,进一步研究易腐和抗腐白桦总酚含量的差异与木材腐朽抗性的关系.为今后在林木遗传改良中筛选适宜的天然抗腐朽植株提供理论基础,同时也为森林培育、木材利用等方面的研究提供相关信息,减少防腐剂的使用,降低防腐剂对环境的污染.     

Study on isozyme electrophoresis ofMartes zibellina L.

Four isozymes, such as Malate dehydrogenase (MDH), Alchol dehydrogenase (ADH), Peroxidae (POD) and Esterase (EST) in six tissues (heart, liver, kidney, muscle, eye, gonad) ofMartes zibellina L., were analyzed by means of vertical polyacrylamide gel electrophoresis (PAGE). The results indicated that the zymograms of these four isozymes in different tissues were different from each other, i.e. there existed apparent tissue-specificitity in these isozymes inMartes zibellina L.. Characteristic enzyme band was found both in POD zymogram and in EST zymogram. Moreover, the characteristic enzyme band in POD isozyme would be of some value to sexual identification ofMartes zibellina L. (Responsible Editor: Zhu Hong)