转几丁质酶-葡聚糖酶基因水稻稻瘟病抗谱分析

用来源于云南各地属于24个稻瘟病菌（[i]Magnaporthe grisea[/i]）生理小种的33个菌株,对受体品种南29及其4个转几丁质酶 β-1,3-葡聚糖酶串联基因水稻T5代品系进行了温室接种鉴定。结果表明,不能侵染受体品种南29 的13个菌株也不能侵染转基因品系,可侵染受体品种南29 的20个菌株一般不能侵染转基因品系,转基因水稻对稻瘟病菌抗性范围较受体对照扩大,证明转几丁质酶 葡聚糖酶基因水稻对稻瘟病具有一定的广谱抗性;诱发条件下,转基因品系大田叶瘟病情指数为0～1级,穗瘟发病率为0.3%～10.23%,抗性较受体对照大幅度提高,表明这些品系在稻瘟病抗病育种中是有应用潜力的。     

抗、感稻瘟病品种的过氧化物酶同功酶分析

用一些对稻瘟病表现抗病和感病的不同品种和近等基因系,进行了过氧化物酶同工酶电泳分析。共检测到12～13条过氧化物酶酶带,在接种和不接种稻瘟病菌的情况下,水稻过氧化物同工酶谱无明显差异,但可发现抗病品种（系）要比感病品种（系）多一条或两条弱的酶带,且个别酶带的活性也较高。表明过氧化物酶与抗病性有关,可以作为鉴定品种抗瘟性的一种生化指标。     

大豆苯丙氨酸解氨酶及其基因的研究进展

苯丙氨酸解氨(phenylalanine ammonia-lyase,PAL)是连接植物初级代谢和苯丙烷类代谢等次级代谢途径关键酶、限速酶.综述了大豆PAL及其基因的研究进展,主要包括大豆PAL的分布及活性、分离纯化及酶活性的测定、对植物生理代谢的意义、在抗病中的作用机制、基因克隆、表达特性、基因的应用展望等.     

抗稻瘟病转基因水稻竹转68的选育

应用基因枪法将抗病基因“水稻碱性几丁质酶（RC24）基因”转入籼稻保持系籼B，选育出了具抗稻瘟病特性的转基因水稻品系竹转68。该品系还表现出穗大粒多的高产特性，平均每穗总数粒比竹籼B增加103．6粒，每穗实粒数增加84．4粒，增长率分别达83．8％和86．6％；与竹籼B相比，对稻瘟病的抗性显著增强；稻米品质好；且竹籼A具有恢复能力，而失去了竹籼B的保持特性。     

抗稻瘟病水稻培育的新进展

本文介绍了美国农业研究中心化学家Leong与同事们研究破解水稻应对不断演变的致病真菌的天然防御能力，取得了重大进展。发现、确认了水稻新的抗性基因，并进行了克隆。同时研发一种新方法，用于水稻和病原菌的操纵基因，培育抗病性敏感的水稻。     

转几丁质酶基因（RC24）水稻中大2号抗纹枯病特性研究

导入外源几丁质酶基因“RC24”的水稻中大2号接种纹枯病菌的结果表明,接种病菌后病斑扩展速率和田间病情指数小,表现为对水稻纹枯病高抗。组织病理学研究表明纹枯病菌能侵入中大2号,并引发纹枯病,入侵时间和症状出现的时间与非转基因感病对照没有显著差异,但病菌菌丝体消解现象出现早于对照,其抗病性主要表现为限制病菌扩展。以中大2号与非转基因水稻材料配制的杂交组合的抗病性表明,杂交组合的抗病性均高于非转基因亲本,但其抗病性也会因母本的不同而有所变化。     

水稻受稻瘟病菌侵染后过氧化物酶定位的超微观察

 利用联苯胺蓝（3，3'-diaminobenzidine, DAB）染色法原位检测了水稻 稻瘟病菌互作过程中H2O2和过氧化物酶被诱导产生和积累的过程。结果表明在病原菌接种后，水稻叶鞘内表皮细胞在伤口、气孔保卫细胞及病菌侵染点等3种情况下可以检测到染色反应。在水稻-稻瘟病菌非亲和性互作中，H2O2产生和过氧化物酶活性上升快，并逐渐积累到较高的水平；而在亲和性互作反应中，H2O2产生和过氧化物酶活性上升被延迟，积累水平较低。超微结构研究表明，在非亲和性互作反应中，过氧化物酶主要定位于被侵染寄主细胞的细胞壁、细胞质、细胞膜、侵染菌丝周围及由膜系统构成的囊泡膜上；而在亲和性互作反应中，早期（接种后16 h）几乎难以观察到过氧化物酶的聚集，后期（接种后30 h）过氧化物酶聚集增多，但仍明显低于非亲和性互作反应。     

几丁质酶产生菌发酵液对水稻生长及防御酶活性的影响

用自然界筛选到的抗稻瘟病几丁质酶产生菌H3发酵液处理水稻幼苗后,检测水稻幼苗质量及其体内苯丙氨酸解氨酶(PAL)、过氧化氢酶(CAT)和过氧化物酶(POD)活性的变化,以期探讨发酵液的作用机理。结果表明,H3菌株产酶发酵液处理2种水稻幼苗后,培两优288苗高和百苗干物重分别比对照分别增加58.9%、35.4%,旱干127苗高和百苗干物重比对照分别增加66.8%、26.2%,苯丙氨酸解氨酶活性和过氧化物酶活性明显增加,过氧化氢酶活性下降。H3菌株发酵液能诱导水稻幼苗防御酶的活性变化,使其朝有利于水稻幼苗生长和抵抗病害的方向发展。     

转Pi-d2基因水稻对稻瘟病的抗性分析

对由pCB6.3kb、pCB5.3kb和pZH01-2.72kb三个不同表达载体转化的转稻瘟病抗性基因Pi-d2水稻株系进行稻瘟病抗性分析。结果表明,转Pi-d2基因水稻的9个高代株系对来自四川的39个稻瘟病菌株表现不同的抗性,抗病频率最高达91.7%;4个转基因早代纯合株系对来自中国农业科学院的58个菌株中的81.48%以上菌株表现抗性,具有广谱抗性特点。稻瘟病菌粗毒素筛选结果表明,来自转基因植株的幼胚愈伤组织诱导率随培养基中粗毒素浓度提高而降低,粗毒素浓度达到40%时,幼胚愈伤诱导率为49.33%,受体对照幼胚愈伤组织诱导率为5%。田间诱发条件下,转基因株系在大田的穗瘟发病率为0%～50%,抗性较受体对照大幅度提高。     

水稻抗病基因同源序列与抗瘟性的关系

利用11对抗病基因同源序列(RGA)引物扩增43个水稻品种的DNA片段和接种33个稻瘟菌株测定它们的抗病性。结果表明,抗病性聚类结果与DNA扩增条带聚类结果基本一致,两者相关系数达0.6117(α=0.01),即利用RGA分析品种的抗病性具有很好的代表性,但相关性在引物间不同,从0.1701到0.5305。结合多态性分析,5对引物S1/AS3、S1 INV/ S2 INV、XLRR For/XLRR Rev、Pto Kin 1 IN/Pto Kin 2 IN、NLRR For/NLRR Rev可用于水稻品种的抗稻瘟病性分析,它们扩增的DNA条带数据与抗瘟性间达极显著相关。此外,除高感品种丽江新团黑谷和CO39两个品种未被聚类到不同的亚种外,RGA扩增的DNA条带还能区分水稻的籼粳亚种类型。     

籼型水稻中稻瘟病抗性基因分布及抗性研究

稻瘟病严重威胁着水稻的安全生产。目前,培育抗性品种是控制稻瘟病危害最经济有效的途径之一。本研究利用11个主效稻瘟病抗性(R)基因(Pi2、Piz-t、Pi9、Pi54、Pik-m、Pid3、Pib、Pit、Pi5、Ptr和Pita)的分子标记对48个常规稻、15个不育系和129个杂交稻进行了检测。结果表明,在常规稻中,Ptr和Pi5的分布频率均为35.42%,Pib、Pi2、Piz-t、Pit的分布频率介于20.0%~30.0%之间,其余均在15%以下;在不育系中,Pita的分布频率为40.0%,其余均在20%以下;杂交稻中,Pita、Pib、Pi54、Ptr和Pi5的分布频率在40.31%~55.04%之间,其余均在20%以下;Pita在各个品系中均广泛存在,频率介于35.42%~51.16%。田间抗性评价表明,R基因较多的品种具有较高的抗性。综上所述,在参试的水稻材料中,不育系中存在抗性基因较少,所有类型材料中广谱抗性基因分布较少,抗性基因聚合可以有效提高稻瘟病田间抗性。     

Genetic Transformation of Rice with Pi-d2 Gene Enhances Resistance to Rice Blast Fungus Magnaporthe oryzae

The gene Pi-d2, conferring gene-for-gene resistance to the Chinese blast strain ZB15, was isolated from a rice variety (Digu) by the map-based cloning strategy. Here, we constructed a control plasmid pZH01-pi-d2tp309 (pZH01-tp309) and three different expression constructs, pCB-Pi-d25.3kb (pCB5.3kb), pCB-Pi-d26.3kb (pCB6.3kb) and pZH01-Pi-d22.72kb (pZH01-2.72kb) of Pi-d2, driven by Pi-d2 gene's own promoter or CaMV35S promoter. These constructs were separately introduced into japonica rice varieties Lijiangxintuanhegu, Taipei 309, Nipponbare and Zhonghua 9 through Agrobacterium- mediated transformation. A total of 150 transgenic rice plants were obtained from the regenerated calli selected on hygromycin. PCR, RT-PCR and Southern-blotting assay showed that the gene of interest had been integrated into rice genome and stably inherited. Thirty-five transgenic lines independently derived from T1 progeny were inoculated with the rice blast strain ZB15. Transformants exhibited resistance to rice blast at various levels. The lesions on the transgenic plant leaves were less severe than those on the controls and the resistance level of transgenic plants harboring the gene of interest from three vectors had no difference. The own promoter of Pi-d2, about 2.2 kb or 3.2 kb, had the similar promoter function as CaMV35S. Field evaluation for three successive years supported the results of artificial trial, and some lines with high resistance to rice leaf blast and neck blast were obtained.     

Relationship Between Blast Resistance Phenotypes and Resistance Gene Analogue Profiles in Rice

A total of 21 rice varieties were assayed based on RGA-PCR using six pairs of RGA primers and evaluated for leaf blast resistance in the nursery as well. Cluster analysis showed that the varieties could be classified into five groups either at the similarity threshold of 0.72 for RGA profiles or at 0.80 for leaf blast severities. Although there did not exist a complete parallel relationship between RGA-based groups and blast resistance-based groups, five out of six varieties with broad spectrum or durable resistance repeatedly fell into same group. This result suggested that application of three primer pairs, viz. RGA1 and RGA2 （both designed from the LRR region of rice Xa21 gene） and RGA3 （designed from the LRR region of tobacco N gene） contributed to better evaluation of the germplasms for their resistance responses to rice blast.     

Relationship Between Resistance Gene Analogue and Blast Resistance in Rice

DNA fragments of 43 rice varieties were amplified with 11 pairs of primers designed based on resistance gene analogue(RGA) of plants,and the blast resistance of the varieties was identified by inoculation with 33 isolates of Magnaporthe grisea collected from Yunnan Province,China.Clustering results revealed a significant correlation between the blast resistance and DNA bands with a correlation coefficient of 0.6117(α=0.01) ,indicating that the resistance analysis based on RGA-PCR clustering analysis coincid...     

云南地方品种子预44中一个新的抗稻瘟病基因的定位

【目的】子预44是具有广谱持久稻瘟病抗性的云南地方粳稻品种。为了揭示子预44广谱持久抗瘟机制并在抗稻瘟病育种中进行有效利用,【方法】利用江南香糯与子预44杂交构建的遗传群体及分离自云南罗平的稻瘟病菌株LP36进行子预44的抗性遗传分析和抗性基因定位。【结果】子预44对LP36的抗性为单显性基因控制,暂定名为Pi-zy4(t),它位于水稻第4染色体长臂上SSR标记RM5503与RM3276之间约318 kb区间内。【结论】Pi-zy4(t)为新的抗稻瘟病基因。研究结果为子预44的育种利用和Pi-zy4(t)基因的克隆提供了重要信息。     

Marker-Assisted Introgression of Quantitative Resistance Gene pi21 Confers Broad Spectrum Resistance to Rice Blast

The quantitative resistance gene pi21 from Sensho was introgressed to an indica breeding line IR63307-4B-13-2, a pyramiding line IRBB4/5/13/21, and a tropical japonica line Kinandang Patong by marker-assisted backcrossing. A total of 192 improved lines at the BC_4F_3 and BC_4F_4 generations were developed and confirmed to have the gene introgression via genotyping using a pi21-specific In Del marker. Thirteen randomly selected improved lines, representing all the three genetic backgrounds, demonstrated resistance against leaf blast composites in the field and a broader spectrum resistance against individual isolates compared to the recurrent parents in the glasshouse. Specifically, the tested lines exhibited pi21-acquired resistance against 11 leaf blast isolates that elicited susceptible reactions from the recurrent parents. All the tested lines maintained a comparative heading date, and similar or improved panicle length, number of primary branches per panicle and number of total grains per panicle relative to the recurrent parents. The physical grain characteristics of the recurrent parents were also maintained in the 13 lines tested, although variability in the amylose content and chalkiness degree was observed. The successful marker-assisted introgression of pi21 in diverse genetic backgrounds and the resulting broader spectrum resistance of improved lines against leaf blast indicate the potential of pi21 for deployment in cultivars grown across other rice growing regions in Asia.     

水稻抗稻瘟病分子机制研究进展

稻瘟病是危害世界水稻生产最严重的真菌病害之一。稻瘟病菌生理小种变异快,水稻品种的抗性一般仅能维持3~5年。培育和种植抗性品种是目前最经济有效的措施。近年来,对稻瘟病菌致病机制和抗性基因分子机理的系统研究,加深了对该病原菌-宿主系统中病原相关分子模式诱导的免疫反应机制和病原菌效应蛋白诱导的免疫反应机制的了解。本文综述了水稻抗稻瘟病的两种天然免疫机制研究的最新进展,并对目前水稻抗稻瘟病分子机制研究中急需解决的问题和挑战进行探讨和展望。     

水稻抗稻瘟病分子机制研究进展

稻瘟病是危害世界水稻生产最严重的真菌病害之一。稻瘟病菌生理小种变异快，水稻品种的抗性一般仅能维持3~5年。培育和种植抗性品种是目前最经济有效的措施。近年来，对稻瘟病菌致病机制和抗性基因分子机理的系统研究，加深了对该病原菌-宿主系统中病原相关分子模式诱导的免疫反应机制和病原菌效应蛋白诱导的免疫反应机制的了解。本文综述了水稻抗稻瘟病的两种天然免疫机制研究的最新进展，并对目前水稻抗稻瘟病分子机制研究中急需解决的问题和挑战进行探讨和展望。