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A putative Ca2+ and calmodulin-dependent protein kinase required for bacterial and fungal symbioses 总被引：1，自引：0，他引：1
Lévy J Bres C Geurts R Chalhoub B Kulikova O Duc G Journet EP Ané JM Lauber E Bisseling T Dénarié J Rosenberg C Debellé F 《Science (New York, N.Y.)》2004,303(5662):1361-1364
Legumes can enter into symbiotic relationships with both nitrogen-fixing bacteria (rhizobia) and mycorrhizal fungi. Nodulation by rhizobia results from a signal transduction pathway induced in legume roots by rhizobial Nod factors. DMI3, a Medicago truncatula gene that acts immediately downstream of calcium spiking in this signaling pathway and is required for both nodulation and mycorrhizal infection, has high sequence similarity to genes encoding calcium and calmodulin-dependent protein kinases (CCaMKs). This indicates that calcium spiking is likely an essential component of the signaling cascade leading to nodule development and mycorrhizal infection, and sheds light on the biological role of plant CCaMKs. 相似文献
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Ané JM Kiss GB Riely BK Penmetsa RV Oldroyd GE Ayax C Lévy J Debellé F Baek JM Kalo P Rosenberg C Roe BA Long SR Dénarié J Cook DR 《Science (New York, N.Y.)》2004,303(5662):1364-1367
Legumes form symbiotic associations with both mycorrhizal fungi and nitrogen-fixing soil bacteria called rhizobia. Several of the plant genes required for transduction of rhizobial signals, the Nod factors, are also necessary for mycorrhizal symbiosis. Here, we describe the cloning and characterization of one such gene from the legume Medicago truncatula. The DMI1 (does not make infections) gene encodes a novel protein with low global similarity to a ligand-gated cation channel domain of archaea. The protein is highly conserved in angiosperms and ancestral to land plants. We suggest that DMI1 represents an ancient plant-specific innovation, potentially enabling mycorrhizal associations. 相似文献
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乙烯在黄瓜体内分布及周年变化动态研究初报 总被引：1，自引：0，他引：1
对黄瓜(CucumissativusL )内源乙烯分布及不同生育期、不同季节对黄瓜内源乙烯含量的影响进行了研究。结果表明,乙烯在黄瓜营养体内分布总趋势是自上而下依此减少,上部器官乙烯含量大于下部器官,具体表现为:上部叶柄中含量最高,茎尖、上茎、上叶次之,而其余各部位很少甚至没有;乙烯的含量变化与其生育期关系不大,而与当时的气候条件关系密切;不同播期处理对乙烯含量的影响不如季节影响显著;在1年之中,以低温短日的冬季含量最高,而高温长日的夏季含量则较少。即:全年中,以1月份含量最高,12月、2月、3月次之,其它月份则很少。 相似文献
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Giraud E Moulin L Vallenet D Barbe V Cytryn E Avarre JC Jaubert M Simon D Cartieaux F Prin Y Bena G Hannibal L Fardoux J Kojadinovic M Vuillet L Lajus A Cruveiller S Rouy Z Mangenot S Segurens B Dossat C Franck WL Chang WS Saunders E Bruce D Richardson P Normand P Dreyfus B Pignol D Stacey G Emerich D Verméglio A Médigue C Sadowsky M 《Science (New York, N.Y.)》2007,316(5829):1307-1312
Leguminous plants (such as peas and soybeans) and rhizobial soil bacteria are symbiotic partners that communicate through molecular signaling pathways, resulting in the formation of nodules on legume roots and occasionally stems that house nitrogen-fixing bacteria. Nodule formation has been assumed to be exclusively initiated by the binding of bacterial, host-specific lipochito-oligosaccharidic Nod factors, encoded by the nodABC genes, to kinase-like receptors of the plant. Here we show by complete genome sequencing of two symbiotic, photosynthetic, Bradyrhizobium strains, BTAi1 and ORS278, that canonical nodABC genes and typical lipochito-oligosaccharidic Nod factors are not required for symbiosis in some legumes. Mutational analyses indicated that these unique rhizobia use an alternative pathway to initiate symbioses, where a purine derivative may play a key role in triggering nodule formation. 相似文献
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为了明确23S rRNA基因数量和定位是否可更好地揭示根瘤菌参比菌株的系统发育关系,采用I-CeuI酶切和脉冲场凝胶电泳(PFGE)结合的方法,对根瘤菌株23S rRNA基因的数量和定位进行分析,并依据其相似性进行聚群.结果显示.根瘤菌参比菌株可聚为19个系统发育群.其中,在属的水平上,13个系统发育群与现行分类群(不包括依据16S rRNA基因序列分析结果)一致,6个不一致.在种的水平上,现行分类群中同种的根瘤菌可进一步细分为不同的系统发育群.这表明:I-CeuI酶切和PFGE结合的方法能从基因组特征角度对根瘤菌参比菌株进行更加细化的系统发育分类,并使其属种间的同质性更好. 相似文献
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逆境胁迫下多胺与乙烯代谢的相关性及其对细胞膜保护系统影响的研究进展 总被引：8，自引：1，他引：8
多胺与乙烯是植物体内广泛存在并具有重要生理作用的两类生长调节物质,具有共同的前体S-腺苷蛋氨酸。在逆境胁迫下,多胺的含量与乙烯的产生速率一般会发生显著的变化并相互影响,具体影响取决于植物的种类、器官、组织及胁迫的程度、方式等。在逆境胁迫下多胺对细胞膜系统具有显著的保护作用,而乙烯则可增加细胞膜的透性,二者代谢上的变化对细胞膜保护系统,特别是对植物体内活性氧、自由基的产生与清除体系具有重要的影响。 相似文献
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高效苜蓿根瘤菌的筛选 总被引：1，自引：1，他引：1
旨在利用celB基因标记技术从土著根瘤菌中筛选出与盛世苜蓿品种相匹配的有效性高、竞争性强的高效苜蓿根瘤菌株。从四川雅安、重庆北碚、万州采集野生苜蓿根瘤,采用平板划线法分离纯化获得93株纯菌株,通过与盛世品种在无氮水培液中进行结瘤试验和有效性分析并结合菌株的地理来源,初筛出了与对照相比有效性较高的4株苜蓿根瘤菌,分别为Y6-1-1、BB1-8-1-1、BB2-2-1-1和WZ-6-2-2。进一步利用celB基因标记技术对这4株菌进行竞争性研究,通过供体大肠杆菌HAMBI2356与根瘤菌接合的方法成功地将celB基因导入4个菌株中,对标记基因可能会对标记菌株产生的影响进行检测,结果表明标记基因在标记菌株内能稳定传代,而且对标记菌株的生长、竞争性及有效性都没有显著影响,从而证明celB基因标记技术可以作为一种简便、直观而又有效的检测手段用于追踪根瘤菌株在土壤中的竞争性。进一步通过田间试验比较分析标记菌与土著菌的竞争结瘤能力和固氮有效性,结果表明Y6-1-1、BB2-2-1-1、WZ-6-2-2与对照相比在占瘤率、瘤重、总瘤数上差异显著,占瘤率都在72%以上,显著提高了植株的干重、叶绿素含量、全氮量和产量,其中WZ-6-2-2的有效性最高、竞争性最强,可以用于苜蓿盛世品种的接种。 相似文献
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张小平 《四川农业大学学报》1991,9(3):348-351
本试验利用两株从合欢树种(Acacia senegal)根瘤中分离获得的菌株TTR—44Mel~+和TTR—6Mel~-作材料,研究了Mel~+基因的稳定性,并与目前广泛使用的抗菌素标记法比较,探讨了Melanin(黑素)在根瘤菌竟争结瘤研究中,用于菌株鉴定的可行性。结果表明:Melanin用作根瘤菌株鉴定是一种可行而且简便的方法。 相似文献
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根瘤菌质粒的研究进展 总被引：2，自引：2，他引：0
快生型根瘤菌中普遍存在1到多个数量不等的内源质粒(indigenous plasmid)。其中,含有根瘤菌结瘤和共生固氮所必需的基因的质粒被称之为共生质粒(pSym);其它的质粒被称为非共生质粒(non-pSym)。根瘤菌的内源质粒一般都非常稳定,能够在不同种属的根瘤菌之间和土壤杆菌中进行转移。根瘤菌质粒在转移、复制过程中可能发生重组等现象。本文综述了根瘤菌共生质粒和非共生质粒的功能,以及根瘤菌质粒的转移、复制等特性。 相似文献
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对celB基因标记法检测苜蓿根瘤菌竞争性的可行性进行了研究。通过供体大肠杆菌HAMBI2356与根瘤菌接合的方法成功地将celB基因导入到4株苜蓿根瘤菌株Y611、BB1811、BB2211和WZ622中,然后对标记基因可能会对标记菌株产生的影响进行了一系列检测,结果表明标记基因在标记菌株内能稳定传代,而且对标记菌株的生长、竞争性及有效性都没有显著影响,从而证明celB基因标记技术可以作为一种简便、直观而又有效的检测手段用于追踪根瘤菌株在土壤中的竞争性。 相似文献
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乙烯是植物体内主要的防御信号途径之一。从乙烯的合成、乙烯与其相关物质在植物信号传导途径、植物体防御体系及乙烯在植物体中的防卫作用方面对乙烯介导的防卫信号途径的研究进展进行了阐述,并对乙烯介导的防卫信号途径研究进行了展望。 相似文献
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植物激素信号传导途径研究进展 总被引：4，自引：0，他引：4
植物激素是植物体内合成的微量有机物质,在植物生长发育的各个阶段以及生物和非生物胁迫适应性中都发挥着重要作用。综述了生长素、赤霉素、脱落酸、茉莉酸和乙烯五种激素信号传导途径及其在植物生长发育中的相互作用等方面取得的最新研究进展,以期为激素的理论和应用研究提供参考。 相似文献
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Limpens E Franken C Smit P Willemse J Bisseling T Geurts R 《Science (New York, N.Y.)》2003,302(5645):630-633
The rhizobial infection of legumes has the most stringent demand toward Nod factor structure of all host responses, and therefore a specific Nod factor entry receptor has been proposed. The SYM2 gene identified in certain ecotypes of pea (Pisum sativum) is a good candidate for such an entry receptor. We exploited the close phylogenetic relationship of pea and the model legume Medicago truncatula to identify genes specifically involved in rhizobial infection. The SYM2 orthologous region of M. truncatula contains 15 putative receptor-like genes, of which 7 are LysM domain-containing receptor-like kinases (LYKs). Using reverse genetics in M. truncatula, we show that two LYK genes are specifically involved in infection thread formation. This, as well as the properties of the LysM domains, strongly suggests that they are Nod factor entry receptors. 相似文献
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Wu Xing-yue Gao Jun Wang Le Wang Bei-nan Yao Hong-li Liu Zhen-yu Yang Hai-peng Liu Zhong-kuan Liang Zi-teng Wang Fang Liu Xiao-yun 《东北农业大学学报(英文版)》2017,24(3)
The clovers that comprise Trifolium genus are naturalized in the subtropical and tropical zones in China.They are valuable bioresources as important green manures and pasture grass,which contribute biologically fixed dinitrogen (N2) and provide nutrition to farming systems.However,there are very few effective strains available for inoculant production and there is little information available about symbiotic rhizobia in Chinese legume clover root nodules.In this study,139 root nodule bacteria were isolated from two clover species (Trifolium repens and Trifolium pretense) growing in the subtropical and temperate regions of China,16S rRNA gene sequence analysis,BOX-PCR,whole cell protein SDS-PAGE,and nodulation tests were performed to characterize these strains.The results showed that phenotypic and genetic diversities among 139 isolates were large,with 83 protein patterns and 66 BOX-AIR profiles,respectively.The rhizobial strains were first divided into two large phenotypic protein groups.The sequencing strains representing the two groups were related to Rhizobium leguminosarum USDA2370T and R.sophorae CCBAU03386T and had 99.6％-100％ similarities.The phylogeny specificity of the rhizobia from clover was elucidated,while showed a large variation in the fingerprints of the phenotypes and genotypes and genetic diversity was high (revealed by Shannon diversity index,H').The rhizobial isolates from subtropical regions,such as Anhui Province,Yunnan Province and Hubei Province,had higher diversities than those from temperate areas,such as Hebei Province and Shanxi Province,which could be used to identify rhizobial strains from clover and screen efficient inoculum strains.A number of diverse rhizobial strains had been identified and a pool of currently available clover rhizobial strains were increased.This would ultimately increase the likelihood of identifying more efficient strains suited for developing a successful inoculation strategy for the production of white clover. 相似文献
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论述了ACC合成酶的分子生物学研究进展,阐述了系统1乙烯和系统2乙烯形成过程中ACC合成酶基因的表达特点. 相似文献