The identification of novel loci required for appropriate nodule development in Medicago truncatula.
The identification of novel loci required for appropriate nodule development in Medicago truncatula.
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DOI：
10.1186/1471-2229-13-157
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发表时间：
2013-10-11
影响因子：
5.3
通讯作者：
Kalo P
中科院分区：
文献类型：
--
作者：
Domonkos A;Horvath B;Marsh JF;Halasz G;Ayaydin F;Oldroyd GE;Kalo P
功能性共生根瘤的形成是豆科植物和根瘤菌之间协调发展的结果。豆科植物的遗传分析已被用来剖析建立豆科植物根瘤菌内共生协会所需的信号转导过程。与共生相互作用的早期事件相比，较少关注根瘤菌定殖和根瘤功能所需的植物位点。在这里，我们描述了一些新的遗传位点的鉴定和表征，在蒺藜苜蓿的发展所需的有效的固氮根瘤。筛选了大约38，000个EMS和快中子诱变的蒺藜苜蓿幼苗的共生固氮缺陷。选择结节发育和有效固氮受损的突变植物进行进一步的遗传和表型分析。9个突变体完全缺乏结节形成（Nod-）代表6个互补组，其中两个新的位点已被确定。8个无效结节突变体（Fix-）代表7个互补组，其中5个是新的单基因位点。修复- M。蒺藜突变体表现出氮缺乏的症状并产生小的白色根瘤。对根瘤的显微分析表明，突变体在根瘤菌从侵染丝中释放、根瘤菌的分化和根瘤细胞中细菌的持久存在等方面存在缺陷。此外，我们监测了共生特异性基因的转录活性，以确定在每个Fix突变体中共生过程的转录阶段被阻断。基于表型和基因表达分析，提出了FIX基因的功能层次。新的共生位点的M。本研究中分离的蒺藜为进一步表征支持结瘤的机制提供了基础，特别是与细菌释放和结节功能相关的后期阶段。
The formation of functional symbiotic nodules is the result of a coordinated developmental program between legumes and rhizobial bacteria. Genetic analyses in legumes have been used to dissect the signaling processes required for establishing the legume-rhizobial endosymbiotic association. Compared to the early events of the symbiotic interaction, less attention has been paid to plant loci required for rhizobial colonization and the functioning of the nodule. Here we describe the identification and characterization of a number of new genetic loci in Medicago truncatula that are required for the development of effective nitrogen fixing nodules. Approximately 38,000 EMS and fast neutron mutagenized Medicago truncatula seedlings were screened for defects in symbiotic nitrogen fixation. Mutant plants impaired in nodule development and efficient nitrogen fixation were selected for further genetic and phenotypic analysis. Nine mutants completely lacking in nodule formation (Nod-) represented six complementation groups of which two novel loci have been identified. Eight mutants with ineffective nodules (Fix-) represented seven complementation groups, out of which five were new monogenic loci. The Fix- M. truncatula mutants showed symptoms of nitrogen deficiency and developed small white nodules. Microscopic analysis of Fix- nodules revealed that the mutants have defects in the release of rhizobia from infection threads, differentiation of rhizobia and maintenance of persistence of bacteria in nodule cells. Additionally, we monitored the transcriptional activity of symbiosis specific genes to define what transcriptional stage of the symbiotic process is blocked in each of the Fix- mutants. Based on the phenotypic and gene expression analysis a functional hierarchy of the FIX genes is proposed. The new symbiotic loci of M. truncatula isolated in this study provide the foundation for further characterization of the mechanisms underpinning nodulation, in particular the later stages associated with bacterial release and nodule function.
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影响因子：
7.4
作者：
Mitra, RM;Long, SR
通讯作者：
Long, SR
影响因子：
64.8
作者：
Krusell, L;Madsen, LH;Stougaard, J
通讯作者：
Stougaard, J
DOI：
10.1073/pnas.0600912103
发表时间：
2006-03-28
影响因子：
11.1
作者：
Mergaert, P;Uchiumi, T;Kondorosi, E
通讯作者：
Kondorosi, E
影响因子：
7.4
作者：
Kumagai, Hirotaka;Hakoyama, Tsuneo;Kouchi, Hiroshi
通讯作者：
Kouchi, Hiroshi
影响因子：
7.4
作者：
Graham, PH;Vance, CP
通讯作者：
Vance, CP