Extreme specificity of NCR gene expression in Medicago truncatula

BMC Genomics

Research Article

Peter Mergaert¹  Pascal Ratet¹  Willem Van de Velde²  Benoît Alunni³  Eva Kondorosi⁴  Marianna Nagymihaly⁴  Ibtissem Guefrachi⁵  Mohamed Mars⁶  Michael K Udvardi⁷  Catalina I Pislariu⁷ 

[1] Institut des Sciences du Végétal, Centre National de la Recherche Scientifique UPR2355, 91198, Gif-sur-Yvette, France;Institut des Sciences du Végétal, Centre National de la Recherche Scientifique UPR2355, 91198, Gif-sur-Yvette, France;Ablynx, Technologiepark 21, 9052, Zwijnaarde, Belgium;Institut des Sciences du Végétal, Centre National de la Recherche Scientifique UPR2355, 91198, Gif-sur-Yvette, France;Département de Biologie, Université Paris Sud 11, 91400, Orsay, France;Institut des Sciences du Végétal, Centre National de la Recherche Scientifique UPR2355, 91198, Gif-sur-Yvette, France;Institute of Biochemistry, Hungarian Academy of Sciences, Biological Research Centre, 6726, Szeged, Hungary;Institut des Sciences du Végétal, Centre National de la Recherche Scientifique UPR2355, 91198, Gif-sur-Yvette, France;Research Unit Biodiversity & Valorization of Arid Areas, Bioressources (BVBAA), Faculty of Sciences, Gabès University, 6072, Erriadh-Zrig, Gabès, Tunisia;Research Unit Biodiversity & Valorization of Arid Areas, Bioressources (BVBAA), Faculty of Sciences, Gabès University, 6072, Erriadh-Zrig, Gabès, Tunisia;Samuel Roberts Noble Foundation, 73401, Ardmore, Oklahoma, USA;

关键词: Symbiosis;    Legume nitrogen fixation;    Nodulation;    Bacteroid;    Medicago truncatula;    Sinorhizobium meliloti;    NCR;    Defensin;    Gene expression;    Transcriptome compendium;   

DOI  :  10.1186/1471-2164-15-712

 received in 2014-05-19, accepted in 2014-08-12,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundLegumes form root nodules to house nitrogen fixing bacteria of the rhizobium family. The rhizobia are located intracellularly in the symbiotic nodule cells. In the legume Medicago truncatula these cells produce high amounts of Nodule-specific Cysteine-Rich (NCR) peptides which induce differentiation of the rhizobia into enlarged, polyploid and non-cultivable bacterial cells. NCRs are similar to innate immunity antimicrobial peptides. The NCR gene family is extremely large in Medicago with about 600 genes.ResultsHere we used the Medicago truncatula Gene Expression Atlas (MtGEA) and other published microarray data to analyze the expression of 334 NCR genes in 267 different experimental conditions. We find that all but five of these genes are expressed in nodules but in no other plant organ or in response to any other biotic interaction or abiotic stress tested. During symbiosis, none of the genes are induced by Nod factors. The NCR genes are activated in successive waves during nodule organogenesis, correlated with bacterial infection of the nodule cells and with a specific spatial localization of their transcripts from the apical to the proximal nodule zones. However, NCR expression is not associated with nodule senescence. According to their Shannon entropy, a measure expressing tissue specificity of gene expression, the NCR genes are among the most specifically expressed genes in M. truncatula. Moreover, when activated in nodules, their expression level is among the highest of all genes.ConclusionsTogether, these data show that the NCR gene expression is subject to an extreme tight regulation and is only activated during nodule organogenesis in the polyploid symbiotic cells.

【 授权许可】

Unknown   
© Guefrachi et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.