The tomato RLK superfamily: phylogeny and functional predictions about the role of the LRRII-RLK subfamily in antiviral defense

BMC Plant Biology

Research Article

Fabyano F Silva¹  Tetsu Sakamoto²  Anésia A Santos³  Michihito Deguchi³  Elizabeth PB Fontes³  Otávio JB Brustolini³ 

[1] Departamento de Estatística, Universidade Federal de Viçosa, 36570-000, Viçosa, MG, Brazil;National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, 36570-000, Viçosa, MG, Brazil;National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, 36570-000, Viçosa, MG, Brazil;Departamento de Bioquímica e Biologia Molecular/BIOAGRO, Universidade Federal de Viçosa, 36570-000, Viçosa, MG, Brazil;

关键词: Receptor-like kinase;    NIK;    NSP;    BAK1;    Virus infection;    Protein-protein interaction;    Functional divergence;    Plant signaling;    Solanum lycopersicum;   

DOI  :  10.1186/1471-2229-12-229

 received in 2012-07-30, accepted in 2012-11-18,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundReceptor-like kinases (RLKs) play key roles during development and in responses to the environment. Despite the relevance of the RLK family and the completion of the tomato genome sequencing, the tomato RLK family has not yet been characterized, and a framework for functional predictions of the members of the family is lacking.ResultsTo generate a complete list of all the members of the tomato RLK family, we performed a phylogenetic analysis using the Arabidopsis family as a template. A total of 647 RLKs were identified in the tomato genome, which were organized into the same subfamily clades as Arabidopsis RLKs. Only eight of 58 RLK subfamilies exhibited specific expansion/reduction compared to their Arabidopsis counterparts. We also characterized the LRRII-RLK family by phylogeny, genomic analysis, expression profile and interaction with the virulence factor from begomoviruses, the nuclear shuttle protein (NSP). The LRRII subfamily members from tomato and Arabidopsis were highly conserved in both sequence and structure. Nevertheless, the majority of the orthologous pairs did not display similar conservation in the gene expression profile, indicating that these orthologs may have diverged in function after speciation. Based on the fact that members of the Arabidopsis LRRII subfamily (AtNIK1, AtNIK2 and AtNIK3) interact with the begomovirus nuclear shuttle protein (NSP), we examined whether the tomato orthologs of NIK, BAK1 and NsAK genes interact with NSP of Tomato Yellow Spot Virus (ToYSV). The tomato orthologs of NSP interactors, SlNIKs and SlNsAK, interacted specifically with NSP in yeast and displayed an expression pattern consistent with the pattern of geminivirus infection. In addition to suggesting a functional analogy between these phylogenetically classified orthologs, these results expand our previous observation that NSP-NIK interactions are neither virus-specific nor host-specific.ConclusionsThe tomato RLK superfamily is made-up of 647 proteins that form a monophyletic tree with the Arabidopsis RLKs and is divided into 58 subfamilies. Few subfamilies have undergone expansion/reduction, and only six proteins were lineage-specific. Therefore, the tomato RLK family shares functional and structural conservation with Arabidopsis. For the LRRII-RLK members SlNIK1 and SlNIK3, we observed functions analogous to those of their Arabidopsis counterparts with respect to protein-protein interactions and similar expression profiles, which predominated in tissues that support high efficiency of begomovirus infection. Therefore, NIK-mediated antiviral signaling is also likely to operate in tomato, suggesting that tomato NIKs may be good targets for engineering resistance against tomato-infecting begomoviruses.

【 授权许可】

Unknown   
© Sakamoto et al.; licensee BioMed Central Ltd. 2012. 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/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.