Fortunella margarita Transcriptional Reprogramming Triggered by Xanthomonas citri subsp. citri

BMC Plant Biology

Research Article

Ana Conesa¹  Joaquin Dopazo¹  Frederick G Gmitter²  Gloria A Moore³  Abeer A Khalaf⁴ 

[1] Centro de Investigación Príncipe Felipe, Valencia, SPAIN;PMCB, Citrus Research and Education Center, University of Florida, Lake Alfred, Fl., USA;Plant Molecular and Cellular Biology Program (PMCB), Horticultural Department,University of Florida, 32611, Gainesville, Fl., Sciences;Plant Molecular and Cellular Biology Program (PMCB), Horticultural Department,University of Florida, 32611, Gainesville, Fl., Sciences;PMCB, Citrus Research and Education Center, University of Florida, Lake Alfred, Fl., USA;

关键词: Gene Ontology;    Hypersensitive Response;    Suppression Subtractive Hybridization;    Sweet Orange;    Citrus Tristeza Virus;   

DOI  :  10.1186/1471-2229-11-159

 received in 2011-06-22, accepted in 2011-11-11,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundCitrus canker disease caused by the bacterial pathogen Xanthomonas citri subsp. citri (Xcc) has become endemic in areas where high temperature, rain, humidity, and windy conditions provide a favourable environment for the dissemination of the bacterium. Xcc is pathogenic on many commercial citrus varieties but appears to elicit an incompatible reaction on the citrus relative Fortunella margarita Swing (kumquat), in the form of a very distinct delayed necrotic response. We have developed subtractive libraries enriched in sequences expressed in kumquat leaves during both early and late stages of the disease. The isolated differentially expressed transcripts were subsequently sequenced. Our results demonstrate how the use of microarray expression profiling can help assign roles to previously uncharacterized genes and elucidate plant pathogenesis-response related mechanisms. This can be considered to be a case study in a citrus relative where high throughput technologies were utilized to understand defence mechanisms in Fortunella and citrus at the molecular level.ResultscDNAs from sequenced kumquat libraries (ESTs) made from subtracted RNA populations, healthy vs. infected, were used to make this microarray. Of 2054 selected genes on a customized array, 317 were differentially expressed (P < 0.05) in Xcc challenged kumquat plants compared to mock-inoculated ones. This study identified components of the incompatible interaction such as reactive oxygen species (ROS) and programmed cell death (PCD). Common defence mechanisms and a number of resistance genes were also identified. In addition, there were a considerable number of differentially regulated genes that had no homologues in the databases. This could be an indication of either a specialized set of genes employed by kumquat in response to canker disease or new defence mechanisms in citrus.ConclusionFunctional categorization of kumquat Xcc-responsive genes revealed an enhanced defence-related metabolism as well as a number of resistant response-specific genes in the kumquat transcriptome in response to Xcc inoculation. Gene expression profile(s) were analyzed to assemble a comprehensive and inclusive image of the molecular interaction in the kumquat/Xcc system. This was done in order to elucidate molecular mechanisms associated with the development of the hypersensitive response phenotype in kumquat leaves. These data will be used to perform comparisons among citrus species to evaluate means to enhance the host immune responses against bacterial diseases.

【 授权许可】

CC BY   
© Khalaf et al; licensee BioMed Central Ltd. 2011