Global gene expression of Poncirus trifoliata, Citrus sunki and their hybrids under infection of Phytophthora parasitica

BMC Genomics

Research Article

Leonardo P Boava¹  Karen Kubo¹  Marcos A Machado¹  Valéria S Mafra¹  Luciano T Kishi¹  Marco A Takita¹  Mariângela Cristofani-Yaly¹  Marcelo Ribeiro-Alves² 

[1] Centro APTA Citros Sylvio Moreira, CP4, 13490-970, Cordeirópolis-SP, Brazil;Centro de Desenvolvimento Tecnológico em Saúde, Fundação Oswaldo Cruz. Av. Brasil, 4365 - 21040-900, Rio de Janeiro-RJ, Brazil;

关键词: Resistant Genotype;    Citrus Tristeza Virus;    Phytophthora Species;    Defense Gene Expression;    Resistant Hybrid;   

DOI  :  10.1186/1471-2164-12-39

 received in 2010-08-11, accepted in 2011-01-17,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundGummosis and root rot caused by Phytophthora are among the most economically important diseases in citrus. Four F1 resistant hybrids (Pool R), and four F1 susceptible hybrids (Pool S) to P. parasitica, were selected from a cross between susceptible Citrus sunki and resistant Poncirus trifoliata cv. Rubidoux. We investigated gene expression in pools of four resistant and four susceptible hybrids in comparison with their parents 48 hours after P. parasitica inoculation. We proposed that genes differentially expressed between resistant and susceptible parents and between their resistant and susceptible hybrids provide promising candidates for identifying transcripts involved in disease resistance. A microarray containing 62,876 UniGene transcripts selected from the CitEST database and prepared by NimbleGen Systems was used for analyzing global gene expression 48 hours after infection with P. parasitica.ResultsThree pairs of data comparisons (P. trifoliata/C. sunki, Pool R/C. sunki and Pool R/Pool S) were performed. With a filter of false-discovery rate less than 0.05 and fold change greater than 3.0, 21 UniGene transcripts common to the three pairwise comparative were found to be up-regulated, and 3 UniGene transcripts were down-regulated. Among them, our results indicated that the selected transcripts were probably involved in the whole process of plant defense responses to pathogen attack, including transcriptional regulation, signaling, activation of defense genes participating in HR, single dominant genes (R gene) such as TIR-NBS-LRR and RPS4 and switch of defense-related metabolism pathway. Differentially expressed genes were validated by RT-qPCR in susceptible and resistant plants and between inoculated and uninoculated control plantsConclusionsTwenty four UniGene transcripts were identified as candidate genes for Citrus response to P. parasitica. UniGene transcripts were likely to be involved in disease resistance, such as genes potentially involved in secondary metabolite synthesis, intracellular osmotic adjustment, signal transduction pathways of cell death, oxidative burst and defense gene expression. Furthermore, our microarray data suggest another type of resistance in Citrus-Phytophthora interaction conferred by single dominant genes (R gene) since we encountered two previously reported R genes (TIR-NBS-LRR and RPS4) upregulated in the resistant genotypes relative to susceptible. We identified 7 transcripts with homology in other plants but yet unclear functional characterization which are an interesting pool for further analyses and 3 transcripts where no significant similarity was found. This is the first microarray study addressing an evaluation of transcriptional changes in response to P. parasitica in Citrus.

【 授权许可】

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