Transcriptome responses to Ralstonia solanacearum infection in the roots of the wild potato Solanum commersonii

Springer Science and Business Media LLC - Tập 16 - Trang 1-16 - 2015
A Paola Zuluaga1, Montserrat Solé1, Haibin Lu1, Elsa Góngora-Castillo2, Brieanne Vaillancourt2, Nuria Coll1, C Robin Buell2, Marc Valls1
1Genetics Department, Universitat de Barcelona and Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB) Edifici CRAG, Campus UAB, Catalonia, Spain
2Department of Plant Biology, Michigan State University, East Lansing, USA

Tóm tắt

Solanum commersonii is a wild potato species that exhibits high tolerance to both biotic and abiotic stresses and has been used as a source of genes for introgression into cultivated potato. Among the interesting features of S. commersonii is resistance to the bacterial wilt caused by Ralstonia solanacearum, one of the most devastating bacterial diseases of crops. In this study, we used deep sequencing of S. commersonii RNA (RNA-seq) to analyze the below-ground plant transcriptional responses to R. solanacearum. While a majority of S. commersonii RNA-seq reads could be aligned to the Solanum tuberosum Group Phureja DM reference genome sequence, we identified 2,978 S. commersonii novel transcripts through assembly of unaligned S. commersonii RNA-seq reads. We also used RNA-seq to study gene expression in pathogen-challenged roots of S. commersonii accessions resistant (F118) and susceptible (F97) to the pathogen. Expression profiles obtained from read mapping to the S. tuberosum reference genome and the S. commersonii novel transcripts revealed a differential response to the pathogen in the two accessions, with 221 (F118) and 644 (F97) differentially expressed genes including S. commersonii novel transcripts in the resistant and susceptible genotypes. Interestingly, 22.6% of the F118 and 12.8% of the F97 differentially expressed genes had been previously identified as responsive to biotic stresses and half of those up-regulated in both accessions had been involved in plant pathogen responses. Finally, we compared two different methods to eliminate ribosomal RNA from the plant RNA samples in order to allow dual mapping of RNAseq reads to the host and pathogen genomes and provide insights on the advantages and limitations of each technique. Our work catalogues the S. commersonii transcriptome and strengthens the notion that this species encodes specific genes that are differentially expressed to respond to bacterial wilt. In addition, a high proportion of S. commersonii-specific transcripts were altered by R. solanacearum only in F118 accession, while phythormone-related genes were highly induced in F97, suggesting a markedly different response to the pathogen in the two plant accessions studied.

Tài liệu tham khảo

Peeters N, Guidot A, Vailleau F, Valls M. Ralstonia solanacearum, a widespread bacterial plant pathogen in the post-genomic era. Mol Plant Pathol. 2013;14(7):651–62.

Coll NS, Valls M. Current knowledge on the Ralstonia solanacearum type III secretion system. Microb Biotech. 2013;6(6):614–20.

Priou S. Integrated management of bacterial wilt and soil-borne diseases of potato in farmer communities of the inter-Andean valleys of Peru and Bolivia. In: Final Technical Report DFID-funded project CRF 7862(C). Lima: CIP; 2004.

Hong J, Ji P, Momol MT, Jones JB, Olson SM, Pradhanang P, et al. Ralstonia solanacearum detection in tomato irrigation ponds and weeds. In: Proceedings of the First International Symposium on Tomato Diseases: 2005. Orlando, FL: ISHS; 2005. p. 309–11.

Ben C, Debell F, Berges H, Bellec A, Jardinaud MF, Anson P, et al. MtQRRS1, an R-locus required for Medicago truncatula quantitative resistance to Ralstonia solanacearum. New Phytol. 2013;199:758–72.

Galván G, Fraguas F, Quirici L, Santos C, Silvera E, Siri M, et al. Solanum Commersonii: una especie con gran potencial para el mejoramiento genético de papa por resistencia a Ralstonia Solanacearum. In: Avances de investigación en recursos genéticos en el cono sur I. Uruguay: Publisher Procisur I. Agrociencia; 2006. p. 87–102.

Ishihara T, Mitsuhara, I, Takahashi H, Nakaho K. Transcriptome analysis of quantitative resistance-specific response upon Ralstonia solanacearum infection in tomato. PlosOne 2012; doi:10.1371/journal.pone.0046763.

Villanueva J, Canals F, Prat S, Ludevid D, Querol E, Aviles FX. Characterization of the wound-induced metallocarboxypeptidase inhibitor from potato. cDNA sequence, induction of gene expression, subcellular immunolocalization and potential roles of the C-terminal propeptide. FEBS Lett. 1998;440(1–2):175–82.