Comparative Transcriptome Profiling of a Resistant vs. Susceptible Tomato (Solanum lycopersicum) Cultivar in Response to Infection by Tomato Yellow Leaf Curl Virus

Abstract

Tomato yellow leaf curl virus (TYLCV) threatens tomato production worldwide by causing leaf yellowing, leaf curling, plant stunting and flower abscission. The current understanding of the host plant defense response to this virus is very limited. Using whole transcriptome sequencing, we analyzed the differential gene expression in response to TYLCV infection in the TYLCV-resistant tomato breeding line CLN2777A (R) and TYLCV-susceptible tomato breeding line TMXA48-4-0 (S). The mixed inoculated samples from 3, 5 and 7 day post inoculation (dpi) were compared to non-inoculated samples at 0 dpi. Of the total of 34831 mapped transcripts, 209 and 809 genes were differentially expressed in the R and S tomato line, respectively. The proportion of up-regulated differentially expressed genes (DEGs) in the R tomato line (58.37%) was higher than that in the S line (9.17%). Gene ontology (GO) analyses revealed that similar GO terms existed in both DEGs of R and S lines; however, some sets of defense related genes and their expression levels were not similar between the two tomato lines. Genes encoding for WRKY transcriptional factors, R genes, protein kinases and receptor (-like) kinases which were identified as down-regulated DEGs in the S line were up-regulated or not differentially expressed in the R line. The up-regulated DEGs in the R tomato line revealed the defense response of tomato to TYLCV infection was characterized by the induction and regulation of a series of genes involved in cell wall reorganization, transcriptional regulation, defense response, ubiquitination, metabolite synthesis and so on. The present study provides insights into various reactions underlining the successful establishment of resistance to TYLCV in the R tomato line, and helps in the identification of important defense-related genes in tomato for TYLCV disease management.

Expression of the β‐glucosidase genePgβglu‐1underpins natural resistance of white spruce against spruce budworm

“…Hence, expression variation is usually less pleiotropic and more directly visible to selection than coding variation (Wray, 2007; Galego Romero et al ., 2012). Recent studies have shown that variations in gene expression contribute to evolutionary changes in systems ranging from crop plants (Chen et al ., 2013; Koenig et al ., 2013) to animals and human diseases (Romero et al ., 2012). Through transcriptional variation and high outbreeding, tree populations may accumulate diverse alleles that enable adaptation to changing conditions over long periods of time.…”

Tomato WRKY transcriptional factor SlDRW1 is required for disease resistance against Botrytis cinerea and tolerance to oxidative stress

“…Overexpression of a tomato WRKY gene in transgenic tobacco plants resulted in increased expression of defense genes and improved abiotic stress tolerance [57]. Furthermore, some tomato WRKY genes were found to show differential expression patterns after infection with viral, bacterial and fungal pathogens [55,[58][59][60] or treatment with pathogen-derived elicitors [61]. However, the biological functions for the majority of the tomato WRKYs are not clear yet.…”

The receptor-like kinase SlSOBIR1 is differentially modulated by virus infection but its overexpression in tobacco has no significant impact on virus accumulation

“…Although the transcriptional modulation of LRR-RLK genes in response to virus infection has been reported for a number of plantviral pathosystems (Naqvi et al 2011;Mandadi and Scholthof 2012;Chen et al 2013;Czosnek et al 2013;Zheng et al 2013;Andolfo et al 2014), their possible role in antiviral defense remains speculative. These genes are induced by virus infection in most cases, but repression has In this study, we focused on SlSOBIR1, a tomato LRR-RLK implicated in plant immunity and described to be a crucial interactor for RLP-mediated resistance against fungal pathogens (Liebrand et al 2013a, b).…”