Expression profiling of genes involved in the biotrophic colonisation of Coffea arabica leaves by Hemileia vastatrix

Abstract

Coffee Leaf Rust, caused by Hemileia vastatrix, is the most important disease of Arabica coffee (Coffea arabica), which prompts studies aimed at understanding the genetic basis of this pathogen as well as its complex interaction with the host. In this work, 11 genes, putatively involved in signalling, establishment and maintenance of biotrophy (transport and metabolism), were characterised, and their expression profiles during host infection were assessed by RT-qPCR in three compatible coffee-rust interactions comprising two different rust races. The profiles of two chitin deacetylases (CD) and a heterotrimeric G-protein α subunit transcripts suggest that these enzymes are involved in host-pathogen recognition and establishment of biotrophy at early stages of infection, and the late expression of the CD1 gene was also recorded. Different expression profiles were observed for a MAP kinase gene between the two rust races, suggesting that this gene may be involved in the differentiation of infection structures in a race-specific pattern. Two amino acid transporters, an invertase, a hexose transporter and a mannitol dehydrogenase presented expression profiles similar to those reported in other rust fungi, indicating a fairly conserved genetic programme related to host infection in rust fungi. The strong upregulation of a Uromyces fabae rust transferred protein 1 orthologous gene was observed in H. vastatrix in planta structures, suggesting that this gene may also play a role during the establishment and the maintenance of biotrophy in coffee leaves. Overall, our results provide valuable Eur J Plant Pathol (2012) 133:261-277

Cellular and molecular analyses of coffee resistance to Hemileia vastatrix and nonhost resistance to Uromyces vignae in the resistance-donor genotype HDT832/2

“…A third level of response, suggested by haustoria-induced cell death in the host interaction, could not be traced at the molecular level, presumably because of the low level of infection sites where haustoria were formed. Interestingly, a similar biphasic activation of fungal genes involved in signalling and pathogenesis was reported at similar differentiation stages of H. vastatrix during colonisation in compatible interactions with C. arabica (Vieira et al 2011).…”

Strategies for Wheat Stripe Rust Pathogenicity Identified by Transcriptome Sequencing

“…The genomes of Pgt and Mlp [23] as well as the secretome of the symbiont Laccaria bicolor [56], were also found to be enriched in chitin deacetylase genes. Expression profiling of the biotrophic stage of the coffee rust Hemileia vastatrix suggested that two chitin deacetylases were most strongly expressed in the early stages of host invasion, coinciding with spore germination and tissue invasion [57]. Likewise, the rust fungus Uromyces viciae-fabae exhibits massive chitin deacetylase activity when the fungus starts to penetrate through the stomata [58].…”

Overview of the functional virulent genome of the coffee leaf rust pathogen Hemileia vastatrix with an emphasis on early stages of infection

“…An in vitro method was used to produce germinating urediniospores and appressoria to ensure the generation of cDNA libraries with no contaminating plant sequences (Azinheira et al, 2001; Vieira et al, 2012). For the germinating urediniospores sample (gU), 19 mg of spores were spread in sterile distilled water in Petri dishes and incubated for 18 h at 24°C under darkness.…”