Abstract
BackgroundPuccinia striiformis f. sp. tritici is a fungal pathogen causing stripe rust, one of the most important wheat diseases worldwide. The fungus is strictly biotrophic and thus, completely dependent on living host cells for its reproduction, which makes it difficult to study genes of the pathogen. In spite of its economic importance, little is known about the molecular basis of compatible interaction between the pathogen and wheat host. In this study, we identified wheat and P. striiformis genes associated with the infection process by conducting a large-scale transcriptomic analysis using cDNA-AFLP.ResultsOf the total 54,912 transcript derived fragments (TDFs) obtained using cDNA-AFLP with 64 primer pairs, 2,306 (4.2%) displayed altered expression patterns after inoculation, of which 966 showed up-regulated and 1,340 down-regulated. 186 TDFs produced reliable sequences after sequencing of 208 TDFs selected, of which 74 (40%) had known functions through BLAST searching the GenBank database. Majority of the latter group had predicted gene products involved in energy (13%), signal transduction (5.4%), disease/defence (5.9%) and metabolism (5% of the sequenced TDFs). BLAST searching of the wheat stem rust fungus genome database identified 18 TDFs possibly from the stripe rust pathogen, of which 9 were validated of the pathogen origin using PCR-based assays followed by sequencing confirmation. Of the 186 reliable TDFs, 29 homologous to genes known to play a role in disease/defense, signal transduction or uncharacterized genes were further selected for validation of cDNA-AFLP expression patterns using qRT-PCR analyses. Results confirmed the altered expression patterns of 28 (96.5%) genes revealed by the cDNA-AFLP technique.ConclusionThe results show that cDNA-AFLP is a reliable technique for studying expression patterns of genes involved in the wheat-stripe rust interactions. Genes involved in compatible interactions between wheat and the stripe rust pathogen were identified and their expression patterns were determined. The present study should be helpful in elucidating the molecular basis of the infection process, and identifying genes that can be targeted for inhibiting the growth and reproduction of the pathogen. Moreover, this study can also be used to elucidate the defence responses of the genes that were of plant origin.
Highlights
Puccinia striiformis f. sp. tritici is a fungal pathogen causing stripe rust, one of the most important wheat diseases worldwide
Isolation of differentially expressed genes during interaction between wheat and the stripe rust fungus The sampling time points ranging from 6 to 168 hpi corresponded to the different stages of stripe rust fungi infection processes, including spore germination, formation of substomal vesicle (8~12 hpi), infection hyphae (12~18 hpi), and haustorial mother cells and haustoria (18~24 hpi), proliferation of intercellular hyphae and numerous haustoria in host tissues (48~120 hpi), and generation of sporogenous cells at about 168 hpi, as described by Wang et al [19]
High throughput coverage of leaf samples across time points during whole infection processes of stripe rust fungus yielded a large number of polymorphic bands using cDNA-AFLP analyses
Summary
Puccinia striiformis f. sp. tritici is a fungal pathogen causing stripe rust, one of the most important wheat diseases worldwide. Tritici is a fungal pathogen causing stripe rust, one of the most important wheat diseases worldwide. In spite of its economic importance, little is known about the molecular basis of compatible interaction between the pathogen and wheat host. Tritici Eriks., the causal fungus of stripe rust on wheat (Triticum aestivum L.), is a biotrophic obligate parasite. Henn.) cause similar damage to wheat production In addition to their economic importance, rust fungi are interesting because of their complex life cycle and the specialized infection structures. The infection process of cereal rust fungi has been closely examined in several species, the molecular mechanisms of compatible and incompatible interactions between the host and pathogen, especially for the wheat-P. striiformis system, are poorly understood [7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
