Abstract:

【Objective】 To clone a conidiation-related gene PsCon1 from Puccinia striiformis f.sp. tritici (Pst) and analyze its expression profile. 【Method】 The cDNA and genomic DNA of PsCon1 were isolated by using RT-PCR and PCR and the gene expression level at different morphological stages was analyzed via real-time RT-PCR. 【Result】 PsCon1 comprised of 3 extrons and 2 introns. Open reading frame (ORF) of PsCon1 was 252 bp in length, encoding 83 amino acids containing two conserved domains of conidiation-specific protein 6. PsCon1, without transmembrane domain or signal peptide sequence, was predicted to be located in cytoplasm. The nucleotide acid identity between PsCon1 and PtCon extrons was 78%, much higher than the 43% between the introns. Phylogenetic analysis indicated that PSCON1 had high similarity to Con protein from Puccinia graminis, Aspergillus fumigatus and Neosartorya fischeri. Real-time PCR analysis showed that the transcripts of PsCon1 of germinating urediospore was 1.69 fold over that of urediniospore. In compatible interaction of Pst and wheat, PsCon1 was up-regulated as early as 6 h post- inoculation (hpi). The maximum induction occurred at 6 and 24 hpi, whose transcripts were 3.21 and 2.91 fold over that of urediospore, respectively. From 24 to 168 hpi, the accumulation of transcripts decreased steadily. However, the amount of PsCon1 transcripts was increased at 216 and 264 hpi, which was 15 times as much as that of 168 hpi. In incompatible interaction of Pst and wheat, the accumulation of PsCon1 transcripts decreased steadily. 【Conclusion】 PsCon1 might have influence on germ tube elongation, haustorium and urediospore formation, so it might play a role in the process of stripe rust infection on wheat. The cloning of PsCon1 served as a good foundation for further analysis of its role in the pathogenic process.

Key words: stripe rust')">stripe rust, conidiation-related gene, conidiation-specific protein 6, real-time PCR