Pathogenesis-related proteins （PRs） play many important roles in plant defense response against pathogen attack. To better understand the molecular mechanism of PR genes involved in wheat adult plant resistance （APR） to stripe rust, based on a differentially expressed transcribed derived fragment （TDF）, a novel PR gene from wheat cv. Xingzi 9104 infected by the Puccinia striiformis Westend f. sp. tritici Erikss. pathotype CY32, which was highly similar to the maize ZmPRIO gene and designated as TaPRIO, was identified using in silico cloning and RT-PCR method. This novel TaPRIO gene was predicted to encode a 160-amino acid protein with a deduced molecular weight of 17.06 kDa and an isoelectronic point （pI） of 5.19. An amino acid sequence analysis of TaPR10 demonstrated the presence of a typical conserved domain of pathogenesis related protein Bet v I family. Multiple alignment analysis based on the amino acids encoded by 10 different PRIO genes from maize （Zea mays）, rice （Oryza sativa）, broomcorn （Sorghum bicolor）, and wheat （Triticum aestivum） indicated that PR proteins of class 10 was conserved among the 4 plant species with about 80% similarity. DNA sequence of TaPRIO suggested the presence of one 84-bp intron with the splicing sites of GT-AT bi-nucleotide sequence between 188 and 271 bp. Using a real-time quantitative RT-PCR （qRT-PCR）, expression profiles of TaPRIO revealed that at the adult-plant stage, TaPRIO transcript was up-regulated as early as 12 h post-inoculation （hpi）, with the occurrence of maximum induction at 24 hpi. At the seedling stage, TaPRIO was also slightly induced 18 hpi. However, the transcript amount was relatively lower than that of the adult-plant stage. Taken together, these results suggest that TaPRIO may participate in wheat defense response of APR to stripe rust.
ZHANG Gang LI Yi-min ZHANG Yi DONG Yan-ling WANG Xiao-jie WEI Guo-rong HUANG Li-li KANG Zhen-sheng
