Temporal and tissue-specific expression of wheat TaHIR2 gene and resistant role of recombinant protein during interactions between wheat and leaf rust pathogen

Abstract

Hypersensitive induced reaction (HIR) protein had been reported to play roles in plant resisting biotic and abiotic stress. In this study, a full length cDNA TaHIR2, encoding a 284- amino-acid protein with deduced MW of 31.34 kDa and predicted pI of 5.42, was cloned and identified from wheat leaves infected by leaf rust pathogen. The amino acid sequence deduced from TaHIR2 shared 99% homology with HvHIR2 from barley and contained prohibitins-domain which is a member of SPFH protein domain. Temporal expression profiles indicated that the TaHIR2 transcripts in the incompatible and compatible interactions begun to increase at 18 h post-inoculation (hpi), and reached the maximum at 36 hpi, then declined, but the relative expression of TaHIR2 transcripts in the incompatible interaction was 4.11 and 1.32 times higher than that in compatible one at 24 and 36 hpi, respectively. The accumulation of TaHIR2 transcript was the highest in wheat leaf. Furthermore, Western blot showed that the maximum accumulation of the TaHIR2 at the protein level occurred at 60 and 96 hpi in the incompatible and compatible interactions, respectively. Based on the above results, we primarily concluded that a novel TaHIR2 gene was successfully cloned from wheat and may play a role in wheat resistant to the leaf rust pathogen.