Isolation and characterization of wheat ice recrystallisation inhibition gene promoter involved in low temperature and methyl jasmonate responses.

It is well known that plant growth, development, survival and geographical distribution are constrained by extreme climatic conditions, especially extreme low temperature. Under cold stress, cold-inducible promoters were identified as important molecular switches to transcriptionally regulate the initiation of genes associated with cold acclimation processes and enhance the adaptability of plants to cold stimulation. Wheat ( L.) is one of the most dominating food crops in the world, and wheat crops are generally overwintering with strong cold resistance. Our previous study already proved that heterologous expression of wheat ice recrystallization inhibition () genes enhanced freezing tolerance in tobacco. However, the upstream regulatory mechanisms of are ambiguous. In this study, the space-time specific expression of genes in wheat was analyzed by quantitative real-time PCR (qRT-PCR), and results showed that the expression of in all tissues was cold-induced and accelerate by exogenous methyl jasmonate (MeJA). Three promoters of genes were isolated from wheat genome, and various 5'-deletion fragments of were integrated into β-glucuronidase (GUS) within vector pCAMBIA1301. The promoter activity of genes was determined through transient expression system of tobacco and stable expression of . Results revealed that the GUS activity were significantly strengthened by cold and MeJA treatments. This study will provide insights into elucidating the transcription-regulatory mechanism of IRI proteins responding to low temperature.