Molecular Cloning And Antioxidant Effect Analysis Of IRT Gene In Chorispora Bungeana

Chorispora bungeana belongs to the rare alpine plants.It can withstand extreme cold and has no special structure,but it is the unearthly material that investigate plant resisting cold mechanism in physiological and molecular level.In this article,we cloned a gene called CbIRT in Chorispora bungeana.We investigated the antioxidant system and the expression of the CbIRT gene in different temperature and Fe concentration.Iron transport protein(IRT)is a unique protein that transports ion across membrane and belongs to iron transport family-ZIP.In the present work,the full-length IRT gene in Chorispora bungeana and its expression under different temperature and different Fe level had been studied by using 3' and 5' RACE-PCR clone and real-time quantitative PCR technology.Sequence alignment and phylogenetic tree analysis showed that the IRT gene from Chorispora bungeana (named CbIRT),comprising 1290 bp with a complete open reading frame of 1035 bp, encoding a peptide of 344 amino acid residues,was highly homologous to AtIRT1(87.4%)and TcIRT-G(86.5%)respectively and the sequence of deduced amino acid has the 89%homology to AtIRT1.Expression analysis by real-time quantitative PCR revealed that CbIRT gene expression can be induced either by shorten Fe treatment or low temperature stress,while depressed by additional Fe treatment.This indicated CbIRT gene may play key roles not only in Fe metabolism but also under low temperature stress.In the low temperature,we find the resisting cold of the Chorispora bungeana is correlative to the enzymes of AsA-GSH system.A few enzyme activities can change by Fe and low temperature stress regularly.So we conclude that the expression of CbIRT and the enzymes of AsA-GSH system the is helpful to the Chorispora bungeana resisting to cold.