Cloning of protein phosphatase 2A regulatory subunit gene TaBβ-1 and its expression patterns under abiotic stresses in wheat.

【Objective】 TaBβ-1,a gene encoding protein phosphatase 2A (PP2A) regulatory subunit (PR55) was cloned and its expression patterns in wheat under abiotic stresses were dissected for the purpose of providing a candidate gene for wheat breeding in response to various abiotic stresses.【 Method】 A wheat (Triticum aestivum L.) cultivar Hanxuan 10 was used as the plant material to clone the full-length cDNA sequence of TaBβ-1 by in silico cloning and RT-PCR.Suitable bioinformatics softwares were adopted to assay the structure of cDNA sequence,and the function of deduced TaBβ-1.The real-time quantitative PCR (qRT-PCR) method was employed to determine the expression patterns of TaBβ-1 in specific tissues and under abiotic stresses in wheat.【Result】 A full-length cDNA sequence encoding regulatory subunit of PP2A was cloned from wheat and designated by the name of TaBβ-1,which is a 1 931 bp sequence with an 1 539 bp open reading frame.The putative amino acid sequence of TaBβ-1 contains 512 amino acids with a molecular mass of 57.1 kD and pI value of 5.87,which contains a CDC55 conserved domain,an alpha/beta domain,two PR55 conserved sites and six WD-repeats of PP2A subunit B.TaBβ-1 was detected in all tissues,including root,leaf and young-spike of wheat.The expression levels of TaBβ-1 at booting stage were root spike leaf.The highest expression level was identified from the seedling leaf among young-leaves at jointing,booting and flag-leaf expansion stages.TaBβ-1 was up-regulated by PEG,NaCl,cold and ABA treatments.Leaf cell membrane stabilities of transgenic Arabidopsis over-expressing TaBβ-1 were detected under well-watered and drought stress conditions.【Conclusion】 TaBβ-1 is a member of PP2A regulatory subunit family.The expression level of TaBβ-1 in seedling leaf is much higher than that in the root and spike at booting stage,and in leaves at different stages.TaBβ-1 responds to multi-abiotic stresses but shows varied expression patterns,implying that TaBβ-1 involves in different signal pathways responding to abiotic stresses.Transgenic TaBβ-1 Arabidopsis lines show significantly higher cell membrane stabilities under drought stress condition than the wild type.