Characterization of two thioredoxins h with predominant localization in the nucleus of aleurone and scutellum cells of germinating wheat seeds

摘要: Two full-length cDNA clones, designated TrxhA and TrxhB, encoding different but very similar thioredoxin h polypeptides were isolated from wheat (Triticum aestivum cv. Chinese Spring) aleurone cells. The deduced proteins show a high similarity to each other sources, in particular T. durum. One of them, TRXhA, was expressed E. coli as His-tagged polypeptide used raise polyclonal antibodies by immunization rabbits. These identified single band (ca. 13.5 kDa) western blot analysis protein extracts all organs analyzed. TRXhA TRXhB when intact polypetides showed indistinguishable electrophoretic mobility, which corresponded the kDa detected extracts. amount transcripts increased scutellum cells during germination GA3 did not exert any stimulatory effect on expression. Although northern band, competitive RT-PCR that this is due accumulation both TrxhB mRNAs. results suggest blots presence at least two polypeptides. Immunolocalization experiments confirmed content thioredoxins cells, low starchy endosperm germinating grains. Interestingly, though these are evenly distributed cytosol, highest levels nucleus, Abbreviations: daa, days after anthesis; NTR, NADPH reductase; PMSF, phenylmethylsulfonyl fluoride; RACE, rapid amplification ends; Trxh,