Ekspresja genów germin pod wpływem wybranych czynników zewnętrznych w tytoniutransgenicznym (Nicotiana tabacum var. Xanthi)

Wheat germin, a glycoprotein mainly localized in the cell wall of monocots,dicots and pine [Pinus caribaea Morelet), is a specific marker of the onset ofgrowth in germinating seeds. There are two genes gf-2.8 and gf-3.8 of germin,isolated from wheat (Triticum aestivum). Because of their structure and biochemistry, both of the germin’s isoforms have been now assimilated to the oxalate-oxidase enzyme (E.C. 1.2.3.4). Several constructs of the gf-2.8 and gf-3.8genes promoters deletion were fused with uidA gene and tested for the GUS activity in the transgenic tobacco plants. The aim of this work was to evaluatewhether some environmental factors induce the activity of germin. Hormonaltreatment (auxins 2,4-D, NAA, giPberellin GA3), salt treatment, salicylic acid,heavy metals (Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg, As) and A1 induced high GUS activity in root apex, cotyledons and hypocotyls in transgenic seedlings and in leavesof the tobacco plants transformed with the entire and one partially deleted construct of the gf-2.8 gene. Neither cold nor heat shock, enhanced significant GUSactivity. The gf-3.8 - GUS constructs of germin did not give a positive responseto any factors mentioned above. Thus, only the gf-2.8 protein seems to be regulated by some factors. The gf-2.8 oxalate-oxidase activity could be then involvedin general stress-induced signalling in higher plants.