| Abstract [eng] |
this investigation is dedicated to evaluate the effects of ethylene, synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) and auxin inhibitors HFCA and PCIB on the flower/inflorescence development of barley double mutants Hv-tweaky spike 2; Hooded/Kap1 (Hv-tw2;Hd) that are characterized by inherited phenotypic instability and by several new features, such as leaf-like structures, long naked gaps in the spike, and variations in the basic and ectopic flowers, which are absent in parental mutants. Experimental data showed that exogenous ethylene induces the partial normalization of the awn development and its effect is genetic background-dependent. Furthermore, plant treatment with 2,4-D causes the partial normalization of the spike and ectopic flower structures, while the opposite effect was noted for both auxin inhibitors. On the ground of the modifications of phenotypic instability features caused by the auxin inhibitors and 2,4-D, auxin imbalance has been described as a cause of phenotypic instability for the first time, moreover, barley Hv-tweaky-type mutations were demonstrated to be associated with defects in the auxin function. Preliminary results of the differential display analysis showed that the mutant Hv-tw2 differs from WT in the expression of several cDNA fragments that are homologous to the genes participating in epigenetic regulation, stress responses and flower development and that may be related to phenotypic instability induction in barley double mutants. |
