| Abstract [eng] |
Domestic apple (Malus × domestica Borkh) is one of the model species suitable for targetted genome analysis, resistance to diseases and reproduction and transformation studies in vitro. It is know that endophytes have a positive effect on plant growth and can help protect against biotic and abiotic stresses. However, in vitro conditions to endophyte effects on plants can become pathogenic and induce plant stress and death. Causes of the adverse effects on plants in vitro are poorly understood. In order to evaluate the effect of endophytic bacteria on the growth of „Gala“ domestic apple shoot in vitro, the shoots were inoculated with two Bacillus spp. bacterial strains Oa_4 and Da_1 and grown under controlled conditions using two different lighting conditions. Analysis of shoot weight and number of auxilary shoots after 21 days of inoculation with bacterial endophytes revealed that endophytes in all experimental groups inhibited the growth of shoots in vitro. In order to evaluate the changes in the domestic apple protein expression after inoculation with endophytes, a proteomic analysis was performed. Differencial expression of 111 proteforms were established, of which 49 were identified. Incubation with endophytes upregulated expression of the proteins involved in oxidation–reduction, defence response, protein metabolism and regulation of their function, cellular organization, and lipid metabolic processes. The largest changes in protein expression were detected for PLAT domain protein 1 (PLAT1), whitch is related to cell migration and tissue reorganization processes, and low temperature activated protein (RD21A), which is involved in responce to stress and pathogens. Conclusions: 1. After evaluation of endophytic Bacillus spp. strain Oa_4 and Da_1 effects on domestic apple shoot in vitro condition, we established that both strains had similarl inhibiting effect on the growth of shoots (from 3,4 to 4,4 times) and the formation of auxilary shoots (from 2,7 to 3,6 times), irrespective of the lighting conditions. After incubation with endophytic bacteria, no morphological lesions were detectable, therefore the inhibition of shoot growth is not a consequence of pathogenesis. 2. Proteomic analysis revealed that the incubation of apple shoot with the endophytic Bacillus spp. strains Oa_4 and Da_1 had mainly protein epression upregulating effect (109 out of 111 significant differences) and a larger effect on protein expression was observed under reduced light conditions. Incubation with Bacillus sp. strain Oa_4 had a larger effect on shoots protein expression. 3. Evaluation cell biological processes and gene functions related to the effects of endophytic bacteria on domestic apple shoots in vitro showed that incubation with Bacillus spp. bacterial strain Oa_4 and Da_1 lead to changes in oxidation–reduction, defence response, protein metabolism and their function regulation, cellular organization and lipid metabolic processes of the apple shoots cells. |
