Expression of plastid genome and development of Arabidopsis thaliana with disturbed synthesis of brassinosteroids

Comparative analysis of growth characteristics, content of auxins and cytokinins, and the level of photosynthetic pigments was conducted in det2 mutant plants of Arabidopsis thaliana (L.) Heynh notable for a disturbed synthesis of brassinosteroids and therefore their low endogenous level. In this mutant line, we observed de-etiolation: the formation of large cotyledons and long hypocotyls in the dark already shown earlier. For the first time, we analyzed transcription of 12 chloroplast genes encoding functionally different proteins and RNAs in rosette leaves of wild type and det2 plants. In rosette leaves of mutant plants, transcription activity of the investigated plastid genes was much higher than in the parental line. On these grounds, we assumed that the low level of brassinosteroids was correlated with the activation of transcription of some chloroplastic genes and realization of the de-etiolation program.