Participation of Endogenous Gibberellins in the Regulation of Transition to Flowering of Arabidopsis thaliana Mutants
Participation of endogenous gibberellins in the regulation of transition to flowering of Arabidopsis thaliana mutants has been shown. Genes responsible for the transition of plants to flowering have been recently revealed and cloned, and it has been shown that the main genes of photoperiodical reaction determining the transition of plants to flowering are CONSTANS (CO) and its homologues like, e.g., CONSTANS LIKE 1 (COL 1). In our experiment, wild facultative long-day plants of Arabidopsis thaliana race Columbia and two COL 1-insertion mutants were used. The rates of plant growth and transition to flowering, as well as growth rates of leaves, flowers, stamens, anthers, and pistils have been compared for mutants and wild plants under long-day conditions. It has been found that insertion mutants significantly differ from wild plants by the rate of transition to flowering. Significant differences in the activity of gibberellins in these plants have also been revealed. The activity of gibberellins in a mutant that effloresces earlier than the wild plants is higher by two times, while a lower content of gibberellins is found in the mutant with the delayed efflorescence. This indicates the significant role of gibberellins in photoperiod-ism processes and confirmes the Chailakhyan hormonal theory of plant development