MOLECULAR APPROACH TO PLANT GROWTH REGULATION BY CONSTITUTIVE OVEREXPRESSION OF NICOTIANA GA₂OX IN KALANCHOË BLOSSFELDIANA

The development of an alternative method to chemical treatment for growth retardation in crop and ornamental plant production has become a top target in recent breeding programs.
The present work describes the phenotypes of transgenic Kalanchoë blossfeldiana plants with overexpressed gibberellin 2-oxidase (GA₂ox) from Nicotiana tabacum under the 35S promoter.
The height of the transgenic Kalanchoë lines was reduced by a factor of almost 2 in comparison to the control plants, while the number of nodes was similar between the transgenic and control plants.
The height of the inflorescence stem of the transgenic lines was approximately three times reduced.
However, the transgenic clones exhibited a delay in flowering that amounted to approximately 24 days.
The flower morphology for all of the investigated transgenic lines was the same as that for the control plants.
The transgenic lines had visibly darker leaves containing approximately two times as much chlorophyll as the leaves of the control plants.
These results demonstrate that the overexpression of GA₂ox may become a useful method for obtaining compact growth of horticultural species without the use of chemical growth retardants.

I International Symposium on Ornamentals in Africa

J.M. Gargul, H. Mibus, M. Serek

GA₂ox, gibberellin 2-oxidase, compact growth, dwarf phenotype

https://doi.org/10.17660/ActaHortic.2015.1077.17