Open AccessEnhancing plant growth and fiber production by silencing GA 2‐oxidase
Author(s) -
Dayan Jonathan,
Schwarzkopf Maayan,
Avni Adi,
Aloni Roni
Publication year - 2010
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/j.1467-7652.2009.00480.x
Subject(s) - gibberellin , biology , oxidase test , gene silencing , xylem , botany , herbaceous plant , enzyme , biochemistry , microbiology and biotechnology , gene
Summary Enhancing plant height and growth rates is a principal objective of the fiber, pulp, wood and biomass product industries. Many biotechnological systems have been established to advance that task with emphasis on increasing the concentration of the plant hormone gibberellin, or on its signalling. In this respect, the most studied gibberellin biosynthesis enzyme is the GA 20‐oxidase which catalyses the rate limiting step of the pathway. Overexpression of the gene resulted in an excessively high activity of the gibberellin deactivating enzyme, GA 2‐oxidase. Consequently, this feedback regulation limits the intended outcome. We assume that silencing GA 2‐oxidase transcription would abolish this antithetical effect, thereby allowing greater gibberellin accumulation. Here, we show that silencing the gibberellin deactivating enzyme in tobacco model plants results in a dramatic improvement of their growth characteristics, compared with the wild type and GA 20‐oxidase over‐expressing plants. Moreover, the number of xylem fiber cells in the silenced lines exceeded that of GA 20‐oxidase over‐expressing plants, potentially, making GA 2‐oxidase silencing more profitable for the wood and fiber industries. Interestingly, crossing GA 20‐oxidase over‐expressing plants with GA 2‐oxidase silenced plants did not yield consequential additive effects. Our findings unveil the benefits of silencing GA 2‐oxidase to substantially increase tobacco growth and fiber production, which suggest using this approach in cultivated forest plantations and industrial herbaceous plants, worldwide.