Biotech Updates

Overexpressed CYP85A3 Confers Enhanced Biomass Production in Transgenic Plants

October 4, 2017

Brassinosteroids (BRs) are essential hormones that play crucial roles in plant growth, reproduction and response to abiotic and biotic stress. In Arabidopsis, AtCYP85A2 catalyzes the final step in the BR-biosynthetic pathway. The team of Yan-Ji Lin from Ludong University in China studied the PtCYP85A3 gene, one of the three AtCYP85A2 homologous genes from poplar (Populus trichocarpa).

PtCYP85A3 was found to be highly similar to AtCYP85A2 and can rescue the retarded-growth of the Arabidopsis cyp85a2-2 and tomato mutants. Constitutive expression of PtCYP85A3 increased the BR levels and significantly promoted the growth and biomass production in both transgenic tomato and poplar. Compared to the wild type, plant height, shoot fresh weight, and fruit yield increased significantly in transgenic tomato plants.

Plant height and stem diameter also increased significantly in transgenic poplar plants. Further analysis revealed that overexpression of PtCYP85A3 enhanced xylem formation without affecting the composition of cellulose and lignin, as well as the cell wall thickness in transgenic poplar.

These results suggest that PtCYP85A3 could be used as a potential candidate gene for engineering fast-growing trees with improved wood production.

For more information, read the article in Plant Biotechnology Journal.