DWARF Overexpression Alters Phytohormone Levels, Plant Architecture, and Carotenoid Accumulation in Tomato

Brassinosteroids (BRs) play a critical role in plant growth and development. However, the BR-controlled regulation of plant growth has not yet been proven. Xiao-Jing Li and researchers from Zhiejang University in China explored the function of DWARF (DWF), the BR biosynthetic gene in tomato, in plant growth and architecture, phytohormone homeostasis and fruit development.

The team compared tomato wild types, with impaired DWF, and DWF-overexpressing plants. Results showed that increases in DWF transcripts and BR levels resulted in improved germination, lateral root development and plant growth. Transgenics also exhibited slender and compact plant architecture. However, overexpression of DWF resulted in the decrease in accumulation of gibberellins.

BRs positively regulated lateral bud growth as well as petiole bending and fruit ripening. Overexpression of DWF did not significantly affect fruit yield per plant, but increases can be expected in fruit yield per square meter in two transgenic lines due to their compact architecture. BR level was also found to positively regulate carotenoid accumulation in the tomato fruits.

The results show that BRs are involved in the regulation of multiple developmental processes related to agronomically important traits.

For more information, read the full article on Plant Biotechnology Journal.