Molecular Mechanism of Flowering Time Regulation in Brassica rapa: Similarities and Differences with Arabidopsis

Abstract

Properly regulated flowering time is pivotal for successful plant reproduction. The floral transition from vegetative growth to reproductive growth is regulated by a complex gene regulatory network that integrates environmental signals and internal conditions to ensure that flowering takes place under favorable conditions. Brassica rapa is a diploid Cruciferae species that includes several varieties that are cultivated as vegetable or oil crops. Flowering time is one of the most important agricultural traits of B. rapa crops because of its influence on yield and quality. The transition to flowering in B. rapa is regulated by several environmental and developmental cues, which are perceived by several signaling pathways, including the vernalization pathway, the autonomous pathway, the circadian clock, the thermosensory pathway, and gibberellin (GA) signaling. These signals are integrated to control the expression of floral integrators BrFTs and BrSOC1s to regulate flowering. In this review, we summarize current research advances on the molecular mechanisms that govern flowering time regulation in B. rapa and compare this to what is known in Arabidopsis.