Delayed flowering time in Arabidopsis and Brassica rapa by the overexpression of FLOWERING LOCUS C (FLC) homologs isolated from Chinese cabbage (Brassica rapa L. ssp. pekinensis)

Abstract

Chinese cabbage plants remain in the vegetative growth phase until they have experienced prolonged exposure to cold temperature, known as vernalization. This inhibition of flowering is caused by the high levels of FLOWERING LOCUS C (FLC) expression. To increase the product value of Chinese cabbage by inhibiting the floral transition, three genes (BrFLC1, BrFLC2, and BrFLC3) homologous to the AtFLC gene, which encodes a floral repressor, were isolated from the Chinese cabbage 'Chiifu'. These genes showed high similarity to AtFLC, although the putative BrFLC1 protein contained ten more residues than AtFLC. The BrFLC genes were expressed ubiquitously, except that BrFLC3 was not expressed in roots. BrFLC1 and BrFLC2 showed stronger expression than BrFLC3 in unvernalized and vernalized Chinese cabbage. The expression levels of the three BrFLC genes were lower in an early-flowering Chinese cabbage, suggesting that the BrFLC transcript level was associated with flowering time. Constitutive expression of the BrFLC genes in Arabidopsis significantly delayed flowering, which was also observed in transgenic Chinese cabbage overexpressing BrFLC3. These results suggest that the BrFLC genes act similarly to AtFLC. Our results provide a technique for controlling flowering time in Chinese cabbage and other crops to produce high yields of vegetative tissues.

Development of primer sets that can verify the enrichment of histone modifications, and their application to examining vernalization-mediated chromatin changes in <i>Brassica rapa</i> L.

“…H3K27me3 addition is catalyzed by the Polycomb Repressive Complex 2 (PRC2) (Simon and Kingston, 2009). Chinese cabbage (Brassica rapa L. var capitata), which is a close relative of A. thaliana, is vernalization-sensitive and has four FLC paralogs whose expression is repressed by vernalization, similar to A. thaliana (Kim et al, 2007;Zhao et al, 2010).…”

Genetic and physiological bases for phenological responses to current and predicted climates

“…While nonetheless variably involved, MIKC C -type MADS box genes including FLC orthologues are implicated in integrating vernalization cues and repressing flowering or growth prechilling across a broad range of plant taxa including sugar beet, citrus and peach (Kim et al 2007;Reeves et al 2007;Li et al 2009;Zhang et al 2009). In cereals, however, not all genes involved in vernalization sensitivity fall in this family (Trevaskis et al 2007;Greenup et al 2009).…”

Nitrate or NaCl regulates floral induction in Arabidopsis thaliana

“…The FCA, FVE, FY, FLK, and FPA genes act as negative regulators of FLC and are involved in the autonomous pathway. When these genes were mutated, FLC expression increased, resulting in delayed flowering time (He & Amasino 2005;Kim et al, 2007). The photoperiod influences flowering through the photoperiod pathway.…”