Characterization of Flowering-related Genes and Flowering Response in Relation to Blue Light in <i>Gypsophila paniculata</i>

Abstract

The flowering response to monochromatic light and flowering-related genes underlying this response need to be characterized to efficiently use light-emitting diodes for lighting culture. The flowering response to far-red light has been well studied in long-day cut flowers, but there have been few studies investigating the response to blue light. Flowering and the expression of the G. paniculata homologs of the FLOWERING LOCUS T and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 genes (GpFT, GpSOC1) were not previously promoted in Gypsophila paniculata, an important long-day cut flower, 'Bristol Fairy' under long-day conditions with blue light. In the present study, we found that flowering was promoted in another G. paniculata 'Million Star', under long-day conditions with blue light, suggesting that there is variation in G. paniculata's flowering response to blue light. Therefore, we analyzed the expression of GpFT and GpSOC1 in the 'Million Star'. The expression of GpFT and GpSOC1 was promoted with flowering in 'Million Star' under long-day conditions with blue light in contrast to 'Bristol Fairy'. We next analyzed the G. paniculata homologs (GpFKF1, GpGI) of FLAVIN-BINDING KELCH REPEAT F-BOX 1 and GIGANTEA genes, which participate in the flowering response to blue light. GpFKF1 and GpGI amino acid sequences were well conserved; gene expression showed a diurnal rhythm with different peaks under short-day and long-day conditions, as previously observed in Arabidopsis thaliana. GpFKF1 interacted with GpGI. There were no important differences in GpFKF1 or GpGI amino acid sequences between the two cultivars. Our results suggest that variation in the flowering response to blue light is associated with GpFT and GpSOC1, rather than GpFKF1 and GpGI.

Characterization of the FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 Homolog SlFKF1 in Tomato as a Model for Plants with Fleshy Fruit

“…FKF1 has three domains: LOV, F-box, and KELCH repeat. In A. thaliana , it forms a gene family with ZTL [ 20 ]. ZTL has been reported to have a different function from FKF1 and is involved in the decomposition of TIMING OF CAB EXPRESSION 1 (TOC1), one of the components of the circadian clock [ 36 , 37 , 38 ].…”

“…In this way, FKF1 plays an essential role in flowering promotion by blue light. As FKF1 in long-day plants, it is suggested that the Gypsophila FKF1 homolog is involved in flowering promotion, besides A. thaliana [ 20 , 21 ]. Reportedly, OsFKF1 promotes flowering in rice, a short-day plant, regardless of the photoperiod condition [ 22 ].…”

Effects of overnight radiation with monochromatic far-red and blue light on flower budding and expression of flowering-related and light quality-responsive genes in <I>Eustoma grandiflorum</I>

“…The effect of LED radiation treatment under dark conditions on the expression of FT and SOC1 or their homologs has been previously reported in Arabidopsis and G. paniculata Hori et al, 2011;Shibuya et al, 2017 . According to these studies, SOC1 expression was induced by far-red light, FT and SOC1 expressions were induced by blue light, and flowering was Days to flower budding after the start of LED radiation were shown.…”

“…In an earlier assessment, expression of the SOC1 homolog was found to be induced by far-red, and expression of neither the SOC1 homolog nor the FT homolog was induced by blue light in G. paniculata 'Bristol Fairy', in which flowering was promoted by far-red light but not blue light Hori et al, 2011 . A possible mechanism for this flowering response to blue light may be associated with variation in nucleotide sequences of the promoter region of the FT homolog, rather than with the function of the homologs of FKF1 and GI, which are involved in blue light signaling Shibuya et al, 2017 . Conversely, in the present study, changes in the levels of both EgFTL and EgSOC1L corresponded to the flowering response in FR and B, suggesting that a variable response of a common gene upstream of EgFTL and EgSOC1L to far-red and blue lights result in differences in flowering response to these wavelengths. In situ analysis of mRNA localization of these genes will be necessary to confirm their function.…”

The chromosome-level genome of Gypsophila paniculata reveals the molecular mechanism of floral development and ethylene insensitivity

“…Similarly, the over-accumulation of APETALA2 / PETALOSA ( AP2 / PET ) due to the defects of miR172 binding reduces the AG expression in the stamens, leading to the double flower phenotype likewise [ 9 , 10 ]. Although this model has been verified in many ornaments, it remains unclear whether it is true in G. paniculata [ 15 ].…”