Flowering Times of Wild Arabidopsis Accessions From Across Norway Correlate With Expression Levels of FT, CO, and FLC Genes

Abstract

Temperate species often require or flower most rapidly in the long daylengths, or photoperiods, experienced in summer or after prolonged periods of cold temperatures, referred to as vernalization. Yet, even within species, plants vary in the degree of responsiveness to these cues. In Arabidopsis thaliana, CONSTANS (CO) and FLOWERING LOCUS C (FLC) genes are key to photoperiod and vernalization perception and antagonistically regulate FLOWERING LOCUS T (FT) to influence the flowering time of the plants. However, it is still an open question as to how these genes vary in their interactions among wild accessions with different flowering behaviors and adapted to different microclimates, yet this knowledge could improve our ability to predict plant responses in variable natural conditions. To assess the relationships among these genes and to flowering time, we exposed 10 winter-annual Arabidopsis accessions from throughout Norway, ranging from early to late flowering, along with two summer-annual accessions to 14 weeks of vernalization and either 8- or 19-h photoperiods to mimic Norwegian climate conditions, then assessed gene expression levels 3-, 5-, and 8-days post vernalization. CO and FLC explained both FT levels and flowering time (days) but not rosette leaf number at flowering. The correlation between FT and flowering time increased over time. Although vernalization suppresses FLC, FLC was high in the late-flowering accessions. Across accessions, FT was expressed only at low FLC levels and did not respond to CO in the late-flowering accessions. We proposed that FT may only be expressed below a threshold value of FLC and demonstrated that these three genes correlated to flowering times across genetically distinct accessions of Arabidopsis.

Characterization of Phytohormones and Transcriptomic Profiling of the Female and Male Inflorescence Development in Manchurian Walnut (Juglans mandshurica Maxim.)

“…In this study, several key genes related to photoperiod, GA pathway, floral pathway integrators, and flowering inhibitory factors were identified ( Figure 12 ). In A. thaliana , CONSTANS-like ( CO ) genes are essential for regulating the flowering time [ 36 ], and its homologous genes are also found in many flowering plants including Vigna radiata [ 37 ], Cannabis sativa [ 38 ], Brassica napus [ 39 ] and Populus trichocarpa [ 40 ]. In particular, CO can activate the transcription of FT , resulting in the transfer of the FT protein from leaf phloem to the shoot apex meristem, which can promote plant flowering [ 39 ].…”

Transcriptome and functional analysis revealed the intervention of brassinosteroid in regulation of cold induced early flowering in tobacco

“…Genes associated with the MADS-box transcription factor family (AGL21, AP1, AGL67, AGL7, and AG), which is a key regulator of the transition into flowering and flower development, were all upregulated in both XY1 and YY85 in response to the cold stress. The upregulation of these genes indicates an advanced flower transition and development in tobacco under the cold treatment, with HUA2 and Flowering locus C (FLC) genes acting as repressors in flower transitioning in Arabidopsis (Jali et al, 2014;Kinmonth-Schultz et al, 2021). It was demonstrated in this study that HUA2 was downregulated in both XY1 and YY85 in response to the cold stress as well as NtFLC expression inhibition (determined by qRT-PCR) in the two tobacco strains when cold stressed (Figure S3).…”

Two alternative splicing variants of a wheat gene TaNAK1, TaNAK1.1 and TaNAK1.2, differentially regulate flowering time and plant architecture leading to differences in seed yield of transgenic Arabidopsis

“…In Arabidopsis , flowering integration factor FLOWERING LOCUS T ( FT ) is involved in regulating the expression of transcription factors FLEAY ( LFY ) and APETALA1 ( AP1 ), the accumulation of appropriate amount of LFY and AP1 is the key to flower organ formation ( Corbesier et al., 2007 ; Mathieu et al., 2007 ). But FLOWERING LOCUS C ( FLC ) as a negative regulator of flowering inhibits the transcription of AtFT ( Helliwell et al., 2006 ; Krzymuski et al., 2015 ; Kinmonth-Schultz, 2021 ). To further elucidate the mechanism by which TaNAK1.1 and TaNAK1.2 affect flowering time, we investigated their effects on the above four hub genes regulating flowering, using TaNAK1.1- OE9 and TaNAK1.2- OE5 as representatives of TaNAK1.1- OEs and TaNAK1.2- OEs, respectively.…”