PRMT6 physically associates with nuclear factor Y to regulate photoperiodic flowering in Arabidopsis

Abstract

The timing of floral transition is critical for reproductive success in flowering plants. In long-day (LD) plant Arabidopsis, the floral regulator gene FLOWERING LOCUS T (FT) is a major component of the mobile florigen. FT expression is rhythmically activated by CONSTANS (CO), and specifically accumulated at dusk of LDs. However, the underlying mechanism of adequate regulation of FT transcription in response to day-length cues to warrant flowering time still remains to be investigated. Here, we identify a homolog of human protein arginine methyltransferases 6 (HsPRMT6) in Arabidopsis, and confirm AtPRMT6 physically interacts with three positive regulators of flowering Nuclear Factors YC3 (NF-YC3), NF-YC9, and NF-YB3. Further investigations find that AtPRMT6 and its encoding protein accumulate at dusk of LDs. PRMT6-mediated H3R2me2a modification enhances the promotion of NF-YCs on FT transcription in response to inductive LD signals. Moreover, AtPRMT6 and its homologues proteins AtPRMT4a and AtPRMT4b coordinately inhibit the expression of FLOWERING LOCUS C, a suppressor of FT. Taken together, our study reveals the role of arginine methylation in photoperiodic pathway and how the PRMT6-mediating H3R2me2a system interacts with NF-CO module to dynamically control FT expression and facilitate flowering time.

Identification and Comparative Analysis of Genes and MicroRNAs Involved in the Floral Transition of the Xinjiang Early-Flowering Walnut (Juglans regia L.)

“…Recently, epigenetic factors have been a major driver for understanding the mechanisms associated with floral transition [1]. For example, various histone modifications have been revealed as being associated with the regulation of the flowering time in model plants [5,36,37]. In woody plants, it has been shown that the complex regulatory networks associated with floral transition are controlled by epigenetic mechanisms [38,39], implying that specific genes and epigenetic mechanisms have essential roles in Xinjiang precocious walnuts.…”

“…Diluted cDNA was used as a template for quantitative real-time (qRT)-PCR, which was performed using a SYBR Premix ExTaq II Kit on an ABI 7500 qPCR instrument (Applied Biosystems, Waltham, MA, USA). The 2 −∆∆Ct method was used to evaluate the relative expression levels of target genes in each sample [5]. All primers used in this study are shown in Table S1.…”

“…In the model plant Arabidopsis thaliana, this transition is regulated by the photoperiodic, vernalization, autonomous, and gibberellin pathways [1,3]. Crosstalk between those pathways in this critical reproductive stage is regulated by a network of flowering-related genes [1,[4][5][6]. For example, FLOWERING LOCUS C (FLC) functions as a flowering repressor in Arabidopsis; in contrast, FLOWERING LOCUS T (FT), or florigen, promotes flower initiation and is directly repressed by FLC under long-day photoperiod (LD) conditions [7][8][9][10].…”

GWAShub: A Web-based Resource to Democratize Genome-Wide Association Studies in Crop Plants

“…One of these genes, ( Ca_20004 /LOC101489300) was again found to encode for protein arginine N-methyltransferase 6 ( PRMT6 ). The PRMTs such as PRMT5/SKB1 and PRMT10 are known to regulate flowering time in plants by fine-tuning the expression of FLC, a major flowering repressor gene ( Wang et al 2007; Zhang et al 2021a ). Recently, AtPRMT6 has been shown to interact physically with a known flowering regulator Nuclear Factors YC3 (NF-YC3), NF-YC9, and NF-YB3 (Hou et al 2014; Siriwardana et al 2016).…”

“…Recently, AtPRMT6 has been shown to interact physically with a known flowering regulator Nuclear Factors YC3 (NF-YC3), NF-YC9, and NF-YB3 (Hou et al 2014; Siriwardana et al 2016). Further, PRMT6 is found to function redundantly with its two homologues PRMT4a and PRMT4b to regulate flowering time in Arabidopsis potentially by suppressing the expression of FLOWERING LOCUS C , which in turn suppresses FLOWERING LOCUS T ( FT ) ( Zhang et al 2021a ). Thus, taking the aforementioned evidence into account, PRMT6 identified in this study can be considered a potential candidate gene for regulating DTM in chickpea.…”