miR824-Regulated AGAMOUS-LIKE16 Contributes to Flowering Time Repression in Arabidopsis    

Abstract

The timing of flowering is pivotal for maximizing reproductive success under fluctuating environmental conditions. Flowering time is tightly controlled by complex genetic networks that integrate endogenous and exogenous cues, such as light, temperature, photoperiod, and hormones. Here, we show that AGAMOUS-LIKE16 (AGL16) and its negative regulator microRNA824 (miR824) control flowering time in Arabidopsis thaliana. Knockout of AGL16 effectively accelerates flowering in nonvernalized Col-FRI, in which the floral inhibitor FLOWERING LOCUS C (FLC) is strongly expressed, but shows no effect if plants are vernalized or grown in short days. Alteration of AGL16 expression levels by manipulating miR824 abundance influences the timing of flowering quantitatively, depending on the expression level and number of functional FLC alleles. The effect of AGL16 is fully dependent on the presence of FLOWERING LOCUS T (FT). Further experiments show that AGL16 can interact directly with SHORT VEGETATIVE PHASE and indirectly with FLC, two proteins that form a complex to repress expression of FT. Our data reveal that miR824 and AGL16 modulate the extent of flowering time repression in a long-day photoperiod.

PSEUDO RESPONSE REGULATORs stabilize CONSTANS protein to promote flowering in response to day length

“…In the FRET assay, high FRET signals between CO:YFP and each PRR:CFP protein were detected (Figs 5A and B, and EV5B). As negative controls, plasmids containing transgenes that express CFP or YFP protein fused to AGAMOUS LIKE 16 (AGL16), a member of the MADS‐box transcription factor family that was reported to localize to the nucleus, were transfected into protoplasts (Parenicova et al , 2003; Hu et al , 2014). Significantly lower FRET signals were observed between each PRR:CFP and AGL16:YFP or between AGL16:CFP and CO:YFP than between PRR:CFP and CO:YFP (Figs 5B and EV5B).…”

Genome‐wide analysis of MIKC‐type MADS‐box genes in wheat: pervasive duplications, functional conservation and putative neofunctionalization

“…a). This diversity of expression patterns and putative functions adds to the complex evolution of AGL17 ‐like genes, as genes from this subfamily have been implicated in various different functions, including root development, flowering time control, tillering, stomata development and stress response (Kutter et al ., ; Guo et al ., ; Puig et al ., ; Hu et al ., ; Xu et al ., ).…”

Phylogenomics reveals surprising sets of essential and dispensable clades of MIKCc‐group MADS‐box genes in flowering plants

“…A fourth superclade for which prominent phenotypes are rare but that has been strongly maintained during evolution is the clade of AGL17-like genes. The four AGL17-like genes in A. thaliana, AGL17, ANR1, AGL16 and AGL21, have different functions: AGL17 has been shown to promote flowering time (Han et al, 2008), ANR1 controls root architecture in response to nitrate (Zhang and Forde,'98) and AGL16 is involved in the regulation of stomata density on leaves and flowering time repression (Kutter et al, 2007;Hu et al, 2014). The function of AGL21 is not known yet.…”