AGAMOUS‐LIKE 17, a novel flowering promoter, acts in a FT‐independent photoperiod pathway

Abstract

SummaryThe photoperiod pathway is a genetically conserved pathway that affects flowering in distantly related angiosperms. Here we report a novel flowering promoter AGAMOUS-LIKE 17 (AGL17) acting in the photoperiod pathway of Arabidopsis. AGL17 transcripts were detectable in various plant organs with the highest expression in the root. Under long-day conditions, expression of AGL17 gradually increased in the aerial part of seedlings during the floral transition. Overexpression of AGL17 caused early flowering, while loss of function of AGL17 exhibited late flowering, particularly under long days. Analysis of AGL17 expression in various flowering-time mutants showed that its transcripts were significantly reduced in the photoperiod pathway mutant co-1. Correspondingly, AGL17 expression was upregulated in transgenic plants overexpressing CONSTANS (CO) and also when CO activity was induced by light. Genetic analysis further showed that overexpression of AGL17 could partially suppress the late flowering of co-1. These results suggest that AGL17 acts to promote flowering and is positively controlled by the photoperiod pathway regulator CO. In contrast, another target of CO, FLOWERING LOCUS T (FT), did not affect AGL17 expression, and vice versa. The expression of two floral meristem identity genes LEAFY (LFY) and APETALA1 (AP1) decreased in agl17-1, while LFY and AP1 could be rapidly induced by AGL17 using a functional estradiol-inducible system. These findings indicate that AGL17 ultimately promotes flowering via regulation of LFY and AP1.

Genome-Wide Identification of the MIKC-Type MADS-Box Gene Family in Gossypium hirsutum L. Unravels Their Roles in Flowering

“…To explore the molecular mechanisms that impact the flowering time in transgentic lines, qRT-PCR was used to detect the expression of flowering-related genes in transgentic lines. LFY is a flowering integration promoting factor, AGL17 can positively regulate the expression of LFY gene (Han et al, 2008), and CO is a photoperiod pathway regulator, AGL17 acts downstream of CO (Han et al, 2008). As shown in Figure 7, the expression levels of LFY gene in lines 35S-L1 and 35S-L3 were three times higher than in the wild type.…”

“…Under long-day conditions, the overexpression of AtAGL17 causes early flowering (Han et al, 2008). As the largest subgroup of the GhMIKC C family, one member of the AGL17s, GhAGL17.9 , was overexpressed in Arabidopsis to explore its biological functions.…”

“…LFY overexpression can prematurely cause plant development and accelerate blossoming processes (Nilsson et al, 1998; Dornelas and Amaral, 2004). AGL17 targets LFY to promote flowering (Han et al, 2008). SOC1 encodes a MIKC protein, a floral pathway integrator, which is regulated by a variety of flower signaling pathways (Lee et al, 2000; Wang et al, 2009; Ding et al, 2013).…”

Enhanced Photosynthesis and Carbon Metabolism Favor Arsenic Tolerance inArtemisia annua, a Medicinal Plant as Revealed by Homology-Based Proteomics

“…It is quite likely that the early onset of flowering and the increased number of florets and capitulum size in As treated A. annua were due to the significant accumulation of LEAFY- (LFY-) like protein, a plant-specific transcription factor involved in growth, development [53], and flowering in Arabidopsis [54], first time observed under As stress. Furthermore, the red coloration of the leaf apex and shoots of 150  μ M As treated A. annua plants could be due to transient accumulation of anthocyanin pigments below the leaf epidermis.…”

Expression profiling of certain MADS-box genes in Arabidopsis thaliana plant treated with silver nanoparticles

“…AGL24, RSB1, AGL72, AGL17 and XAL1 genes play a role in the regulation of flowering time as activators of flowering (Michaels et al 2003;Hsu et al 2003;Han et al 2008;Tapia-López et al 2008;Dorca-Fornell et al 2011). AGL16, AGL21, SHP1 and XAL1 have specific functions during root morphogenesis with AGL17 (Burgeff et al 2002;TapiaLópez et al 2008;Moreno-Risueno et al 2010).…”