Melatonin mediates the stabilization of DELLA proteins to repress the floral transition in Arabidopsis

Abstract

Precise floral transition from vegetative growth phase to reproductive growth phase is very important in plant life cycle. In flowering genetic pathways, DELLA proteins are master transcriptional regulators of gibberelic acid (GA) pathway, and FLOWERING LOCUS C (FLC) is a core repressor of vernalization pathway as well as downstream of DELLAs. As a crucial messenger in plants, the possible involvement of melatonin (N-acetyl-5-methoxytryptamine) in flowering and underlying molecular mechanism are unknown in Arabidopsis. In this study, we found that exogenous melatonin treatment delayed floral transition in Arabidopsis. Exogenous melatonin treatment conferred protein stabilizations of DELLAs [REPRESSOR of ga1-3 (RGA) and RGA-LIKE3 (RGL3)], without regulating the transcripts of DELLAs and endogenous GA level. Notably, exogenous melatonin delayed plant flowering and DELLA-activated transcripts of FLC were alleviated in della mutants, and those were exacerbated in DELLA overexpressing plants. Taken together, this study provides direct link between melatonin and floral transition, and indicates the novel involvement of DELLAs-activated FLC in melatonin-mediated flowering in Arabidopsis.

Exogenous Melatonin Improves Plant Iron Deficiency Tolerance via Increased Accumulation of Polyamine-Mediated Nitric Oxide

“…Although several physiological roles of melatonin in plants have been characterized [5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22], regulation of plant Fe deficiency responses and Fe homeostasis by melatonin have not been reported. The present study provided evidence that exogenous melatonin conferred improved plant adaptation to Fe deficiency by promoting Fe remobilization in Arabidopsis plants.…”

“…In animals, melatonin is involved in regulating diverse physiological processes, such as biorhythms, seasonal reproduction, antioxidant functions, and immune stimulation [2,3,4]. Recently, much attention has also been attracted to study the functions of melatonin in plants; it acts as a crucial messenger molecule to regulate lateral root formation [5], flowering [6], fruit ripening [7], and leaf senescence [8]. Apart from its roles in plant growth and development, melatonin can improve the tolerance of plants to adverse environments [9,10,11,12,13].…”

Melatonin Regulates Root Meristem by Repressing Auxin Synthesis and Polar Auxin Transport in Arabidopsis

“…Numerous studies have shown that melatonin is widely involved in regulating both the biotic and abiotic stress tolerance, biological rhythms, plant growth and development (seed germination, root architecture, shoot development, plant flowering, fruit ripening, and yield; Kang et al, 2010; Okazaki et al, 2010; Wang et al, 2012; Byeon et al, 2013, 2014b; Yin et al, 2013; Zhang et al, 2013, 2014; Zhao et al, 2013; Byeon and Back, 2014a; Shi and Chan, 2014; Weeda et al, 2014; Shi et al, 2015a,b,c,d,e, 2016). …”

Physiological response of plants to polyethylene glycol (PEG-6000) by exogenous melatonin application in wheat

“…Melatonin, a growth regulator identified in higher plants in 1995, has been reported successively on regulating various biological processes, including root formation , flowering and fruit ripening (Shi et al, 2016), and leaf senescence (Wang et al, 2012 a). In particular, melatonin can trigger the plant defense responses against abiotic stress, playing an important role in improving the tolerance of plants to adverse environment (Li et al, 2012;Turk et al, 2014;Meng et al, 2015;Bałabusta et al, 2016).…”