Regulation of flowering by green light depends on its photon flux density and involves cryptochromes

Abstract

Photoperiodic lighting can promote flowering of long-day plants (LDPs) and inhibit flowering of short-day plants (SDPs). Red (R) and far-red (FR) light regulate flowering through phytochromes, whereas blue light does so primarily through cryptochromes. In contrast, the role of green light in photoperiodic regulation of flowering has been inconsistent in previous studies. We grew four LDP species (two petunia cultivars, ageratum, snapdragon and Arabidopsis) and two SDP species (three chrysanthemum cultivars and marigold) in a greenhouse under truncated 9-h short days with or without 7-h day-extension lighting from green light (peak = 521 nm) at 0, 2, 13 or 25 μmol m s or R + white (W) + FR light at 2 μmol m s . Increasing the green photon flux density from 0 to 25 μmol m s accelerated flowering of all LDPs and delayed flowering of all SDPs. Petunia flowered similarly fast under R + W + FR light and moderate green light but was shorter and developed more branches under green light. To be as effective as R + W + FR light, saturation green photon flux densities were 2 μmol m s for LDP ageratum and SDP marigold and 13 μmol m s for LDP petunia. Snapdragon was the least sensitive to green light. In Arabidopsis, cryptochrome 2 mediated promotion of flowering under moderate green light, whereas both phytochrome B and cryptochrome 2 mediated that under R + W + FR light. We conclude that 7-h day-extension lighting from green light-emitting diodes can control flowering of photoperiodic ornamentals and that in Arabidopsis, cryptochrome 2 mediates promotion of flowering under green light.

Anatomical observation and transcriptome analysis of buds reveal the association between the AP2 gene family and reproductive induction in hybrid larch (Larix kaempferi × Larix olgensis)

“…2017 ). These studies have shown that in the process of floral induction, plants need to first sense various environmental signals, such as light ( Meng and Runkle 2019 ) and temperature ( Verhage et al. 2014 ), combine them with the internal state ( Simpson 2004 ) and finally summarize the signal via floral integrators, such as FLOWERING LOCUS T ( FT ) ( Lee et al.…”

UV and Visible Spectrum LED Lighting as Abiotic Elicitors of Bioactive Compounds in Sprouts, Microgreens, and Baby Leaves—A Comprehensive Review including Their Mode of Action

“…In addition to physiological and morphological changes, light from different regions of the electromagnetic spectrum is also responsible for mediating genetic responses, which trigger the biosynthesis of chlorophylls, carotenoids, phenolic acids, flavonoids, anthocyanidins, anthocyanins, and glucosinolates (Figure 3). Specific photoreceptors (Figures 1 and 3), such as UV RESISTANCE LOCUS 8 (UVR8) as the main UV photoreceptor [44]; cryptochromes, phototropins, and zeitlupe family proteins as the UV-A/blue/green photoreceptors [45,46]; and phytochromes as red and far-red photoreceptors [47], are in charge of absorbing light signals that the plant receives. When UV/blue light activates photoreceptors, they activate transcription factors, which link with elongated hypocotyl-5 (HY5) as the main phytoene synthase (PSY) stimulator [48].…”

Modulation of Phototropin Signalosome with Artificial Illumination Holds Great Potential in the Development of Climate-Smart Crops

“…Although no photoreceptors are known yet to be able to sense green light, supplementation of green light in some plant species promotes growth. Green light also controls the flowering in ornamental plants like petunia, ageratum, chrysanthemum, and marigold [ 281 ]. Flowering in Arabidopsis under green light is mediated by CRY2 [ 281 ].…”

“…Green light also controls the flowering in ornamental plants like petunia, ageratum, chrysanthemum, and marigold [ 281 ]. Flowering in Arabidopsis under green light is mediated by CRY2 [ 281 ]. Short pulses of UV light not only increased the yield and content of bioactive compounds but also reduced the infection during the storage of potato, tomato, and almonds.…”