NUCLEAR FACTOR Y, Subunit C (NF-YC) Transcription Factors Are Positive Regulators of Photomorphogenesis in Arabidopsis thaliana

Abstract

Recent reports suggest that NF-Y transcription factors are positive regulators of skotomorphogenesis in Arabidopsis thaliana. Three NF-YC genes (NF-YC3, NF-YC4, and NF-YC9) are known to have overlapping functions in photoperiod dependent flowering and previous studies demonstrated that they interact with basic leucine zipper (bZIP) transcription factors. This included ELONGATED HYPOCOTYL 5 (HY5), which has well-demonstrated roles in photomorphogenesis. Similar to hy5 mutants, we report that nf-yc3 nf-yc4 nf-yc9 triple mutants failed to inhibit hypocotyl elongation in all tested light wavelengths. Surprisingly, nf-yc3 nf-yc4 nf-yc9 hy5 mutants had synergistic defects in light perception, suggesting that NF-Ys represent a parallel light signaling pathway. As with other photomorphogenic transcription factors, nf-yc3 nf-yc4 nf-yc9 triple mutants also partially suppressed the short hypocotyl and dwarf rosette phenotypes of CONSTITUTIVE PHOTOMORPHOGENIC 1 (cop1) mutants. Thus, our data strongly suggest that NF-Y transcription factors have important roles as positive regulators of photomorphogenesis, and in conjunction with other recent reports, implies that the NF-Y are multifaceted regulators of early seedling development.

The Arabidopsis thaliana Nuclear Factor Y Transcription Factors

“…NF-Y also functions in plant photomorphogenesis, especially in hypocotyl elongation (Leyva-González et al, 2012; Mu et al, 2013; Huang et al, 2015b; Myers et al, 2016). Previous genetic evidence showed that overexpression of AtNF-YA1 and NF-YA9 changed cell identity, and led to the hypocotyl becoming greener and swollen (Mu et al, 2013).…”

“…Previous genetic evidence showed that overexpression of AtNF-YA1 and NF-YA9 changed cell identity, and led to the hypocotyl becoming greener and swollen (Mu et al, 2013). In addition, overexpression of most NF-Y A subunits significantly reduced hypocotyl elongation (Leyva-González et al, 2012; Myers et al, 2016). However, the underlying molecular mechanism by which different A-type subunits of NF-Y regulate hypocotyl elongation requires further investigation.…”

“…Recent reports demonstrated that five NF-YC subunits (C1, C3, C4, C6, and C9) also function in hypocotyl elongation by interacting with HDA15 (Myers et al, 2016; Tang et al, 2016). The triple mutant of nf-yc3 nf-yc4 nf-yc9 displayed longer hypocotyls under blue, and red light conditions; therefore these NF-YC subunits positively regulate photomorphogenesis (Myers et al, 2016; Tang et al, 2016).…”

“…The triple mutant of nf-yc3 nf-yc4 nf-yc9 displayed longer hypocotyls under blue, and red light conditions; therefore these NF-YC subunits positively regulate photomorphogenesis (Myers et al, 2016; Tang et al, 2016). Although all three types of NF-Y subunits function in hypocotyl elongation, the underlying molecular mechanism by which NF-Y complexes regulate photomorphogenesis and hypocotyl elongation remains elusive.…”

In Silico Identification and Expression Analysis of Nuclear Factor Y (Nf-Y) Transcription Factors in Cucumber

“…In recent years, the NF-Y gene family has been identified and characterized in a number of plant species, including 23 NF-Y genes in barley (Hordeum vulgare) [12], 24 in Citrus grandis [13], 24 in peach (Prunus persica) [14], 25 in castor bean (Ricinus communis) [15], 35 in tea plant (Camellia sinensis) [16], 42 in sorghum (Sorghum bicolor) [17], 44 in banana (Musa acuminata) [18], and 51 in cassava (Manihot esculenta) [19]. Many reports have shown that NF-Y TFs are involved in various physiological and biochemical processes of plants, such as flowering [20,21], seed germination [22], hypocotyl elongation [23], photomorphogenesis [24], root development [25,26], and grain filling and endosperm development [27][28][29]. In addition, the NF-Y TFs have been found to play critical roles in responses to a variety of biotic and abiotic stresses [2,5,19], and the biological functions of some NF-Y TFs in regulating plants' responses to various abiotic stresses have been studied in detail.…”