The Photoperiodic Flowering Time Regulator FKF1 Negatively Regulates Cellulose Biosynthesis

Abstract

Cellulose synthesis is precisely regulated by internal and external cues, and emerging evidence suggests that light regulates cellulose biosynthesis through specific light receptors. Recently, the blue light receptor CRYPTOCHROME 1 (CRY1) was shown to positively regulate secondary cell wall biosynthesis in Arabidopsis (Arabidopsis thaliana). Here, we characterize the role of FLAVIN-BINDING KELCH REPEAT, F-BOX 1 (FKF1), another blue light receptor and well-known photoperiodic flowering time regulator, in cellulose biosynthesis. A phenotype suppression screen using a cellulose deficient mutant cesa1 aegeus ,cesa3 ixr1-2 (c1,c3), which carries nonlethal point mutations in CELLULOSE SYNTHASE A 1 (CESA1) and CESA3, resulted in identification of the phenotype-restoring large leaf (llf) mutant. Next-generation mapping using the whole genome resequencing method identified the llf locus as FKF1. FKF1 was confirmed as the causal gene through observation of the llf phenotype in an independent triple mutant c1,c3,fkf1-t carrying a FKF1 T-DNA insertion mutant. Moreover, overexpression of FKF1 in llf plants restored the c1,c3 phenotype. The fkf1 mutants showed significant increases in cellulose content and CESA gene expression compared with that in wild-type Columbia-0 plants, suggesting a negative role of FKF1 in cellulose biosynthesis. Using genetic, molecular, and phenocopy and biochemical evidence, we have firmly established the role of FKF1 in regulation of cellulose biosynthesis. In addition, CESA expression analysis showed that diurnal expression patterns of CESAs are FKF1 independent, whereas their circadian expression patterns are FKF1 dependent. Overall, our work establishes a role of FKF1 in the regulation of cell wall biosynthesis in Arabidopsis.

Candidate Domestication-Related Genes Revealed by Expression Quantitative Trait Loci Mapping of Narrow-Leafed Lupin (Lupinus angustifolius L.)

“…It is pathogen-associated molecular pattern-induced gene with unknown function, putatively participating in jasmonic acid pathway [78]. Lup011739 encodes a homolog of GALACTURONOSYLTRANSFERASE-LIKE 10 , which is involved in cell wall organization and its expression is regulated by FLAVIN-BINDING KELCH REPEAT, F-BOX 1 ( FKF1 ), blue light receptor, and well-known photoperiodic flowering time regulator [79]. Lup011836 encodes general transcription factor IIH subunit 2 ( GTF2H2 ), performing basic functions in transcription and nucleotide excision repair of damaged DNA.…”

Transcriptomic Analysis of Changes in Gene Expression During Flowering Induction in Sugarcane Under Controlled Photoperiodic Conditions

“…For that to happen, CO needs to be induced by the GIGANTEA (GI) protein, which is itself repressed by the gene CYCLING DOF FACTOR 1 ( CDF1 ). Hence, the latter must be repressed by the combined action of genes FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 ( FKF1 ), GI , and PSEUDO-RESPONSE REGULATOR ( PRR ) 5, 7 , and 9 ( Huq et al, 2000 ; Imaizumi et al, 2005 ; Mizuno and Nakamichi, 2005 ; Seaton et al, 2015 ; Yuan et al, 2019 ). These PRR genes can be activated by expression of a MYB-related transcription factor called LATE ELONGATED HYPOCOTYL (LHY), which, in turn, is activated by photoreceptor transcription factor PHYTOCHROME INTERACTING FACTOR 3 (PHY3) while under red light exposure ( Martínez-García et al, 2000 ; Mizuno and Nakamichi, 2005 ; Lu et al, 2009 ).…”

Characterization of the FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 Homolog SlFKF1 in Tomato as a Model for Plants with Fleshy Fruit

“…Although FKF1 has been reported as a negative regulator of cellulose synthesis [ 25 ], there are still few reports on its physiological roles other than flowering promotion. FKF1 in A. thaliana is expressed in the vascular bundle sheath of leaves in relation to flowering control.…”