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

Abstract

FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 (FKF1) is a blue-light receptor whose function is related to flowering promotion under long-day conditions in Arabidopsis thaliana. However, information about the physiological role of FKF1 in day-neutral plants and even the physiological role other than photoperiodic flowering is lacking. Thus, the FKF1 homolog SlFKF1 was investigated in tomato, a day-neutral plant and a useful model for plants with fleshy fruit. It was confirmed that SlFKF1 belongs to the FKF1 group by phylogenetic tree analysis. The high sequence identity with A. thaliana FKF1, the conserved amino acids essential for function, and the similarity in the diurnal change in expression suggested that SlFKF1 may have similar functions to A. thaliana FKF1. CONSTANS (CO) is a transcription factor regulated by FKF1 and is responsible for the transcription of genes downstream of CO. cis-Regulatory elements targeted by CO were found in the promoter region of SINGLE FLOWER TRUSS (SFT) and RIN, which are involved in the regulation of flowering and fruit ripening, respectively. The blue-light effects on SlFKF1 expression, flowering, and fruit lycopene concentration have been observed in this study and previous studies. It was confirmed in RNA interference lines that the low expression of SlFKF1 is associated with late flowering with increased leaflets and low lycopene concentrations. This study sheds light on the various physiological roles of FKF1 in plants.

Natural variation of FKF1 controls flowering and adaptation during soybean domestication and improvement

“…Indeed, OsFKF1 also interacts with OsGI and OsCDF1 in rice and activates the transcription of Heading date 1 ( Hd1 ), the rice CO ortholog, but OsFKF1 can also regulate the expression of rice‐specific genes such as Early heading date 2 ( Ehd2 ), Grain number , plant height , and heading date7 ( Ghd7 ), and Ehd1 (Han et al ., 2015). In addition to regulating flowering in long‐day and short‐day plants, FKF1 also influences flowering in tomato ( Solanum lycopersicum ), a day‐neutral plant (Shibuya et al ., 2021). However, the function of FKF1 in soybean is unclear.…”

Multi‐environment association study highlights candidate genes for robust agronomic quantitative trait loci in a novel worldwide Capsicum core collection

“…Lastly, FLAVIN‐BINDING , KELCH REPEAT , F‐BOX 1 ( SlFKF1 ) may impact lycopene concentrations in tomato (Shibuya et al., 2021), suggesting that the pepper homolog of the F‐box/kelch‐repeat protein At3g18720 underlying FCa‐P3.1 could impact FCa.…”

Genetic mapping identified three hotspot genomic regions and candidate genes controlling heat tolerance-related traits in groundnut

“…Similarly, in the second cluster (Cluster-2-Ah12), plausible candidate genes underlying the mapped QTLs were identified. Genes encoding flowering locus protein T ( arahy.9X2P9A ), FRIGIDA-like protein ( arahy.0C3V8Z ), and Kelch repeat F-box protein ( arahy.I7X4PC ) were found to be associated with regulation of flowering time ( Vieira et al., 2019 ; Jin et al., 2021 ; Shibuya et al., 2021 ). The F-box family protein ( arahy.S5CNIB ) family genes regulate antioxidant competence and accumulation of ROS under stress conditions ( An et al., 2019 ).…”