EjFRI, FRIGIDA (FRI) Ortholog from Eriobotrya japonica, Delays Flowering in Arabidopsis

Abstract

In the model species Arabidopsis thaliana, FRIGIDA (FRI) is a key regulator of flowering time and can inhibit flowering without vernalization. However, little information is available on the function in the Rosaceae family. Loquat (Eriobotrya japonica) belongs to the family Rosaceae and is a distinctive species, in which flowering can be induced without vernalization, followed by blooming in late-autumn or winter. To investigate the functional roles of FRI orthologs in this non-vernalization species, we isolated an FRI ortholog, dubbed as EjFRI, from loquat. Analyses of the phylogenetic tree and protein sequence alignment showed that EjFRI is assigned to eurosids I FRI lineage. Expression analysis revealed that the highest expression level of EjFRI was after flower initiation. Meanwhile, EjFRI was widely expressed in different tissues. Subcellular localization of EjFRI was only detected to be in the nucleus. Ectopic expression of EjFRI in wild-type Arabidopsis delayed flowering time. The expression levels of EjFRI in transgenic wild-type Arabidopsis were significantly higher than those of nontransgenic wild-type lines. However, the expression levels of AtFRI showed no significant difference between transgenic and nontransgenic wild-type lines. Furthermore, the upregulated AtFLC expression in the transgenic lines indicated that EjFRI functioned similarly to the AtFRI of the model plant Arabidopsis. Our study provides a foundation to further explore the characterization of EjFRI, and also contributes to illuminating the molecular mechanism about flowering in loquat.

A WRKY Transcription Factor, EjWRKY17, from Eriobotrya japonica Enhances Drought Tolerance in Transgenic Arabidopsis

“…Total RNA extraction, first-strand cDNA synthesis, and qPCR were performed as described previously [ 47 ]. The 5′ and 3′ RACE clones were amplified with the SMARTer RACE 5′/3′ Kit (Clontech, Mountain View, CA, USA) and 3′-Full RACE Core Set (TAKARA, Shiga, Japan).…”

An Integrative Analysis of Transcriptome, Proteome and Hormones Reveals Key Differentially Expressed Genes and Metabolic Pathways Involved in Flower Development in Loquat

“…), an important tropical and subtropical fruit tree species that belongs to the family Rosaceae and is broadly cultivated in many countries such as China, Japan, Spain, the United States, and Australia [1]. Reproductive development of loquat is a continuous process that is not interrupted by winter dormancy [2,3]. Moreover, almost all shoots that develop on the loquat tree are flowering shoots, whereas the number of panicles remains practically constant every year [2].…”

Gibberellin Induced Transcriptome Profiles Reveal Gene Regulation of Loquat Flowering

“…Although the flowering habit of loquat is very special, there are few reports about it. So far, several flowering-related genes have been cloned from cultivated loquat, including EjAP1, EjAP3, EjFT, EjLFY, EjSOC1, EjSVP, EjSPL, EjFRI and EjTFL1 (Esumi et al, 2005;Liu et al, 2013Liu et al, , 2017Reig et al, 2017;Jiang et al, 2019a,b,c;Chen W. et al, 2020). EdCO, EdGI, EdFT and EdFD have been cloned from wild loquat Eriobotrya deflexa Nakai forma koshunensis Zhang et al, 2019).…”