Isolation and Expression Profiling of a CONSTANS-Like Gene and Two FLOWERING LOCUS T-Like Genes from Spinacia oleracea L.

Abstract

Spinach (Spinacia oleracea L.) develops leaf rosettes under short-day conditions, and starts reproductive growth including bolting and flowering under long-day conditions. Japanese people prefer Oriental spinach that bolts easily with a shorter photoperiod than European spinach. This is one of the main reasons that Oriental spinach is difficult to grow year-round. In order to understand spinach flowering mechanisms and obtain knowledge for spinach breeding, we isolated one CONSTANS-like (COL) and two FLOWERING LOCUS T (FT) homologs, which are key components of photoperiodic regulation of flowering time, from a Japanese cultivar. The expression of SoCOL1 showed diurnal rhythm with the highest expression at the end of the dark cycle. This diurnal rhythm is similar to the expression of BvCOL1 from sugar beet (Beta vulgaris), whose flowerpromoting effect was observed when overexpressed in Arabidopsis. Phylogenetic analysis showed that SoCOL1 is the closest homolog of BvCOL1, suggesting that SoCOL1 is an ortholog of BvCOL1. SoFT1 and SoFT2 are closely related to BvFT1 and BvFT2, respectively. The expression of SoFT1 and SoFT2 were induced in advance of flower bud formation after changing the photoperiod, but the expression level of SoFT1 was much lower than SoFT2. Currently, we are speculating that SoFT2 is a flower-promoting factor of spinach, and that SoFT1 has a role in light signaling because the expression of SoFT1 showed a diurnal rhythm.

Multi-omics sequencing provides insight into floral transition in Catalpa bungei. C.A. Mey

“…Therefore, floral transition is guaranteed [ 87 , 88 ]. Interestingly, several studies have revealed that DELLA regulates hypocotyl elongation by interacting with PIFs [ 75 ], contributing to floral transition by interacting with SPL [ 7 ], FD [ 10 ] and SOC1 [ 24 , 62 ]. SOC 1 plays an important role in regulating floral transition by integrating signals involved in all pathways, as well as interacting with many other genes to regulate floral transition [ 24 ].…”

“…Great progress has been made in understanding the factors that trigger floral transition [ 4 ]. A set of floral transition-related genes, such as SPL ( Squamosa-promoter binding protein-like ) [ 5 – 7 ], TOC ( Timing of cab expression 1 ) [ 8 ], LUX ( Luxarrhythmo ) [ 8 ], PIF ( Phytochrome interacting factor ) [ 9 ], CO ( constans ) [ 10 ], FRI ( Frigida ) [ 11 ], GA20ox ( GA20oxidases ) [ 7 ], GA3ox ( GA3oxidases ) [ 12 ], SOC1 ( Suppressor of overexpression of constans 1 ) [ 13 ], have been detected, in addition to others [ 14 , 15 ]. These genes are mainly categorized into five major pathways that regulate floral transition, including the age pathway, photoperiod and circadian clock pathway, autonomous pathway, vernalisation pathway and GA pathway [ 4 ].…”

Quantitative Trait Locus Mapping and Identification of Candidate Genes Controlling Bolting in Spinach (Spinacia oleracea L.)

“…It is typically consumed as a fresh, cooked or canned vegetable ( Morelock and Correll, 2008 ; Ma et al, 2016 ). The reproductive process usually begins with bolting (the elongation of the stem) ( Mutasa-Göttgens et al, 2010 ), which leads to decreased yields and low quality ( Abe et al, 2014 ). Spinach is easily influenced by the photoperiod ( Chun et al, 2000b ), and bolts in spring ( Tang et al, 2018 ).…”

Management of the Tolerance to Bolting for Spinach (Spinacia Oleracea L.): Retrospect and Prospects

“…The onset and development of the reproductive phase involve the distinct and sequential processes of bolting followed by flowering Mutasa-Göttgens, et al [7]. After transition to the reproductive stage with flowering and bolting, spinach loses its value as an agricultural product, becoming bitter and hard Abe, et al [8]. Bolting is an important agronomy trait to consider in relation to developing spinach cultivars for year-round production, because of its sensitivity to photoperiod Chun, et al [9].…”

“…Regulations of spinach flowering and bolting by photoperiod and gibberellin have been reported Zeevaart, et al [20,26]; Lee & Zeevaart, 2002, Lee, et al [27,28]. To understand spinach floweringand bolting mechanisms at a genetic level, one CONSTANS-like (COL) and two FLOWERING LOCUS T (FT) homologs were isolated and characterized, which are known to be key factor of the flowering pathway in many plants Abe, et al[8]. Detecting the mechanisms to regulate pathways in control of spinach bolting could promote the related genetic discovering.…”