Soybean adaption to high‐latitude regions is associated with natural variations of GmFT2b, an ortholog of FLOWERING LOCUS T

Abstract

Day length has an important influence on flowering and growth habit in many plant species. In crops such as soybean, photoperiod sensitivity determines the geographical range over which a given cultivar can grow and flower. The soybean genome contains ~10 genes homologous to FT, a central regulator of flowering from Arabidopsis thaliana. However, the precise roles of these soybean FTs are not clearly. Here we show that one such gene, GmFT2b, promotes flowering under long‐days (LDs). Overexpression of GmFT2b upregulates expression of flowering‐related genes which are important in regulating flowering time. We propose a ‘weight’ model for soybean flowering under short‐day (SD) and LD conditions. Furthermore, we examine GmFT2b sequences in 195 soybean cultivars, as well as flowering phenotypes, geographical distributions and maturity groups. We found that Hap3, a major GmFT2b haplotype, is associated with significantly earlier flowering at higher latitudes. We anticipate our assay to provide important resources for the genetic improvement of soybean, including new germplasm for soybean breeding, and also increase our understanding of functional diversity in the soybean FT gene family.

Photoperiod and Vernalization Control of Flowering-Related Genes: A Case Study of the Narrow-Leafed Lupin (Lupinus angustifolius L.)

“…In the economically most important legume crop worldwide, a soybean, Glycine max, mutations in FT genes are responsible for at least three loci conferring early/late flowering, namely E9 (GmFT2a), E10 (GmFT4), and qDTF-J1 (GmFT5a) (Takeshima et al, 2016;Zhao et al, 2016;Samanfar et al, 2017). Moreover, natural variations of the GmFT2b sequence are associated with soybean adaption to high−latitude regions (Chen et al, 2020). In M. truncatula, vernalization responsiveness and early flowering are conferred by the FTa1 gene, whereas photoperiod response by the FTb gene (Laurie et al, 2011;Putterill et al, 2013).…”

Soybean AP1 homologs control flowering time and plant height

“…Clustered regularly interspaced short palindromic repeats (CRISPR) -CRISPR-associated protein 9 (Cas9) mutagenesis of GmFT2a and GmFT5a delayed flowering, potentially leading to expanded regional adaptability in soybean (Cai et al 2020). Recently, another ortholog of FLOWERING LOCUS T, GmFT2b, has been reported to improve soybean adaption to high-latitude regions (Chen et al 2020).…”

Quantitative Control of Early Flowering in White Lupin (Lupinus albus L.)

“…In pea, FT genes showed transcriptional sub-functionalization and one of those, FTa1 , underlies the pea GIGAS locus, essential for flowering under long-days and positive for flowering under short-days [ 50 ]. In soybean, which is a vernalization independent species, three genes belonging to FTa and FTc clades confer just the photoperiod response [ 52 , 53 , 54 , 55 ]. In chickpea, altered expression of a cluster of three FT genes ( FTa1 , FTa2 and FTc ) is associated with early phenology [ 56 ], however, a major QTL for vernalization response in this species is localized in a genome region lacking any FT homolog [ 57 ].…”