GmFULa, a FRUITFULL homolog, functions in the flowering and maturation of soybean

Abstract

A FRUITFULL homolog GmFULa was cloned and found to play roles in the flowering and maturation of soybean. Soybean varieties exhibit great diversity in terms of flowering and maturation due to differences in their photoperiodic responses. The underlying mechanism remains unclear despite the fact that some upstream flowering genes have been studied. FRUITFULL (FUL) genes are one group of downstream flowering genes known to have major roles in reproductive transition, floral meristem identity, and floral organ identity. However, FUL homologs and their functions are poorly understood in soybean. Here, a soybean FUL homolog was cloned from the late-maturing photoperiod-sensitive soybean variety Zigongdongdou (ZGDD) and designated GmFULa. In ZGDD, GmFULa exhibited a terminal-preferential expression pattern, with higher expression in the root and shoot apices than in the middle parts. Diurnal rhythm analysis revealed that photoperiod regulates the GmFULa expression level but does not alter its diurnal rhythm. ZGDD was maintained under different photoperiod conditions (long day, LD; short day, SD; LD after 13 short days, SD13-LD) to assess GmFULa expression in newly expanded leaves and in the shoot apex. From this analysis, GmFULa expression was detected in the floral meristem, floral organs and their primordia; trifoliate leaves; and the inflorescence meristem, with the expression levels induced by SD and inhibited by LD. GmFULa expression was also associated with maturity in seven soybean varieties with different photoperiod sensitivities. Therefore, photoperiod conditions affect the expression level of GmFULa but not its diurnal rhythm. The gene plays pleiotropic roles in reproductive transition, flowering, and leaf development and is associated with maturity in soybean.

Natural variation in GmGBP1 promoter affects photoperiod control of flowering time and maturity in soybean

“…The amplitude and overall level of these genes mRNA increased more in SDs than that in LDs in WT. GmFULc (Glyma05g0738) , a homolog GmFULa MADS box transcription factor played roles in the flowering and maturation of soybean (Jia et al ., ). We analyzed the mRNA profiles of flowering promoters GmFT2a,GmFT5a , and GmFULc in the GmGBP1‐i‐4 soybean, whose transcript levels in the GmGBP1‐i‐4 soybean were much lower than those in WT in both SDs and LDs (Figure a–c), although all the transcript levels were very low in WT and GmGBP1‐i‐4 in LDs.…”

“…Of these, GmFT2a and GmFT5a , encoding components of ‘florigen’, coordinately controlled flowering in soybean (Kong et al ., ). GmFULa , a homolog of GmFULc (Glyma05g0738), promoted flowering and maturation in soybean (Jia et al ., ). Soybean GmFT1a delayed flowering by repressing the expression of GmFULa (Liu et al ., ).…”

Functional diversification of Flowering Locus T homologs in soybean: GmFT1a and GmFT2a/5a have opposite roles in controlling flowering and maturation

“…06g184200 and Glyma.13g092500), along with two sucrose metabolism homologs (Glyma.10g217900, Glyma.02g075000), were also down-regulated. Notably, the flowering repressor genes SHORT VEGETATIVE PHASE (SVP) (Andr es et al, 2014) (Glyma.08g068200) (Jung et al, 2012) and TERMINAL FLOWER1 (TFL1) (Hanzawa et al, 2005) (Glyma.10g071400) were up-regulated, but two flowering promoter gene FRUITFULL (FUL) homologs (Balanz a et al, 2014) (GmFULa: Glyma.06g205800; GmFULb: Glyma.04g159300) (Jia et al, 2015) were down-regulated. The expression of genes associated with floral meristem identity, including AGAMOUS (AG) (Favaro et al, 2003) (Glyma.15g088600), SEPALLATA 1 (SEP1) (Glyma.08g250700, Glyma.18g273500), SEPALLATA 3 (SEP3) (Glyma.05g148800, Glyma.08g105500, Glyma.…”

GsMAS1 Encoding a MADS-box Transcription Factor Enhances the Tolerance to Aluminum Stress in Arabidopsis thaliana

“…A gain-of function MADS-box gene, Dt2, determines stem growth by repressing Dt1 expression to promote early conversion of the shoot apical meristems into reproductive inflorescences [82]. Furthermore, GmAGL15 can enhance the development of somatic embryogenesis both in Arabidopsis and soybean by promoting a dedifferentiated state, and partially by the control of ethylene biosynthesis and response [76,[83][84][85]. Heterologous expression of GmMADS28 in tobacco resulted in abnormal flower organ development in transgenic tobacco plants and promoted the flowering and dwarfing of transgenic plants in advance [77].…”