RESUMEN
Flowering time and maturity are crucial agronomic traits that affect the regional adaptability of soybean plants. The development of soybean cultivars with early maturity adapted to longer days and colder climates of high latitudes is very important for ensuring normal ripening before frost begins. FUL belongs to the MADS-box transcription factor family and has several duplicated members in soybeans. In this study, we observed that overexpression of GmFULc in the Dongnong 50 cultivar promoted soybean maturity, while GmFULc knockout mutants exhibited late maturity. Chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) revealed that GmFULc could bind to the CArG, bHLH and homeobox motifs. Further investigation revealed that GmFULc could directly bind to the CArG motif in the promoters of the GmZTL3 and GmZTL4 genes. Overexpression of GmZTL4 promoted soybean maturity, whereas the ztl4 mutants exhibited delayed maturity. Moreover, we found that the cis element box 4 motif of the GmZTL4 promoter, a motif of light response elements, played an important role in controlling the growth period. Deletion of this motif shortened the growth period by increasing the expression levels of GmZTL4. Functional investigations revealed that short-day treatment promoted the binding of GmFULc to the promoter of GmZTL4 and inhibited the expression of E1 and E1Lb, ultimately resulting in the promotion of flowering and early maturation. Taken together, these findings suggest a novel photoperiod regulatory pathway in which GmFULc directly activates GmZTL4 to promote earlier maturity in soybean.
RESUMEN
Flowering is an important developmental process from vegetative to reproductive growth in plant; thus, it is necessary to analyze the genes involved in the regulation of flowering time. The MADS-box transcription factor family exists widely in plants and plays an important role in the regulation of flowering time. However, the molecular mechanism of GmFULc involved in the regulation of plant flowering is not very clear. In this study, GmFULc protein had a typical MADS domain and it was a member of MADS-box transcription factor family. The expression analysis revealed that GmFULc was induced by short days (SD) and regulated by the circadian clock. Compared to wild type (WT), overexpression of GmFULc in transgenic Arabidopsis caused significantly earlier flowering time, while ful mutants flowered later, and overexpression of GmFULc rescued the late-flowering phenotype of ful mutants. ChIP-seq of GmFULc binding sites identified potential direct targets, including TOPLESS (TPL), and it inhibited the transcriptional activity of TPL. In addition, the transcription levels of FLOWERING LOCUS T (FT), SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) and LEAFY (LFY) in the downstream of TPL were increased in GmFULc- overexpressionArabidopsis, suggesting that the early flowering phenotype was associated with up-regulation of these genes. Our results suggested that GmFULc inhibited the transcriptional activity of TPL and induced expression of FT, SOC1 and LFY to promote flowering.
Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Glycine max/genética , Plantas Modificadas Genéticamente/genética , Relojes Circadianos/genética , Flores/genética , Regulación del Desarrollo de la Expresión Génica/genética , Regulación de la Expresión Génica de las Plantas/genética , Fotoperiodo , Hojas de la Planta/genética , Reproducción/genéticaRESUMEN
This study explores the impact of environmental regulations on the clean product exports of firms and the mechanism of this impact from the dual perspectives of the extensive and intensive margins. It uses matched micro data and aims to explore the clean road to international trade. According to the benchmark regression, environmental regulations improve the export intensity of clean products. However, their impact on the export probability of clean products is not significant. That is, environmental regulations promote the intensive margin of enterprise clean product exports but do not promote the extensive margin of enterprise clean product exports. The mechanism analysis shows that the cost effect is an important way for environmental regulations to promote the cleanliness of export products. However, the channel of technological innovation is not verified. In addition, compared with command-and-control and voluntary public policy tools, market-inspired environmental regulations have a stronger promoting effect on the cleanliness of export enterprises. This study provides microevidence and a policy basis for improving the environmental policy system and for the sustainable development of international trade.