| Flowering is a process of transition from vegetative to reproductive growth in higher plants.Only flowering at the proper time can ensure the normal development of plant individuals and progeny reproduction.Therefore,the study on the regulation of flowering period is of great value.At least four flowering regulatory pathways have been identified in Arabidopsis thaliana,namely photoperiod pathway,vernalization pathway,autonomous pathway and gibberellin pathway.These flowering pathways regulate flowering time by controlling the expression intensity of integrators commonly controlled by several flowering pathways.In Arabidopsis thaliana,it has been found that FLOWERING LOCUS C（At FLC）is the most critical flowering determinant in this flowering regulatory network,while At SOC I,At FT,and At LFY are important flowering integration factors.In addition,in the autonomic and vernalization pathways,At FLC inhibits the expression of At SOC I promoter and At FT by binding to the region of the CAr G-box structure,thereby delaying plant flowering.Chinese cabbage（Bassica rapa L SSP.Pekinensis）is a brassica vegetable of cruciferae,and is one of the most important vegetable crops in northern China.Compared with Arabidopsis thaliana,there are multiple copies of homologous genes in the Chinese cabbage genome.Four,five,and four homologous gene copies of BraFLCs,Bra SOC Is and BraFTs have been identified in the flowering regulation pathway of Chinese cabbage,but their functional differentiation has not been well understood.As a third gas signaling molecule,hydrogen sulfide（H2S）is just beginning to be studied in plants.H2S is involved in a variety of plant growth and development regulation and abiotic stress response processes,and the main mechanism of H2S is sulfhydrylation modification of proteins.It was found that H2S could significantly promote the flowering of Chinese cabbage.This article is based on the following The functional differentiation of BraFLCs,Bra SOC Is and BraFTs,the effect of H2S on the regulation of the combination pattern of BraFLCs and BraFTs were investigated in vegetables.The experimental results show that:（1）Four BraFTs homologous genes in Chinese cabbage contained six CC（A/T）6AG binding sites,and the results of binding test between four BraFLCs and six BraFTs promoter probes showed that all BraFLCs proteins were bound to all six CAr G-box probes,This binding experiment showed that the transcription factor BraFLCs can act by binding downstream genes;（2）Only BraFLC 1 and BraFLC 3 in BraFLCs could undergo sulfur sulfhydrylation modification,which is consistent with our previous experimental results.Moreover,the binding ability of the modified BraFLC 3protein to part of the BraFTs probes disappeared,indicating that H2S signal may effect the binding ability of downstream genes through the modification of BraFLCs;（3）The eukaryotic expression vector pBraSOC Is::GUS has been constructed.Arabidopsis thaliana pBraSOC I 2::GUS,pBraSOC I 3::GUS,pBraSOC I 4::GUS still need to be further identified,and pBraSOC I 1::GUS,pBraSOC I 5::GUS are still in transformation.Further systematic GUS staining experiments still need to be completed later;In summary,physiological concentration of H2S can modify the sulfur mercaptoylation of transcription suppressor BraFLCs and affect the binding mode of BraFLC 3 and some BraFTs promoter probes.Therefore,it Is speculated that H2S affects BraFLCs through sulfur mercaptoylation,affects the binding mode of Bra SOC Is and BraFTs,and thus affects the expression of downstream genes to promote flowering.The analysis of the specific expression characteristics of promoter in the system is still to be completed. |
