Genetic And Phenotypic Analysis Of Arabidopsis SOP24 Mutant

Polycomb group(Pc-G)suppresses the transcription of genes by depositing H3K27me3 marker in Arabidopsis.Most genes in plants could be marked by the Pc-G family,It plays a crucial regulatory role in different stage of growth and development.The Trithorax group(Trx-G)has H3K4 me2/3 activity,which can activate gene expression and functionally functional antagonize the Pc-G family.At present,there are few studies on the Trx-G family,and the family members have not been fully discovered.Therefore,the original purpose of the project to find new members of the Trx-G family that can inhibit the function of the Pc-G family and further improve the epigenetics mechanism.CLF is a component of PRC2,a core component of Pc-G.In this experiment,we used the material SOP24(Suppress of Polycomb 24)inserted by Agrobacterium T-DNA in clf-50 background.SOP24 was screened to partially suppress the phenotype of the clf mutant,and T-DNA was inserted into the TIR3(AT3G02260)gene by sequencing.clf-50 is a deletion mutant of CLF gene,with obvious phenotype,including leaf curly,early flower,long root,more lateral roots and so on.However,we found that SOP24 exhibited a phenotype of slightly curled leaves,late flowers,and normal root length.Therefore,this experiment will focus on the reasons for the change of SOP24 phenotype.The SOP24 mutant was obtained through forward genetic screening,and back-crossed with wild type to obtain a completely new unreported tir3 mutant,named tir3-24.We verified that its phenotypic separation is compatible with genotype.The CLF gene inhibits the transcription of the auxin transporter PIN1.Therefore,in the clf mutant,the PIN1 transcription level is increased and the auxin level is increased.tir3 mutant will lead to a decrease in polar auxin transport and a decreased level of auxin.Moreover,the leaf and root phenotypes in SOP24 are restored.In the clf mutant,the ectopic expression of the AG and the flowering time promoting genes FT and SOC1 are high expression,which response for the early flowing phenotype of the clf mutant However,in the tir3 mutant,the flowering time suppressor gene FLC transcription level is higher,Suggest SOP24 is affected by these two reasons,the flowering time rescued.In addition,we also crossed the clf mutant with some auxin-related mutants auxl-7,from the experiment observed the weak curly leaf phenotype similar to SOP24 in the auxl-7 clf-28 double mutant,further explore the relationship between auxin and leaf curly.