Cloning And Functional Analysis Of BpJMJ18 Gene In Betula Platyphylla

JMJ(Jumonji)proteins can not only participate in the expression of many genes,but also regulate many chromatin activities.It is mainly involved in the regulation of histone demethylation and interaction with other chromatin modifications,thereby affecting the growth of organisms.Biological processes such as development,metabolism,and environmental response.In plants,the research of JMJ protein is mainly concentrated in model plants such as Arabidopsis thaliana and rice.Although not as extensive and in-depth in animal research,there have been studies that show that JMJ protein is involved in plant organ development,reproductive growth processes,and regulation.Hormonal response plays a very important role in many biological processes.In order to explore the function of the BpJMJ18(Betula platyphylla Jumonji 18)gene of Betula platyphylla,we used PCR technology to clone the BpJMJ18 gene and its promoter from Betula and transfer it to Betula.By observing the phenotypic changes of the transgenic plants,we investigated the BpJMJ18 gene in plant growth.Developmental functions.The main results are as follows:(1)The pUC19-35S::BpJMJ18-GFP vector was constructed and transformed into the haploid protoplasts of Populus tomentosa.The results showed that the BpJMJ18 gene was located in the nucleus,indicating that the BpJMJ18 gene biological functions in the nucleus..(2)The birch BpJMJ18 gene is 3165 bp in length and encodes 1055 amino acids.Through tissue-specific analysis of the BpJMJ18 gene,it was found that the gene has different expression in different tissue parts,and the expression level is higher in mature leaves,followed by root and also expressed in young leaves,primary stems?transitional stems and Apical bud,but relatively low expression levels in mature stems.(3)The pBI101-BpJMJ18pro::GUS vector was constructed,and the birch was transiently transformed and analyzed by GUS staining.It was found that the BpJMJ18 gene promoter can drive the expression of the GUS gene in the main root,lateral roots,root tips,leaf vascular bundles and tender stems of birch.At the same time,by analyzing and predicting the bioinformatics online software,it is known that the promoter sequence not only contains basic cis-acting elements such as TATA-box and CAAT-box,but also has light-responsive elements and various hormone response-related elements.The above results indicate that the gene may affect plant growth and development.(4)The pGBKT7-BpJMJ18 and pGADT7-BpJMJ18 yeast expression vectors were constructed.The self-activation verification of Y2Hgold-pGBKT7-BpJMJ18 showed that there was no self-activation of the BpJMJ18 gene.Therefore,yeast two-hybrid technology was used to co-transform BpJMJ18 and BpFLC to verify the interaction between Bp JMJ 18 and BpFLC proteins.The results show that BpJMJ18 and BpFLC can form a complex that activates the expression of four reporter genes,indicating that BpJMJ18 can participate in the regulation of flowering pathways and affect the reproductive growth of plants.(5)The BpJMJ18 gene was constructed into the plant expression vector pROKII and transformed into wild-type birch to obtain transgenic plants.The morphological observation and vernalization of the over-expressing plants showed that BpJMJ18 overexpressed transgenic lines had significant phenotypic changes during growth and development.Compared with the wild type,the transgenic plants were mainly short,ground diameter and stem nodes thickened,stem nodes lengthened and slow growth.After vernalization,the expression of BpJMJ18 increased.The above results indicate that the overexpression of BpJMJ18 leads to changes in the morphology of vegetative organs of the transgenic lines.