The Function And Mechanism Of Arabidopsis VQ3 Gene In Regulating Plant Growth And Development

VQ proteins is a class of plant-specific transcriptional regulatory cofactors involved in growth and development and response to environmental stress,their amino acid sequences are only highly conserved at the VQ domain.most Arabidopsis VQ genes contain no introns,the number of protein amino acid residues encoded by them is mostly less than 300.Studies have shown that proteins containing the VQ(Fxxx VQx LTG)domain interact with the WRKY protein,further analysis indicates that the conserved V and Q residues in the VQ domain are particularly important for interaction with WRKY.In addition,the VQ protein does not interact with all WRKY family members,but only with the WRKY proteins of the subfamily I and the subfamily IIc.After the VQ protein binds to the WRKY protein,a protein complex is formed to regulate the downstream target gene.This study carried out related research on the VQ3 gene whose function is unknown in Arabidopsis.The main results obtained are as follows:1.Functional analysis of the At VQ3 gene in ArabidopsisThe pCAMBIA2300GFP-AtVQ3 vector carrying the GFP reporter gene was constructed and then injected into the N.benthamiana using a transient expression system to find that the protein was localized in the nucleus.atvq3 mutant plants were obtained using the CRISPR/Cas9 gene editing system,and the F1 generation was phenotypically identified.It was found that the functional deletion mutant was dwarfed compared to the wild-type Arabidopsis plants and the rosette leaves were oval.2.Analysis of expression pattern of At VQ3 gene in ArabidopsisThe expression pattern of AtVQ3 gene in different organs showed that AtVQ3 was most expressed in fruit pods,and it was expressed more in leaves and roots of rosettes,and its expression in stems and stems was relatively low.The least expression.The expression pattern of At VQ3 gene under different treatment conditions showed that the expression of At VQ3 gene was induced by PEG,Na Cl,low temperature(4°C)and high temperature(37°C),especially when PEG treatment.3.Interaction analysis between VQ3 protein and WRKY proteinFirstly,the p GBKT7-VQ3 vector was constructed as a bait for yeast screening.38 WRKY proteins were screened and 5 WRKY proteins interacting with VQ3 were obtained,which were WRKY3,WRKY4,WRKY8,WRKY25 and WRKY33,respectively.The above five WRKY interaction proteins were verified by bimolecular fluorescence complementation assay(Bi FC).The results showed that they could interact with VQ3 and interact with each other in the nucleus.4.Functional analysis of At VQ3 candidate target gene(At2g18680)Firstly,the p CAMBIA2300GFP-At2g18680 vector carrying the GFP reporter gene was constructed,and then the N.benthamiana was injected into the tobacco using the transient expression system.The At2g18680 protein was localized in the cell membrane and nucleus,and then the at2g18680 gene-deficient mutant plant was obtained by using the CRISPR/Cas9 gene editing system.It was found that the growth and development of the mutant strain became sluggish,the growth period was significantly prolonged,and the leaf hypertrophy was irregular,which was shorter than that of the wild type Arabidopsis.5.Expression pattern analysis of At VQ3 candidate target gene(At2g18680)The expression pattern of At2g18680 gene showed that At2g18680 had the highest expression in stem leaves,and the expression level of At2g18680 was relatively high in rosette leaves and pods and stems,and the expression level was the lowest in flowers.In addition,the expression of At2g18680 gene was also induced by PEG,Na Cl,high temperature(37°C)and low temperature(4°C),especially at low temperature(4°C).