Functional Identification Of Arabidopsis Microfilament Binding Protein AtVLN1 Regulating Cell Growth In Different Organsand Tissues

Microfilament binding protein villin?VLN?is a member of the gelsolin superfamily.The dynamic changes of microfilaments are closely related to the growth and development of the plant's root hair cells.Microfilament desclusion causes increased root hair length and also causes swelling of the root hair.Microfilament not only regulates the length of root hair,but also participates in maintaining the polarity of root hair cells.In other words,microfilaments play an important role in the growth of root hair cells.At present,some microfilament binding proteins have been involved in the growth of root hair cells,but there are still some molecular mechanisms that regulate the growth of root hair cells.AtVLN1 is a member of the VLN family of Arabidopsis thaliana.AtVLN1 regulates the bundle formation of microfilaments.At present,there is no research on the function ofAtVLN1 in vivo.Therefore,the function of AtVLN1 on the cell growth of different organswas identified.In this experiment,Arabidopsis wild-type,two mutants?Atvln1-1 and Atvln1-2?and AtVLN1 restore mutation?AtVLN1-COM?were used as experimental materials.TheAtVLN1 promoter was cloned and the GUS expression vector was constructed to successfully screen P_AtVLN1-GUS homozygous plants.The AtVLN1 restore mutant vector was constructed and the transgenic plants screened.AtVLN1-COM homozygous plants were successfullyscreened.AtVLN1 localization and its effect on cell growth in different tissues,AtVLN1 was observed in the main root,lateral root true leaves,cotyledon,hypocotyl,apical and root hairs,and statistics were measured WT,Atvln1-1,Atvln1-2 and AtVLN1-COM plants had nosignificant difference in cotyledon cell area and leaf plate cell complexity,hypocotyl cell length and width,and cell length and width in the apical elongation zone,indicating that AtVLN1 may not have cotyledon,hypocotyl,and root The cell growth plays a regulatoryrole.Through the localization of AtVLN1 in root hairs and its effect on cell growth,expression of AtVLN1 in root hairs under salt and osmotic stress,and its effect on cell growth,AtVLN1was observed to be expressed in Arabidopsis root hair under normal conditions.Root hairlengths of Atvln1-1 and Atvln1-2 were significantly longer than WT and AtVLN1-COM at 3,6,and 9 days after growth,suggesting that AtVLN1 plays a negative regulatory role in root hair growth in Arabidopsis,with salt and osmotic stress.Over time,the expression of AtVLN1 in Arabidopsis wild-type root hairs was gradually reduced.Under salt and osmotic stress,theroot hair lengths of Atvln1-1 and Atvln1-2 were significantly longer than those of WT and AtVLN1-COM,indicating that AtVLN1 was under salt and osmotic stress.It also negatively regulates the growth of root hair cells.In summary,microfilament binding protein AtVLN1 has no significant effect on the growth of cotyledon,hypocotyl,and root cells,but AtVLN1 plays a negative regulatory role in the growth of Arabidopsis root hair cells,and AtVLN1 also under salt and osmotic stress.Negatively regulates root hair cell growth.Thus,the Arabidopsis microfilament bindingprotein AtVLN1 was shown to regulate the growth of root hair cells.