Actin Depolymerization Factor AtADF11 Regulates Root Hair Growth In Arabidopsis Drought Stress Tolerance

Drought is the most important abiotic stress.Under drought stress,plants increase root hair growth to improve the ability of absorbing water to increase plant drought tolerance.Therefore,it is an important for understanding the mechanisms of plant drought tolerance to study root hair growth under drought stress.Microfilament Cytoskeleton is an essential factor to regulate root hair growth.ADF11 is a member of ADFs family.At ADF11 is mainly located in the root hairs of Arabidopsis thaliana,but its function of At ADF11 in vivo has not been reported.This study analyzed the effect of At ADF11 on root hair growth and explored the process of At ADF11 response to drought stress in Arabidopsis thaliana through regulating root hair growth.The results of this experiment are as follows:(1)The homozygous mutants of Atadf11-1 and Atadf11-2 were identified by three primers,which were used as test materials for At ADF11 gene deletion.At ADF11 gene was cloned,and At ADF11 expression vector was constructed and transferred into Atadf11-1 mutant plant.At ADF11-COM plant was obtained through identification and screening,which was used as At ADF11-COM for restoration mutation.Under normal conditions,Atadf11 mutant plants showed longer root hairs than wide type(WT)seedlings,and the root hair growth of At ADF11-COM was similar to that of WT.The results showed that At ADF11-COM negatively regulated root hair growth.(2)q RT-PCR demonstrated that drought stress inhibited the expression of At ADF11 gene in Arabidopsis roots.The At ADF11 promoter was fused with GUS gene to construct and screen the p At ADF11::GUS plants of Arabidopsis thaliana.GUS staining of p At ADF11::GUS plants showed that At ADF11 was mainly located in root hair cells,and the expression of At ADF11 in root hair was significantly decreased with the increase of drought treatment time.The results illustrated that drought stress negatively regulated the expression of At ADF11 in root hairs;(3)Drought induced root hair growth of WT plants.Under drought treatment,the root hairs of Atadf11-1 and Atadf11-2 mutants were significantly longer than that of WT.The root hair length of At ADF11-COM plants was similar to that of WT.The results illustrated that At ADF11 negatively regulated root hair length under drought stress.(4)Under drought conditions,compared with WT,Atadf11-1 mutant plants showed better growth status,higher dry weight and water content,and At ADF11-COM plants were similar to WT.The results illustrated that At ADF11 negatively affected water uptake and plant drought tolerance under drought stress.Combined,this study firstly demonstrates that At ADF11 negatively regulates root hair growth,and At ADF11 participates in Arabidopsis adaptation to drought stress through root hair growth.This study provides a new scientific basis for the function of At ADF11 in vivo in Arabidopsis thaliana and root hair growth response to drought stress.