ERF020 participates in regulating drought avoidance in rice

Objective Rice is one of the most important food crops in China and requires a large amount of water in production.Frequent droughts have seriously affected rice production and threatened food security in China.Research on the utilization of rice drought-resistant genes and the development of water-saving and drought-resistantce rice has become important in rice research.Among various drought resistant，DREB subfamily transcription factors play an important role in regulating plant tolerances to abiotic stresses and are important gene resources in improving rice drought resistance. Method Protein sequence alignment and phylogenetic analysis were used to determine the classification of transcription factors for ERF020 and its evolutionary relationship. Real-time quantitative PCR was used to analyze the spatiotemporal expression pattern of ERF020.And its expression pattern in response to osmotic stress in the roots of typical lowland rice genotype（Zhonghua 11）and a typical upland rice genotype（Caopigu）.To further study the effect of ERF020 on drought avoidance ability，the performance of ERF020 overexpression lines and the wild-type Arabidopsis thaliana under osmotic stress were compared. Result ERF020 contains an AP2 domain and belongs to the DREB subfamily of transcription factor.The expression level of ERF020 is relatively high in the root and it is upregulated in response to osmotic stress.The expression of ERF020 in Caopigu is higher than that of Zhonghua 11，especially under osmotic stress conditions.Before the treatment，the root length of Zhonghua 11 was significantly higher than that of Caopigu，but after the treatment，the root length of Zhonghua 11 was significantly lower than that of Caopigu.Furthermore，there was no significant difference in the ratio of root-shoot in Zhonghua 11 before and after the treatment，but the ratio of root-shoot in Caopigu was significantly higher after the treatment than before.The expression of ERF020 significantly increased after treatment in both typical rice and typical upland rice backgrounds，and the expression of ERF020 in Caopigu background was significantly higher than that in Zhonghua 11 background before and after treatment.The experimental results on osmotic stress in Arabidopsis showed that the root length of ERF020 overexpression lines was significantly shorter than that of wild type before and after treatment，and the maximum leaf area of a single plant in wild type was significantly larger than that in overexpression lines after treatment. Conclusion ERF020 contains an AP2 domain and belongs to the DREB subfamily of transcription factor and it has a relatively high expression level in the roots of rice.The expression of ERF020 responds to osmotic stress，and its expression level is higher in Caopigu than in Zhonghua 11.Overexpression of ERF020 in Arabidopsis can effectively alter the root growth of the plant under osmotic stress，indicating that it may have potential roles in drought avoidance.ERF020 is a valuable resource of rice drought-resistant genes that is worthy of further research and utilization.