The Role Of AITRL In Abscisic Acid Signal Transduction In Arabidopsis Thaliana

Abscisic acid(ABA),one of the six major types of plant hormones,regulates many aspects of plant growth and development.At the same time,abscisic acid also plays an important role in regulating abiotic and biotic stress responses in plants.Our laboratory previously found a class of ABA-induced transcription factors AITRs(ABA Induced Transcription Repressors)that are highly conserved among angiosperms.AITRs regulate the expression of core component genes of ABA signal transduction,and play a positive feedback regulation role in regulating plant response to abiotic stresses.When we searched for ABA response genes with unknown functions through transcriptome sequencing analysis,we found that the expression of DRG(Drought Response Gene)is regulated by ABA.Due to the close relationship between DRG and AITRs,we renamed DRG to AITRL(AITR-like).DRG has been shown to play a role in drought and cold stress response in plants,however its role in ABA signaling is unclear.In this study,Arabidopsis wild-type Col-0,AITRL gene mutants(aitrl-1 and aitrl-2)and AITRL overexpressing transgenic Arabidopsis(35S:AITRL)were used as materials to study the function of AITRL in ABA response.The main findings are as follows:1.By using RT-PCR(Reverse Transcription-Polymerase Chain Reaction)analysis,it was found that AITRL was up-regulated by ABA.2.By using protoplast transfection experiments,it was found that AITRL is localized in the nucleus and has transcriptional suppression activity.3.The ABA response of wild-type Col-0,aitrl mutant and 35S:AITRL transgenic Arabidopsis was studied,and it was found that when compared with Col,the seed germination and green seedling rate of aitrl mutant significantly increased sensitivity to exogenous ABA.AITRL may negatively regulate Arabidopsis response to ABA.4.By using real-time quantitative PCR,we detected the changes in the expression levels of some core component genes in the ABA signaling pathway,the results indicating that AITRL may be involved in regulating ABA signal transduction.