Identification Of The Interacting Between OsAE7 And ZFP36 And The Role Of OsAE7 In Response To Drought And Salt Stress In Rice

In the natural environment,plants are frequently exposed to multi-abiotic stresses,such as drought and salt stress.ABA(Abscisic Acid),an important plant hormone,plays an important role in regulating the growth development and abiotic stress of plants.It is widely involved in the physiological response to environmental stresses in plants.As a stress signal,ABA can enhance the generation of important signal molecule ROS(Reactive Oxygen Species)and promote the activities of antioxidant defense enzymes,thus improving the plant tolerance.Transcription factors(TFs)such as MYB,NAC,ZFP and so on are involved in ABA signaling pathway.ZFP36 belongs to the kind of C2H2 zinc finger protein.Previous study in our lab revealed ZFP36 could induce the expression of Rboh and participated in the ABA-induced antioxidant protection pathway.In order to clear the role of ZFP36 in ABA-induced antioxidant defense,we used full-length ZFP36 as a bait to screen the rice leaves cDNA library by Y2H(Yeast two-hybrid system).We obtained a positive colony——OsAE7(ASYMMETRIC LEAVES1/2 ENHANCER7).OsAE7 participated in CIA(Cytosolic Iron-sulfur cluster Assembly)to maintain the stability of DNA.We investigated the role of OsAE7 in the ABA signaling pathway and abiotic stresses.To verify the authenticity of the interaction between ZFP36 and OsAE7,Y2H,GST pull-down and LCI(Firefly luciferase complementation imaging assay)assays were tested.Subcellular localization assay revealed that OsAE7 was localized in the cell cytoplasm and the nucleus,and ZFP36 was localized in the nucleus,ZFP36 and OsAE7 were both located at nucleus,which confirmed the interaction in space.The expression of OsAE7 in leaves was induced under different treatments like ABA,H2O2,PEG and NaCl.We treated rice plants with DPI or DMTU before ABA treatment.Results showed that pretreatment with DPI or DMTU significantly blocked ABA-induced OsAE7 expression.These data suggested that H2O2 was required for ABA-induced OsAE7 expression.We successfully obtained osae7-KO mutant by agrobacterium-mediated genetic transformation.After PEG and NaCl treatment,the activity of SOD,the activity of APX,the content of proline and relative water were lower than WT.osae7-KO mutant was less tolerant to drought and salt damage and more sensitive to ABA treatments.After treating WT,ZFP36-RNAi and osae7-KO mutant with ABA,analyzed the expression of OsAE7 and ZFP36 by qRT-PCR.The results showed that the interference of ZFP36 hindered ABA-induced OsAE7 expression.The results showed that OsAE7 participated in ABA induced-antioxidant defense and played a role in response to salt and drought stress.