Functional Analysis Of The Histone Acetylation Influenced Phosphatase Gene AhPDCP37 In Peanut

Objective:The plant hormone ABA is involved in plant response to stress and plant growth and development through signal transduction,while the protein phosphatase PP2 C is a negative regulator of the ABA signaling pathway.Histone acetylation modifications play an important role in the regulation of gene transcription.By studying the expression characteristics of the AhPDCP37 gene in different tissues of peanut under stress and the genetic characteristics of transgenic plants,and combining the transcriptional characteristics of the AhPDCP37 gene under the altered intracellular histone acetylation,we initially revealed the molecular mechanism of epigenetic regulation of the AhPDCP37 gene affecting ABA signaling,which can provide an in-depth interpretation of the PP2 C gene.This study provides a theoretical basis for the interpretation of the drought resistance of PP2 C gene in peanut and a new research idea for breeding new resistant peanut varieties.Methods:(1)Transcriptional characterization of the peanut protein phosphatase family: protein phosphatase genes Ah PP2 Cs were screened using a multi-omics database and analyzed for their tissue specificity in four-leaf stage peanut and for salt stress and dehydration at different time points.(2)Genetic characterization of plants transgenic for AhPDCP37 overexpression and knockout vectors were constructed,and transgenic hairy roots and Arabidopsis thaliana were obtained by using Agrobacterium tumefaciens K599 and EHA105 to infiltrate the second leaf stage peanut leaves and wild-type Arabidopsis thaliana,respectively.The relative water content and the expression of Ah AREB1 and Ah NCED1 genes in the transgenic hairy roots were analyzed under 20% PEG6000 treatment for 2 h.The germination rate of seeds of different strains was measured within 72 h of 0.1 μM ABA treatment and the expression of germination-related genes ABI5,FUS3,DOG1 and HDA6 were examined.The expression patterns of ABI5,ABF3,RD29 A,RD29B and NCED3 genes were analyzed after 6 h and 24 h of treatment on 20% PEG6000 and 150 m M Na Cl plates,respectively.(3)Histone acetylation affects the transcriptional profile of peanut AhPDCP37: analysis of the expression of Ah AREB1,Ah NCED1 and AhPDCP37 genes in peanut tissues and transgenic hairy roots at the four-leaf stage under 1 μM TSA treatment;counting the germination rate under 1 μM TSA treatment and analyzing the changes in the expression of ABI5,FUS3,DOG1 and HDA6.Results:(1)All eight Ah PP2 Cs genes were expressed in peanut leaves and roots,while the expression of AhPDCP37 gene was induced by salt and dehydration stress.(2)The relative water content of overexpressed peanut hairy roots was higher under normal conditions and the water retention capacity under drought stress was higher than that of knockout peanut hairy roots,and the expression levels of Ah AREB1 and Ah NCED1 were increased in overexpressed peanut hairy roots under drought stress induction.The expression of ABF3,NCED3,RD29 A and RD29 B genes were significantly up-regulated in the overexpression lines under PEG treatment,and the expression of ABI5 and NCED3 was also significantly increased under salt stress;it was hypothesized from these results that AhPDCP37 gene overexpression may affect plant drought resistance and early plant germination through the regulation of genes related to the ABA signaling pathway.(3)When peanut was treated with 1 μM TSA at the four-leaf stage,the expression of AhPDCP37 was up-regulated,reaching the highest at 29 h in leaves and 26 h in roots,and the expression trend of Ah NCED1 was consistent with AhPDCP37.The germination rate of Arabidopsis thaliana seeds treated with 1 μM TSA ranged from 40% to 70%,while the germination rate of wild type was 99%,indicating that TSA significantly inhibited the germination of AhPDCP37 overexpressing Arabidopsis seeds and increased the expression of ABI5,FUS3,DOG1 and HDA6 genes during the germination process.Conclusion:AhPDCP37 has high homology with Arabidopsis thaliana PP2 C,and overexpression of peanut hairy roots improves plant drought resistance,while overexpression of Arabidopsis thaliana seeds is sensitive to ABA,suggesting that overexpression of AhPDCP37 gene can affect related genes through regulation of ABA pathway and thus affect plant drought resistance and germination process;similarly overexpression of Arabidopsis thaliana decreased germination rate under TSA treatment,suggesting that this gene alters the role of histone acetylation modification in plant embryonic development.